Home

Nano-R™ AFM User`s Manual - Fusion Energy Research Program

1. DEMOD DEMOD LO PASS TO PHOTOCELL oe 2 T B T GAIN PHASE FILTER L_ZPM SENSORS TR lt PHOTO L R gi CELL BR 10 100 1kHz 10kHz 2 SUM gt Z SUM Z MOD lt LO PASS SELECT Z DFB Z SEN O zSIG lt 4 DEMOD LO PASS ZAM AMPLITUDE FILTER C gt Z gt ZS 10 100 1kHz 10kHz LO PASS SELECT ZS gt LO PASS FILTER zs 10 100 1kHz 10kHz L R LO PASS LO PASS AMPLIFIER FILTER __ gt L RADC SELECT Z SEN 10 100 1kHz 10kHz OFFSET 8BIT LO PASS SELECT OFFSET GAIN 8BIT 8BIT Pacific NanoTechnology Incorporated 1421 Warner Suite B Tustin California 92780 174 258 0190 This drawing was originated by and is the exclusive property of Pacific NanoTechnology It is furnished for recipients only and is not an authorization or license to make this construction or to furnish this information to others Any unauthorized use of this information will result in prosecution to the fullest extent of the law lt EXTERNAL REF 35 gt INTERNAL REF Z SIGNAL PROCESSING NANO R AFM USER S MANUAL 4 3 Windows XP Network Setup SETTING UP PNT PSCAN2001 COCKPIT FOR WINDOWS XP Introduction This procedure will set up your system and install Cockpit These are the steps to preparing the computer setting up XP for networking and installing and configuring Cockpit Setting up User A A special user account needs to be s
2. Using this optical technique oscillation amplitudes of between 3 nm and 100 nm were achieved Because the probe comes into close contact with the surface upon each oscillation Wickramsinghe was able to sense the materials on a surface The differences between photo resist and silicon were readily observed 1 G Bennig and H Rohrer Scanning Tunneling Microscopy From Birth to Adolescence Rev of Mod Phys Vol 59 No 3 1987 P 615 2 Uber Glatte und Ebenheit als physikalisches und physiologishes Problem Gustev Shmalz Zeitchrift des Vereimes deutscher Ingenieurte Oct 12 1929 pp 1461 1467 3 US Patent 2 7288 222 4 UK Patent 2 009 409 5 R Young J Ward F Scire The Topografiner An Instrument for Measuring Surface Microtopography Rev Sci Inst Vol 43 No 7 p 999 6 G Bennig H Rohrer Ch Gerber E Weibel Surface Studies by Scanning Tunneling Microscopy Vol 49 No 1 1982 p 57 7 G Bennig C F Quate Ch Geber Atomic Force Microscope Phys Rev Letters Vol 56 No 9 p 930 8 Y Martin C C Williams H K Wickramasinghe Atomic Force Microscope Force Mapping and Profiling on a sub 100 A scale J Appl Phys Vol 61 No 9 1987 p 4723 NANO R AFM USER S MANUAL 1 2 AFM Tutorial This tutorial serves as a basic introduction to the design and operation of an atomic force microscope Background The following four sections cover the basic concepts and technologies that help understand the construction a
3. software is selected from the X Pert mode software and facilitates complete analysis and display of images 25 NANO R AFM USER S MANUAL Technical Guide 4 1 Nano R Specifications 1 0 Nano R Stage Specifications 1 1 AFM Scanner Head Modes DC Contact Mode Lateral Force Mode Vibrating Close Contact Mode Non Contact Mode Material Sensing Mode Other Force Distance Pulsed Force optional Scanning Method Tip cantilever moves over stationery sample X Y Scan Range gt 80 Microns Resolution lt 2nm with scan correction Linearity lt 1 non rotated lt 2 rotated Zoom TBD Orthogonality TBD Z Scan Range 8 Microns Sensor Noise lt 0 13 nm with external sensor Instrument Noise lt 0 05 nm Sensor Linearity lt Z XY Orthogonality lt 100nm for 80 Micron Scan lt 2 Probe handling Cantilevers pre mounted on steel crescents Size scanner module 1 H 4 W 2 5 D 25 mm 102 mm 64 mm with 0 2 5 mm extension of scanning probe below Optical viewing ports Top View 31 mm from top to tip 45 degree from vertical 50 degree from face onto cantilever 1 2 X Y Stage Specifications Automated X Y Stage Range Step Size Slew Rate maximum Sample Holder Std Sample Size Sample Height Sample Holder Sample Holder opt Sample Size 26 25 4 x 25 4 mm lt 3 microns 2 5 mm sec TBD lt 1 inch magnetic NANO R AFM USER S 1 3 Color Video Microscope Magnification Field of View Resoluti
4. NON LINEAR SCL_CORR 0 SX1 1 SX2 0 0054 SX3 0 00095 SY1 1 SY2 0 0054 SY3 0 00085 IMG_CORR 1 Al 1 A2 0 00025 A3 0 B1 1 B2 0 00048 B3 0 X OFS0 0 Y_OFS0 0 ZOOM0 0 PIX0 256 IDLE PARK ENABLE 1 TIME 30 AUTO LINEARIZER XOFS_ADJUST 400 YOFS_ADJUST 400 XPIX_ZOOM 0 93 YPIX_ZOOM 0 93 FORCE DIST F_SCALE 0 F_UNIT NN SPRING_K 1 ZDAC_S 0 73 NANO R AFM USER S MANUAL ZDAC_E 4095 CH 8 PIX 128 FORCE_RATE 2 DEF_LIMIT 6553 NUMBER 1 CONTINUE 0 STAGE ZOOM_DIR 0 DCMTR_FWD 127 DCMTR_TIME 10000 F_STEP_DIR 0 F_PULSES 50 XY_TBALL 0 DCMTR_REV 127 F_STEP 0 DELAY_US 1000 X_STEP_DIR 0 X_STEP 0 X_PULSES 33 Y_PULSES 0 Y_STEP_DIR 1 LIGHT_ON 1 LIGHT_DAC 200 XY_MGAIN 1 74
5. Pacific Scanning format Open Raw Scan Data This function opens a Raw Scan Data file for viewing The image may then be saved in another format or saved in a standard format for exporting into other word processing and spreadsheet program files Export Displayed Images Images may be saved for export as Bitmap bmp GIF gif JPEG jpg or TIF tif files Preferences Configuration The user may select a default directory for storing and retrieving Configuration cfg files Raw Data The user may select a default directory for storing and retrieving Raw Data files Export Image The user may select a default directory for storing and retrieving Image files bmp gif jpg tif formats for exporting into other programs 51 NANO R AFM USER S MANUAL Device Image Files The user may select a default directory for storing and retrieving Image files in TopoMetrix Nanoscope and Digital Surf formats Auto linearizer The user may select the size of the lower and upper buffer regions for use by the auto linearizer routine The size of the buffers for the X and Y axis may be set separately The lower buffer is set as a voltage that is typically 200 to 700 mV The smaller the value the smaller the buffer region If the setting is too small then the lower voltage side of the scanned image depending on rotation angle will appear distorted along that axi
6. Check a few initial parameters in Settings gt In Scan Image Setup folder set Resolution to 256 Scan Rate to 1 Channels to 4 gt In XY Control set Zoom to 15 gt In Input Selects to ADC select Channel 1 Z HGT topography Channel 2 Z ERR amplitude Channel 3 Z DEM phase and Channel 4 Z SEN for a 3 axis system gt In Z feedback set set point to 0 4 Press Red Dot icon K2 and make sure the spot is at the center of the cross It is more important to have it centered up and down than it is right to left 5 Press Frequency Sweep icon Make sure Z ERR is selected Type in 250 000 for Start and 350 000 for End Click on Auto to set the voltage range Y axis For convenience have the set point for the initial sweeps is set at 0 gt Press Start Sweep A sharp inverted peak should appear gt To reduce the sweep range left click on the left side of the peak and drag the mouse to the right side Release the left mouse and right click on the shadow area Press Yes and start sweep again gt To select the modulation frequency double click at a point somewhat to the left of the resonant peak When queried if these are the values you 43 NANO R AFM USER S MANUAL want click Yes In the Typical operating mode the Autoset button will pick a frequency just to the left of the peak where the amplitude is 90 of the resonant peak height
7. However if the green outline is outside of the white dotted line the scanned area is not linear and will cause a distorted image For convenience the Start and Stop points are indicated When scanning at angles other than 0 90 180 and 270 degrees the actual scan area is marked by the red outline Extra Zoom By double clicking the left mouse button when the cursor is within the scanned image a new window is opened The grid region represents the current zoomed area The user may zoom 2x or 4x anywhere within the area by clicking on a zoom button at the bottom of the window and moving the outlined area by pointing the cursor within the area and dragging the outline 65 NANO R AFM USER S MANUAL while pressing the left mouse button Clicking the Apply button locks in the new scan region Force Distance Curve This function allows the user to measure a force distance curve at any arbitrary location within a scan area Typically the F D curve refers to measuring the Error signal Z Err which is the cantilever deflection as a function of the Z actuator position It represents how the cantilever bends as the tip approaches the surface until contact and the degree of adhesion of the tip onto the surface on retraction There may or may not be deformation of the surface depending on the hardness of the surface relative to the stiffness of the cantilever The F D location is selected by pressing the control key and clicking the left
8. consumables other than those specified by Pacific Nanotechnology Parts and accessories that are expendable and replaceable in the course of normal operation Products not properly placed and installed per our installation instructions Products not operated within the acceptable parameters noted per our installation instructions Products that have been altered or customized without prior written authorization from Pacific Nanotechnology Products that have had their serial number removed altered or otherwise defaced Improper or inadequate care maintenance adjustment alteration or calibration by the user NANO R AFM USER S MANUAL Binary License Agreement The use of the Pacific Nanotechnology instruments per the instructions in this manual includes executing a program The Licensee assumes responsibility for the executed program chosen for your purposes and for the use installation and results received from it YOUR LICENSE WILL BE TERMINATED AUTOMATICALLY IF YOU COPY MODIFY USE OR TRANSFER THE PROGRAM OR ANY COPY MODIFICATION OR MERGED PORTION COMPLETELY OR PARTIALLY EXCEPT AS SPECIFICALLY PROVIDED IN THIS LICENSE License The licensee may use the program on a single machine and copy the program into any machine readable or printed form for the support or the backup of the use of the program on the single machine The licensee may modify the program and or merge it into another program for your use on the single machine
9. gt Adjust the modulation amplitude so that the demodulated signal level the height of the peak is about 1100 mV when the demodulation gain setting in the Demod selects folder in Settings is 1x The peak height referred to here is also known as the Error Signal amplitude Z ERR This value depends on the size of the oscillation amplitude desired For example the Nanosensors cantilevers 100 micron length 300kHz have an amplitude sensitivity of 0 12 nm mV of drive amplitude At the modulation frequency the observed amplitude Z ERR is about 1100 mV for a drive amplitude of 1000mV The oscillation amplitude of the cantilever is about 120 nm gt Check the height of the peak The peak height is adjusted by changing the Z feedback set point Decreasing the set point lowers the feedback amplitude and increases the amount of intermittent force of the tip contacting the surface gt Set the set point Value in Z feedback folder to 2 3 of the amplitude at the modulated frequency gt Between 0 5x and 0 7x of the Error Signal amplitude is considered hard intermittent contact and 0 8x to 0 9x is considered light intermittent contact The set point value is what determines the instantaneous force applied during imaging and therefore greatly affects the quality of the image Also blunter tips will require more force gt Doa Z gt sweep This varies the force actually the applied voltage from 0 to 10 V to 0 again at
10. o O lt ADC7 o i a DO O X SEN ADC8B ZSUM HI Y SEN RI EXTERNAL REF gt INTERNAL REF 30 AUX DACS ADC MUX NANO R AFM USER S MANUAL ZSET lt MON 1 X SEN lt MON 6 Y SET lt MON 14 ZSIG lt lt MON 2 X SEN lt MON 7 X SEN lt MON 15 Z MOD lt MON 3 X SEN lt MON 8 Y SEN lt MON 16 ZDMO lt MON 4 gt LR lt gt MON 9 xcTL lt ee lt MON 17 X SEN lt lt MON 5 Y CTL lt lt MON 18 TB lt lt MON 10 Z PIZ lt lt MNO 19 XDAC lt gt MON 1 ZSUM lt lt MON 20 Y DAC lt KMON 12 Pacific NanoTechnology Incorporated 1421 Warner Suite B Tustin California 92780 174 258 0190 This drawing was originated by and is the exclusive X SET MON 13 O O property of Pacific NanoTechnology It is furnished for S lt lt M N I T R recipients only and is not an authorization or license to U S make this construction or to furnish this information to B F F E R others Any unauthorized use of this information will result in RK EXTERNAL REF prosecution to the fullest extent of the law i gt INTERNAL REF 31 NANO R AFM USER S MANUAL gt X SET V AMP IIN
11. 1980 s uses a sharp probe to magnify surface features With the AFM it is possible to image an object s surface topography with extremely high magnifications up to 1 000 000X Further the magnification of an AFM is made in three dimensions the horizontal X Y plane and the vertical Z dimension As acknowledged by Bennig and Roher the inventors of the tunneling microscope such a powerful technique has its origins in the stylus profiler Stylus Profilers Magnification of the vertical surface features of an object those features leaving the horizontal plane and extending in the vertical direction have historically been measured by a stylus profiler An example of an early profiler is shown in Figure 1 1 This profiler invented by Schmalz in 1929 utilized an optical lever arm to monitor the motion of a sharp probe mounted at the end of a cantilever A magnified profile of the surface was generated by recording the motion of the stylus on photographic paper This type of microscope generated profile images with a magnification of greater than 1000X NANO R AFM USER S MANUAL A common problem with stylus profilers was the possible bending of the probe from collisions with surface features Such probe bending was a result of horizontal forces on the probe caused when the probe encountered large features on the surface This problem was first addressed by Becker in 1950 and later by Lee Both Becker and Lee suggested oscillating t
