1. Basic Information about SPM Certus
Contents
1. fu CL On Off button for feedback sensors When you turn feedback sensor button turns green NCL On off button of the non linearity correction When you turn on correction of non linearity button turns green PC File Opening PC File with calibration PC File Saving to PC File with calibration DSP Memory Load calibrations form DSP memory of the controller DSP Memory Save calibrations to DSP memory of the controller From the above theory non linear conversion of the voltage U applied to piezostacks is required the appropriate direction of movement of X In the system of EG 3000 U X AXX BXX CXX DXX E U voltage in DACs counts 0 65535 X displacement in um 0 Xina range this function is working at NLC is ON Qa nic if NLC button is off voltage is calculates as linear X U A 65535x X 2 max Therefore to calculate the coefficients of the non linearity is necessary to conduct the following steps e switch off correction and feedback sensors O CL C3 NLC gt e establish a scanner range 65 535 x 65 535 um e scan test pattern Fig 7 15 with the full amount of points 1000 x 1000 in the direction of the calibration and the full range direction and a starting point we choose the upper left the direction of the fast scan X measure ments should occur on the growth of the voltage from minimum to maxim e produce a horizontal section of the image Fig 5 13 Nano Sc2. Fig 6 1 External objective application Possible range of the micro objective position is 0 180 relatively to the axis passing through a probe tip The maximum diameter of the lens used in the case of dir ect microscope 40 mm and in case of an inverted microscope the diameter of the lens used is limited only by lens design Working distance of the lens used WD is 12 mm for direct microscopy and for the inverted microscope is limited only by the thickness of the used substrate 6 2 Examples The combination of the upright optical microscope allows to study both transpar ent and opaque objects Example of such a combination 1s given in Fig 6 2 Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 67 SPM Certus head application with external optical equipment Fig 6 2 Combination with upright microscope In this case you should align microscope field of view and tip position Fig 6 3 Fur thermore using optical micro scopy techniques and develop ments for the sample to high light areas on the surface of the object of research and scans The combination with an inverted optical microscope has meaning only in the study of the surface of transparent samples An example of such a combination is given in Figure 6 4 Nano Scan Technologies Ltd Fig 6 3 Sample and cantilever tip image Certus Scanning Probe Microscope User manual 68 SPM Certus head
3. Fig 4 12 Signal maximum 4 2 4 Reflected beam alignment to PSD center After finding the maximum of the reflected signal is necessary to combine the center of the laser spot to the center of the photodiode To do this use the positioning screws of the photodiode to move the laser spot in the center of the SPM Feed Back window and obtain close to zero values of indicators DFL and LFL as possible Figure 4 13 In the drop down menu beneath the SPM Feed Back should be set OFF SPM Feed Back DFL 0 LFL 0 Fig 4 13 Laser Beam is in the PSD center Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 48 SPM Certus operation E 4 2 5 Probe resonant frequency acquisition After finding the maximum of the reflected signal and overlapping centers of the laser spot and the photodiode in the case of contact mode you can proceed to feedback parameters settings and approach of the probe to the surface In the case of non contact methods you should find the resonant frequency of the cantilever For non contact methods in the field FB Input Signal SPM Mode must be set to Probe Magnitude Tapping Mode Required steps Scan kHz Channel MAG OFF Curent f Height DFL i LFL MAG MAG Sin Input Gai MAG Cos Phase NFL ADC pint o LEU INT ADC 3 x1 in the Scan window SPM in drop down list Channel choose the MAG Fig 4 13 set the search range of frequenc
4. 300 310 320 330 340 350 Probe Resonant Frequency kHz Scan kHz come MAG Jrn zoo Jrolaso r e Curent Frequency KZ Drive Intensity V 0 200 400 600 800 1000 0 2 4 6 8 10 I 328 A A A O 1 901 Fig 4 16 Cantilever resonant frequency manual set Generally it is necessary to achieve the resonant frequency of 1 V in the absence of information about the properties of the sample Take this value as reference value 4 3 Feedback tuning To control feed back parameters PID regulator for Z probe positioning you can use sliders FB P FB I FB D Set Point in SPM or in tab FEEDBACK SCAN window more derailed information you can find in par 5 1 Software user manual Set all PID parameters to 1 when sample is unknown After some images acquisi tion using data you can change feedback parameters The maximum value of the feedback 1s determined by the beginning of the feed back signal oscillations with large amplitude and short period during the installation of the probe at a point Oscillation may occur at the same parameters for different samples For each type of sample selection of the feedback parameters is different Basicly the softer surface sample and the larger difference in height parameters of the feedback should be the bigger The same is for the influence of noise and external vibrations You must adjust the parameters FB P and FB D Nano Scan Technologies Ltd Certus Scanning Probe Microscope User man
5. Certus Scanning Probe Microscope User manual Nano Scan Technologies Ltd Zavodscaya St 7 Dolgoprudniy Russian Federation 141700 Pnone 7 495 665 00 85 7 495 642 40 68 7 495 642 40 67 E mail info nanoscantech com web www nanoscantech com 2011 r This user guide is intended for installation and operation of a Scanning Probe Mi croscope Certus Scanning Probe Microscope is a combination of XYZ scanner canti lever tip sensor deflectometer SPM controller EG 3000 and software NSpec Scan ning Probe Microscope Certus is used in NST devices Certus Standard Certus Optic Certus NSOM model based on Certus Standard and Certus Optic Centaur HR and is used as a standalone tool for objects positioning Before installation and operation this appliance please read the manual On all matters related to technical support and upgrades for this product under the additional features contact the following addresses Phone 7 495 665 00 85 7 495 642 40 68 7 495 642 40 67 E mail info nanoscantech com web www nanoscantech com Skype NanoScanTech Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual Ea Laser radiation When you work in certain modes using a scanning probe microscope Certus laser light sources of varying power and wavelength are used Before working with SPM Certus we encourage you to read the documentation for the specified source of la
6. displacement in um 0 Xmax range function works at NLC X Ga Buc is on if NLC button is off C X 65535x 3 max e Set scanner range to 65 535 um x 65 535 um e Scan test pattern Figure 7 17 for the full amount of points 1000 in the direction of the calibration and with full range direction and a starting point we choose the upper left the direction of X measurements should occur on the growth of the voltage from minimum to maximum Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 6 Scanner calibration Fig 7 17 17 Test pattern e Make a horizontal section Fig 7 18 A B A X 0 0 um C 0 1000 x measured value X in um B X n n x T um T period C n 1000 x measured value X in um Fig 7 18 Horizontal section Fill the table of the capacity and displacement as follows for the zero movement Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 65 Scanner calibration E on the left select the first point which is uniquely characterized by a new period a shift which will then be formed will be automatically taken into account t X 0 0 um C 0 accurately measured value of the X axis section in microns multiplied by 1000 In the same way to fill the remaining values X n n T where T time in microns and C n 1000 accurately measured the beginning of period n in microns Then using the s
7. User manual 37 Start operation P ml SCANNER A HEAD oe AE EEE 5 Piezo stacks high voltage and displacement sensors digital interface Supply voltage and analog signals Back stepping motor connector J O OU gt Side stepping motors connector Fig 3 10 Certus scanning head and EG 3000 controller correspondents 3 3 PC connection After scanning head connection to the controller it is needed to connect the USB controller to your computer Certus scanning head has no direct connection to the com puter In this case the computer must have installed software to control SPM system and USB driver USB driver will be installed automatically by Window 7 after connect ing to controller If no you need to install driver you by self drivers is located in folder drivers 3 4 NSpec software installation Before working with the program NSpec an archive containing the program files you need to unzip to a local or removable drive Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 38 Start operation Installation 1s not required The program runs directly from the exe file To work with the program 1s to start by double clicking the left mouse button or file nst exe or NSpec_Ne exe in the folder Soft Package Ne The example in Fig 3 11 When you run nst exe or NSpec_ No exe will run the program Figure 3 12 BSE L J R m Soft_package_8 1 v i Mo
