Leica S430 Scanning Electron Microscope Operations Checklist
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OVERVIEW
The SEM Operation checklist in Section 2 contains step by step instructions to operate the SEM. Note that these steps reference Procedures described in #PROCEDURES. These are listed in alphabetical order. For troubleshooting, see TROUBLESHOOTING.
SEM OPERATION
STARTUP
- Verify power switch in Standby, vacuum pumps running.
- If not, go to #POWER / VACUUM TROUBLESHOOTING.
- Power switch to On.
- Enter BIOS Password.
- Run LEO UIF.
- Select user directory.
- View -> DataZone.
- Check vacuum.
- No vacuum / right pulldown says At Air – follow #PUMP CHAMBER procedure.
- Vacuum in e-4 torr range:
- Follow #VENT CHAMBER procedure.
- Wait 3 minutes for chamber to fully vent.
- Follow [[#PUMP CHAMBER}} procedure.
- Vacuum in e-5 torr range or better: Proceed.
- Vacuum in e-4 torr range:
- Set X to 50.00
- Set Z to 31.0 (or less if a tall sample is in the chamber)
- Set Tilt to 0
BEAM ON
- Press Stoplight icon.
- Wait for image.
- Adjust Brightness. (Contrast / Brightness icon)
- Set EHT appropriate to sample.
- Locate sample.
- Focus. (see #FOCUS procedure)
- After 5 minutes since adjusting EHT have elapsed, follow #FILAMENT CURRENT procedure.
- If an aperture other than #2 is required, follow #CHANGE APERTURE procedure. NOTE: #2 aperture is usually the best aperture, so changing apertures isn’t necessary.
OPERATION
- Move sample as required to center item of interest.
- Zoom (Magnifying glass icon, left mouse button) as required.
- When zooming, stop to focus (see FOCUS procedure) frequently.
- At very high magnification, move field of view with beam shift:
- Beam -> Stigmation..
- Click Beam Shift.
- Drag scroll bars or position dot as needed.
- Press HOME key to undo all beam shift.
- Consider noise reduction (see #NOISE REDUCTION procedure) if necessary prior to exporting images.
- Export images as needed. (see #EXPORT IMAGE procedure)
SHUTDOWN
- Change to aperture #2 and align aperture if you previously changed to a different aperture. Follow #CHANGE APERTURE procedure.
- Set X to 50.00
- Set Z to 31.0 (or less if a tall sample is in the chamber)
- Set Tilt to 0
- Single click upper left box.
- Click SEM Shutdown.
- Shutdown: Save Operating Conditions? Click No.
- Follow #PUSH IMAGES procedure if you saved images.
- Double click upper left box of Program Manager.
- Click OK.
- At DOS prompt, click Standby power button.
PROCEDURES
ALIGN APERTURE
- Zoom in to 1000x.
- Center on noticeable object or feature.
- Follow #FOCUS procedure, including anti-hysteresis. (F2)
- Reduced raster (Monitor icon with square) - size and drag to cover noticeable object or feature in question.
- Scan rate to fastest. (Click Fast Forward icon 3 times)
- Click Focus Wobble icon. (Icon with red half sine wave at bottom)
- Adjust X and Y aperture controls, one at a time, to cancel movement.
- Click Off button in focus wobble box.
CHANGE APERTURE
- Beam -> Apertures.
- Select aperture number.
- Click OK.
- Turn Y aperture control to select proper aperture:
- Turn knob IN for 1, OUT for 3
- E.g. to change from aperture #2 to #1,turn clockwise
- Adjust Y for maximum brightness.
- Follow #ALIGN APERTURE procedure.
EXPORT IMAGE
- File -> Export TIFF
- Click Freeze if image not already frozen.
- Click OK to export.
- Image -> Unfreeze
FILAMENT CURRENT
- Scan rate to fastest. (Click Fast Forward icon 3 times)
- Click light bulb icon.
- Left mouse button – adjust I(M) for 1st peak.
- Lower Brightness (Contrast / Brightness icon) if too bright to differentiate peak, then continue adjusting filament current.
- WARNING: Increasing filament current substantially past 1st peak shortens filament life.
- NOTE for 2nd peak operation:
- Possible IF AND ONLY IF you can identify a well-defined 1st and 2nd peak.