12. 210 Hz lt 75 mPa 210 500 Hz The noise level inside the enclosure must not exceed 75dBc 0 112Pa integrated from 10 to 10 000 Hz Compressed Air for air table option only 6 8 8 1 bar 100 120 PSI The compressed air must be dry regulated filtered and oil free The regulator must be accessible at the installation site A 25 inch female NPT connector or 25 inch quick connect connector is required 49 NANO R AFM USER S MANUAL Appendix B Description of SPMCockpit Software User File Typical Mode This mode is intended for the occasional user It provides access to a limited number of functions on the PScan2 Controller These functions are arranged as a sequential menu and offer a step wise method for initializing the scanner setting scanning mode beam alignment tip engagement and retract selected scanning options image display and direct access to an image analysis program optional program This mode will over ride certain parameters in the configuration file using instead typicalmode default parameters which minimize the possibility of a improper cantilever tip engagement Expert Mode This mode provides access to all the functions currently available on the PScan2 Controller Open Configuration File The configuration file contains the operating parameters which have been previously set and saved Any directory can be accessed the default directory can be set under Pre
13. AFM USER S MANUAL 8 9 damage The tip is retracted before the stepper motor is incremented by a small amount about 3 5 microns Then the Z actuator is incremented checking several times after each increment for zero crossing The stepper actuator sequence is repeated until the zero crossing is reached Then the GPID feedback loop is turned on With proper adjustment of the Advanced settings the Z actuator will be positioned at approximately mid range ready for scanning Press Image Display icon HA two times selecting Z HGT and Z ERR as the inputs of the four Display Scanned Image windows gt Also a Scan Line Cut hit the Line Mode Icon twice can be displayed Set the size of the area to be imaged and pick the image location on the sample Click on the Display Scanned Image window twice The new window is titled X Y offset and zoom This window will allow the image size to be changed via the zoom setting Press Star on the Scan Control Panel window Now you are getting your first topography amplitude phase and Z sensor 3 axis only images in the oscillating mode gt Incrementally increase the GPID settings to improve the quality of the image gt Save images in digital surf format The data may be saved with lineby line leveling as needed gt To change the image size or location double click on the display scanned image window The new window is titled X Y offset and zoom This
14. Any portion of the program that is merged into another program will continue to be subject to the terms of this Agreement The licensee must reproduce and include the copyright notice on any copy modification or portion merged into another program If the licensee transfers the program and license to another party within your organization said party must agree to accept the terms and conditions of this Agreement The licensee must when transferring the program either transfer all copies in any form machine readable or printed to the same party and destroy any copy machine readable or printed or copies not transferred The licensee may not transfer the program to anyone outside of the licensee s organization without the written and express permission of Pacific Nanotechnology This license is effective from the date you take delivery of the software as purchased from Pacific Nanotechnology and remains in effect until terminated as indicated above or until the licensee terminates it The licensee agrees to destroy or return the program together with all copies modifications and merged programs in any form on their termination of this license NANO R AFM USER S MANUAL Copyright Notice covers all attached documents Pacific Nanotechnology Incorporated 2001 2002 All rights reserved Pacific Nanotechnology retains all ownership rights to this documentation and all revisions of the Nano R computer program and other related software
15. PID Channel One of three inputs may be selected for the Z Feedback Loop 1 T B Photodiode from the AFM scanner 2 External and 3 Z Sensor if option is installed Input Polarity The PScan2 Controller is capable of engaging in feedback for both positive going and negative going error signals Typically SPM users are more familiar the former i e with the error signal response from a lower more negative signal to a more positive signal For contact mode the Input Polarity is set for Positive and for the oscillating mode it is set for Negative Set point Polarity For contact mode the set point is typically set to zero and the set point Polarity setting is not important If a positive set point value is required the setting is Positive and visa versa if a negative set point value is needed For oscillating modes the Error Signal is always negative see above the set point Polarity is Negative Set point Value The set point value controls the relative force that the tip interacts on the surface The set point range is from 0 to 10 volts the sign depends on the Set point Polarity For contact mode the set point typically set for zero volts initially may be increased or decreased to change the force on the cantilever For the oscillating modes involving a resonance of the cantilever a negative error signal see above the set point is usually negative As an example the
16. center of the Z actuator range 0 V 7 Press Image Display icon H twice and select Z HGT and Z ERR as the inputs for the Display Scanned Image windows Also the Scan Line Cuts click on the Line Mode Icon twice can be displayed for each input 8 Press Start on the Scan Control Panel window This action will provide your first topography deflection friction and Z sensor 3 axis only images in the contact mode gt The GPID settings may be adjusted to optimize the quality of the topographical image 9 Press Image Display icon four times select Z HGT Z ERR Z L R and Z SEN for 3 axis system as the inputs of the four Display Scanned Image windows Press Start on the Scan Control Panel window and image acquisition will commence providing topography deflection friction and Z sensor 3 axis only images in the contact mode 42 NANO R AFM USER S MANUAL 5 3 2 OSCILLATING MODE oe 1 Click on Open Configuration File icon Select the configuration file for oscillating mode for example g5 229 OSC 991110 2 Open XY Offset and Zoom window Press A LIN icon Bed and then Yes to run auto linearization gt This must be run 2 to 3 times before consistent offset and zoom values are obtained This has to be repeated both to warm up the piezo s and because their behavior is somewhat history dependent Repeat until the X amp Y offsets differ by less than 100 mV between successive scans rr 3
17. is vibrated and changes in the vibration properties are measured Deflection Mode Using the feedback control in the AFM it is possible to scan a sample with a fixed cantilever deflection Because the deflection of the cantilever is directly proportional to the force on the surface a constant force is applied to the surface during a scan This scanning mode is often called contact mode However because the forces of the probe on the surface are often less than a nanonewton the probe is minimally touching the surface Figure 1 2 g In contact mode AFM the probe directly follows the topography of the surface as it is scanned The force of the probe is kept constant while an image is measured 10 NANO R AFM USER S MANUAL Vibrating Mode The cantilever in an AFM can be vibrated using a piezoelectric ceramic When the vibrating cantilever comes close to a surface the amplitude and phase of the vibrating cantilever may change Changes in the vibration amplitude or phase are easily measured and the changes can be related to the force on the surface This technique has many names including non contact mode and intermittent contact mode It is important that the tip not tap the surface because the probe may be broken or the sample may be damaged Vy Ace Figure 1 2 h In vibrating methods changes in probes vibrations are monitored to establish the force of the probe onto the surface The feedback unit is used to keep the vibrati
18. mode This mode is for determining the characteristics of a demodulated signal as a function of driving frequency and amplitude It provides a convenient means for frequency scanning nominally 50 kHz 500kHz determining the resonance frequency setting the driving frequency and amplitude and 61 NANO R AFM USER S MANUAL measuring the signal amplitude as a function of applied Z piezo voltage The scaling boxes are similar to the modes above To the lower left of the graph is the selected Signal The Sweep Rate is typically set to 5 10 ms The Start and End frequencies are typically set around the anticipated resonance frequency or they may be set to scan the full range The Start and Stop Sweep initiate and terminate the frequency sweep The driving amplitude and phase for phase detection mode may be set at anytime Two successive sweeps are displayed the current sweep is green the previous sweep is red For convenience the left mouse key may be pressed while the cursor is within the graph screen in order to sweep a particular range The range is fixed and the graph screen reset to the new sweep ranges by a right mouse click Positioning the cursor on the desired frequency and double clicking the left mouse button sets the indicated frequency amplitude and phase into the Settings windows when the user is ready for tip cantilever approach The Z gt button is used to ascertain whether the cantilever and mount are in satis
19. near any heat or cold sources or windows that could contribute to temperature changes Humidity must also be considered as failure is possible if the piezoelectric ceramics are operated while wet or if the humidity is in excess of 60 Vibration The most important consideration in the placement of the instrument is vibration as image noise can cause a substantial decrease in resolution due to disproportionate motion between the probe tip and the sample The best images are obtained by minimizing vibration The manufacturer suggests a ground floor laboratory and a vibration free table Testing for Vibration A rudimentary test for vibrations can be obtained by placing a glass of water on a surface where the microscope will be used The ripples on the surface of the water indicate that vibrations may cause difficulty in imaging A lack of ripples doesn t necessarily mean that vibrations aren t present 47 NANO R AFM USER S MANUAL The major sources of vibration noise are as follows 1 Structure Vibrations coming through the floor of your building such as those from elevators air conditioners transformers and other machinery can be a problem Try to place the microscope near a load bearing wall avoiding hallways and heavy doors that are used often 2 Sound Minimize acoustic waves as they can cause vibration induced noise in the cantilever 3 Support The microscope should be separated from the other components to minimize
20. not typically needed cannot be acquired at the same time If a conflict during selection occurs an error message will be displayed One or more channels are only available for oscilloscope line display and image acquisition if the appropriate channel number is selected in the Scan Image Setup section All four channels are available in the oscilloscope time mode Lateral Force Normally a gain of one and offset of 255 is sufficient for most lateral force imaging situations If a higher gain is needed the Red Dot should be set to the left of the vertical mid line near the left border of the green zone The gain and offset can then be adjusted while scanning for optimal image acquisition An optimal filter setting full range 1000 Hz 100 Hz and 10 Hz can also be established Z Sensor Z Sen These parameters are only active for 3 axis sensor scanners The Z sensor gain and offset are factory calibrated to approximately overlap the Z Hgt span in microns 7 10 microns For correct ranging the gain is typically set at 6 or 7 and the offset is adjusted so that the center of the Z Hgt range zero volts and the center of the Z Sen range are approximately the same If the decade filter is engaged the noise will be lower allowing for more precise height measurements although at lower scan rate 54 NANO R AFM USER S MANUAL Error Signal Z Pos Filter The Z Pos signal is the inverted Z Err wit
21. options Reproduction of any portion of this document or any image depicted in this publication without prior written authorization with the exception of archival purposes or for the specific use of the program with Pacific Nanotechnology equipment is prohibited by law and is a punishable violation of the law PACIFIC NANOTECHNOLOGY INCORPORATED PROVIDES THIS PUBLICATION ASIS WITHOUT WARRANTY OF ANY KIND EITHER EXPRESS OR IMPLIED INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OR CONDITIONS OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE IN NO WAY SHALL PACIFIC NANOTECHNOLOGY INCORPORATED BE LIABLE FOR ANY LOSS OF PROFITS LOSS OF BUSINESS INTERRUPTION OF BUSINESS LOSS OF DATA LOSS OF USE OR FOR SPECIAL INCIDENTAL INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND EVEN IN THE EVENT OF SUCH DAMAGES ARISING FROM ANY DEFECT OR ERROR IN THIS PUBLICATIONS OR IN THE X PERT MODE OR EZ MODE SOFTWARE The trademarks or registered trademarks of Pacific Nanotechnology are Nano R X Pert Mode and EZ Mode vi NANO R AFM USER S MANUAL Safety Statement LASER OPERATION AFM SCANNING HEAD LASER LASER LIGHT AVOID DIRECT EYE CONTACT WARNING NEVER LOOK DIRECTLY INTO THE LASER BEAM IN ORDER TO AVOID THE POSSIBILITY OF THE USER INADVERTENTLY LOOKING INTO THE LASER ALWAYS USE THE SOFTWARE OR HARDWARE TO SWITCH THE LASER OFF BEFORE RAISING THE HEAD TO EYE LEVEL The diode laser in the Nano R