8. electric field Fig 2 2 le Piezoelectric properties of the materi Fig 2 2 Piezoelectric phenomena als described by a set of piezo factors As a rule even for a relatively small extension high voltage should be attached to the ma terial For example for lead titanate PZT Pb Zro ssTio4s O with additions of Nb Cr La Fe etc piezo factor is dz 374x10 m V for PZT 5A To reduce the voltage control signal serial connection of layers of piezoelectric Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual E Operating principles O ceramics with electrodes on each layer are used Fig 2 5 In a more advanced version solid array of piezoelectric ceramics with electrodes in the piezostack body is used v v Q S S Piezo ceramics Control electrodes Fig 2 5 Piezostacks 2 2 3 Lever translation systems In general the displacement caused by the inverse piezoelectric effect relative to the size of the piezo ceramic element is a very small amount The strain usually does not exceed 0 1 of total elongation of the device displacement value is several tens of mi crometers To increase the displacement variety of mechanical devices such as levers hinges Fig 2 6 and devices running on a bend Fig 2 7 are used Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual ES Operating principles A Pi
9. Certus head PSD with laser spot is shown in Fig 2 13 Fig 2 13 PSD Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 2 Operating principles E 2 4 2 Shear force registration system The method of shear force is based on recording changes in the oscillation fre quency of the probe caused by the tangential component of interaction forces between the probe surface To determine changes in frequency tuning fork resonators used type tuning fork Fig 2 14 with fluctuations which are detected by a direct piezoelectric effect of quartz crystals Probe tip B Probe Electrodes that are used to measure voltage changes occurring on the sides of a quartz crystal direct piezoelectric effect due to changes in frequency during the interaction with the surface Information about the change of voltage to determine the current frequency of the resonator Quartz crystal piezoelectric E Piezoelectric Driver Used to create a forced oscillation of the cavity setting the initial frequency of the resonator Fig 2 14 Shear force registration system This registration method is used in cases where it 1s necessary to avoid interaction of the substance of the sample with a laser beam or in systems of near field micro scopy In the case of near field microscopy instead of needles on the probe type of tun ing fork establish a dedicated probe for near field microscopy using a spe
10. Scanning Probe Microscope User manual 57 Scanner calibration of the piezoelectric element Normal values are 15 20 of the scanner range i I E UNO E j L s i s f i 7 ij I 4 l 1 i l q l b 1 L h i g ia 1 i 1 1 l MH 11111111 Fig 5 4 Si grating SPM image periodicity is 3 um shows scanner non linearity and hysteresis along x axes Scan size in X 100 um Voltage raster form is triangular Left image obtained at forward direction left obtained at back ward direction 5 1 3 Scanner hysteresis loop properties The main properties of the hysteresis loop 1s used for software scanner nonlinear correction It is assumed that the scanner is fed periodic control voltage of a triangular shape as in Fig 5 8 a a Symmetry Fig 5 5 shows two AYL C hysteresis loops AnCmA and AnBlA for Ds different amplitudes of the piezo control voltage Branches AnC and CmA obtained from each other symmetry are about the center of the segment AC which thus is the center of symmetry of the entire loop A similar statement is true for smaller loops AnBIA and the center of the seg U ment AB Fig 5 5 The position dependence of the scanner on the b Shape independence from amp magnitude and direction of the applied voltage litude variations At the same rate of change of control voltage branch AnB of smaller loop coincides w
11. SpUsb0 1 cnf 16 11 2010 15 57 Pann CNF 1KB M NONAME TK SpUsb0 1 dll 16 11 2010 15 57 Pacwnpenne Mpuno 397 KB StrHexToInt dll 24 04 2003 10 44 Pacwnpenne npuno 209 KB L SNeMeHTOB 34 4 Fig 3 11 NSpec running Under Ot 4 7 release Developers team Igor Dushkin Anton Ikonnikow Fig 3 12 NSpec running Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual Start operation E After performing the above action main window NSpec displays Following the withdrawal of the main window on the screen you can start work ing with the program and connected equipment A detailed description of the program NSpec is given in software NSpec user s guide 3 0 In the main window NSpec SPM controller connection indicator appears as SPM Certus on off regulation 3 5 1 On rules Turn PC power On Run PC Run NSpec software Turn controller power On Check system functionality case of correct connection of the controller in the upper right corner of the The indicators on the front of the SPM controller means PWR USB FNC RDY SCN FB Oo Oo FP Ww N Power indicator USB data transfer indicator Service indicator stand By indicator scan indicator SPM Feedback status indicator 3 5 2 Off rules Stop scanning Save data if needed Move up scanning head from sample to avoid tip damage Close NSpec software Turn
12. controller power Off Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 40 SPM Certus operation E 4 SPM Certus operation To get started you must enable scanning probe microscope Certus This section describes the operation modes of scanning probe microscope For other methods look additions to the user manual Before reading this section we suggest reading the software NSpec user manual 4 1 Probe mounting Before you start you must install the probe into the probe holder shown in Figure 4 1 Fig 4 1 Probe Holder Probes or cantilevers are stored either in the form of plates on which to break off before the work of individual probes or already prepared for work in special containers Fig 4 2 Usually cantilevers tips directed toward the cover package Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual a SPM Certus operation Fig 4 2 Cantilevers in gel park boxes Fig 4 3 Cantilever mounting to holder Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 42 SPM Certus operation E Installation procedure e use tweezers to capture probe for the side surfaces so that the bulk with the tip was directed toward the hand e probe holders have to be turned over and pressed to the surface to reveal clip so that the button was pressed on the upper side of the probe holder Fig 4 4 e Mount pr
13. in amplifier equipped with a highly stable master oscillator which is made on the basis of the digital frequency synthesizer High speed digital data processing implemented using programmable logic FPGA allows synchronous detection of signals at frequencies up to 1 5 MHz Controller provides stepper motors control allowing to connect from 4 to 12 drives in a micro stepping mode Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 16 Basic Information about SPM Certus E The device has additional analog inputs and outputs for connecting external devices as well as inputs and outputs for synchronization with external equipment USB interface 1s used for communication with the host computer The controller 1s man aged by the specialized software NSpec and EG3000 DII EG 3000 detailed information is described in the manual SPM controller mod el EG 3060 and EG 3060A 1 6 3 NSpec Software NSpec software is used to control devices e Certus Light including SPM head Certus e Certus Standard including the SPM head Certus e Certus Optic including SPM head Certus e Certus NSOM including SPM head Certus e Centaur including SPM head Certus e Centaur HR including SPM head Certus e Snotra e Ratis The program is based on multythread kernel written in C and built by com piler GCC4 The program interface is built using cross platform libraries and libraries QT4 QWT The p
14. the image For the correction of displacement many types of displacement sensors can be used It can be optical inductive magneto capacitor etc In the two dimensional scanning stage Ratis capacitive sensors are used The op erating principle of such sensors are displayed in Figure 2 9 Since the capacity of a flat capacitor consisting of two parallel plates is given by 2 1 S C e s7 2 1 T C capacitance S capacitance plates area d plate distance g dielectric factor dielectric constant _ N When the distance between the plates changes the sensor capacitance offset of the axis can be measured Fig 2 9 Capacitance sensors diagram Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 25 Operating principles E 2 3 Probes 2 3 1 Probes main parameters The main element of any scanning probe microscope 1s the probe Based on the interaction of the probe with the surface image of the surface 1s constructed and the dis tribution on the surface of local physical characteristics In general a scanning probe microscope 1s a conical needle or pyramidal shape The most common material for the probes are metals tungsten platinum and similar to scanning tunneling microscopy silicon and silicon nitride Si3N4 for atomic force mi croscopy silica coated magnetic and conducting techniques silicon with a diamond coating
15. 11 0 05632 5 42715 782 27740 1178 5695 Y 0 00024 0 05233 3 71705 756 18225 4408 5424 Z 0 00000 13107 000 0 00200 0 00200 0 00200 Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 3 Scanner calibration Then you must enable the correction of non linearity EcL c Scan once more a test object make sure the correct operation of the system and find the max imum range of scan and bring it to the table and the file Scanner range sensors scale Range mkm Scale factor Scale factor 0 X 60 0000 22000 40 Y 60 0000 20500 30 i 10 0000 16000 60 5 3 Capacitance sensors correction The procedure is very similar to the correction of non linearity of the piezo with the only difference being that it is necessary to recalculate the capacitance value in stead of the voltage Procedure is following e Switch on capacitive sensors feedback and switch off the nonlinear correc tion b CL NLC all the processes now is taking place in the mode of feedback for capacitive sensors Close loop and NLC button now turns on and off the correction of sensors rather than the scanner e C X AXX BXX 4 CXX DXX E C sensor capacitance 0 65535 X
16. 5 1 Piezoelectric actuators properties ecccssseccscssscecossesceccssseceossecssecssecsssesssesoo 55 LL O a E E A E E EE A 55 5 1 2 Non linearity and hySteresiS oooooononooonnnnnnnnnnnnnnnnonoccnnnnnnnonnnnnnnnnnnnnnnnnncnnnnns 57 5 1 3 Scanner hysteresis loop PYOPrtl8S ooooonnccccnnninonoononccnnnnnnnananncnnnnnnnnnnnnncnnnns 58 5 1 4 XY non linearity cCOrrecTiOnH eee 59 5 2 Scanners calibration and non linearity correction in NSpec Software 60 5 3 Capacitance sensors COR TOOT ON ii ias 64 6 SPM Certus head application with external optical equipment 67 6 1 Basic principles of optical equipment application ccccccssscssssccssscoees 67 A 0 510 E E UE o A 67 Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual de Introduction E Introduction This user guide describes SPM Certus specifically designed to work with optical equipment such as optical microscopes spectrometers and other similar devices SPM Certus 1s the basis of such devices and systems as Certus Optic Certus NSOM Certus Standard Centaur and Centaur HR Universal SPM controller EG 3000 and software NSpec is need for SPM Certus operation Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual Ed Basic Information about SPM Certus E 1 Basic Information about SPM Certus 1 1 SPM Certus application Certus specialized scanning probe microscope SP
17. M specially designed to work with optical equipment for combining the techniques of scanning probe micro scopy and optical microscopy and spectroscopy XYZ scanning head with piezoceramic stacks is a base of the system SPM Certus is designed for imaging and studying the surface properties of vari ous substances materials and structures both natural and artificial For example the study of surface properties of polymer biological inorganic and semiconductor materi als biological cells tissues individual biological structures and biomolecules covered electronic equipment etc SPM Certus possible applications e Topography imaging e Surface roughness determination e Surface spectroscopy e Nano lithography e To obtain relevant information about the physical and chemical properties of the sample surface e When combined with optical methods to receive and collate information about the spectral and topographic depending on the technique the surface properties of objects under investigation General list of tasks implemented by the SPM Certus determined by the used method Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual LA Basic Information about SPM Certus 1 2 Specification 1 2 1 Data Sheet 1 SPM scanning head 1 1 Built in XYZ scanner flat stage 1 1 1 Range 1 1 2 XY resonant frequency 1 1 3 Z resonant frequency 1 1 4 Lateral XY resolution 1 1 5 Vertical Z resolut
18. O 5 ee ee ee ee ee ee eee eee 13 AA OVC OW 13 1 6 Description of DASIC UDIES siscisececcis senscesinsincbesnsesonetespanassasenesessiaedenseseasavansesnaesees 14 TIO Scanning Cartus Nead nato 14 L62 PODIDO Contool T rers rinn en E RAEE EEA E e ERES 16 PE E e O TON O e ae EE EEA E E E E R EE ere 17 1 6 4 Systems and devices which includes Certus SPM Hedd sss 17 Ze Operatino principles eenen Eer E EE EESE 19 Dele SPM common PPUMCIPIOS secesssacacxcssecesccesavesscencacstosanassasasceacerenssvorsinvactsseesvsasenesis 19 2 2 Probe scanning positioning secccssseecccossecccosescecoosssecsossscecoossesecsssecossessseesoe 21 Di D T a e a E E E E E 21 2 2 2 Piezoelectric PhenOMENd ooooooooccoocncccnnnnnnnnnnnnnnnnnnnononocnnnnnrnnnnnnonnnnnnncnnnnninons ZZ 2 2 3 Lever translation CNS iii 23 224 DISC MEN SUSO iden 25 o Sn O AE 26 2 3 1 Probes main POr amelerS oooooonnnnccnnnnnnnnnnnnnnnnnnnnononnnnnnnnnnnnnonnnnnnonnnnnnonnnnnncnnns 26 BO ALOE INS ona oF Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual EN Contents 2 4 Cantilever Z position detection SYStemM cccccccccccssssssssccccccssssscccsssscseees 28 2 4 1 Deflector registration SYStCM ooooooonnnccononononnnnnnnnnnnnnnnnnnnonnnnnonnnnnnronnnnnocnnnns 28 2 4 2 Shear force registration SSG 30 Dede Ped AAA E o A 32 AP 33 Sal DEM CCE AAA ESERE RaT ERa 33 3 1 1 SPM Certus head descriptiOM ooo
19. an Technologies Ltd Certus Scanning Probe Microscope User manual ce Scanner calibration A B A Zero point X 0 0 um U 0 1000 x measured X in um B Point N X n n x T um T period U n 1000 x measured X in um Fig 5 14 Horizontal section Fill in the table of values of voltages and displacements as follows for the zero movement on the left select the first point which is uniquely characterized as the be ginning of a new period a shift which will then be formed will be automatically coun Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual e Scanner calibration E ted 1 e X 0 0 um U 0 accurately measured value of the X axis section in microns multiplied by 1000 In the same way fill the remaining values X n n T where T period in microns U n 1000 just measured the top n period in microns Then using the supporting software perform fitting of tabular data by a polynomial of degree four U X AXX BXX CXX DXX E Do the exact same procedure for the axis Y with the only difference being that the direction and the starting point of scanning to be selected like the bottom left corner and the direction of a quick scan is Y axis NN 70000 60000 50000 40000 Y Axis Title 30000 20000 10000 A mkm The data obtained should be recorded in the table and save the file Piezo Calibration A B C D E X 0 000
20. and sample For Certus head control universal controller EG 3000 and software NSpec are using 1 6 2 EG 3000 Controller EG 3060 3060A controller designed to control the operation of scanning probe optical or confocal microscope The controller collects data from various sensors and external devices and provides control outputs to the piezoelectric positioning devices in addition all the gathered information is to be sent to the control computer for sub sequent processing and visualization Also computer controls all parameters of move ment and scanning Exterior view of the controller is shown in Fig 1 4 ALAD ud F e z k Bit hari Ll sn O Fig 1 4 EG 3000 SPM controller For the control of positioning devices system uses a digital feedback and the ori ginal scheme for measuring capacitance displacement sensors based on the TDC time to digital converter Capacitance measurement is carried out in the scanning device and controller receives a digital signal Such a system increase accuracy and significantly improve the device immunity Any of the signals available in the system can be used to operate the feedback of the tip sample distance The controller keeps the feedback on the six channels simultan eously which allows to scan by tip or by sample In order to implement the modulation technique microscopy such as for ex ample non contact atomic force microscopy controller provides dual channel lock
