SNE-1500M Manual_eng_042308
Contents
1. Filament Cartridge Tungsten Filament Remove the Filament Cartridge Power off the Mini SEM high voltage and press the Exchange Button to vent the column Power the unit off for safety and let the blown filament cool for a few minutes The tungsten filament is heated to approximately 1800 degrees Kelvin or 2780 degrees Fahrenheit Be careful it can be very hot Loosen the gun adjustment knobs and remove the gun from the column Unscrew the filament retaining ring and remove the filament cartridge You may have to rock it back and forth but it should pull right out of the gun Once you have the filament in your hand put the gun back on the column and pump the column down This will keep the gun area clean Fig 35 Remove Cartridge Fig 36 Loosen Filament Rubber gloves should be worn to prevent the oils in your skin from contaminating the filament cartridge 54 SEC Scanning Electron Microscope SNE 1500M Remove the old filament Loosen the 4 hex screws that hold the filament to the cartridge Then remove the old filament from the bottom of the cartridge Now is a good time to do a little maintenance By the way you can save the old filaments and get them rewired Fig 37 Remove Filament Fig 38 Blown Filament Fig 39 Filament with 4 adjustment screws The quality of your image is partly based on the cleanliness of your column so before you replace the filament lets breakout the metal polish and polish all the compon2. L Standard Specifications sa ee tede Oni beim OE 13 2 Installatrom CONDOM ERE 16 3 Standard System Composition eese eene nennen en nen rennen net net nennen nne 17 TE Installation u n mn m un u u n died er md HE 18 l Installation Requirements 5 peer REESE RE u Susu 19 2 Installation Configuration asan GAGANA 20 JR 21 1 Moving PrecautiOD 2 uu u rre enne eee rea a ee ERIN Ses ev E eaae ene Fe E ee FRE CH RE HEN ANA dans 22 2 Electric Power Precautions uie eee rH PE REP NAO EE aaa aa Fre BRAD 23 SSalety PrecautioBs u aus 24 4 General Precautions ceccecesccesscecsseceeececesecesececsaceeeceecsaeeseneecsaeeeeeeecsaeeseaeecsaeeeeaeecaeeeeneeceaeeseaeesas 25 5 Sample and Chamber Precautions sesssssssseeeeeenerenrene eene nem nenne nennen nennen 26 V Program Configuration eee a I oia 27 1 System MED 29 PAUL SNP MC ER 32 Se TMA Be WINQOW a 33 4 Image Adjustment rene OU D ate wee eRe ae 34 O 35 6 Imape AdJ uStIne tuu u ERE 36 XT Installation Instructions a IR GG AR NAGANA NEA NANANA NALANG GARA LABANAN 37 1 Installation Configuration y u a E aD ua nus E E E EE umasa 38 2 Connection of the nit u ALS E Eb Kreko daqa ata 39 VIL OpeTallOn maman GS 40 Ie System Dek eeoj nko ETT TT AP
3. Turbo Pump Abnormal noise vibration O Chamber Door inside Foreign matter O High voltage Screen O Fuse short Power ON OFF O circuit Others Front lamp Lighting O FAN Abnormal noise vibration O 67 SEC Scanning Electron Microscope SNE 1500M Appendix Drawing n y s Appendix 1 1 w SEC Scanning Electron Microscope SNE 1500M A Power Appendix 1 1 Power Appendix 1 2 SEC Scanning Electron Microscope SNE 1500M B Cable drawing I Appendix 1 2 Cable Drawing Appendix 1 3 Scanning Electron Microscope SNE 1500M Appendix 1 3 Back Appendix 1 4 SEC Scanning Electron Microscope SNE 1500M D VO Appendix 1 5 w SEC Scanning Electron Microscope SNE 1500M L ELI FUP d gt I f I 8 j i CI mui zai pi RW Appendix 1 4 I O Appendix 1 6
4. Microscope SNE 1500M 6 Quick Guide ol Load the SEC Application E lt Loading ActiveScan o 2 Select Accelerating Voltage 24 Sy 04 Move the position of the sample by using I position knobs 0 5 Select magnification 0 7 Save image J 0 6 Adjust the focus gt output x Fig 29 Quick Guide 46 SEC Scanning Electron Microscope SNE 1500M Searching Image area 2A s ans Select Scan Mode by Slow Scan Search the area to look by rotating X Y axis Handle of Door Rotate image un the use of R axis Handle of Door if necessary If more precise rotation is necessary rotate it am in the use of scanning rotation in program Fig 30 Image Searching Image improvement O In case of not being in complete focus Push Auto Focus C32 button If not being in complete focus after Auto Focusing execute the following procedures e C r Select Scan Mode to Fast Scan m Lower magnification if image is entirely not seen GP Make edge of image seen clearly in the use of Focus button Adjustit so that the edge can be seen clearly up to the magni fication one step bigger than those to look actually In the magnification one step bigger than those to look make minute adjustmentin the use of precision focus button A Observe image by changing the magnification to desired mag ED nific
5. Ny SEC Scanning Electron Microscope SNE 1500M 4 General Precautions O Refer to the proper section in the manual for any maintenance that will be performed Call your service engineer if any questions arise O Customers should only attempt the below repairs on the Mini SEM Any other service should be performed by a trained amp qualified SEC service engineer Filament replacement Wehnelt Cap cleaning and polishing Cleaning and polishing the anode and sleeve Changing apertures Cleaning and replacement of Chamber door O ring Change rotary pump oil O Keep the column under vacuum if not in use Do not install the Mini SEM in an area with high humidity or large temperature swings Keep the Mini SEM where it was installed O Try to keep the Mini SEM under vacuum If the system is not used for an extended period of time recycle the vacuum This will keep the column clean and dry 25 SEC Scanning Electron Microscope SNE 1500M 5 Sample and Chamber Precautions O Be careful in choosing different types of samples to use in the SEM Some samples especially powders may contaminate the chamber The electron beam may react with the sample and oxidation may occur This oxidation may contaminate the column and can react with the column walls causing corrosion This contamination will also affect the apertures secondary detector scintillator and other parts of the column degrading the image quality O Pay atte
6. SEC Scanning Electron Microscope SNE 1500M 4 Mini SEM Description Filament Exchange Cover Chamber Door Power Switch Exchange Switch Stage Control Knobs Fig 2 Front of Mini SEM SNE 1500M Power Switch This is the main power on off switch Push the red button to apply power to the unit when operating Push the button again to shut the unit down Exchange Switch This is the main vacuum switch OFF Vacuum is released the column is at air ON The column is under high Vacuum Slow flickering Column is pumping down Fast flickering Release vacuum Ny SEC Scanning Electron Microscope SNE 1500M Vacuum LED This indicates the degree of vacuum in the chamber Chamber Door Pull open the door when the column is at air to change the sample To view the sample close the door pump down the column and turn on the beam Stage Control Knobs Manual stage controls in X axis Y axis and sample Rotation Filament Exchange Cover Remove this cover if replacing a filament or if gun alignment is necessary w SEC Scanning Electron Microscope SNE 1500M RS 232 Fig 3 Back of Mini SEM SNE 1500M Main A C Circuit Breaker A 220 VAC main circuit breaker with ground fault protection controls the power to the Mini SEM Power Connector This is connected to 220 VAC power outlet Rotary Pump Vacuum Hose Connector This connects the rotary pump to the back end of the turbo molecular pump Rotary Pu
7. long time is discolored on the surface because of electron gun with high temperature Wash them by metal compound of spare parts to maintain cleanness and use it O As much emission of gas is generated in the exchanged filament and in the column and chamber that are opened to the air after replacing filament set vacuum by sufficient time Caution in image adjustment after replacement O In arraying optic axis by Electron Gun Centering Handle pair facing Centering Handle and rotate to the same direction and then search the point where the brightest image is displayed on image window of PC 0O Set emission in Emission located at Program Tool Adjustment OSEM Microscope Setup Microscope Profile 20KY AS Ge Condensor Lens Focus Magnification Detector Rotation pamanang Acceleration Voltage Beam Emission Alias Filament 0 J Voltage Current 0 Grid 2 Yoltage 0 Current 0 51 SEC Scanning Electron Microscope SNE 1500M O Electron beam is generated by heating tungsten filament Approx 1800K Radiation volume of electron beam is controlled by increase decrease of heating current of filament Increasing heating current emission current is also increased but passing over heating current in the fixed level emission current is not increase any more Such current area in the fixed level is called saturation area Set emission current value at nearing the point where saturation area is started an
8. marked Rotary Pump 4 Connect the USB cable from the back of the Mini SEM to the USB port on the PC 5 Connect the RS 232 cable from the rear of Mini SEM to the RS 232 port on the PC 39 SEC Scanning Electron Microscope SNE 1500M VII Operation e 40 SEC Scanning Electron Microscope SNE 1500M 1 System Description Caution before operating O Make sure there is no object or device that can generate vibration or electromagnetic fields in the area O Check that all cables and hoses are connected O Check the chamber door o ring is clear of any debris This may cause a vacuum leak Caution while operating 11 Do not bang on the Mini SEM O Do not cut off electric power while running the Mini SEM O Do not try to open the door by force This may cause a quick change in pressure and rupture the X ray detectors thin window if one is installed O Close the door after a sample exchange this will keep the chamber free of dust 41 w SEC Scanning Electron Microscope SNE 1500M 2 Electric Power 1 Main Circuit Breaker The system is equipped with a main circuit breaker on the rear of the Mini SEM Switch the circuit breaker to the ON position This is 220vac GFI breaker This will allow the main power button in the front of the Mini SEM to control the system power Switch the circuit breaker off if the unit is not in use for long periods Fig 23 Rear of Mini SEM 42 SEC Scanni
9. may occur wear protection device by all means before checking up for fault repair X Turn off power before fault repair X Review the cautions before fault repair If it is uncertain what action should be taken in fault repair do not progress any more and contact SEC Co Ltd 63 SEC Scanning Electron Microscope SNE 1500M 2 The Fault of the Unit System power breakdown O Phenomenon System is not operated since power is not supplied to system after turning on front power switch in SNE 1500M not putting on the lamp O Cause Power is not supplied to 220V plug for power supply E L B leakage circuit breaker switch turns off due to overload of SNE 1500M inside O Action Check if 220V plug for system power supply is pulled out Check if E L B leakage circuit breaker switch at the back of SNE 1500M is ON or not O If ON is certain and not turning OFF artificially do not turn ON and ask serviceman for it In case of being pulled in power cord if E L B Earth Leakage Breaker switch Caution is ON power is supplied to SMPS and the other apparatus be careful of it specially 64 SEC Scanning Electron Microscope SNE 1500M PC Booting and Running Defect O Phenomenon Power of PC is not turned on or nothing is displayed on screen It is not being progressed any more in the middle of PC booting Program is not normally run O Cause Power is not supplied to PC Trouble
10. 0V AC 1kW 60Hz O Supply electrical power in the fixed volume in using the unit Do not exceed 10 of supplied electric power volume as the variation allowable value of electric power volume Earth L1 Apply the first degree earth SEC Scanning Electron Microscope SNE 1500M 2 Installation Configuration Fig 8 Installation Configuration 20 SEC Scanning Electron Microscope SNE 1500M IV Precaution T n n r a R j gt gt v TV 21 SEC Scanning Electron Microscope SNE 1500M 1 Moving Precaution O Do not carry or move the unit while power is on The unit produces very high voltages and is a shock hazard Also the turbo molecular pump spins at a very high speed and any sudden movements while it is spinning may cause the turbo to fail O The total weight of the unit is about 100kg Care must be taken when carrying the unit to avoid a back injury or damage to the equipment service person or co worker should help in any transportation O Provide a strong vibration free table for the instrument Place the provided feet on each leg of the unit this will give a firm resting position for the microscope 22 SEC Scanning Electron Microscope SNE 1500M 2 Electric Power Precautions O Ensure there is proper power to the Mini SEM An A C transformer that converts 110vac to 220vac will be provided The transformer will provide a common ground to the Mini SEM and
11. ANG MATANG E E E E ER 41 2 Judo dias 42 3 Vacuum Control and Maintenance GNNGG0NENG GNNGG0NENGENAGGNNGNGCNAGG0 NENG none innen 43 4 Sample Exchan pet aaa NINA ANA AKA NANG NG ANU E RE 44 SEC Scanning Electron Microscope SNE 1500M S Mini SENM Applica O Mito NANALANGIN 45 6 Quick Guide dee AA 46 T Filament Replacement maam NAGIN 49 8 Checkup and Replacement of Anode sleeve Aperture anna anna sana swaawnaawaaanasswsasasssasana 59 9 Inspection OF Vacuum system ooo ges GAAN p o cen Ron RE Fake ko CRAS Ree eas eee oder seki ania 61 VIIT Fault Dias nosis citant 62 Fault CI INST Non NANA SA seo sa bes 63 2 The Fault of the Dir 64 3 In case of requiring maintenance and repair nennen nennen 66 4 Periodical Checkup Last 33 bieten a e D EU ERES IB AA 67 Appendix 1 Drawing SEC Scanning Electron Microscope SNE 1500M SEC Scanning Electron Microscope SNE 1500M I Mini SEM Introduction SEC Scanning Electron Microscope SNE 1500M 1 General The Scanning Electron Microscope SEM is used for observing the surface structure of a sample The column 1s made up of an electron gun that generates a stream of electrons The stream passes through apertures and an electronic lens system that controls the flow of electrons The electron stream then passes through scan coils that raster the beam over the sample Seconda