22. other ADC voltages are given the same full scale factor and units For direct reading in volts Aux inl 20000 mV Aux in2 20000 mV other ADC 20000mV Non linearity X Y To correct for non linearity of the X amp Y actuators or linearization sensors several options are available for up to third order correction Scale Correction With the Image Correction tumed off and the Correct box checked the image scale is corrected to positional non linearity for any zoomed region within the full scan area Image Correction Off line A correction is applied to an uncorrected scanned image The data is then re sampled when stored in the Digital Surf format The Correct box of the Scale Correction may be either on conveniently displaying the proper range when scanning or off On line A correction is applied during scanning eliminating the need for off line correction The actual correction parameters for all options are factory set 60 NANO R AFM USER S MANUAL Tools Red Dot Display This display provides a convenient means for aligning the laser beam onto the detector For contact mode AFM the red dot is located below the horizontal median line within the green region The set point is typically set at zero volts so that the red dot crosses the median line in an upward direction as the cantilever tip contacts the surface The more negative lower the red dot the higher the contact force If Lateral Force images are to be ac
23. recently stored source either a hard disk drive or an image in the image buffer used for image acquisition The line profile icon enables a window that facilitates the measurement of distances and surface roughness on many types of line profiles The line profiles may be horizontal vertical random or circular Surface roughness parameters include the standard values of Ra and Rs Adjusting the range of colors in an image is enabled with the histogram adjustment option Also the histogram adjustment option may be used for measuring step heights in images Plane Correction Several type of filtering may be applied to images with the image filter window After filtering the images may be saved with the save icon that is located on the toolbar T EERE k Ele ke E Fast Fourier filter of images is possible with the FFT option 3 Dimensional isometric images may be displayed with this option After displaying this option images may be displayed with light shading from may angles Also the color palette of the image may be changed 24 NANO R AFM USER S MANUAL Editing and printing images from the PNI analysis software Images may be captured from the PNI analysis software by using the print screen function on your computer Once the print screen function is selected the image window may be pasted into any Microsoft windows compatible program such as Word or Powerpoint 3 2 2 PACIFIC MAP SOFTWARE Pacific Map
24. setting ranges from 0 5x to 0 7x of the Error Signal out of feedback for hard 57 NANO R AFM USER S MANUAL intermittent contact mode to 0 8x to 0 9x for light intermittent contact mode The actual preferred setting depends on the cantilever tip characteristics as well as the particular experiment at hand Demodulation Bypass is selected for contact mode Demod activates the demodulator circuits and is selected for any oscillating mode Error Signal Gain The Error Signal Gain compensates for variations in cantilever reflection intensity For contact mode if Z Sum is at or near max about 40 of full scale the Error Signal Gain is typically 1 increasing to a value of 10 15 for Z Sum at its minimal value The Error Signal Gain ranges from 1 to 255 GPID Values G overall feedback Gain P Proportional I Integral and D Derivative setting may range from 1 to 255 The higher the value the greater the influence of the parameter A suggested initial GPID setting for contact or intermittent contact modes is 1 8 20 1 Frequency Synthesizer Frequency The frequency of the driving oscillator for the oscillating modes may be set from a few Hertz to several MHz The typical range for this system is from 50 kHz to 500 kHz Amplitude The peak to peak amplitude may be set from a few millivolts to 10 volts in approximately 20 mV increments Phase For Phase Detection the contrast o
25. to bottom Fast Approach 500 50 20 20 1 Medium 500 200 20 20 1 and Slow 500 500 20 20 1 The approximate approach rates for each speed overall rate followed by actual ramp rate in microns per second Fast 2 0 0 9 Medium 0 9 1 5 Slow 0 5 0 6 Monitored Value As the tip cantilever approaches the surface the feedback error signal is periodically updated in this box Retract For DC motors the extent to which the cantilever tip is retracted from the surface is set by a combination of the applied Voltage and the Duration in ms of the voltage pulse For steppers the Step Size Direction and Number of steps are set The rate is preset at the maximum rate for reliable operation The Distance movement of the cantilever tip is indicated in the box adjacent to the step number Scan Control Panel Scanning and image acquisition is controlled from this window with the Start and Stop buttons If the Repeat Scan box is checked the scan routine will restart a few seconds after completion The Elapsed Time and Lines Remaining for the scan are updated during scanning Display Scanned Image By successively clicking on the grid icon up to four different signals can be imaged during scanning See the Settings section for selecting available signals Any of the displayed images may be expanded to full screen 64 NANO R AFM USER S MANUAL The color bar on the left of the image represents the range of signals for the dat
26. vibration as even the use of the mouse can generate vibration Mechanical devices such as fans can also cause excessive vibrations Air Table The air table optional vibration isolation platform will require an air line that supplies 100 120 psi of regulated dry filtered air Acceptable Parameters for the placement of the Nano R Room Location The location should be free of chemical dust and other contaminants Telephone Accessibility A phone nearby the operator is recommended for reaching Customer Support while using the system Operating Temperature Range 15 25 C 59 77 F Note The maximum allowable gradient is C h 4 F h Storage Temperature Range 0 C 40 32 F 104 F Operating Humidity Range 30 60 non condensing Storage Humidity Range 10 100 48 NANO R AFM USER S MANUAL Maximum Acceptable Vibration Parameters Vertical Acceleration lt 50uG f 0 800 Hz 1G 9 81 m s The RMS value of the tip sample motion must not exceed 0 01 nm when integrated over f Horizontal Horizontal values are generally smaller than vertical values and have less effect on tip vertical motion Acceleration smaller than vertical acceleration values Operating Electrical Power Tolerances 110 220 240 VAC 450 60 Hz 1 Phase AC Voltage Stability 1 5 1 Hz Maximum Acceptable Sound Pressure lt 5mPa 10 90 Hz lt 15 mPa 90
27. ACKET 100 SYNC_FOCUS 1 LOG_PACKET 1 LASER LASER 1 DC MOTOR DCMTR_FWD 127 DCMTR_REV 127 DCMTR_TIME 20000 SCAN IMAGE POINTS 256 LINES 256 SCAN_RATE 0 3 ROTATE 0 XYMODE 0 DIR 2 CH 4 DATA 0 SKEW 0 7 OVERSCAN 0 PRESCAN 0 LINE_CUT 0 ZXY_CROSS 1 ZXY_STORE 1 TIP APPROACH ZMTR_TIP 1 CH_TIP 8 SRE_TIP 16384 ZADC_TIP 0 DCREV_TIP 127 DCTIME_TIP 2000 70 NANO R AFM USER S MANUAL ZHGT_TIP 0 DIRUP_TIP 1 STEPUP_TIP 0 PULSES_TIP 120 DCFWD_TIP 0 DIRDWN_TIP 0 STEPDWN_TIP 1 CYCLES_TIP 50 PACKET_TIP 500 DEV_TIP 16384 TIP_INC 1 RUN_INC 40 RAMP_INC 4 DELAY_INC 1 CHK_ZSUM 0 FAST_INC 1 FAST_PRCNT 4 00 SLOPE_INC 0 SLOPE_PRCNT 0 01 SLOPE_RATIO 1 00 SAFE_PRCNT 30 00 AUTO_SET 0 SET_PRCNT 70 00 FAST_RUN 4 SLOPE_RUN 1 RUN_SLW 4 RAMP_SLW 4 DELAY _SLW 1 TEST_DSETP 100 00 TEST_ZHGT 1638 SETPO_PRCNT 10 00 SETP1_PRCNT 25 00 INC_DSETP 600 00 SETP_AUTO 1 ZERR_G 128 PID_P 10 PID_I 10 PID_D 1 71 NANO R AFM USER S MANUAL FREQ SWEEP FREQ _S 57756573 FREQ_E 62051540 F_AMP 20 F_PHASE 0 SWEEP_RATE 5 OSC TIME TIME_BASE 300 OSC STORAGE TIME _BASE 3000 DUTY_TIME 1200 XYZ SCALE X_SCALE 312 X_UNIT 0 Y_SCALE 312 Y_UNIT 0 Z_SCALE 4000 Z_UNIT 1 ZS_SCALE 12000 ZS_UNIT 1 ADC_SCALE 20000 ADC_UNIT 4 AUX1_SCALE 20000 AUX1_UNIT 4 AUX2_SCALE 20000 AUX2_UNIT 4 ZSEN_G0 43 ZOOM_OUT ZOOM 45 TIP XY X_POS 2048 Y_POS 2048 72 NANO R AFM USER S MANUAL PID_ON 0 SETP_UP 0
28. AIN lt KY RET lt gt Y CTL gt Y DAC RI EXTERNAL REF AMP q i gt INTERNAL REF 33 NANO R AFM USER S MANUAL Z OFFSET oo Z DAC 10V REKL oo X1 X2 GAIN Z DAC 12BIT LO FILTER Z POS Z PIEZO 10 100 1kHz 10k POSITIONER gt Z ERR LO SELECT lt Z PY1 4 Z PID 2 SET 10V RERC__ ROPORTIONA Z ERR EATN GAIN Z MOTOR SET z HB DERIVATI BAIN Z PIEZO MODULATOR INTEGRA FREQUENC JSAINx SYNTHSZ T Z PY2 Pacific NanoTechnology t42t Warner Suite B Tustin California 174258 0190 This drawing was originated by and is the Z MOB lt __ D A C amp Tropeity of Pacific NanoTechnology It is furnished for recipients only and is not an authorization or license RK EXTERNAL AMP take this construction or to furnish this information to aie others Any unauthorized use of this information will result in gt INTERNAL REF prosecution to the fullest extent of the law 34 NANO R AFM USER S MANUAL XT EXTERNATI EXT EXT E
29. Controller Create Configuration Diskette Before the PScan2 Controller can recognize the existence of the Master Computer on the Ethernet a Configuration Diskette must be generated by the Master Computer and installed on the Slave Using an empty diskette follow the instructions displayed in the window Remember to disconnect the Ethernet cable to the Controller before rebooting the Controller in order for the Controller to accept and read the diskette generated from the Master Computer This operation takes only a few minutes A series of four medium length beeps indicates that the diskette was read and information transferred Also remember to reconnect the Ethernet cable when the configuration file installation is complete and the Controller is rebooted A hi lo hi series of three beeps indicates that the Controller has been successfully connected to the Ethernet This may be confirmed by using the Ping function Ping This function provides a quick means for confirming that the PScan2 Controller is connected to the Master Computer and is operating properly If network and controller are working there is an almost immediate response indicating that the system is operational A time out error message is displayed after a few seconds if the system is not working Multiple Unit Setup Two or more controller scanners can be operated from one master workstation This function allows the user to set up one program to operate t
30. Frequency range DC to 20 Hz min Noise Ground 3 mV rms nominal External 5 VDC 3 mV rms nominal Instantaneous max output current 500 mA min per axis Average continuous output current 50 mA per axis power supply limited Power Rating of output amplifier 0 V to 140 V 85 Watts 4 6 Accessory Functions Auxiliary Analog I O Input Output Number 2 differential buffered 2 Signal range 10V to 10V 0 to 10 or 0 to 10 V Resolution 1 2 mV 2 4 mV Update rate 16 kHz min 10 kHz min 28 NANO R AFM USER S MANUAL DC Motor Driver Use Operate probe approach motor Output voltage range 5 to 5 VDC 8 bit resolution Output current 150 mA max Stepping Motor Drivers Use Operate for probe approach and coarse X Y amp Z motions Number on controller 6 each Operating voltage 12 VDC maximum Current rating 0 50 A maximum Software functions enable reduced current set direction step Options Chip bypass for larger external stepper drivers 6 bit port for additional steppers or other use Other features Digital Flags Output FLGSS Start Scan indicator Output PIXCLK X amp Y increment indicator Output FLGPT Set clear bit to flag a data point Input EXTSS External start scan 16 bit Digital I O bus 10 KHz min update 4 7 Signal Access Console Option External flat cable amp BNC type connector box to monitor more than 25 incoming outgoing and internal signals and connecti
31. L 2 1 3 NANO R AFM PROBES There are two basic types of probes for the Nano R AFM contact mode probes and close contact mode probes SN Cantilever Chip es oe Metal Substrate Figure 2 1 d The cantilever is held in the AFM scanner with a metal substrate that is magnetically coupled to the bottom of the scanner 2 1 4 NANO R SOFTWARE There are several software modules available for acquiring AFM images and for the display and the analysis of AFM images Figure 2 1 c shows a top level block diagram of the Nano R AFM software EZMode Acquisition SPMCockpit Figure 2 1 e The two acquisition modules are EZMode and X Pert software EZMode is useful for people that use the AFM only occasionally and the X Pert software is used by advanced users with substantial experience with an AFM Image Analysis software modules are the PNI software and the Pacific Map software The PNI software is included with all Nano R AFM systems and Pacific Map software is offered as an option for the Nano R AFM 16 NANO R AFM USER S MANUAL 2 2 Measuring an Image in 12 Steps or Less Measuring AFM images with the Nano R is greatly facilitated with the EZMode software EZMode software is ideal for learning the basic operation of the Nano R AFM The following flow chart gives the step required for measuring and analyzing an AFM image of a silicon test pattern Launch Software Selec