21. anning probe microscope Certus is a scanning head of a new gen eration The main distinguishing features of SPM Certus are Built in XYZ flat scanner scanning stage with capacitive displacement sensors Modular architecture allows to use different lasers for deflectometer in cluding external laser sources easily removable probe holder which allows the use of fundamentally dif ferent types of probes open work area the contact point of the probe and the sample which provides easy monitoring of the probe the input of external radiation etc parallel to the probe to sample approach system with the ability to automat ically align the head over the plane of the sample Full digital connection between the head and controller Plane scanner stage is a monolithic metallic body made of quality Al alloy in which with EDM and other methods of precision machining formed channels for piezo electric actuators piezoelectric stacks mobile elements of the scanner etc This design provides excellent linearity and flatness of travel in contrast to piezoelectric tubes a scan surface which is a sphere In addition the plane scanners have high mechanical stability compared to the brittle piezoelectric tubes Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 14 Basic Information about SPM Certus Certus head body with built in XYZ flat scanner stage Probe holder Screws for l
22. application with external optical equipment Fig In this case a basic al gorithm for combining simil ar reconciliation with the up right optical microscope However please be aware that look to the bottom And the optical image and the SPM image in the presence of similarities in the image will be mirrored each other Example image of the probe and the object of study is given in Figure 6 5 Nano Scan Technologies Ltd Fig 6 5 Image of the sample and cantilever tip Certus Scanning Probe Microscope User manual e
23. aser beam to cantilever bulk alignment screws for reflected laser beam to PSD diode alignment moov gt High precision actuators for approach system Fig 1 3 SPM Certus head Certus head scanner is equipped with capacitive displacement sensors The meas uring method is based on TDC time to digital converters that are physically located as close as possible to the sensors that give digital signal proportional to measured ca pacitance This method enables high precision measurements and transmission current sensors position to the controller with long cables without sacrificing the quality of measurements In the standard configuration deflectometer diode laser with a wavelength of 650 nm is used At the request of the customer may use another for example infrared laser In addition fiber optic port can be installed for connecting an external laser The head comes with several detachable probe holder standard cantilevers probes such as tuning fork with a vertical or horizontal At the request of customers can be de veloped mount virtually any original probes Unique open design SPM Certus enables high multiples of the external lenses illuminators condensers microscopes etc to illuminate the work area monitor the Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 15 Basic Information about SPM Certus E sample and the probe to take stock of the radiation to the point of contact tip
24. cialized probe holder Figure 2 15 Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 30 Operating principles A Tuning fork type probe B Probe holder C NSOM fiber D Certus SPM head Fig 2 15 Shear force registration system Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual aL Operating principles E 2 5 Feed Back To generate the control signal is commonly used proportional integral differential PID controller see the scheme 2 16 in the feedback loop of scanning probe micro Scopes Process P The proportional component of the signal is proportional to set point error An integral component is used to smooth out the statistical errors in the input signal D Differential component needed to predict the controlled variable deviations setpoint The set value of the controlled variable Error The difference between the actual and set value of the controlled variable Process Controlled process Output Out form the process sensor The sign of the term to calculate the difference between the actual and set value for actual value Fig 2 16 PID control PID controller generates a control signal based on the components of the propor tional signal the integral of the input signal and the derivative of the input signal Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual sa Start operati
25. cover and the casing Cables connecting disconnecting to device connectors can be done while device is off Only specialists of Nano Scan Technology certified specialists in con sultation with Nano Scan Technology Only in agreement with the company Nano Scan Technology Not accepted In accordance with the class of security established by the laser safety class and characteristics of the laser described in the SPM head under the label shown in Fig 1 2 In accordance with the marking on external sources of laser radiation Fig 1 2 The warning label on the laser source Certus Scanning Probe Microscope User manual E Basic Information about SPM Certus E 1 5 Terms of storage and transportation 1 5 1 Storage The device should be stored in compressed form in a special room with no abrupt changes in temperature and humidity 1 Temperature 22 10 C 2 Humidity Maximum 80 1 5 2 Transportation When transporting instrument should be packed in the original package or in any other package which excludes the damage After transport at temperatures below 0 C before starting the device wait 3 hours Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual EZ Basic Information about SPM Certus 1 6 Description of basic units SPM Certus includes Certus scanning head EG 3000 Controller NSpec software 1 6 1 Scanning Certus head The basis of sc
26. creep in the direction of this shift with a decreasing rate For slow direction the rate of creep more than the average speed during scanning at the initial moment Outcome of assess ment using the relation 5 1 is as follows speed on a slow direction reaches zero a time equal to 50xB 1 e about 1 of the total scan time After a period of time equal to 10 of the time creep rate would be 10 times smaller than the average speed on a slow scan direction Measurements confirm this assessment Creep does not not make noticeable distortion we must wait to be scanned 5 10 of the entire region and then restart the scan A typical example of creep on Z the distortion of the profile in the measurement step When filing for the scanner voltage corresponding to a height of the step the scanner is reduced by a specified distance and then some more time continues to creep in the same direction To save a contact probe with the sample you must Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 56 Scanner calibration E provide power in the opposite direction Because the topography is recorded as a signal applied to the Z element scanner voltage the measured profile will look like in Fig 5 4 ZA a ZA b X x Fig 5 3 Creep influence to step profile a Real profile b Measured profile For the motion of the scanner under the action of periodically varying voltage creep causes the displacement
27. difference between scanning probe microscopy techniques is in selected for the registration parameters and methods of registration 2 2 Probe scanning positioning XY XYZ scanning process 1s used to get the image in scanning probe micro scopes 2 2 1 Scanning The scanning process proceeds as follows The scanner performs a raster move ment of the object Fig 2 3 System takes signal measurement and digitizes data at nodes of the raster to receive information about the surface characteristics The direction of lines along which scanner moves is called the fast scan direction Perpendicular dir ection is called slow scan direction Fast scan direction forward Scan node Fast scan direction backward AA A A A A A BK BM A A A A A A A KM KK 7 Slow direction scan step Slow scan direction Return to start point ee Le m E T LE T e edi J I j l l i i i d al ea so L S P L a y U L W N sae Fast direction scan step Fig 2 3 Scanning process illustration Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual El Operating principles E One can write data on direct and on reverse the course of scanning producing a shift in the perpendicular direction In this case the speed of image acquisition doubles However for scanners without sensors such scanning method is not applicable since for scanning probe microscopes there is d