12. Acquires a small 320 240 pixels High speed preview This mode is used when modifying the image focus or contrast and brightness Acquires a higher resolution image of 640 480 pixels The pixel time is the same as the fast scan This button stops the preview and freezes the image This is mainly used with the measurement tool Acquires a high resolution 1280 960 pixel image Acquires the highest resolution 2560 1920 pixel image Ny SEC 6 Image Adjustment Scanning Electron Microscope SNE 1500M The image adjustment slide bars control the contrast and brightness of the image These controls are applied to the acquired image and do not change the secondary detector levels This is merely a software adjustment of the 8 bit gray scale The internal hardware has a O to 4096 histogram that the image can shift around in The O to 256 image can shift up or down using the Brightness slide bar or can expand or retract using the Contrast slide bar Clicking the auto button will allow the computer to set the video levels Brightness Contrast Video aw Halka Contrast Brightness Video Fig 21 Image Adjustment Brightness Control Left click and drag the slide bar up or down will increase or decrease the Brightness or offset of the image Left click on the plus or minus signs will change the brightness by a very small amount Contrast Control Left click and drag the slide bar up or down will increase or dec
13. PC O Power down the Mini SEM when opening the cover or replacing accessories O Do not operate the Mini SEM without a good earth ground The system may malfunction and there is a chance of electrical shock O To limit personal injury do not attempt any service without first contacting an EVEX service engineer O Do not use any power supplies except for the one provided with the Mini SEM This may cause damage to the unit or start a fire O Do not break down the high voltage tank in the Mini SEM this may cause serious damage to the unit or electrical shock 0O Avoid any undue stress on the electrical cord from the Mini SEM Do not apply too much twisting bending or tension which may cause the cable to fail A serious risk of electrical shock or a fire is possible 23 Ny SEC Scanning Electron Microscope SNE 1500M 3 Safety Precaution El O Do not disassemble or service the Mini SEM without first contacting an SEC service engineer Due to the complexity of the unit problems may occur including poor image quality unit malfunction or damage Do not use the PC for anything but controlling the microscope Loading the PC with programs could have a serious effect on the quality and speed of the Mini SEM In some cases errors in the program or damage to the unit may occur Rotary pump service is essential to a smooth running vacuum system Periodically check the oil level every few months Rep
14. SEC CO LTD SNE 1500M User Manual 415 Factory World 332 2 Woncheon dong Yeongtong gu Suwon Korea SEC Scanning Electron Microscope SNE 1500M O Copyright 2007 SEC Co Ltd This user manual and software and hardware that are described in it are protected by copyright law Besides copying it for general use within copyright law 1t is prohibited to copy the contents in a part or on the whole of user manual without permission by SEC Co Ltd SNE 1500M is a trademark by SEC Co Ltd We are making efforts to improve our documentation If any error or misprint is found in this manual please forward the information to the address below It would be very helpful for us and our customers SEC Co Ltd 415 Factory World 332 3 Woncheon dong Yeongtong gu Suwon Korea Tel 031 215 7341 Fax 031 215 7343 Scanning Electron Microscope SNE 1500M User Manual Issued on October 1 2007 Revised on April 7 2008 SEC Co Ltd SEC Scanning Electron Microscope SNE 1500M Contents I Mini SEM Introduction ee ee eeeceescecsseceencecssecesceecaecesneecaeeseeeecaecseneecsaeceeeeecaeceeneecsaecseeeecaeceeeeesnaeeenees 1 DOM s a O AA 2 2 ME ERES 3 3 Basic Principles of Scanning Electron Microscopy sese 4 4 Mini SEM DesScriptlOD uci esent ttn e desee cotes TUNA Sai dune iii 7 II Mini SEM SNE 1500M Specification nennen ren een rennen nre 12
15. Sleeve and Aperture Y Insert Aperture Combine Aperture washer washer Insert Aperture Combine Combine Insert grid sleeve sleeve Combine Anode Sleeve assembly parts Completion Fig 51 Assembly of Anode Sleeve and Aperture 60 SEC Scanning Electron Microscope SNE 1500M 9 Inspection of Vacuum system Checkup and replacement of O ring O ring in the inside of chamber or gun has high exposure frequency dye to sample exchange or filament replacement So vacuum sealing may be deteriorated because of dust or pollution Execute periodical washing and maintenance O Pull out O ring out of attachment groove Do not use metal tool at that time occurring scar or deformation on the surface of attachment groove or O ring it may be the cause of vacuum defect O Remove dust or contaminated matter from pulled out O ring in the use of gauze soaked with ethanol in small amount Do not touch skin or cloth in which contaminated matter may exist with once wiped O ring O Check if there is minute dust or scar in O ring fully Replace O ring with scar or deformation and attach new one O Smear Vacuum grease in small amount and spread evenly overall O ring O Wash O ring attachment groove by ethanol O Insert Vacuum grease spread O ring into attachment groove and turn it to the original state Checkup and replacement of Rotary pump oil Lack of Rotary pump oil amount or deterioration and discoloratio
16. Stig Synchronize It is used for adjustment of astigmatism Align stigmatism Adjustment may be required after exchanging filament or Aperture CED GO CE Cs Fig 14 System Stig Alignment X Y Alignment Select X Y array Sympathy Operate Wobble function Adjust Open or close Wobble adjustment window Default Call basic value Initial Set it to 0 Save Set present value to basic value Close Close the present window 30 de SEC Scanning Electron Microscope SNE 1500M 2 Tools The Tool menu contains various tools for image column adjustments Crosss Point Measure Tools Adjustment Fig 15 Tool O Measure Tools Cross Point Indicates the center position of the image inside the image window When adjusting the magnification or rotation the new image will center on this point Measure tools This menu option enables various tools for measuring and image annotation The measurement tool contains various tools for measuring image features including size and angle measurements There are also useful image annotation tools for drawing on the image or writing text Fig 16 Tool Measure tools x LOJ EI s 4 DI 6 EI 2 Select measuring tool Measure the distance between tow points Connect three point and measure the angle between the points Measure the length of several line segments Measure the
17. an increase in filament current does not increase the image brightness At this point the Gun is centered and filament is saturated Microscope Setup Wii Microscope Profile 12 Microscope Prete DON Acceiation Cordenva Lens Focus Magoication Detector Rot ton Abono voltage Deo Emassan Abad Condensor Lens Foa Acceleration Voltage ge Kama ET Fig 44 Microscope Setup Alias tab Fig 45 Microscope Setup Beam Tab Fig 46 Microscope High Voltage Key Switch 57 SEC Scanning Electron Microscope SNE 1500M Beam Alignment Before any adjustments are made a few things need to be checked Check the contrast and brightness slide bars the image area should be grey with just background noise in the preview window Set the condenser lens slide bars to O and set the magnification to 20x Adjust the centering knobs until an image appears When you do get an image go back to the Filament heating section and saturate the filament Beam Alignment When the filament is replaced or your notice a drop in image intensity you should check the beam alignment The first thing to look at is the emission meter Even if the filament is blown there will be a background current seen on the meter The Emission meter will display 000 uA when the high voltage is off When the High voltage is on and the filament slide bar is at O the meter should read 40UA A properly saturated filament should read around 80UA at 20kv Ba