32. PACIFIC NANOTECHNOLOGY Nano R AFM Users Manual Pacific Nanotechnology Inc 2002 3350 Scott Boulevard Building 29 Phone 408 982 9492 Fax 408 982 9151 NANO R AFM USER S MANUAL Table of Contents Before you Start ii CHAPTER 4 Technical Guide 2 4 1 Specifications 26 29 Warranty iii iv SERIES 4 2 Data Station Block Diagram 30 35 4 3 Network Setup 36 38 Copyrights Vi Safety Statement Vii CHAPTER 5 HowTo Guide 2 5 1 Exchanging Probes 39 CHAPTER 1 Introduction to AFM 5 2 0 ting the Track Ball 40 1 1 AFM History 1 3 a ri acdc H H 3 TM 4 2 AFM Tutorial 4 12 5 3 Measuring with X Pert Software 41 46 5 3 1 Contact mode 41 42 5 3 2 Oscillati d 43 46 CHAPTER 2 Getting Started sas a MeTS 2 1 Description of the Nano R 13 18 2 1 1 Stage 14 Appendix A Site Specifications 47 49 H it E 2 4 2 AFM Scanner 15 Appendix B SPM Cockpit software 50 67 2 1 3 Probes 46 Appendix C System Configuration File 68 74 2 1 4 Software 16 2 2 Imaging in 12 Steps or Less 17 18 CHAPTER 3 Software Manual 3 1 Image Acquisition Software 19 25 3 1 1 EZMode 20 3 1 2 X Pert Mode 21 23 3 2 Analysis Software 24 25 3 2 1 PNI Analysis 24 3 2 2 Pacific Maps Software 25 NANO R AFM USER S MANUAL Before You Start The Nano R AFM can be operated with little or no understanding of the components in an AFM However Pacific Nanotechnology recommends that if you are not f
33. TEGRAL EAIN PROPORTIONAL EATN gt zs XSEN XSEN x OFFSET 8BIT X ZOOM 8BIT X DAC lt X DAC lt Pacific NanoTechnology Incorporated 1421 Warner Suite B Tustin California 92780 174 258 0190 This drawing was originated by and is the exclusive property of Pacific NanoTechnology It is furnished for recipients only and is not an authorization or license to make this construction or to furnish this information to others Any unauthorized use of this information will result in prosecution to the fullest extent of the law gt X DAC X PIZ EX RET gt X CTL R EXTERNAL REF X D AC amp q f gt INTERNAL REF AMP 32 YSEN YSEN Y ZOOM 8BIT Y DAC lt Y DAC lt NANO R AFM USER S MANUAL Pacific NanoTechnology Incorporated 1421 Warner Suite B Tustin California 92780 174 258 0190 This drawing was originated by and is the exclusive property of Pacific NanoTechnology It is furnished for recipients only and is not an authorization or license to make this construction or to furnish this information to others Any unauthorized use of this information will result in prosecution to the fullest extent of the law gt ZS gt Y SET HV AMP Y PIZ Y OFFSET INTEGRAL 8BIT G
34. USER S MANUAL Click on Start click on Control Panel click on Network and Internet Connections click on Network Connections double click on Local Area Connection click on Properties Looking at the General menu click on Install select Protocol and click on Add to see list of protocols Select NETBEUI protocol and click OK Restart computer at the request After restarting go back to the Properties menu to verify you now see NetBEUI protocol in the list for the network card Installing the software updated for 1 30 02 version A B Insert CD open setupCD dir locate and run Setup Accept default choice for Program Group After the install finishes close file folder click on Start menu click on All Programs you should see an directory for Pscan SPM Cockpit 2001 AFM System click on it then click on the icon for Cockpit to start program Open the Device menu select Create Device Directory You should see a default of C Pscan PScan2001 DemoDevice Change to C Pscan PScan2001 PScan238 A box asking you to share the directory before use appears click yes There will be a response that sharing is successful clear the box lt note due to a bug it will NOT have shared the directory at this point despite the statement and will need the following steps gt Go to Start menu and right click on it to open the smaller menu click on Explore find the C Pscan PScan2001 PScan238 directory you created and right click on i
35. a 500 mm computer screen 1s MAGNIFICATION 500 MM 100 NM 1 MM 1 000 000 NM 5 000 000 X NANO R AFM USER S MANUAL Piezoelectric Ceramic Transducer Mechanical motion is created from electrical energy with an electromechanical transducer Electrical motors such as are used in washing machines are the most common type of electromechanical transducer The electromechanical transducer most commonly used in an atomic force microscope is the piezoelectric ceramic A piezoelectric material undergoes a change in geometry when it is placed in an electric field The amount of motion and direction of motion depends on the type of piezoelectric material the shape of the material and the field strength Figure 1 2 a shows the motion of a piezoelectric disk when exposed to an electric potential g Apply Voltage Figure 1 2 a When a voltage is applied to the top and bottom surface of the piezoelectric disc the disc will expand A typical piezoelectric material will expand by about 1 nm per applied volt Thus to get larger motions it is common to make piezoelectric transducers with hundreds of layers of piezoelectric materials illustrated in Figure 1 2 b Apply Voltage Figure 1 2 b Applying a voltage to the top and bottom surface of this stack of piezoelectric disks causes the entire stack to expand The amount of expansion depends on the applied voltage piezo material and number of disks By using one thousand layers of piezoelectri
36. a acquired Checking the Histogram Correction box allows the user to define the Z scale of interest with the upper and lower limits set as a percent of full scale For some viewing situations the quality of the image may be enhanced by 1 checking the Shading box and 2 selecting the apparent direction of the light source N S E amp W The image can be leveled on a line by line basis by checking the Auto leveling box The color bar and scaling are corrected automatically Zoom An area to be zoomed may be defined by pressing the left mouse button on the upper left region to be outlined and drawing the cursor across the scanned image The zoomed area is locked in by releasing the left mouse button and clicking on the right button To zoom out to a previously zoomed region a small box is formed just outside the scanned image but within the window This procedure may be performed successively expanding the zoomed area until the maximum scanned area is accessed An alternative means for zooming is accomplished by double clicking the left mouse button when the cursor is outside of the scanned image A new window is opened which defines the entire area accessible by the X Y sensors The maximum scanned area is defined by white dotted lines this represents the region in which the linearizing routine has selected By pointing the cursor within the outlined green region the scan area may be positioned anywhere within the range of the sensor
37. amiliar with the parts in an AFM you take the time to read the AFM Tutorial in section 1 0 Getting optimal result from the Nano R is greatly facilitated by having some understanding of the theory of an AFM system NANO R AFM USER S MANUAL PACIFIC NANOTECHNOLOGY PRODUCT WARRANTY Coverage Pacific Nanotechnology warrants that products manufactured by Pacific Nanotechnology will be free of defects in materials and workmanship for one year from the date of shipment The product warranty provides for all parts excluding consumables and maintenance items labor and software upgrades Instruments parts and accessories not manufactured by Pacific Nanotechnology may be warranted by Pacific Nanotechnology for the specific items and periods expressed in writing on published price lists or quotes However all such warranties extended by Pacific Nanotechnology for those specific items and periods expressed in writing on published price lists or quotes are limited in accordance with all the conditions terms and other requirements noted in this warranty Pacific Nanotechnology makes no warranty whatsoever concerning products or accessories not of its manufacture except as noted Customers outside the United States and Canada should contact their local Pacific Nanotechnology representative for warranty information that applies to their locales CUSTOMER RESPONSIBILITIES Complete ordinary maintenance and adjustments as stated in Pacific Nanotec
38. c material it is possible to get motions as large as 1000 nm per volt Thus with 100 volts it is possible to get 0 1 mm of motion with a multiple layer piezoelectric transducer Force Sensors The construction of an atomic force microscope requires a force sensor to measure the forces between a small probe and the surface being imaged A common type of force sensor utilizes the relationship between the motion of a cantilever and the applied force The relationship given by Hook s law is NANO R AFM USER S MANUAL K is a constant and depends on the material and dimensions of the cantilever D is the motion of the cantilever For a cantilever made of silicon that has dimensions of L 100 MICRONS W 20 MICRONS T 1 MICRON The force constant K is approximately 1 newton meter Thus if the cantilever is moved by 1 nm a force of 1 nanonewton is required Measuring the motion of the cantilever is possible with the light lever method In the light lever method light is reflected from the back side of the cantilever into a photo detector See figure 1 2 c Laser Photodetector gt Cantilever Figure 1 2 c The light lever sensor uses a laser beam to monitor the deflection of the cantilever When the cantilever moves up and down the light beam moves across the surface of the photodetector The motion of the cantilever is then directly proportional to the output of the photo detector Motions as small as 1 nm are routin
39. constant voltage to determine the amplitude of motion This sweep is performed at the selected modulation frequency fixed frequency variable voltage before it was fixed voltage variable frequency gt The height and shape of the peak can be modified somewhat by changing the laser alignment Also adding a very small amount of glycerol glycerin can ensure a good mechanical coupling which in turn will improve the Z sweep results gt The effect of the Z piezo position on the amplitude can be checked by clicking on the Z gt icon within the frequency sweep window This function moves the Z piezo actuator from an extended to retracted and back to extended position The change in amplitude should be less than 44 NANO R AFM USER S MANUAL 15 and at no time should it exceed the zero crossing of the error signal If the Z sweep variation is too high it can be improved by adjusting the alignment The alignment can be further optimized by doing a frequency sweep and selecting a modulation frequency Then look at the line oscilloscope and adjust the photodiode knobs to minimize the voltage reading This in turn is maximizing the response amplitude on the frequency sweep and minimizes Z sweep NOTE also that the quality and cleanliness of the cantilever s reflective surface greatly affects the Z sweep variation Possible problems include the presence of interference fringes of the reflected beam due to a poor reflective coatin
40. ely measured with the light lever method in atomic force microscopes Feedback Control Feedback control is used commonly for keeping the motion of an object in a fixed relationship to another object A simple example of feedback control occurs when you walk down a sidewalk As you walk down a sidewalk you constantly control your motion by viewing the edge of the sidewalk If you begin to walk off the sidewalk you correct your motion so that you stay on the sidewalk Feedback control is used routinely for many common applications such as the automatic control airplanes and controlling the temperature in buildings In the AFM feedback control is used to keep the probe in a fixed relationship with the surface while a scan is measured NANO R AFM USER S MANUAL Atomic Force Microscope The theory and operation of an atomic force microscope is similar to a stylus profiler The primary difference is that in the atomic force microscope the probe forces on the surface are much smaller than those in a stylus profiler Because the forces in an AFM are much smaller smaller probes can be used and the resolution is much higher than can be achieved with a stylus profiler AFM Theory In an AFM a constant force is maintained between the probe and sample while the probe is raster scanned across the surface By monitoring the motion of the probe as it is scanned across the surface a three dimensional image of the surface is constructed The constant fo
41. er of Pulses may be sent to the motor the controller sends pulses to the stepper motor as a packet the size of which is determined by the Packet number usually 10 20 This packet method for pulse transfer allows the controller to check for a user interrupt between packets such as STOP The Step size may be Full or Half Step DC Motor Some scanners incorporate a 5 V DC motor for controlling the tip cantilever approach and withdrawal The Forward e g 2000 mV and Reverse voltages e g 5000 mV are controlled separately for a given Duration e g 200 ms The Stop button sets the voltage to zero 59 NANO R AFM X Y Z Scales USER S MANUAL X amp Y Full Scale The X amp Y axis scales may be set independently and can be expressed in Angstroms A nanometers nm or microns um If the two axis are not in feedback the numbers entered represent the actual full scale of the scanned image For systems with X amp Y feedback and linearization the situation is more complicated resulting in the need to enter larger numbers than the actual scan range For the PTrak3 Scanner for example the scaling numbers are ranged from 190 to 220 Z Full Scale The Z Hgt represents the voltage applied to the actuator in the Z PID loop in order to maintain feedback Z Sen is the output of the optional independent sensor The scales for both signals may be presented in the three units mentioned above All