28. e is a triangular shape Fig 5 8 a in some way measured by its position e g on a test grid As a result the relationship of the provi sions of this axis with a control voltage X U Next using the inverse relationship U X we can calculate the voltage sweep such that the movement in X was linear Fig 5 8 b Properties b and c and d hysteresis loops allow the use of the dependence U X for all sizes and positions of the scanned area as well as for different scanning rates Using 5 2 introduces the correction field size of the scanning speed Correction gives good results when the following conditions e periodic motion of the scanner over time e Trajectory is monotonous between the extreme points t These conditions are always satisfied Fig 5 7 a Scanner motion along x direction with for fast scanning axis If the size of the field E A on the slow axis is comparable with the full range of the scanner along this axis the soft ware nonlinear correction works satisfactor ily for the slow direction If the scan area is small to eliminate distortions in the slow axis scan area may need to be re scanned t see explanations to Fig 5 9 and Fig 5 10 Fig 5 7 b Scanner motion with software non linearity p 8 8 correction Program scan correction allows to Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 59 Scanner calibration T reach the residual non linear
29. ed at right head side Fig 3 7 Fig 3 7 Connector for the probe holder Probe holder plug connects to a similar manner 3 1 2 Probe holder connection Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 35 Start operation E Probe holder must be connected to scanning head Fig 3 8 Regardless of the mode of a scanning probe microscope the principle of holder connecting is same Fig 3 8 Probe holder The holder is attached to SPM head with magnetic tablets Appropriate mounting is located on the bottom of the head To fix the holder of the probes it is necessary to move to the corresponding fastening the SPM head and install the appropriate slot To prevent damage of the probes after their installation is recommended initially install the holder on the AFM head and then connect the plug to the jack on the head Fig 3 9 Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 36 Start operation Fig 3 9 probe holder mounting 3 2 EG 3000 controller connection After connecting all cables and installation of the probe holder scanning head must be connected to SPM controller EG 3000 series Pin and connectors description are given in Figure 3 10 A complete description of the connectors on the controller front panel there is in the SPM controller EG 3000 User Guide Nano Scan Technologies Ltd Certus Scanning Probe Microscope
30. ent there is a long term drift Fig 5 1 Scanner calibration E Creep in the XY plane 1s well seen after large displacements of the scan ning area Fig 5 3 When you try to move the scanner at a given point for example for vector lithography or nano manipulation as well as in select ing the scanning area creep along with the hysteresis of piezoelectric ceramics is the main source of error To determine the creep after the a B voltage jump Fig 5 2 one can use Fig 5 2 XY Creep the expression AX est AX Bn 5 1 B 0 01 0 03 AXo displacement after t seconds caused by voltage jump t 0 1 1 sec Let suppose B 0 02 we get one minute after power surge creep is 8 of the movement in the 1 second then for every time moment 10 times bigger 4 6 1s ad ded to the initial displacement Equation 5 1 1s true in the time interval of a second to at least several hours You can use this ratio as an estimation of creep for any other monotone change of control voltage Coefficient B for the piezo depends on the value of the control voltage jump Also there 1s the dependence of creep on the direction of the jump So do not expect that us ing the formula 5 1 you can enter the exact software compensation of creep in the plane XY Each time you run a scan on a slow scan direction creep 1s observed The fact that the scanner was shifted from field center at the starting point continues to
31. eric pressure mm Hg 760430 Power requirements 4 1 Voltage V 220 10 15 4 2 Frequency Hz 90 60 4 3 Ground required 5 Noise and vibration 9 1 Vibration sensitivity range Hz 1 100 9 2 Maximum vibration magnitude in range 0 5 um 9 3 Maximum sound pressure within 10000 Hz 39 dB 6 Shield from 6 1 Direct sun light required 6 2 Heating required 6 3 Electromagnetic radiation required 64 Air gas flow required 7 Extra recommendation 7 1 Frequent and abrupt changes in temperature and humidity affect to performance and the quality of the results 1 2 Running compressors traction control laminar boxes cooling devices and similar sources of periodic or random noise can create background noise 7 3 Recommended to place Ratis with maximum possible distance from the computers monitors and peri pheral devices 74 Avoid strong mechanical influences on Ratis as this may lead to failure of the mechanics and control electronics unit Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual a Basic Information about SPM Certus 1 4 Safety regulations 1 Safety regulation 1 1 Ground 1 2 Opened parts 1 3 Cables connect disconnect 1 4 mount dismount device units 1 5 External equipment connec tion 1 6 Liquid 2 Laser radiation sources 2 1 Deflectometer laser 2 2 External lasers Nano Scan Technologies Ltd Recommended to check equipment ground Work is prohibited with the removed
32. es Certus head in SPM part of the system Raman system combining the techniques of scanning probe microscopy Raman fluores cence confocal microscopy spectroscopy conventional optical microscopy e Centaur HR includes Certus head in SPM part of the system Raman system combining the techniques of scanning probe microscopy Raman fluorescence confocal microscopy spectroscopy conventional optical mi croscopy and spectrometer with high resolution Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 18 Operating principles 2 Operating principles 2 1 SPM common principles Scanning Probe Microscope device for surface imaging and local properties information In basic case Scanning Probe Microscope fig 2 1 includes e Probe e XYZ scanning positioning system e Probe sensor for determination interaction with surface Feedback system Sensor by probe XY Z scanner by sample XY Z Fig 2 1 SPM basic system The operation of scanning probe microscope based on the principle of obtaining information about the interaction of the probe to the surface at one point At a small dis tance between the surface and the probe one can fix the forces of interaction repulsion attraction and other forces and the appearance of different effects for example tunnel ing of electrons These interactions and effects can be detected with modern means of registration To register
33. ezo stack B Elastic Point C Lever Fig 2 6 Lever displacement system diagram A Piezo stack B Bulk Fig 2 7 Bending displacement system diagram Typically the piezoelectric driving element is used only for forward movement for the return traffic the fact that in the range of applied loads the materials used are subject to Hooke s law 1 e the strain is directly proportional to the applied voltage and the material of the device undergoes only elastic deformation As a result after the ter mination of the external force elements of such a system take initial size shape and ac cordingly the position in space 2 2 4 Displacement sensors Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 24 Operating principles E Because of the nonlinear properties of piezoelectric ceramics obtained image contains distortions Because of nonlinear properties of piezoelectric ceramics it 1s 1m portant to understand features of the dependence between the control electric field and the deformation of the piezo ceramic sample namely non linearity and ambiguity of this relationship Usually the nonlinear properties of ceramics are divided into creep hysteresis and non linearity itself Also nonlinear properties includes volatility and sens itivity of the piezo ceramic Non linearity and ambiguity of the dependence of the con trol voltage the situation often leads to significant distortions of
34. for indentation etc General view of the probes 1s shown in Figure 2 9 ve R A Probe body B Coating R Tip curvature H Tip Height Cone angle Fig 2 9 Probe drawing Resolution and accuracy of mapping elements on the surface depends on the corner radius of the probe and the cone angle Maximum height difference on the sur face available for display depends on height of the probe Coverage probes allow to use Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 26 Operating principles E of various techniques of scanning probe microscopy In addition to these parameters on the quality of the image a set of techniques and the ability to study samples of different nature 1s influenced by two parameters This rigidity of the probe or the force constant N m and the resonant frequency of the probe resonant frequency kHz 2 3 2 Probe drawings In general probes for scanning probe microscopy can be a needle but using in dustrialized methods of lithography and various methods of coating the probes cab be made with specialized forms Fig 2 10 Chip Bulk Tip Cantilever with rectangular bulk E Cantilever with triangular bulk F SEM tip image J O OU gt Fig 2 10 Cantilever tip drawings and images Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual E Operating principles E 2 4 Cantilever Z position detect