18. area Draw the arrow to point specific point Draw text tool Draw rectangle on image Draw circle on image Delete all measuring 31 SEC Scanning Electron Microscope SNE 1500M 2 Tool Bar The tool bar that is located just above the image window contains all the basic functions for acquiring an image opening an old image displaying the measurement tool defining the center of the image saving the image and printing the image Ca Fig 17 Tool Bar High Voltage On Off This button toggles the high voltage on and off Clicking the button enables iS the high voltage and produces an image in the image window Clicking the button a second time will shut off the high voltage Open file Opens a directory dialog box for selecting and viewing previously stored images Display measurement tool Opens the measurement tool for measuring features and annotating the image Display Cross Point Defines the center of the image for zooming in and scan rotation 988 B Save Opens the Save File Dialog box Images are saved as jpg or tif files E JJ Print Output the image to the defined printer 32 SEC Scanning Electron Microscope SNE 1500M 3 Image Window This is the main viewing area of the Mini SEM software It holds the acquired image and a status bar When the high voltage is turned on the microscope will automatically adjust to provide a low magnified previewed image The image adjustments like mag
19. ation Fig 31 Focus Adjustment 47 SEC Scanning Electron Microscope SNE 1500M O In case that image is too dark or bright Click Auto button If it is not fully improved after clicking Auto Brightness Contrast rus CD contrast button adjust brightness 48 SEC Scanning Electron Microscope SNE 1500M 7 Filament Replacement Break Vacuum dim rum off power of front BEES rum off circuit breaker at the back Exchange Filament and open exchange cover Break down Electron Gun Replace Filament Assemble Electron Gun di E Exchange Filament and close exchange cover Fig 32 Filament Replacement 49 w SEC Scanning Electron Microscope SNE 1500M Image adjustment after replacement Adjust Electron Gun Centering handle looking the image for best image Exchange Filament and close exchange cover Fig 33 Filament Correction 50 SEC Scanning Electron Microscope SNE 1500M Cautions in replacing filament O Do not contact filament immediately after putting off electron beam it may be dangerous against burn because of high temperature O In releasing filament and grid that covers filament use vinyl gloves in spare parts to prevent contamination O In replacing to another filament in reserve stocks check if tungsten hairpin of filament is arrayed in the middle of grid O The inside and outside of grid that were being used for
20. ble light and a system of lenses to magnify and view the sample Our eyes obtain visible light from the sun during the day to see and we use electricity indoors to power lamps and lighting fixtures to see in dark areas Most optical microscopes use an adjustable light source to control the brightness of the viewed image Optical microscopes have a long history in the analytical sciences and are very useful in low magnification conditions The resolution of a typical optical microscope is limited to the lens system and the wave length of visible light which is 400nm to 700nm The maximum magnification is around 1500x and at this magnification the depth of field is very small In comparison the naked eye has a resolution of approximately Imm A typical optical microscope resolution is approximately 200nm or 2um The resolving power of the Mini SEM is approximately 8nm or 008um at 20kv The reason for the increase in resolution is the Mini SEM has an electron source which emits an electromagnetic wave or beam of electrons which is much smaller in frequency than light This huge increase in resolution means a much higher magnification gt 20 000x and a larger depth of field The Mini SEM is positioned as an alternative to a high end optical microscope with greater resolving power and the ability of using different detectors such as Backscatter or X ray Electron Microscope Features The electron microscope creates a beam of electrons by thermionic emissi
21. cation 20x to 15 000x Electron Optics LI Electron Gun Thermo electron emission type O Accelerating voltage 0 to 20kV O Lens system Electromagnetic lens reduction system O Objective lens aperture O Stigmator coil Electromagnetic type O Scanning coil Two stage electromagnetic deflection O Scanning rotation 360 Specimen Stage D X movement 0 to 20 mm Q Y movement 0 to 20 mm Rotation 360 Maximum sample size 75 mm in Diameters Maximum Sample thickness 12 mm Image Display Detector SE detector Display 17inch LCD Scanning mode and speed Fast Scan 0 1s X 320lines Y 240lines Slow Scan 3s X 640lines Y 480lines Fast Photo 10s X 1280lines Y 960lines Slow Photo 30s X 2560lines Y 1920lines SEC Scanning Electron Microscope SNE 1500M Data display Date Time Scale Bar Accelerating Voltage Magnitude Image Memory For Fast Display 320 x 240 x 8bits For Display 640 x 480 x 8bits For High Resolution 1280 x 960 x 8bits For Ultra High Resolution 2560 x 1920 x 8bits Memory functions Image Integration in Fast Scan mode Brightness control Contrast control O Memory Device HDD of PC Any recording medium in the PC Image format BMP JPG PNG GIF Measuring Tool O Length Two Point length measuring Multi Point length measuring Multi Point Area Marking Arrow Marking Text Marking Square Mar
22. d use it Setting emission current value over saturation area filament is overheated so the life is shortened setting emission current value under saturation area emission is unstable so good image cannot be obtained O Put emission in the minimum increase it slowly and look at the image displayed on image window for setting emission current value to the unit The brightness of screen is gradually increasing and it becomes not being changed any more passing a certain point consider the area to saturation area and set the emission current value 52 w SEC Scanning Electron Microscope SNE 1500M Assembly Order of filament and grid Prepare assemb Tighten Filame ly tools Tighten grid Align Filament Completion Fig 34 Assembly order of Filament and Grid 53 w SEC Scanning Electron Microscope SNE 1500M Filament Replacement Overview There is only so much life in a filament and eventually you will have to replace it When the filament dies the tungsten wire opens and the ability to heat the filament is lost The emission current will be at O and the current meter will show a minimum amount Evex gives you two options on replacing the filament cartridge You can order from Evex pre centered filament cartridges These cartridges are cleaned polished aligned and the Wehnelt cap height is set for you Or you can order standard filaments and adjust them yourself will explain the how to center the filaments below