42. et up on the computer Click on the Start menu click on Control Panel click on User Accounts click on Create a New Account Enter PSCAN2 in capital letters as the name for the account ick Next Select Computer administrator as the account type ick Create Account OO You will now see the new account in the User Accounts menu ick on the account You will see a different menu with choices for this account Click on Select Password QO Type in a password for the account Note that you must use this same password later in the Cockpit software configuration so make a note of it Click the create password button You should now see the PSCAN2 user icon with Computer administrator and Password protected beside it Setting up networking A Insert a Windows XP disk or a Windows XP Recovery disk XP will open a window asking what to do when you insert CD s select Open Files with Windows Explorer You should see folders select VALUEADD then MSFT then NET then NETBEUI You should see three files NBF SYS NETNBF INF NETBEUI TXT Copy NBF SYS and NETNBF INF to the C WINDOWS SYSTEM32 DRIVERS This next step is required to see a hidden directory C WINDOWS INF While still in Windows Explorer click on Tools click on Folder Options click on View and locate Hidden Files and Folders Click on Show Hidden Files and Folders Click OK Now copy NETNBF INF to C WINDOWS INF Exit Windows Explorer 36 NANO R AFM
43. f the acquired image may be enhanced by changing the phase of the detected signal relative to the reference signal The range is 0 to 360 degrees AUX 1 amp 2 Outputs The Auxiliary outputs AUX1 and AUX2 provide the user with 0 10 V DC 10 mA outputs with 12 bit resolution 58 NANO R AFM USER S MANUAL Demod Selects Demod Gain Four settings are available 1x 2x 3x and 4x The higher gains are used to assure a satisfactory signal level for the demodulator section Demod Filter High frequency effects can be reduced after demodulation by the use of decade filters 10 Hz 100 Hz 1000 Hz and full range Demod Type This switch selects the type of detection in the demodulator Amplitude Detection typical for oscillating mode and Phase Detection used to control the PID loop by sensing small changes in the phase of the oscillating cantilever tip Laser Motors Laser The Laser is ON under typical program initialization It can be turned off at any time Stepper Motors Motor Select Any of six micro stepper motors rated at 12 V 0 5 A per phase can be selected Just to the right of the select window is a window that indicates the motor location on a relative scale The primary approach motor for AFM is motor 1 Control An individual stepper may be moved in the Forward or Reverse direction and Stopped at any time In a typical set up Forward moves the tip towards the sample Reverse lifts it up Any numb
44. factory mechanical contact as a function of the applied Z piezo voltage Once the desired frequency is selected pressing the Z gt button will ramp the output voltage to the Z actuator from high to low to high voltage and return to the initial state The resulting plot of the amplitude at the selected resonance frequency should be relatively flat less than 10 variation This assures that the amplitude is substantially constant over the Z actuator range When operating in the Typical Mode two additional functions are presented Full Range sets the sweep range from 50kHz to 400kHz Auto set sets the frequency at 90 of the maximum value to the left of the peak and sets the set point so that error signal Z Err is zero at two thirds of maximum amplitude Detector Sensitivity The amplitude of the cantilever oscillation under typical conditions for cantilevers in the 250 350 kHz resonance frequency range is approximately 0 12 nm mV drive amplitude for Nanosensor cantilevers and approximately 0 31 nm mV drive amplitude for K Tek cantilevers Dual trace Storage Scope Mode This mode is similar to the time mode except that the full scale time ranges from 2000 to 10000 ms Although only two signals may be displayed at any time the two signals are synchronized to within 15 to 45 microseconds 62 NANO R AFM USER S MANUAL depending on which channels are selected This mode is useful for observing long term drift effects Automa
45. ferences The SPM Cockpit program opens with the setup and scanning parameters from the previous session Save Configuration File as This function will save the setup and scanning parameters in the current session at any time Edit Configuration File Under some conditions it may be useful to manually change a particular parameter in the Configuration File A text editor is opened to allow changes The file must be saved when exiting the editor in order for the changes to take place 50 NANO R AFM USER S MANUAL Save Images An image is acquired for each of the selected channels see Scan Image Setup 1 through 4 They may be saved in one or any of three formats TopoMetrix ThermoMicroscopes Nanoscope 3 Digital Instruments Veeco and Digital Surf that can be accessed by the corresponding image analysis software A list of extensions for each type of image acquired is provided in the appendix of the User s Manual Please note that in the Typical Mode only one image the clicked on highlighted image can be saved in the image bank under scanner controls However all the images can still be saved under the file menu selection as in the X pert Mode Open Images Images of any of the three above mentioned formats may be opened for viewing The image can then be saved in another format or exported discussed below Save Raw Scan Data The primary scan data may be saved in a
46. g and adsorbed chemicals on the surface often removed by a water rinse and a blow dry with dry nitrogen or a pressurized air can 6 Click on the Tip Approach Retract icon Mal and then engage tip gt gt Z ERR should be chosen in the select channel box If the error signal crosses the set point value before the surface is not contacted the Z actuator will retract and a high frequency oscillating sound occurs Click on tip retract which will lift the cantilever tip from the surface and disengage the PID loop Recheck the alignment and the frequency sweep 7 After the stepper motor stops press Time Mode icon and select Z HGT as input gt Click on Full to make Y axis to the full scale 10 to 10 V Mostly Z HGT is at 10V right after the motor stops indicating the tip is not really engaged Click on the Time Mode Icon again and select Z ERR as input Which will Click on Full to make Y axis to the full scale 10 to 10 V Typically Z Hgt will be at 9 to 10 V after the motor stops indicating that the tip is in contact and the Z actuator is at or near full extension Select Laser Motors in Settings Stepping down Fwd 30 60 pulses 30 pulses 2 microns should bring Z HGT into the center of the Z actuator range 0 V By activating the Incremental approach and addition routine is initiated during tip approach one which will reduce the chances of tip 45 NANO R
47. h the surface i e the feedback error signal may be selected Typically it is Z Err for contact mode and Z Dem for oscillating modes Surface Value amp Deviation In order to provide for both positive going and negative going feedback error signals as the tip cantilever approaches the surface the motor can be stopped within any range of positive or negative signal voltage The Surface Value is the center of the required voltage range and Deviation is the voltage above and below the center voltage For example for most AFM systems the feedback error signal is negative going positive with zero volts as the cross over i e the voltage above which will stop the approach motor A Surface Value and Deviation 63 NANO R AFM USER S MANUAL setting of 5000 mV and 5000 mV respectively will stop the motor if the feedback error signal is between zero and 10 V Incremental Approach This function activates a Z voltage ramp between step increments This provides a gentler interaction of the tip with the surface during tip engagement Prior to each downward motion of the stepper motor a few microns the Z piezo is ramped at a set rate with the PID feedback loop off The process is stopped when the Z Err becomes positive and PID loop is activated If the recommended parameters displayed when the Advanced window is opened the tip will be positioned approximately mid scale for Z Hgt The parameter settings are listed from top
48. h the addition of decade filters full range 1000 Hz 100 Hz and 10 Hz When monitoring the error signal the Z Pos signal is useful for reducing noise and noise spikes in either contact mode or oscillating mode Z Hgt Gain The Z Het bit resolution can be doubled particularly for enhancing the image quality of features of small height The Z range is also reduced a factor of two with the upper half of the range being active 0 to 10 V of the 10 to 10 V The extended portion of the Z piezo is active Z Piezo With the PID setting off and the Fast Retract set to Z DAC applied the Z piezo voltage may be set directly with this function The voltage range of the piezo is the inverse of the set voltage i e set voltage is 10 000 to 0 mV for 0 to 130 V output to the Z piezo 140V in newer units For normal scanning the set voltage is zero volts The fully retracted setting of the fast retract function is intended for a specialized application the normal setting 1s Z DAC applied PID On Off The PID loop may be turned on or off manually at any time In any event during tip approach the PID is turned on before the approach motor is activated During tip retract the PID is turned off after the motor pulls back Scan Image Setup Resolution Over all scan ranges the images may be acquired at resolutions from 16 x 16 to 1024 x 1024 pixels Initially 256 x 256 resolution is used Overscan Unde
49. he probe from a null position above the surface to contact with the surface Becker remarked that when using this vibrating profile method for measuring images the detail of the images would depend on the sharpness of the probe In 1971 Russell Young demonstrated a non contact type of stylus profiler In his profiler called the Topographiner Young used the fact that the electron field emission current between a sharp metal probe and a surface is very dependent on the probe sample distance for electrically conductive samples In the Topographiner the probe was mounted directly on a piezoelectric ceramic used to move the probe in a vertical direction above the surface An electronic feedback circuit monitoring the electron emission was then used to drive the piezoceramic and thus keep the probe sample spacing fixed Then with piezoelectric ceramics the probe was used to scan the surface in the horizontal X Y dimensions By monitoring the X Y and Z position of the probe a 3D image of the surface was constructed The resolution of Young s instrument was controlled by the instrument s vibrations Scanning Tunneling Microscopes and Atomic Force Microscopes In 1981 researchers at IBM were able to utilize the methods first demonstrated by Young to create the scanning tunneling microscope STM Bennig and Rohrer demonstrated that by controlling the vibrations of an instrument very similar to Young s Topographiner it was possible to monitor the e
50. he probe to the surface 4 Start the scanning of the probe over the surface and view the image of the surface on the computer screen 5 Save the image on a computer disk Resolution in an atomic force microscope Traditional microscopes have only one measure of resolution the resolution in the plane of an image An atomic force microscope has two measures of resolution the plane of the measurement and in the direction perpendicular to the surface In Plane Resolution The in plane resolution depends on the geometry of the probe that is used for scanning In general the sharper the probe the higher the resolution of the AFM image In the figure below is the theoretical line scan of two spheres that are measured with a sharp probe and a dull probe Figure 1 2 f The image on the right will have a higher resolution because the probe used for the measurement is much sharper Vertical Resolution The vertical resolution in an AFM is established by relative vibrations of the probe above the surface Sources for vibrations are acoustic noise floor vibrations and thermal vibrations Getting the maximum vertical resolution requires minimizing the vibrations of the instrument NANO R AFM USER S MANUAL Probe Surface Interactions The strongest forces between the probe and surface are mechanical which are the forces that occur when the atoms on the probe physically interact with the atoms on a surface However other forces between
51. his the basic settings for operating a particular scanner and scanning mode Open XY Offset and Zoom window Bed Press A LIN icon and then Yes to run auto linearization gt The autoline function should be repeated two to three times in order to obtain consistent offset and zoom setting gt In Scan Image Setup folder set Resolution to 256 Scan Rate to 1 Channels to 4 gt In XY Control set Zoom to 12 this gives about a 10 Um image gt In Input Selects to ADC select Channel 1 Z HGT topography Channel 2 Z ERR deflection Channel 3 Z LR friction and Channel 4 Z SEN height measured by Z sensor for a 3 axis system with a Z sensor Press Red Dot icon and make sure the spot is in the green area below the horizontal axis NOTE the Z Setpoint value is zero so that when the cantilever tip contacts the surface the approach motor will stop when the Z ERR is zero red dot in center Press Tip Approach icon and engage the tip 41 NANO R AFM USER S MANUAL 6 After the stepper motor stops press Time Mode icon and select Z HGT as input gt Click on Full to make Y axis to the full scale 10 to 10 V Typically Z Hgt will be at to 10 V after the motor stops indicating that the tip is in contact and the Z actuator is at or near full extension gt Select Laser Motors in Settings Stepping down Fwd 30 60 pulses should bring Z HGT into the