35. ifference between the surface profile at the for ward and reverse course because of the nonlinear properties of piezoelectric ceramics and this is usually essential Scanners with sensors also have a distinction between dir ect and reverse profile although not always visible This cause of the error feedback in the direction of fast scanning These errors are reduced with decreasing scanning speed As a result it often turns out that to obtain the desired image quality is advant ageous to use record data only on the direct or only on reverse course 2 2 2 Piezoelectric phenomena All modern scanning probe microscopes scanning positioning systems regard less of design for positioning and movement uses the inverse piezoelectric effect Inverse piezoelectric effect the effect of mechanical strain in dielectrics under the action of an electric field It occurs in crystals which cells have no center of sym metry resulting to permanent electric dipole in such cells The application of such a crystal an external electric field causes deformation of the dipoles leading to a change in crystal size Since the growth of single crystals of materials with piezoelectric properties is of considerable difficulty usu ally use polycrystalline materials ceramics dipoles in the crystals are oriented predom inantly in one direction of polarization in a strong magnetic field Accordingly they change its size caused by appearance of
36. ion 1 1 6 Residual non linearity 1 1 7 Minimum step 1 2 Displacement sensors 1 2 1 Sensors type 1 2 2 Operation principle Main data sheet 100x100x15 um 1 kHz 7 kHz lt 1 nm lt 0 1 nm lt 0 3 0 1 nm Capacitance TDC time to digital convertors 1 3 Scanner material Aluminum alloy 1 2 2 Sample size min any max with system holder Up to 125 mm and 16 mm height max without system holder any 1 2 3 Deflectometer lasers Default 650 nm lt 1 mW Class IR 1300 nm lt 1 mW Class Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual Basic Information about SPM Certus 1 2 4 SPM head Certus Drawings 210 136 Fig 1 1 SPM Certus drawings Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 10 Basic Information about SPM Certus E 1 3 Operating conditions SPM Certus 1s a complex high precision research instrument To ensure normal operation of the device are advised to observe the following conditions of use and stor age 1 Temperature 1 1 Range 10 50 C 1 2 Optimum 22 3 C When delivered SPM Certus scanner adjusted to the optimum operating temperature When the room temper ature is different from the optimum but within the permissible operating temperature range necessary to calib rate the scanner at current temperature in the room 2 Humidity 2 1 Maximum 80 2 2 Optimum 65415 Atmosph
37. ion system Different registration systems are using to register the movement of the probe and its position relative to the surface For atomic force microscopy two types of regis tration systems are using 2 4 1 Deflector registration system The most common registration system based on laser deflectometer Schematic diagram of the system shown in Fig 2 11 A Tip A Deflection of cantilever bulk B Laser PSD Position Sensitive Diode with 4 sensitive areas sample E PSD image Sections is marked A B C D F4 Laser spot position at PSD center F Random laser spot position at PSD Fig 2 11 Deflectometer scheme The laser beam is focused on the probe bulk The reflected beam falls on the 4 cell photodiode On the ratio of the intensity in the sections of the photodiode position of the reflecting part of the probe in space 1s determined When the probe is moved Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 28 Operating principles E along the Z axis or rotation of the beam changes the position of the laser spot on the photodiode As a result according to predetermined relationships the position of the probe relative to the surface In scanning probe microscope Certus registration system based on deflectometer shown in Fig 2 12 PSD with 4 cells Probe cantilever laser JU O WwW gt Probe holder and scanner Fig 2 12 Deflectometer system in SPM
38. irection of laser spot travel In case of contact of the laser beam with cantilever bulk diffraction pattern will be clearly visible Fig 4 8 Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 45 SPM Certus operation Fig 4 8 Laser beam aligned to bulk and diffraction pattern is clearly visible 4 2 2 PSD position sensor diode alignment You have to align reflected laser beam from bulk with center PSD to do this you can use PSD positioning screws Fig 4 9 Fig 4 9 Compliance of the direction of rotation with direction of PSD travel SPM Feed Back window shows laser spot position at PSD and it s intensity Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 46 SPM Certus operation Fig 4 10 a reflected beam 1s out of PSD b laser beam 1s within PSD area 4 2 3 Reflected beam maximum intensity finding Once the SPM Feed Back window will display the signal from the photodiode 19 necessary to find the maximum reflection from the bulk Red sphere size corresponds to laser spot position and its intensity during alignment must be on a blue field PSD area Figure 4 11 Z Range 0 0 C1 MAG 0 00 Fig 4 11 PSD signal Using laser beam alignment screws try to get signal maximum fig 4 12 Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 47 SPM Certus operation SPM Feed Back
39. ith the initial sec XYZ tion of the branch AnC of larger loops as in Fig 5 6 c Saving the form when chan ging the constant component of the control voltage The shape of the hysteresis loop does not depend on the constant compon ent of the control voltage Fig 5 7 shows the hysteresis loop for a maximum amp u hude of the control voltage Depending on how the power supply the scanner may be Fig 5 6 Hysteresis loops at different constant components of the voltage Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 58 Scanner calibration E at any point U X inside the loop Loops 2 3 and 4 were obtained at the same amp litude but different constant components of the control voltage These loops are the same the shape of their branches roughly coincides with the initial section of the lower branch of the loop 1 d The weak dependence of shape loop on the velocity A decrease in the rate of change of control voltage in accordance with 5 2 varies the amplitude of scanner movements At the same time in a fairly wide range of values of speed we can assume that the hys teresis loop simply changes the scale of the axis of movement 5 1 4 XY non linearity correction Fig 5 8 shows the motion of the scanner at two cases software nonlinear correc tion of the axis X on and off From this figure we can see what s inside your correction algorithm First the scanner voltag
40. ity of less than 1 Typically for a fast scan direction resid ual non linearity is about 0 3 for the slow 0 5 5 2 Scanners calibration and non linearity correction in NSpec Software To implement the nonlinear correction go to the option Oscilloscope click ing in the upper toolbar the corresponding icon In the right pane find the section Scan ner test calibration Fig 5 12 Scanner testicalibration PC File Fa PC File DSP Memory y DSP Memory Tu Ko 0 Saw une 0 c Qu dg HEAD R since Proportional Integral Derivalive A A 0 0500 0 0010 0 0000 0 0500 0 0010 0 0000 0 0300 ooy Scale factor 20500 15000 Piezo Calibration A A C D F T i X 0 000 7 0 05632 5 42715 782 27740 1178 5695 Y 0 00074 0 08335 3 71705 756 18725 4408 5474 Z 0 00000 13107 000 0 00200 0 00200 0 00200 Sensors Calibration A B C D E U S RIA ES EA E EE 0 00035 0 01168 2 84601 454 22290 1488 1655 5 00000 4 90000 4 30000 4 70000 4 60000 PID regulator for capacitance sensors Scanner range scanners software correction for open loop mode OO WwW gt scanners capacitance sensors non linearity correction table for close loop mode Fig 5 12 Non linearity correction tables Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 60 Scanner calibration E
41. nck Soft_package_8 1 2 a n Npaska Bug Cepsuc CnpasKa Ynopanowth Y AobasuTb 5 Gubnuotexy Y 3anucaTe Ha onTuyeckm anck Hogas nanka lt Gl a z6 Uma Mata usmeHeHna Tun Pasmep BB 3arpy3km S InstrumentManipulator_N_Spectr dll 16 11 2010 15 57 Pacwnpenne npuno 2 386 KB 1 Heaasnne mecta amp libgcc_s_dw2 1 dll 16 11 2010 15 57 Pacwnpenne npnno 42 KB R Pabounii cron 23 libgfi211 dll 16 11 2010 15 57 PacwMpeHve npuno 852 KB M266 dll 16 11 2010 15 57 Pacumpenve Mpuno 416 KB K anan mingwm 10 dil 16 11 2010 15 57 Pacwnpenne npuno 12 KB bos gi N_Spectr dll 16 11 2010 15 57 Pacumpenme npuno 416 K5 VizobpaxeHna Nspec_8 1 exe 16 11 2010 15 57 NpunomxeHne 2 185 Kb B My3bika plot dll 16 11 2010 15 57 Pacwnpenne Mpuno 796 KB QtCore4 dll 16 11 2010 15 57 PacumpeHve Mpano 2 478 KB Y Aonawnss rpynna QtGui4 dll 16 11 2010 15 57 Pacumpenne npuno 9 584 KB 0 konnorep QtOpenGLA dll 16 11 2010 15 57 Pacwnpenne Mpuno 852 K6 E de qwts dil 16 11 2010 15 57 PacumpeHve Mpano 783 KB Ga Morano anck D 2 RZCamAPI dll 16 11 2010 15 57 Pacumpenne npuno 188 KB Ga NokaneHel anck E si_ctrl_demo dll 16 11 2010 15 57 PacumpeHve npuno 90 KB a NokaneHeld auck F SLS_SI_Calc dll 16 11 2010 15 57 Pacwnpenne npuno 459 KB 2 DVD RW anckosoa G 8 sis_si_ctrl_bk dil 16 11 2010 15 57 PacumpeHme npuno 107 KB ca Moran ano UI 25 sas in 16 11 2010 15 57 MapameTpbl kOH M 1KB Eu p _