23. ents in the filament cartridge This includes the Wehnelt Cap Filament Retaining Ring and Filament holder Rinse off all the pieces and sonicate them in a methanol bath Blow them dry with compressed air and now you are ready to install the new filament Installing the New Filament Cartridge Remove the new filament from the box be very careful not to bend the wire Turn the filament cartridge upside down and place the filament inside Tighten the 4 hex screws and flip the cartridge over Screw the Wehnelt cap onto the cartridge and with a magnifying glass slowly rotate the Wehnelt cap down onto the filament If it looks like the filament is not centered in the Wehnelt cap hole you will have to adjust the 4 hex screws until it is centered Then keep lowering the Wehnelt cap until the filament is flush and centered in the hold Now rotate the Wehnelt cap until the filament is flush and centered in the hole Now rotate the Wehnelt cap 1 2 to 3 4 of a turn counter clockwise to set the proper filament height Tighten the Wehnelt cap set screw and replace the filament cartridge in the gun Place the gun assembly back onto the column and press the Exchange Button to evacuate the chamber Fig 40 Properly Adjusted Filament 55 SEC Scanning Electron Microscope SNE 1500M Filament Adjustments Overview The filament saturation point needs to be set to maximize the efficiency of the filament If the filament is under saturated the image wil
24. fine that acceleration voltage such as the filament current and emission current Lowering the acceleration voltage will reduce charging but will also reduce the beam resolution and intensity Increasing the acceleration voltage will give a stronger image and higher resolution but a well grounded sample is needed System Tool Configuration AHA Go luma l ikv 35 GE Stig Adjustment KV JF ZE Stig Alignment 10k 2p RE 15kV 2p HE 20kV 35 RE ASHA SSSL ABJA HASLE Fig 10 System Menu O Detector Selecting the detector menu item will allow you to change the secondary detector parameters There are two slide bars that control the rate of collection and the amplification or gain The rate of electron collection is controlled by adjusting the scintillator high voltage The amplification is adjusted by changing the gain of the preamp Fig 11 System Detector O Stig Adjustment It corrects astigmatism of electronic magnetic lens Using it wrong image due to the distortion of electron beam can be corrected It can regulate the spot phenomenon of electron beam 29 Fig 13 System Stig Adjustment Setup O Stig Alignment Scanning Electron Microscope SNE 1500M Stig adjustment Regulate astigmatic pencil to X axis or Y axis Initial Set it to 0 Default Recover to basic value Save Set present value to basic value Close Close the present window
25. h an x ray system 3 The microscope was shipped with a tool that measures the height of the sample The height is approximately 8mm from the bottom of the pole piece Fig 26 Sample Height jig Fig 27 Adjusting Sample Fig 28 Sample on Stage 4 Insert the sample holder onto the stage then tighten Slowly slide the door closed and push the exchange button again This will start the pump down cycle which takes 2 to 3 minutes When the vacuum gauge on the front of the unit reaches its highest level the unit will beep and the system high voltage can be turned on 44 SEC Scanning Electron Microscope SNE 1500M 5 Mini SEM Application Loading the Software 1 Check that both the USB and RS 232 cables are connected to the computer and the Mini SEM 2 Turn on the PC 3 Double click the Mini SEM icon the application will load 4 Select SEM high voltage settings from the System Configuration menu 5 If the SEM is under high vacuum left click on the HV on off button 6 After a few seconds an image will appear inside the image viewing area At this point the microscope saturated the filament adjusted the condenser lens focused the image adjusted the contrast and brightness and is scanning the image at a low magnification These are only basic setting to get you started You have full manual control of the stage and microscope parameters to achieve a beautiful high quality digital image 45 SEC Scanning Electron
26. ig 7 Packing List ea SEC Scanning Electron Microscope SNE 1500M III Installation e SEC Scanning Electron Microscope SNE 1500M 1 Installation Requirements General Mini SEM SNE 1500M should be installed avoiding the following conditions since it is sensitive to surrounding vibration electric power fields and magnetic fields U Do not place near a transformer O Do not place near an elevator O Do not place near equipment with a large consumption of electric power O Do not place the instrument where a high frequency field may be generated or near something that products an electrical spark discharge O Do not place near any chemical or gas that the possibly of corroding the instrument O Do not expose to direct sun light or wind O Do not place in an area that has unregulated temperature and humidity O Place the instrument on an isolated ground O Do not place in a location with large sound waves Temperature and Humidity Place in a temperature controlled humidity controlled environment O Temperature Maintain the temperature of the place where the unit installed at 150 300 at all times do not exceed 51 in temperature change when the unit is being operated O Humidity Maintain humidity of the unit installed place under 70 at all times Electric Power O Electric power for major equipments Single phase 100 240V AC 2kW 60Hz O Electric power for peripheral equipments Single phase 100 24
27. ion Current gt False Pesk Emis Flament Curent gt Fig 51 Filament vs Emission Current maa Z D FI a o am 2 EEB Fig 52 Configuration Profile Fig 53 Microscope adjustments 56 w SEC Scanning Electron Microscope SNE 1500M Heating the Filament With the high voltage on slowly bring the filament slide bar up to around 20 Let the filament sit there for a minute As you increase the slide bar the current through the filament will rise making the filament hotter Increase the current slowly and watch the emission meter When the Emission meter starts to increase an image may appear in the image area If no image is seen and there is emission current then the beam is out of alignment In order to saturate the filament you must first have an image Follow the beam alignment procedure if necessary to find the Image If an image is visible then adjust the gun alignment knobs See fig 57 and fig 58 for the brightest image To adjust the gun alignment knobs you must first loosen all of them Then adjust them in pairs Tighten one side and loosen the other of pair A then switch to pair B Adjust them while watching the image Next increase the filament slide bar a little more If the image goes dark move the slide bar to the previous position and take a smaller step in filament current If the image goes dim then use the gun adjustment knobs to center the filament again Repeat this process until