52. hnology manuals Use only Pacific Nanotechnology replacement parts Use only Pacific Nanotechnology approved consumables such as filters lamps cantilevers etc Provide safe and adequate working space for servicing of the products by Pacific Nanotechnology personnel REPLACEMENTS AND REPAIRS e Any product part or assembly returned to Pacific Nanotechnology for examination or repair must have prior approval e Jt must be identified by a Return Materials Authorization or RMA number obtained from Pacific Nanotechnology prior to shipment It must be returned freight prepaid to the designated address by the customer Return freight costs will be prepaid by Pacific Nanotechnology if the product part or assembly is defective and under warranty Pacific Nanotechnology will either replace or repair defective instruments or parts at its option Repair and replacement of instruments or parts does not extend the time of the original watranty e Replacement parts or products used on instruments out of warranty are themselves warranted free of defects in materials and workmanship for 90 days with the exception of consumables such as filters lamps cantilevers etc NANO R AFM USER S MANUAL WARRANTY LIMITATIONS This warranty does not cover 1 SV OTS Sos Any loss damage and or product malfunction caused by shipping or storage accident abuse alteration misuse or use of user supplied software hardware replacement parts or
53. k ball is available for activating many of the Nano R stage features These features include the video Microscope Zoom Focus as well is the automated X Y positioning stage Nano R Stage The Nano R stage includes the sample stage video optical microscope and the AFM Scanner Also included in the stage are the modules for the AFM Scanner calibration sensors 2 1 1 NANO R STAGE AFM Scanner Motorized Approach Sample Holder Figure 2 1 a The Nano R AFM stage includes a motorized zoom focus video microscope an AFM scanner three motors for moving the probe towards the sample a sample puck and a motorized X Y positioning stage At the rear of the Nano R stage there are five cables that are connected to the stage controller The sample puck holder is easily removed from the stage Sample holders for specialized applications can be easily designed 14 NANO R AFM USER S MANUAL 2 1 2 NANO R AFM SCANNER The Nano R AFM scanner uses a light lever design A red laser is focused on the back of a cantilever and is then projected onto a four section photodiode There are two adjustment knobs to position the laser light on the backside of the cantilever and there are two knobs for moving the photodetector into the light path Laser E Photodetector Cantilever Figure 2 1 b Optical Viewing Port Detector X Laser X Detector Y Laser Y Figure 2 1 c 15 NANO R AFM USER S MANUA
54. larity and Set point Polarity are positive for contact mode and negative for oscillating mode Demodulator Mode is at BYPASS for contact mode and DEMOD for oscillating mode These settings are all in the configuration files Nonlinearity XY Mainly used to correct the second order nonlinearity of the X and Y sensors Only On line correction Acquire image is used The numbers are pre set at factory 23 NANO R AFM USER S MANUAL 3 2 Analysis Software 3 2 1 PNI IMAGE ANALYSIS SOFTWARE There are several shortcut icons at the top of the SPMCockpit image analysis software the icons as well as a description of the icon functions are listed below f PScan SPM Cockpit Metrology Series 2001 AFM System Mode File Device Settings Tools Process Display Window Help y Coy VY alt 22 7 open Figure 3 2 SPMCockpit image analysis software interface The acquisition icon is used for changing to the image acquisition window in the SPM cockpit software After choosing the acquisition icon either EZMode or X Pert software may be selected With the open icon an image is loaded from a source such as a floppy disk or a hard disk Images must be stored in the SPMCockpit format to be opened with this icon Images are saved with the save icon Saved images may be retrieved at a later time with the open icon Using the select image icon retrieved an image from the most
55. lectron tunneling current between a sharp probe and a sample Since electron tunneling is much more sensitive than field emissions the probe could be used to scan very close to the surface The results were astounding Bennig and Rohrer were able to see individual silicon atoms on a surface Although the STM was considered a fundamental advancement for scientific research it had limited applications because it worked only on electrically conductive samples A major advancement in profilers occurred in 1996 when Bennig and Quate demonstrated the Atomic Force Microscope Using an ultra small probe tip at the end of a cantilever the atomic force microscope could achieve extremely high resolutions Initially the motion of the cantilever was monitored with an STM tip However it was soon realized that a light lever similar to the technique first used by Schmalz could be used for measuring the motion of the cantilever In their paper Bennig and Quate proposed that the AFM could be improved by vibrating the cantilever above the surface NANO R AFM USER S MANUAL The first practical demonstration of the vibrating cantilever technique in an atomic force microscope was made by Wickramsinghe in 1987 with an optical interferometer to measure the amplitude of a cantilever s vibration Photographic Film M uo Source Moving Stage Flexure Figure 1 1 An example of a surface profiler made in 1929
56. mage To display a selected input image signal hal Scan Control Tools gt Scan Control Panel Start or stop scans Settings Laser Motors Stepper functions for the motor and ON OFF switch for the laser Fwd moving the tip towards the sample Stepper motor is used quite often to bring the tip really engaged right after the stepper motor stops by automatic approach Scan Image Setup To set up common scan controls such as pixel resolution scan rate number of input channels to be displayed rotation angle and image acquisition direction Overscan is the number of pixels scanned before acquisition starts for each line Prescan is the number of lines scanned before acquisition starts for each image Skew pre set at factory corrects non orthogonal angle of the X and Y scanners Input Selects to ADC To specify the type of input signals to be displayed Z Sensor s Gain and Offset are pre set at factory Frequency Synthesis Showing the driving frequency and amplitude in oscillating mode X Y Control Showing the X Y offset and zoom size Proportional and Integral gains in X Feedback and Y Feedback are pre set at factory These are for the X and Y sensors in the closed X Y loop 22 NANO R AFM USER S MANUAL XYZ Scales X Y and Z calibration factors pre set at factory Z feedback To adjust gains and set point while scanning to improve the image Initial gains are provided in the configuration files Input Po
57. mouse key when the cursor is pointing at the location within the scanned image display A black dot appears on the scanned image By selecting Force Distance Curve under the pull down Tools menu a new window appears for selecting the F D parameters activating the F D routine and displaying the approach Curve 1 green line and retract curves Curve 2 red line provided the cantilever is sufficiently stiff The F D curve may be obtained when the Z PID loop is in feedback and the Z actuator Z Hgt is in mid scale The range of the Z actuator is approximately 10 microns The Z DAC voltage is the inverse of the extension The actuator is fully retracted at 10000 mV and fully extended at 0 mV The Start position should be a higher value less extended than the Stop position If Z Hgt is about mid scale 5000 mV then a typical Start position might be 8000 mV and Stop position at initially 3 4000 mV The degree of deflection of the cantilever relative to the Z actuator position is dependent on a number of factors The user should refer to the large body of F D literature for further understanding of the nature and implications of the measurement In addition to the usual scaling parameters for the display the user may select the resolution Pixels usually 256 and the rate of data acquisition When the data rate is set to 0 ms pixel the data acquisition rate is set for maximum about 15 to 25 microseconds depending on the controller p
58. nd operation of an atomic force microscope It is essential to understand the contents of these sections for a complete understanding of how an atomic force microscope works Dimensions and Magnification An atomic force microscope is optimized for measuring surface features that are extremely small thus it is important to be familiar with the dimensions of the features being measured An atomic force microscope is capable of imaging features as small as a carbon atom and as large as the cross section of a human hair A carbon atom is approximately 25 nanometers nm in diameter and the diameter of a human hair is approximately 80 microns um in diameter The common unit of dimension used for making measurements in an atomic force microscope is the nanometer A nanometer is one billionth of a meter 1 METER 1 000 000 000 NANOMETERS 1 MICRON 1 000 NANOMETERS Another common unit of measure is the Angstrom There are ten angstroms A in one nanometer 1 NANOMETER 10 ANGSTROMS Magnification in an atomic force microscope is the ratio of the actual size of a feature to the size of the feature when viewed on a computer screen Thus when an entire cross section of a human hair is viewed on a 500 MM computer monitor 20 inch monitor the magnification is MAGNIFICATION 500 MM 08 MM 6 250 X In the case of extremely high resolution imaging the entire field of view of the image may be 100 nanometers In this case the magnification on
59. ng amplitude or phase constant Material Sensing Modes The interaction of the probe with the surface depends on the chemical and physical properties of the surface It is possible to measure the interactions and thus sense the materials at a sample s surface Vibrating Material Sensing Mode The AFM cantilever may be vibrated to measure the force between a probe and surface during an AFM scan The magnitude of amplitude damping and the amount of phase change of the cantilever depends on the surface chemical composition and the physical properties of the surface Thus on an inhomogeneous sample contrast can be observed between regions of varying mechanical or chemical composition Typically in the vibrating material sensing mode if the amplitude is fixed by the feedback unit then the contrast of the material is observed by measuring phase changes This technique has many names including phase mode phase detection and force modulated microscopy Torsion Modes In contact mode AFM it is possible to monitor the torsion motions of the cantilever as it is scanned across a surface _ en Figure 1 2 1 Torsions of the cantilever are measured in the AFM Changes in the torsion of the cantilever are an indication of changes in the surface chemical composition 11 NANO R AFM USER S MANUAL The amount of torsion of the cantilever is controlled by changes in topography as well as changes in surface chemical properties If a s
60. ng becomes the skew angle Scan Data Transfer Image data can be transferred form the Controller to the Master Computer on a line by line basis usually selected or after the whole image is acquired Scan Image Direction The image may be acquired in the Forward Reverse or both directions along the fast axis X Y Control The X Offset Y offset and Zoom set the effective scan range and start of scan position which is also dependent on the rotation angle The initial offsets and maximum zoom are set by the configuration file or by running the Auto linearizer routine see below These values can be adjust for smaller scan range and location by using the two zoom features box click mouse on the image for zoom in or box click mouse adjacent to the image for zoom out or double click adjacent to the image to open a 56 NANO R AFM USER S MANUAL separate window for zoom in or zoom out Alternatively the user may adjust these boxed values to select a particular value In addition to the zoom features above an Extra Zoom with Offsets can be selected for higher resolution or positioning capability By double clicking within an image a new extra Zoom window is opened The user may select a zoom value of 2X or 4X and locate scanning region The X amp Y Feedback parameters are also set within this section The respective feedback loops may be manually turned on or off for test purposes Zfeedback
61. nnection to the Cockpit PC J The Controller will reboot and if it successfully reads the floppy there will be four beeps Now remove the floppy turn off the Controller reconnect the Ethernet cable and turn on the Controller K A dual tone indicates a successful configuration a single tone indicates an unsuccessful one You should see Device Initialized in the bottom bar of the Cockpit window and the traffic signal indicator should have turned from red to green 38 NANO R AFM USER S MANUAL Ci How To Guide 5 1 Exchange Probes Probes in the Nano RIM are mounted on a metal substrate that is magnetically mounted to the bottom of the AFM scanner The probe and metal substrate are removed with tweezers Cantilever and Substrate Figure 5 1 39 NANO R AFM USER S MANUAL 5 2 Operating the Track Ball Track Ball Left Button Right Button Figure 5 2 Left Button Right Button Track Ball Move X Y Stage off off Active Move Z Stage off on Active Focus on on Active Zoom on on Active The Track Ball active icon must be activated in the Nano R stage window to use the track ball for moving the stage 40 NANO R AFM USER S MANUAL 5 3 Measuring an image with X Pert Software 5 ji Check a few initial parameters in Settings 3 1 CONTACT MODE z Click on Open Configuration File icon gt Select the contact mode configuration file for example g5 229 CON 991110 T