42. obe to holder e Release the probe fix button e Mount probe holder to scanning head with p 3 1 2 A Probe B Spring knob Fig 4 4 Probe mounting Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 43 SPM Certus operation 4 2 Deflectometer system adjustment Initially you must configure the system of probe deflection To do this e Align laser beam to cantilever bulk e Align reflected from bulk beam approximately to PSD center e Find appropriate parameters for resonant mode e Ger probe resonant curve 4 2 1 Laser beam alignment to cantilever bulk Procedure e Open SPM window in NSpec software e Define current system configuration Two different choices 1s shown at fig 4 5 e Align laser beam to cantilever bulk SPM Feed Back NA Ip ee es es Z Range 0 0 Z Range 30 2 MAG 0 00 INT 2 8 MAG 2 79 b Fig 4 5 a Not aligned system b Aligned system In the case of fully disaligned registration system laser beam may come out can tilever bulk or come to the probe holder Fig 4 6 Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 44 SPM Certus operation Fig 4 6 a out of cantilever chip b Laser spot located at holder In this case using the positioning screws make coinsidience laser beam with can tilever bulk Fig 4 7 Fe Fig 4 7 Compliance of the direction of rotation with d
43. on 3 Start operation 3 1 SPM Certus installation To install the SPM Certus scanning head Certus SPM controller series EG 3000 the holder of probes cable k1t computer are required 3 1 1 SPM Certus head description Initially you must arrange scanning head on a hard flat surface Fig 3 1 O J gt XYZ scanning system Stepping motors Stepping motors cables Screws for laser beam to cantilever bulk alignment moO wD T Screws for reflected laser beam to PSD diode alignment Fig 3 1 Certus scanning head Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 33 Start operation E The SPM head Certus needs to connect cables for high voltage signals and digital interface analog signals cable and power Fig 3 3 Fig 3 3 Scanning head signals cable Additional cables are connected to the back side of the head Fig 3 4 o o ns a A High voltage cable and digital interface cable B Analog signals cable and power Fig 3 4 Connections diagram Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 34 Start operation Fig 3 5 Scanning head cables connection Cable plugs are designed so that they can be connected only one way To do this connect the plugs and gently rolling to determine the position where we can close the connectors on the head and tail Probe holder connector is locat
44. oonnncccnnnnninnnnnncconnnnnnnnnononnnnnnnnnnnnnnnnnnnninnnns 33 3 1 2 Probe holder connection 35 3 2 EG 3000 controller connection sssceccseccossssssssececeeeoossssssesseseoesesssssesosssssoso 37 SY PCCE COM an E AEAEE E EESE 38 3 4 NSpec software installation ssssssceccssssecccssseccoosssccecsssececcssseceoossssecosssesesssseo 38 3 5 SPM Certus on off TOO UA CIO aiii ri airada 40 ee CTI TCS orita atari 40 A OA atraco cea 40 ds TOP IVE COTOS OC AUG Ihe enera E E ESS 41 dle a AAA E O on EEEa 41 4 2 Deflectometer system AdjUStMent ccccccccssssssccccsssssccssssccssssccsssscsssssceeeses 44 4 2 1 Laser beam alignment to cantilever Duk 44 4 2 2 PSD position sensor diode alignment 46 4 2 3 Reflected beam maximum intensity finding 47 4 2 4 Reflected beam alignment to PSD Center 48 4 2 5 Probe resonant frequency ACQUISIION oooonononncccnnnnonnnnnononnnnnnanonanonnnanoninnns 49 De Feedback TO aee E EEE E NE 51 Ad SEE DOMME CUMING ocer avenues cesndcsateaseciocsessaxcaiecoasnesnsonteeeneseeaeesnavsnaness 52 Ade AAA ier aS 52 43d TOUCH AI Mo norte once anaes 52 432 CANNING head CUMO dones 52 FMD e lt Ere Tr EEA E EA E 53 a E o e 53 Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 5 Contents Ale SCAMS LOCOS Sarita 54 4 8 Primary image processing and SAVING cccccccsccccccccccssssscccsssscccsssccceeesecees 54 H e O O TT 55
45. ping motor e Return to the option of all motors control e Start rough approach to sample Use rough approach till approximately 3 mm from the surface Decrease approach speed for closer distance Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual E SPM Certus operation E 4 5 3 Tip landing After the implementation of the rough approach is necessary to switch on feed back section 4 4 software NSpec manual And the press Landing Upon reaching the surface and the magnitude of the oscillations of the probe equal to the specified value approach process will stop Next you need to verify the absence of oscillations You must open the box OSC curve through a group of instruments Plot Mode Control Section 4 1 details software NSpec manual 4 6 Scan settings After tip landing to the surface open SCAN window A detailed description of the functions of the window is in the software NSpec User Guide in Section 5 It is recommended to obtain big overview scan for correct selection of feedback parameters oscillation parameters of the probe We recommend following parameters for data acquisition with maximum resolu tion e Full scan area e Scan size 300x300 pixels e Scanning speed 1 line sec Hz e Signals Height and Phase for forward and backward directions After getting the test images you may select desired scan settings and the inter esting area on the surface To select
46. rate dependence from voltage rate For example when applied to any section of the scanner control voltage is a triangular shape with constant amplitude and decrease the rate of change of voltage the amplitude of movement of the scanner will increase Amplitude of logarithmic velocity S v S 1 8 187 5 2 v Vo voltage rate S displacement amplitude rate S velocity amplitude rate v Investigation of dependence 5 2 are The range of the scanner in XY and Z at the maximum possible amplitude control voltage depends on the rate of change of voltage When measuring the topography of the voltage supplied to the Z section scan ner the height of any object on the sample surface at different scanning speeds are dif ferent Value 5 2 is used for software correction field size in the XY plane depending on the speed of scanning 5 1 2 Non linearity and hysteresis In general the piezo ceramic is characterized by nonlinear dependence of strain on the control of the electric field This dependence is also ambiguous hysteresis Ac cordingly the piezo has a non linearity and hysteresis of the position of the control voltage for each axis Fig 5 4 is an example of image distortion caused by non linearity and hysteresis of the scanner along the axis X The width of the hysteresis loop for the scanner Figure 5 6 on the axis depends on the control voltage amplitude and properties Nano Scan Technologies Ltd Certus
47. rogram is compatible with all current versions of OS Windows XP 2003 Vista 7 Upon request the program can be transferred to the operating system Linux BSD MacOS Only basic functions of data processing are implemented to NSpec software and tools for optimal adjustment of scanning parameters Specialized software 1s recommended to use for full data processing such as Gwyddion For pro cessing the spectral data is also recommended to use specialized programs such as GRAMS To facilitate the transfer of data to other applications NSpec program supplied by the filters of import export formats ASCII gwy Gwyddion spc GRAMS 1 6 4 Systems and devices which includes Certus SPM head e Certus Light minimum configuration includes Certus head simple basement with sample holder controller and software e Certus Standard normal SPM configuration includes Certus head basement with sample holder and translator video microscope controller and software e Certus Optic Extended SPM configuration integration with inverted or Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual FA Basic Information about SPM Certus E upright high resolution microscope includes Certus head scanning base ment with XY XYZ scanning stage 6 9 channel controller and software e Certus NSOM Near Field Optical Microscope SPM Certus head adapta tion for near field microscopy e Centaur includ