28. iques will dramatically increase the quality of the image Close the door and push the exchange button again This time the column will start to pump down and the vacuum gauge bar graph will start to rise When the system beeps the high voltage is ready to be turned on Poor vacuum as a result of column contamination or a vacuum leak will affect the quality of the image and shorten the life of the filament Try to keep the chamber and column as clean as possible Always check the chamber door o ring for any dirt or debris Have your column serviced once a year by SEC service engineer 43 w SEC Scanning Electron Microscope SNE 1500M 4 Sample Exchange 1 Preparing the sample Due to the nature of the SEM the sample should have a good electrical ground to the stage This prevents charging and the quality of the secondary image is increased The sample should be mounted on the Evex provided sample stubs There a two diameter stubs a 15mm diameter for smaller samples and a 25mm diameter for larger samples The stubs sit inside the sample holder that is screwed down to the stage Fig 24 Sample Stubs Top Fig 25 Sample Stubs Bottom 2 Vent the chamber by pressing the exchange button This will power off the turbo pump and rotary pump and leak the chamber to air After the chamber is vented open the front door by pulling on the handle Do not force the door open prematurely this may rupture a detector window if the SEM is equipped wit
29. king Rectangle Marking Automatic Function Auto brightness and contrast Auto focus SEC Scanning Electron Microscope SNE 1500M Operation support functions O Operation Environment Graphic User Interface Simplified Menus O Control devices Power Switch Vacuum Button Dedicated Rotate Knob O Condition registration Pre defined 6 conditions Vacuum System O Ultimate vacuum Electron gun 0x10 Pa Specimen chamber Ox10 Pa O Rotary pump 100L min x 1 unit O Turbo molecular Pump TMP 70L sec x 1 unit O Vacuum gauge Pirane gauge Control Unit PC Specification 0 OS Windows XP Professional SP2 Korean O CPU Intel Pentium Core 2 0 Gt O Memory 1GByte O Interface connector USB 2 0 and RS 232 O User Interface device Keyboard Mouse Dimension and Weight O Main Unit 240 W x 390 D x 515 H mm O Control Unit Laptop Computer 178 W x 280 D x 515 H mm O Rotary Pump 150 W x 200 D x 215 H mm Ny SEC 2 Installation Condition O Room temperature O Humidity D Power source Grounding Scanning Electron Microscope SNE 1500M 15 30 0 70 RH or less 220 110 VAC 100 Q or better w SEC Scanning Electron Microscope SNE 1500M 3 Standard System Composition SNE 1500M Rotary Pump PC lunit lunit lunit User Manual USB Cable Power Cable lcopy lunit lunit Air Hose Spare and consumable parts Standard tools lunit leet lset F
30. l be weak and noisy If the filament is oversaturated the image may be strong but the filament life will be short See the chart below There is a happy medium called the saturation point Saturation Saturation occurs when an increase in filament current does not produce an increase in beam current which is directly related to image brightness To saturate the beam takes a little tweaking Saturation Setup Select Configuration in the System menu to set the configuration profile to 20kv Under the Tool menu select Adjustment then Microscope Enter the password HBKIM and a new form will be displayed labeled Microscope Setup Left click on the Microscope Profile drop down box to select a profile to match the acceleration voltage you are using i e 20kv see figure 54 Select the Beam tab in the 20kv profile and adjust the Filament slide bar to 0 and the Grid slide bar to midscale see fig 55 Click Apply at the bottom of the form to accept those parameters A Dialog box will appear Configuration Saved close the dialog box Click the High voltage Key Switch On see fig 56 The high voltage will turn on and the Mini SEM will use the Microscope Parameter page you just configured to setup the image Since the filament slide bar was set to O the emission current will be very low on the emission meter and no image will appear in the preview window Saturation s
31. lace or refill the oil if discolored If this is ignored a degrading vacuum will occur and the overall image quality will suffer The possibility of permanent damage to the vacuum system is possible Remove power from the Mini SEM while changing the filament The Mini SEM creates very high voltages when in use as a precaution power down the unit After replacing and saturating the filament center the electron beam using the alignment knobs This procedure increases the intensity of the beam on the sample A poorly aligned beam will have a major impact on the quality of the image Do not move the electron gun assembly or the cable after the high voltage has been turned on The high voltage may be as high as 30kv and may cause serious injury or damage to the unit If a vacuum problem has occurred do not keep pumping on the column This will only wear out the rotary and turbo pumps Look for the source of the leak i e Dirty O ring and then retry the vacuum system If there is still a problem call your SEC service engineer Do not modify any hardware or software on the Mini SEM without permission from SEC Electrical shock or permanent damage to the unit may occur Do not open the cover except in the case of replacing a filament This will limit any possibility of injury due to electrical shock If the need arises that you think you need to open the cover please contact an SEC service engineer first 24
32. mp Power Connector This is the power cable to the Rotary pump USB Connector USB cable that transfers the video signal to the PC RS 232 connector Controls the column parameters to the Mini SEM SEC Scanning Electron Microscope SNE 1500M Electron Gun Fig 4 Electron Gun Housing and Beam centering adjustments Electron Gun The electron gun assembly holds the tungsten filament To access the electron gun open the Mini SEM top cover If a filament is blown and needs replacing vent the column to air and lift the electron gun to access the filament Beam Centering Knobs The four knobs control the centering of the beam to the Anode This adjustment is critical for maximizing the beam signal down the column after a new filament is installed de SEC Scanning Electron Microscope SNE 1500M Ik VOLTAGE oenion Fig 5 Rotary Pump Vacuum Hose Connection The rotary pump vacuum hose connects to the rear of the Mini SEM This pump is used as a rough pump for the column and the turbo molecular pump Fig 6 Laptop Computer A C Power Connector This is the rotary pumps main A C power connection and connects to the rear of the Mini SEM labeled PUMP SEC Scanning Electron Microscope SNE 1500M IL Mini SEM SNE 1500M Specification EE SEC Scanning Electron Microscope SNE 1500M 1 Standard Specifications Resolution 15 0nm at accelerating voltage of 20kV working distance of 8mm Magnifi
33. n of oil lowered the vacuum exhaust capability so periodically checkup and replacement are required 0O Refill Refill oil in case that oil is not deteriorated oil is less the fixed level when it is not discolored Refill oil through oil inlet looking at Rotary pump oil gauge L Exchange Exchange oil in every 6 months or 1 year periodically or in case that color of oil seen at Rotary pump oil gauge is changed Break down Air hose and oil mist that are connected to main body of the unit Break down Disjoin Drain bolt and pull out oil If waste oil is completely exhausted tighten drain bolt and fill new oil into oil inlet The bottom limit of Rotary pump oil gauge and 2 tow third of the top limit are appropriate amount Tighten main body of the unit and Air hose oil mist 61 SEC Scanning Electron Microscope SNE 1500M VIII Fault Diagnosis A AAA AA Ss 62 SEC Scanning Electron Microscope SNE 1500M 1 Fault Repair In case of occurring in trouble in the middle of using the unit take an action according to the instruction mentioned in this chapter In case of occurring in fault not being mentioned in this chapter stop operation of the unit and contact SEC Co Ltd X Checkup of fault repair should be executed by the person who is aware of the danger matters of system and educated for them X If not wearing proper protection device during checkup of fault repair death accident or severe injury