62. on Motorized Control Manual Control 1 4 Physical Specifications Dimensions 2 0 Software Specifications 2 1 Expert Mode 2 2 Typical Mode 2 3 Standard Analysis 2 4 Software Platforms 3 0 Master Computer Specifications 3 1 Processing 3 2 Connectivity 4 0 Control Electronic Specifications 4 1 Basic A D Conversion MANUAL Standard 5X Optional 10X Standard Optional Standard Optional Focus Zoom X Y Lens Position Width Length Height Weight Pixels Image Rotation Acq Direction Channels 3D Display Line Analysis Light Shade Top View Filter Master Computer Conversion range Resolution Number of Input Channels Sampling rate Freq Response before Demod Freq Response Z PID loop 27 330X 660X 410 X 540 Microns 203 X 270 Microns 4 Micron 1 5 Micron DC Motor DC Motor 1mm 14 Inch 14 Inch 12 Inch 55 Lbs 64x64 128x128 256x256 512x512 1024x1024 0 90 180 270 and any arbitrary angle Forward Reverse Forward amp Reverse 1 to 4 Channels Selected from Z Sensor Lateral Force Z Voltage Visual Basic operating under Windows 95 98 NT XP C based operating under MS DOS Linked to Master by DCEx Protocol via Ethernet Pentium III 800 Mhrz 40 Gbits Hard Drive USB Ethernet Serial Parallel 10 V to 10 V or 0 to 10 V 16 bits 1 to 4 g t 20 kHz 1 2 or 3 channel acquisition g t 16 kHz 4 channel acquisition DC
63. ons for Digital Flags 4 8 Physical Specifications Size 15 H 13 W 17 D 38 1 cm 33 0 cm 43 2 cm Weight 35 Ibs 16 kg 4 9 Operating Specifications Voltage 115 230 VAC 50 60 Hz Current 0 95 0 45 Amp Temperature 50 95 deg F 10 35 C Humidity 5 60 RH 4 10 Safety Europe CE Certification 4 11 Control Computer Specifications Processing PC based 266 MHz or greater 32 Mbyte RAM 3 2 Gbyte Hard Disk Drive 1 44 Mbyte Floppy Drive SVGA video card for diagnostics Connecting AC Power Ethernet 10 100 Mbit sec Scanner Stage Input Output lines Linearizer Inputs X Y amp Z Stepper Motor Port Signal Access Port 29 NANO R AFM USER S MANUAL 4 2 Data Station Block Diagrams AUX1 gt AUX IN1 AUX1 AUX2 gt AUX IN2 AUX2 AUX OUT1 10V AUX1 DAC 10V AUX OUT2 410V AUX2 DACI 10V Pacific NanoTechnology Incorporated 1421 Warner Suite B Tustin California 92780 174 258 0190 This drawing was originated by and is the exclusive property of Pacific NanoTechnology It is furnished for recipients only and is not an authorization or license to make this construction or to furnish this information to others Any unauthorized use of this information will result in prosecution to the fullest extent of the law AUX IN1 Z DEM Z ERR AAAA AUX IN2 a a ADC5 ae
64. quence jPScan SPM Cockpit Metrology Series 2001 AFM System Mote pie Device SO Jods Process lt Disaiay Windia Help iiearize Select Align Frequency Tip Scanner Image Mode Laser Sweep Approach Controls Figure 3 1 Screen shot of the EZMode Software Interface Shortcut Icons for At the top of the EZMode Screen is a series of actions in the EZMode order that is required for measuring and image with the Nano R AFM Each of the buttons at the top of the page can be activated in any sequence For example if during image acquisition it becomes necessary to check the laser alignment it is possible to click on the align laser button A description of each option in the EZMode Icon Bar software follows Lineatizeg The linearize calibrate window is used for testing the system to see a if it is calibrated in the X Y axis Select An imaging mode is selected in this window The two primary modes Mode are contact and close contact mode Other modes such as lateral force may be selected here Align The align laser window is used for assuring that the laser light is Laser projected from the back of the cantilever onto the photodetector Frequency If close contact mode is selected this window shows the resonance Swee peak of the cantilever Also the feedback setpoint is selected here Tip After the probe is in the AFM head and is aligned the tip approach Approach button is u
65. quired which may require increased gain settings for Lateral Force see Settings then the red dot should be set slightly to the left of the vertical median line and below the horizontal median line The bar meter to the right of the red dot region shows the total light intensity on the detector Z Sum For more precise beam positioning at low light levels a 1x to 4x Scale switch is provided This scale setting does not affect the Z PID loop For convenience the Laser may be turned on and off from this window Oscilloscope time mode The time dependence of up to 4 signals may be presented in graphical form The time base ranges from 10 to 1000 ms The update interval depends on the time base setting and the performance of the master computer but is typically several times a second As with all oscilloscope modes the voltage range is 10 volts The scaling may be set at Full scale one time Auto scale or continuous auto scale with box checked With the Auto box unchecked the Half Range and Offset settings can be independently controlled Oscilloscope line mode This mode is similar to the time mode except that the abscissa becomes the voltage ramp of a line scan The repetition rate is set under the Scan Image Setup scan rate as is the resolution pixels If the Z Hgt or Z Sen signals are selected an Auto leveling box is available for observing the line scan corrected for background slope Oscilloscope frequency sweep
66. r some conditions it may be useful to reduce artifacts associated with reversing tip scan direction When scanning in the forward direction up to 127 pixels may be removed at the beginning of the line Depending on the resolution the range will be reduced proportionally However the resulting image is still at the specified scanning resolution 55 NANO R AFM USER S MANUAL Prescan As above under some conditions it is useful to scan a few lines at the beginning before an image is acquires Up to 127 lines may be eliminated from the acquired image Again the resulting image is still at the specified scanning resolution Scan Rate The scan rate may be varied from a few thousandths of a line per second up to about 15 lines per second for four channel acquisition Above 0 2 Ips user interrupts are only allowed at the end of a scanned line interrupts are allowed after each point below 0 2 Ips Channels One to four channels may be acquired simultaneously and stored Skew The extent of skew between the X amp Y axis is corrected during image acquisition It is typically less than one degree Rotation The angle for the fast scan axis can be set manually or by clicking on one of the primary axis setting The slight distortion effect of the skew correction setting in the first few scanned lines along the X axis may be removed by setting the rotation angle the same as the skew angle thereby the zero angle for scanni
67. rce is maintained by measuring the force with the light lever sensor and using a feedback control electronic circuit to control the position of the Z piezoelectric ceramic See Figure 1 2 d X Piezoelectric Y Peizoelectric Z Peizoelectric Feedback Unit Figure 1 2 d This figure illustrates the primary components of the light lever atomic force microscope The X and Y piezoceramics are used to scan the probe over the surface The motion of the probe over the surface is generated by piezoelectric ceramics that move the probe and force sensor across the surface in the X and Y directions NANO R AFM USER S MANUAL AFM Instrumentation Figure 1 2 e Shows all of the components and subsystems of an atomic force microscope system Z Coarse Z motion translator This translator moves the AFM head towards the surface so that the force sensor can measure the force between the probe and sample The motion of the translator is usually about 10 mm T Coarse X Y translation stage The XY translation stage is used to place the section of the sample that is being imaged by the AFM directly under the probe X P X and Y piezoelectric transducer With the X and Y piezoelectric transducer the Y P probe is moved over the surface in a raster motion when an AFM image is measured FS Force Sensor The force sensor measures the force between the probe and the sample by monitoring the deflection of a can
68. rocessor speed Display Color palette This feature opens a directory that contains the available color palettes that can be selected for displaying images 66 NANO R AFM USER S MANUAL Window The contents listed are the windows that have been opened in the Main Window Help Additional information on the various functions listed above Information on the version of image acquisition software that is currently in operation 67 NANO R AFM USER S MANUAL Appendix C Nano R Configuration File The following is a list of the items in the configuration file that is loaded into the Nano R AFM controller These settings are typically set by Pacific Nanotechnology at the factory INPUT SELECTS CH1 1 CH2 8 CH3 5 CH4 7 ZSEN_G 43 ZSEN_O 137 ZSEN_F 2 ZPOS_F 0 ZADC_G 0 LR_G 255 LR_OFS 255 LAT_F 0 LR_F 0 ZHGT_G 0 Z FEEDBACK PID_CH 0 PID_DEM 1 PID_POL 1 PID_SET 1 ZERR_G 13 PID_P 8 PID_I 10 PID_D 100 Z_SET 1013 18 DEMOD SELECTS 68 NANO R AFM USER S MANUAL DEM_G 0 DEM _F 1 DEMOD 1 PID ON OFF PID_ON 1 Z PIEZO Z OUT 2048 Z OFS 0 X5 0 XY CONTROL X OFES 73 Y_OFS 67 ZOOM 8 XFBK P 51 XFBK 50 YEFBK P 255 YEBK_I 40 EXTRA_ZOOM 1 XPI ON 1 YPLON 1 EXTRA_XOFS 0 EXTRA_YOFS 0 FREQUENCY SYNTH F_AMP 15 FREQ 59801795 PHASE 0 OSC_AMPL 1500 AUX 1 amp 2 AUX1 0 AUX2 0 STEPPERS MOTOR 264 69 NANO R AFM USER S MANUAL STEP_DIR 0 STEP 1 PULSES 5 P
69. ry Setup To select the device directory e g C Pscan2 created in Section 3 3 Ping Device gt Ping To test whether a controller is on network or not Cl Settings Settings To activate the Settings folders Items in Settings SET will be briefly explained in the next subsection Red Dot Tools gt Red Dot Alignment To show the position of the laser spot on the detector Time Mode Oscilloscope time To display a selected input signal as a function of time Up to four windows can be displayed simultaneously bee 21 NANO R AFM USER S MANUAL signal for a scan line Up to four windows can be displayed i i Line Mode Tools gt Oscilloscope line mode To display a selected input simultaneously Frequency Sweep Tools gt Oscilloscope frequency sweep For oscillating mode only To find the resonance frequency of a cantilever and to select the right driving frequency and amplitude Dual Trace Scope Tools gt Dual trace Storage Scope Similar to Time E Mode It displays two input signals at the same time a Auto Linearization Tools gt Automatic Linearizer Range To map the maximum scan area to a linear range of the X and Y sensors Tip Approach Tools gt Tip Approach Retract Engage or withdraw the Yip tip The parameters in Tip Approach Retract window should not be changed by new users Image Display Tools gt Display Scanned I
70. s The upper buffer is set as a percentage and is typically 90 to 96 If this value is set too high then the higher voltage side of the scanned image will be distorted for that axis Smaller mV and higher percent value will increase the scan range However thermal effects and piezo performance may cause small changes in the operating range of the actuators requiring more frequent use of the auto linearizer function Miscellaneous The user may select several among display and activity options for operating convenience Typical Mode The user may select certain properties as to how the Typical Mode is displayed and as to which image analysis program is activated Calculate Non linearity This function is reserved for qualified technical persons Exit This function closes the image acquisition program Directory Setup The Input output I O directory for a particular PScan2 Controller may be selected from this menu item Be sure to double click on the directory of choice in order to bring the directory name into the lower window before clicking OR 52 NANO R AFM USER S MANUAL Create Device Directory When first installing a new PScan2 Controller to the Master Computer a new directory must be created Usually the name of the directory is the same as serial number of the Controller For example the directory can be named PscanXXX where XXX is the last three digits of the serial number of the
71. scanning head complies with US 21 CFR 1040 10 and is certified as a Class IIa laser The laser wavelength is 670nm and the maximum power is 3 mW In addition to the above please follow laser safety control measures in American National Standards Institute Z136 1 1986 HIGH VOLTAGE Wherever high voltage is present on the system extreme care should always be taken to avoid direct contact while the instrument hardware is powered on Always power off the equipment before attempting to remove any panels or PC boards and before touching any connectors by hand or with electrically conductive tools vii NANO R AFM USER S MANUAL Chapter Introduction to AFM 1 1 History of AFM Introduction Typically when we think of microscopes we think of optical or electron microscopes Such microscopes create a magnified image of an object by focusing electromagnetic radiation such as photons or electrons on its surface Optical and electron microscopes can easily generate two dimensional magnified images of an object s surface with a magnification as great as 1000X for an optical microscope and as large as 100 000X for an electron microscope Although these are powerful tools the images obtained are typically in the plane horizontal to the surface of the object Such microscopes do not readily supply the vertical dimensions of an object s surface the height and depth of the surface features The atomic force microscope AFM developed in the mid