48. rtus Scanning Probe Microscope User manual E Scanner calibration 5 Scanner calibration All SPM scanning and positioning systems use piezoceramic materials Besides the obvious advantages in terms of accuracy and control of movements of these materi als they have several disadvantages The main disadvantage is the non linearity Nonlinear properties of piezoelectric ceramics is dependence between the control electric field and the deformation of the piezoceramic sample 1 e non linearity and am biguity of this relationship Usually the nonlinear properties of ceramics are divided into creep hysteresis and non linearity itself Nonlinear properties includes sensitivity volatility of the piezoceramic Scanner not equipped with sensors control voltage on the axis is an indication of its position on this axis Non linearity and ambiguity of the dependence of the control voltage the situation often leads to significant distortions of the image 5 1 Piezoelectric actuators properties 5 1 1 Creep Ux a 6 6 mma AU AA creep AXo to t t Fig 5 1Scanner response for voltage step Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 55 Creep of the piezoceramic results in the fact that after the change of control voltage the dimensions of piezoelectric scanner contin ues to change For example after the voltage step supply to the piezoelectric elem
49. ser radiation and safety for the class of the laser source In the case of an external laser in the recording system of the microscope or with a com bination of SPM Certus with external laser sources we recommend that you study the documentation and safety for your laser source Precautions SPM Certus this 1s a complex research tool Strong physical impacts operation in hostile environments changes in the structure during use storage or transportation can result to device damage Modification and user self alignment of SPM Certus with research equip ment In the case of user self alignment of SPM Certus with research equipment or modification to the specific research tasks recommended to agree the matter with the company Nano Scan Technology because the user self interference in the construc tion without the agreement deprives the guarantee Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual Ed Contents Contents T S OG UCU CE 1 OAE E 7 1 Basic Information about SPM CertuUS cccococooooccccnnninonooccccnnncciccccnnnonos 8 1 B SPM CCE CUS Ap DCA AMM PPP E EEEE EET 8 1 e An E O 9 Ltd TIA T e E R T E E AAE A N E E EE E 9 LL DO E e E N TR 9 1 2 3 Deflectometer lasers sese 9 1 2 4 SPM head Certus Drawings sese 10 LL ADEE AIO COCIDAS srta lector REEE 11 Ra AAA o AI A 12 1 5 Terms of storage and transportatin ccccccccssssssccssssccssssccssssccssscosscoes 13 LoL D
50. the number of pixels in the image should be guided by the following rules e For non contact techniques does not make sense to put the number of points which is equal to resolution less than the probe curvature radius e Scanning speed depends on size of the scanning field for the same number of points It is recommended to reduce the number of points with decreas ing field scan to save the scanning speed in proportion to the size of the scanning field or increase the scanning speed e For different sizes of the scanning field may need to change the parameters of the feedback Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual E SPM Certus operation E 4 7 Scanning process At the scanning process in the absence of vibration and acoustic protection 1s re commended not to affect scanning probe microscope Certus to mechanical or acoustic impacts This may cause artifacts in the image and even the movement of the sample rel ative to the microscope and probe damage 4 8 Primary image processing and saving For primary results processing and saving use built in tools to work with images and graphics A detailed description of the location and functions of these instruments 1s given in the software NSpec user manual in sections e Par 2 Interface tools e Par 3 DATA window We recommend you to save data without filters processing and extra filters Nano Scan Technologies Ltd Ce
51. ual se SPM Certus operation a For hard materials with a relatively small difference in altitude a few tens of nanometers on small scan areas feedback parameters can be set are close to 0 For ex ample from 0 1 to 0 3 At high scanning speeds for any of the samples are recommended to set the para meters of the feedback of more than 1 Nearly to the values near the onset of oscillation in the feedback loop 4 4 Set point tuning After setting the resonant frequency and amplitude and feedback parameters us ing the value of MAG in the field of SPM Feed Back set in the FB INPUT SIGNAL SPM MODE sets the setpoint value for the feedback For the assessment scan is re commended to install 50 of the current value of MAG Normally value is depends on the surface characteristics of the sample 4 5 Tip to sample approach 4 5 1 Rough approach For rough approach use functions described in the software NSpec user manual Section 4 3 stepper motors 4 5 2 Scanning head tilting In some cases it is recommended to scan with the probe tilted at a certain angle to the surface or to compensate for the slope of the surface samples Use individual control of each stepper motor by the algorithm e Move down head roughly in the 5 10 mm from the highest point of the SPM head e Go to the stepper motors control menu with each individual control Sec tion 4 3 1 software NSpec manual e Move up to a maximum SPM head rear step
52. upporting software perform fitting of tabular data by a polynomial of degree four C X AXX 4 BX X 4 CXX DXX H E 70000 60000 50000 40000 30000 Y Axis Title 20000 10000 A mkm Do the exact same procedure for the axis Y with the only difference being that the direction and the starting point of scanning to be selected like the bottom left corner and the direction of a quick scan is Y axis i The obtained data should be recorded in the table Sensors Calibration and save the file Y Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 66 SPM Certus head application with external optical equipment E 6 SPM Certus head application with external optical equipment 6 1 Basic principles of optical equipment application Scanning probe microscope is designed for use with optical equipment The design of the SPM head Certus can combine it with both direct and inverted micro scope to sum up additional sources of light such as lasers microscopes using regular light sources etc One of the major limitations of scanning probe microscope is the difficulty in finding the site of interest on the surface of the research object as well as the installa tion of the probe to a selected point on the surface Circumvent this restriction allows the use of methods of optical microscopy and spectroscopy Example of possible posi tions of the upright microscope lens is given in Figure 6 1
53. use different types of sensors whose sensitivity allows you to record such disturbances To construct a bitmap image uses a system of probe movement scanning system relative to the surface in XY or XYZ coordinates The recording system records the value of each item Basicly the recorded value depending on the magnitude of the interaction between the probe and the sample sur Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 19 Operating principles E face On the basis of known or suspected plots of the interaction of the distance between the probe and surface during scanning constructed surface topography 3 D image co ordinates XYZ In that case 1f the registration of change of the interaction from a dis tance does not make sense or 1t can not be determined uniquely then constructed the distribution of the measured parameter on the surface 3 D image where XY is based distribution parameter and the Z value of a parameter F1g 2 2 The system of negative feedback controls the position of the sample or the probe by one of the coordinates in most cases Z As a system of feedback 1s most commonly used PID controller Object of research Imaging process Scan and cross section Profile in cross section Fig 2 2 Common principles of SPM surface imaging Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual EN Operating principles E The main
54. y from 0 to 500 or in the case of canti levers with a large resonant frequency 1s greater In the Input Gains set all values of multiplier equal to 1 Set Drive Intensity slider value equal to 1 Press Run From 100 000 To 200 000 p 0 Drive Intensity W 1000 0 2 4 6 D 10 mnm l l l l l l 0 LL Low Pass Filter kHz Phase Shift Degree 10 20 30 100 0 100 O y ooo oO oOo 5 2 _ gt 26 8 me Fig 4 13 Probe resonant data After that Plot will show the current resonant curve of the cantilever Figure 4 14 If you know roughly the resonance frequency value of the cantilever search range can be narrowed Figure 4 15 If necessary resonant frequency can be set manually Figure 4 16 using ob tained resonant curve Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual 49 SPM Certus operation Amplifier Ou 300 Probe Resonant Frequency kH7 E MAG y gt From o To 1500 e 100 ent Frequency KHS _ i Drive intensity Y Fig 4 14 Cantilever resonant frequency acquisition IA O O A 1 ra G Pa z Amplifier O 300 310 320 330 340 350 Frobe Resonant Frequency kHz Fig 4 15 Cantilever resonant frequency acquisition Nano Scan Technologies Ltd Certus Scanning Probe Microscope User manual so SPM Certus operation E e o L gt Z a E 4 we A R
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