34. ng Electron Microscope SNE 1500M 3 Vacuum Control and Maintenance For acquiring image fix sample on the sample stage and then set vacuum in the unit It takes time to set and release vacuum Setting and releasing vacuum can be made by pushing Vacuum button at the front of SNE 1500M Like a standard SEM the Mini SEM has an advanced turbo controlled high vacuum system The SEM should always be kept under vacuum except when changing a sample When the unit is powered up the rotary pump evacuates the chamber and pulls on the base of the turbo pump The LED bar graph on the front of the Mini SEM displays the vacuum level in the chamber When the bar graph is at its limit the system will beep indicating it is OK to turn on the high voltage This process takes about 2 3 minutes When the system is powered off the chamber will stay under vacuum Pressing the exchange button will vent the column allowing for a sample change Mount the sample on a standard pin stub with proper grounding techniques Use Carbon tape or paint to adhere the sample to the stub If the sample is not conductive sputter coat the sample with Gold Carbon or Palladium This will increase the conductivity of the sample which will prevent the sample from charging Charging occurs when there is a buildup of electrons on the surface of the sample which cannot discharge to ground The symptoms are very bright or dark areas on the acquired image Using proper sample preparation techn
35. nification focus contrast and brightness will have an immediate effect on the display The viewing area on the LCD is approximately 640 480 pixels This is only for initial viewing the acquired image resolution is much higher Fig 18 Image Window Status Bar The status bar contains the user information high voltage and micron bar 33 de SEC 4 Image Adjustment Scanning Electron Microscope SNE 1500M This area controls the Focus Magnification and Scan Rotation of the image Q Cw EX Focus Control Knob Manual focus control by left mouse click and dragging the mouse left or right Auto Focus Allows computer control of the image focus Reset Sets focus to mid scale Buttons Allows for very small focus adjustments Magnification Arrows Controls the image magnification up or down from 20x to 25 000x Left click the magnification arrows to increase or decrease your image magnification Scan Rotation Controls the electronic image rotation Left clicking the CW or CCW arrow buttons will cause the image to rotate by 1 degree The rotation degrees will be displayed it the center window This should not be confused with stage rotation 34 W SEC 5 Scan Select Scanning Electron Microscope SNE 1500M The select scan buttons control the rate and resolution of the preview and acquired images Fast Scan Select Slow Scan Stop fa Fast Photo Slow i Photo 35
36. ntion to the size of the sample Do not allow the sample to contact the column pole piece secondary detector or the EDS detector if an EDS detector is installed Major problems can occur with the column or the EDS detector if the sample hits them O Ensure the chamber door is closed completely before evacuating the column 26 SEC Scanning Electron Microscope SNE 1500M V Program Configuration 27 SEC Scanning Electron Microscope SNE 1500M EB SEC NanoEye Mini SEM COR File System Tool Help Focus Contrast Brightness Fig 9 Main Screen Image adjustment Scan Select Adjusting light and shade Adjusts scan rate and size brightness of screen Magnification Image Window Adjusts image Magnification and Image acquisition area Electronic Scan Rotation F Tool Bar Mind Manual and Automatic Image Focus Start Scanning Open Image Cross Point Image Acquisition Print Main Menu Filament Information Configuration Sets High Voltage Secondary Detector Emission Current Meter Parameters amp Beam Alignment Tools Cross Point Measurements Microscope and Scanning Adjustments 28 SEC Scanning Electron Microscope SNE 1500M 1 System Menu O Configuration Left click on the configuration menu to select the predefined acceleration voltage that best fits your samples requirements If the acceleration voltage is changed several set points are also changed that de
37. occurred in S W since system was not successfully ended Cable between PC and SNE 1500M is not correctly connected O Action Check if plug for power supply in PC is pulled out from socket Check if battery in PC was discharged Check if cable connection between PC and SNE 1500M Check if SNE 1500M turns on Check if unnecessary program is being run Check if PC is infected by virus Vacuum system Defect O Phenomenon Beeps are sounded without stop from board in the middle of vacuum setting O Cause Air Hose between Rotary pump and SNE 1500M is not correctly connected There is trouble in Rotary pump There is trouble in turbo pump Door is not fully closed O Action Check Air Hose connection between Rotary pump and SNE 1500M Firmly Close the Door Replace oil in Rotary pump 65 SEC Scanning Electron Microscope SNE 1500M 3 In case of requiring maintenance and repair Filament snap L Phenomenon Image is not displayed and noise is heard after running program O Cause Filament was snapped O Action Replace filament 66 SEC Scanning Electron Microscope SNE 1500M 4 Periodical Checkup List Checkup Period UNIT Item Checkup and Repair Details Day Week Month Year Filament Screen O Align Column Aperture Screen O contamination Abnormal noise vibration O Rotary Pump Vacuum Pump Oil O System
38. on A tungsten filament is heated to approximately 1800K in a high vacuum An electrostatic field is used to pull the electrons from the heated filament In order to achieve this a high voltage is placed on the filament and the Anode is held at ground As the electrons leave the filament tip the Wehnelt cap is used to focus the beam towards the anode A hole in the anode plate allows the beam to travel down the column liner towards the sample A series of apertures and electromagnetic lenses refine the beam to a small diameter The beam is then shaped by Focus and Stigmator coils which reduce it to a finely focused dot A set of scan coils control the X amp Y raster on the sample When the electron beam hits the sample a few things happen Some of the electron beam gets scattered back out of the sample as backscattered electrons Some interact with the surface of the sample they are called secondary electrons These electrons are too weak and must be pulled away from the sample with a high voltage attached to the secondary detector The electrons then hit a phosphor plate which converts them to light The signal is amplified and used as a display signal This signal is then adjusted with brightness and contrast amplifiers then digitized for viewing on a PC w SEC Scanning Electron Microscope SNE 1500M Scanning Electron microscope structure Scanning electron microscope is made up the figure shown as Figure 1 Electron that was accelerated by elec
39. ple occurs All of these interactions are very close to the surface of the sample Some of these secondary electrons scatter towards the surface If the energy of these electrons is stronger than the energy binding them to the sample they may leave the sample as secondary electrons These secondary electrons are weak in energy and need to be pulled away by a high voltage on the secondary detector The secondary electrons carry with them a lot of surface detail and are the main viewing signal on the Mini SEM How to detect Secondary Electron Detection The desktop Mini SEM uses an E T secondary detector for image acquisition The detector was developed by Everhart Thornley in 1960 It is capable of detecting secondary and backscattered electrons In the secondary mode a positive bias voltage is placed on the Faraday cage of the detector This draws the weak secondary electrons to the detector and to the phosphor plate The electrons that collide with the phosphor plate generate a small light signal that is amplified and converted to an electrical signal The backscatter mode allows the collection of a backscatter electron signal by removing the positive voltage from the Faraday cage Due to the position of the E T detector and its fixed geometry and the fact that the stage cannot tilt towards the detector the backscatter mode is limited Special 45 degree sample stubs and geometries need to be aligned with the detector to view a backscatter image
40. rease the contrast or gain of the image Left click the plus or minus signs will change the contrast by a very small amount Auto Clicking on the auto button allows the computer to adjust the contrast and brightness of the image The 256 gray scale image can be multiplied and shifted within a 0 to 4096 window Noise Left click on the noise filter to increase pixel averaging This filter will lessen the noise by taking multiple reads at each pixel then averaging the data to that pixel 36 SEC Scanning Electron Microscope SNE 1500M VI Installation Instructions xx J _ 37 SEC Scanning Electron Microscope SNE 1500M 1 Installation Configuration O Install the unit on a strong table top to reduce any vibration O Install the rotary pump on the floor as far as possible from the column O Install the PC to the right of the column leaving access to the chamber door O Do not put any device that generates vibration or electromagnetic waves near the unit 38 w SEC Scanning Electron Microscope SNE 1500M 2 Connection of the Unit Rear of Notebook PC Power Transformer Rotary Pump Fig 22 Components Connection 1 Connect the A C power cable from the back of Mini SEM to the Power Transformer 2 Connect the supplied vacuum hose to the vacuum hose nipple on rear of the Mini SEM The other end of the hose goes to the rotary pump 3 Connect the power cable of the rotary pump to Mini SEM connector
41. ry electrons are emitted from the sample and are then collected by the secondary electron detector The secondary electron signal is digitally captured processed and ported through a USB connector to a PC for viewing The PC software also controls the column settings The column settings are the magnification high voltage condenser lens vacuum and other microscope setting The microscope was designed with an intuitive easy to use software interface Automatic and manual operations are completely software driven The only manual adjustment is changing and aligning the filament Also cleaning the column liner and replacing the apertures The Mini SEM has a 3 axis manual stage that is controlled by the three knobs on the stage door SEC Scanning Electron Microscope SNE 1500M 2 Features Features O Fast and easy to use electronic microscope O Table top size O Automatic and manual adjustments O Fast sample exchange At 3 minutes after sample exchange image observation is ready O Intuitive Graphic User Interface O Providing images of high resolution and high depth Application O Life Science O Food O Cosmetics O Healthcare O Pharmaceutics O Textiles O Materials Science O Semiconductor CO Education SEC Scanning Electron Microscope SNE 1500M 3 Basic Principles of Scanning Electron Microscopy Optical Microscope Limitations An Optical Microscope is an analytical tool that uses visi
42. sically if you have an emission current above 40UA at 20kv then there should be some type of image on the display HY cable Vacuum E Port Gun Alignment Knobs Fig 57 Gun Alignment knobs Fig 58 Gun Alignment knobs top view HV off Emission meter reads 000uA Minh SEM HV on Filament not saturated Emission D m r3 pa meter reads 40uA HV on Filament Saturated at 20kv Emission Fig 59 Emission Meter meter reads approximately 80uA 58 w SEC Scanning Electron Microscope SNE 1500M 8 Checkup and Replacement of Anode sleeve Aperture Anode and sleeve are optical distance of electron beam Contaminated matter may be evaporated in vacuum by high energy In case of critical pollution the parts should be replaced but in ordinary cases they can be used by washing after checkup Aperture is contaminated by evaporation colliding to electron through long time using Contaminated Aperture can be identified by naked eye since the hole in the center of it is blocked up or the circumference of hole is discolored Replacement of Anode Sleeve and Aperture Break Vacuum Turn off power of the front Turn off circuit breaker at the back Exchange Filament and open exchange cover Break down Electron Gun Replace Sleeve Assemble Electron Gun Exchange Filament and close exchange cover Fig 50 Replacement of Anode Sleeve and Aperture 59 w SEC Scanning Electron Microscope SNE 1500M Assembly of Anode
43. tron gun is made to small spot through focused lens and vector is adjusted to go to the specific point of time through object lens Electron that reached to sample generated various signals by colliding to sample Detector to detect Second Electron SE in the signals is attached to SNE 1500M The signal passed through detector is displayed on monitor being converted to the image to be seen by people through signal processor Electron Gun a A Objective Lens EY r el Fig 1 SEM Schematic View Generation an Electron Beam The Mini SEM comes standard with a Tungsten filament The filament is part of a gun assembly which consists of a filament Wehnelt cap and an anode plate An electron beam is produced through thermionic emission The filament is heated in a vacuum and a high voltage from Ikv to 30kv is applied The filament heat is increased until the electrons can overcome the work function energy barrier Ew This allows the electrons to leave the filament wire and head towards ground The Wehnelt cap controls the flow and focuses the beam towards the Anode The beam travels down the column liner tube where an assortment of electromagnetic lenses and spray apertures reduce and refine the beam into a very small spot SEC Scanning Electron Microscope SNE 1500M Generation of a Secondary Electron When the accelerated electron collides with the sample an inelastic scattering of the electron in the sam
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