72. sed for moving the probe to the sample Scanner This window displays the image as it is measured and allows Controls changes to the feedback parameters scan rates and scan range Image Images can be displayed and analyzed by selecting this button Processin 20 NANO R AFM USER S MANUAL 3 1 2 ACQUISITION X PERT SOFTWARE To Access E Launch SPMCockpit Software Click on mode in the toolbar m Click on X Pert mode 1 Pacific Scanning Corp SPM Cockpit Eile Setings Device Tools Display Window Help srl S Figure 3 1 a Screen shot of the X Pert Mode Software Interface Shortcut Icons for After the Nano R AFM system is started fifteen short cut x Pert Mode icons appear under the top pull down menu Most of the icons Software are used frequently during imaging The following definitions and functions are explained below Open Configuration File Will open a configuration file in the Program fy Files MISeries2000 ConfigFiles directory A configuration file contains Config appropriate parameters including the scanner s calibration and initial operation parameters in Settings Save Configuration File File gt Save Configuration As To save new parameters or settings Save Image File gt Save Image s gt Save Image s in digital Surf format To save image s in digital surf file format iL a 22 Device Directory Device gt Directo
73. t click on Sharing and Security You should be in a properties menu with a couple of choices in Network Sharing and Security you will see the Share this Folder on the Network and the Allow Network Users to Change my Files boxes checked Uncheck Share this Folder on the Network click Apply recheck the box and click Apply again Click OK to exit your directory is now shared A box asking to switch to the directory now appears click yes The software will detect a missing file in your newly created directory slave ini click yes and select slave ini fo put a copy into it Click on the Device menu click on Directory Setup you should see your C Pscan PScan2001 PScan238 directory selected as the default click OK Return again to the Device menu click on Create Configuration Diskette verify that the computer name and the device directory share name are correct then enter the same password from the 37 NANO R AFM USER S MANUAL PSCAN2 user account that you created earlier These two passwords MUST be the same H At the prompt insert an empty 3 5 floppy disk into the computer s floppy drive Click OK A small setup file is written on the floppy At the prompt remove the floppy insert it into the Controller s floppy drive disconnect the Ethernet cable from the Controller and reboot power off and on the Controller Removing the Ethernet cable causes the Controller to read the floppy rather than trying to make a co
74. t EZMode Raise AFM Scanner Put In Sample Install Cantilever Contact Close Contact Set Resonance Move Scanner Down to Sample Locate Feature Probe Approach Scan Sample Image Analysis Move Scanner Up 17 NANO R AFM USER S MANUAL Measuring an Image in 12 Steps Launch SPM Cockpit Software Click Mode then EZMode Raise the AFM Head Put in Sample Install Align Cantilever Set Resonance only for Close Contact Move Probe to Sample Locate feature for imaging Probe Approach Scan Analysis of Image Move Probe away from Sample 18 NANO R AFM USER S MANUAL Ci Software Manual 3 1 Acquisition Software There are four main screens in the Nano R software package They are Acquisition EZMode Acquisition X Pert Software Analysis PNI Analysis Pacific Map To Access the Acquisition Software Click on the Pacific Map Software A description is found in Appendix C 19 NANO R AFM USER S MANUAL 3 1 1 ACQUISITION EZMODE EZMode software is ideal for beginners that want to learn to use the Nano R AFM and for those that use the AFM system on an occasional basis To Access m Click on SPMCockpit Icon on Windows Desktop a Click on modes a Click on EZMode Measuring an image with EZMode software is achieved by following the steps on the shortcut bar from left to right The shortcut icons can be opened in sequence or out of se
75. the probe and surface can have an impact on an AFM image These other forces include surface contamination electrostatic forces and surface material properties Surface contamination In ambient air all surfaces are covered with a very thin layer lt 50 nm of contamination This contamination can be comprised of water and hydrocarbons and depends on the environment the microscope is located in When the AFM probe comes into contact with the surface contamination capillary forces can pull the probe towards the surface Electrostatic forces Insulating surfaces can store charges on their surface These charges can interact with charges on the AFM probe or cantilever Such forces can be so strong that they bend the cantilever when scanning a surface Surface_material properties Heterogeneous surfaces can have regions of different hardness and friction As the probe is scanned across a surface the interaction of the probe with the surface can change when moving from one region to another Such changes in forces can give a contrast that is useful for differentiating between materials on a heterogeneous surface Topography Modes When scanning a sample with an AFM a constant force is applied to the surface by the probe at the end of a cantilever Measuring the force with the cantilever in the AFM is achieved by two methods In the first method the deflection of the cantilever is directly measured In the second method the cantilever
76. tic Linearizer This function automatically maps the X and Y actuator movements onto a selected region within the sensors full scale range From the Preferences window the lower limit selected as a millivolt offset and the upper limit selected as a percentage of the maximum available range for each axis provide a buffer zone below the lower limit and above the upper limit respectively This assures that the signal in the feedback loop will not exceed the actuator s mechanical range A succession of eight windows are displayed in order to provide a visual sense as to how well each axis is operating Tip Approach Retract The primary control of engaging and retracting cantilever tip relative to the scanning surface are three icon buttons Stop is in the center of the window Retract is just above and Approach is just below the Stop icon The motor for Z motion is selected in the box just to the right of the Stop icon If a stepper motor is selected then the relative position of the tip cantilever is shown in the box just below the motor selection box Approach For systems using DC motor the rate of approach is set by the Voltage box The voltage may be positive or negative For systems using Steppers the Step Size and Direction may be selected The approach rate is fixed but may be changed if needed See User s Manual DCEx initialization file structure Select Channel Any signal sensing the Z cantilever tip interacting wit
77. tilever ZP Z piezoelectric Ceramic Moves the force sensor in the vertical direction to the surface as the probe is scanned with the X and Y piezoelectric transducers FCU Feedback control unit The feedback control unit takes in the signal from the light lever force sensor and outputs the voltage that drives the Z piezoelectric ceramic This voltage refers to the voltage that is required to maintain a constant deflection of the cantilever while scanning SG XY signal generator The motion of the probe in the XY plane is controlled by the X Y signal generator A raster motion is used when an image is measured CPU Computer The computer is used for setting the scanning parameters such as scan size scan speed feedback control response and visualizing images captured with the microscope NANO R AFM USER S MANUAL F Frame A solid frame supports the entire AFM microscope The frame must be very rigid so that it does not allow vibrations between the tip and the surface NOTE Not shown is an optical microscope that is essential for locating features on the surface of the sample and for monitoring the probe approach process Measuring images with an atomic force microscope 1 Place a probe in the microscope and align the light lever sensing system 2 With the XY sample and the optical microscope place the region of the sample that will be imaged directly under the AFM probe 3 Engage the Z translation stage to bring t
78. to 500 kHz nominal DC to 20 kHz NANO R AFM USER S 4 2 Z feedback Loop 4 3 Demodulator 4 4 Modulator 4 5 Output Amplifiers MANUAL Digitally controlled analog Internal 4 Inputs for 4 sector Photodetector Tuning fork Sensor External For other AFM sensors and STM sensing Range 10 V to 10 V Differential buffered input Z height sensor Provision for a sensor absolute Z piezo motion e g strain gauge to be incorporated into a z feedback loop for absolute Z positioning Differential buffered input Range 0 to 10 V Balanced Demodulator 50 kHz 500kHz DC 20 kHz 1x 2x 3x or 4x Type Frequency range Demodulated bandwidth Input gain range Output Waveform Sinusoidal digitally synthesized Frequency Range 50 to 500 kHz Frequency Resolution lt 0 01 Hz Output Voltage Range Output Voltage Resolution Output Connections 0 to 10 V peak to peak 10 bits 10mV Two options capacitive coupled to 1 Z piezo driver via ext resistor 2 toan independent piezo driver Z Driver output from PID loop Driver output voltage range 0 to 140 V Frequency range DC to 20 kHz Noise Ground 3 mV rms nominal External 5 VDC 3 mV rms nominal Instantaneous max output current 500 mA min Average continuous output current 50 mA power supply limited Power Rating of output amplifier 85 Watts X amp Y Scan Drivers Driver output voltage range
79. urface is perfectly flat but has an interface between two different materials it is often possible to image the change in material properties on a surface This technique is similar to lateral force microscopy LFM 12 NANO R AFM USER S MANUAL Ci Getting Started 2 1 Description of the Nano R AFM The Nano R AFM is a high performance tabletop microscope system that is intended for research development and process control applications Figure 2 1 is a block diagram of the Nano R AFM showing the main components Video Microscope Monitor Computer Monitor Master Computer Master Computer Monitor The IBM PC type computer is the virtual interface to the Nano R AFM stage Software programs resident on the computers hard disk drive are used for measuring AFM images as well as the visualization and analysis of AFM images AFM Nano R Control AFM Electronics Stage controller om Figure 2 1 Video Monitor A video monitor displays the optical microscope image of the probe and of the sample In some cases the computer monitor may be used as the video monitor Controller The controller has most of the electronics that are required for operating the Nano R AFM stage It is connected to the Master Computer with a standard Ethernet cable 5 Cables are used for the connection between the controller and Nano R stage 13 NANO R AFM USER S MANUAL Stage Track Ball A trac
80. window will allow the image size to be changed via the zoom setting gt Before changing the location of the image use the Laser Motors tabsheet in the Settings window to lift motor in reverse direction the tip Note that you will probably have to change the set point as in step 7 gt In the XY offset and zoom window the displayed image area may now be moved to the desired location on the sample Changing the zoom changes the spatial field of view FOV As the resolution in number of pixels is fixed the spatial resolution is degraded as the FOV is increased 46 Appendix A Installation Procedures To install the Nano R scanning probe microscope please follow the procedures listed to establish the site for your instrument before it arrives It is your responsibility to ensure that the site specifications conform to the guidelines and specifications delineated before the installation Site Specifications Installation Requirements Needed Fork Lift to move the shipment from the truck to your loading dock 3 Shelf Utility Carts to move the shipment from the dock to its destination capable of supporting 100 Ibs Pallet Truck if a vibration table is included Location The scanning probe microscope is designed for use in a standard laboratory environment Temperature changes can cause the metal parts in the microscope stage to expand and contract and images to drift The microscope should not be placed
81. wo controllers independently by setting a multiple device capability During operation each controller scanner can be operated by simply selecting the device menu Park Idle Piezos The performance characteristics of the piezo actuators may deteriorate if substantial voltage is applied to the actuators over an extended period This function provides a time out capability when the controller is in Idle Mode that is when there is no active data acquisition such as oscilloscope or image acquisition modes The piezo voltages are brought to zero volts after a specified time period If the tip is in feedback a tip retract operation will be performed Any movement of the mouse will reactivate 53 NANO R AFM USER S MANUAL the actuator voltage setting but the tip engagement routine will not be performed The minimum time out range is 1 minute the maximum is 1000 minutes Diagnostics This function is reserved for qualified technical persons Settings Input Selects to ADC Channel Selects Up to four channels of twelve possible signals may be monitored using the various oscilloscope functions and scan image functions see the User s Manual for a list and description of these signals Normally Z HGT Z ERR ZDEM and Z SEN if the Z axis sensor option is active are used for oscillating mode and Z HGT Z ERR Z L R and Z SEN for contact mode Certain channels ones in which simultaneous monitoring is

Nano-R™ AFM User`s Manual - Fusion Energy Research Program

Contents

Download Pdf Manuals

Related Search

Related Contents

Nano-R&trade; AFM User`s Manual - Fusion Energy Research Program

Contents

Download Pdf Manuals

Related Search

Related Contents

Nano-R™ AFM User`s Manual - Fusion Energy Research Program