- Increase I(M) current SLOWLY. Note that a falling off after 1st peak and sharp rise to 2nd peak should be identifiable when increasing filament current.
- If these features are not visible within 0.1A to 0.2A beyond 1st peak, STOP. DECREASE FILAMENT CURRENT and operate at 1st peak only.
- If well defined 2nd peak is visible, adjust for maximum brightness such that ANY decrease in current decreases image intensity. NOTE: Any operation above this point even more drastically shortens filament life and must be avoided.
FOCUS
- Consider anti-hysteresis (F2) after major parameter changes. (zoom changes
- Consider reduced raster. (Monitor icon with square, size and drag as appropriate)
- Set appropriate scan rate. (Fast Forward / Rewind arrow icons)
- Select Focus. (Magnifying glass icon)
- Middle button: drag to set Working Distance and focus image.
- Full screen raster. (Monitor icon without square)
- Set appropriate scan rate.
- NOTE: The image noticeably shifting during focus adjustment indicates the aperture is not in alignment. Follow #ALIGN APERTURE procedure.
- NOTE: Auto-focus can be done via F key but it can sometimes make focus worse.
NOISE REDUCTION
- Scan rate to slowest. (Click Rewind icon 3 times)
- Image -> Noise Reduction..
- For Frame Mode, which scans at the same rate but averages multiple successive frames, making the image clearer:
- Increase “Frames to average” slider.
- Click Frame Avg. button.
- For Line Mode, which scans each line repeatedly and averages each line:
- Increase “Line Avg.” slider.
- Click Line Avg. button.
- After making adjustments, wait for scan to pass the bottom of the screen and, when visible at the top, click Freeze mode / At end button.
- When blue square appears in the lower right corner of the screen, the image is frozen and can be exported. Follow EXPORT IMAGE procedure.
- Restore both sliders to the left and click Frame Avg. button.
- Close Noise Reduction window.
- Image -> Unfreeze.
PUSH IMAGES
- WARNING: Only do this when LEO UIF software is shut down!
- Double click “Push [Your Name]” from list of icons in User Operations window.
- Black screen and lots of scrolling text: Success.
- Download images from ftp://semsrv.pumpingstationone.org to a laptop or other device.
- Double click “Delete [Your Name]” from list of icons in User Operations window. This deletes the images from the SEM hard disk.
- NOTE: No automatic delete happens on the SEM hard disk. Users must delete images once they have been safely transferred off the SEM.
- Images will be deleted automatically from the server in two weeks.
- OR black screen and one line of text, and everything has paused: Failure. NOTE: This failure mode is fairly common after operating the SEM.
- Hit Ctrl-Alt-Delete. At blue screen, hit Enter.
- Shut down Windows as usual.
- At the DOS prompt, Ctrl-Alt-Delete to reboot.
- Enter BIOS Password.
- Repeat this procedure WITHOUT LAUNCHING LEO UIF.
PUMP CHAMBER
- Press V (if vacuum window not open).
- Click Pump.
- OK to start beam once vacuum stabilizes at or below 6e-5 torr.
- Close Vacuum window.
- If vacuum does not reach this level in 20 minutes, report to mailing list.
VENT CHAMBER
- Press V (if vacuum window not open).
- Click Vent.
TROUBLESHOOTING
MOUSE TROUBLESHOOTING
- In case of erratic mouse movement:
- Lift mouse, shake it, blow into track ball
- Shift the cord around.
- If mouse is stuck changing something (magnification, focus, brightness, contrast, etc.) when the button is no longer held down:
- Press Escape.
- Click anywhere else within the image.
POWER / VACUUM TROUBLESHOOTING
- If Off light is illuminated:
- SEM likely lost power. Report loss of power to mailing list.
- Press Standby.
- Wait 30 seconds.
- Press On.
- Proceed as normal, but follow #PUMP CHAMBER instructions.
- If no lights illuminated:
- If the vacuum pump is running:
- Bulb likely burnt out. Report to mailing list.
- Press On, proceed as usual.
- If the vacuum pump is not running:
- Likely a power problem or a blown breaker.
- STOP. Report to mailing list.
- If the vacuum pump is running: