Leica S430 Scanning Electron Microscope Operations Checklist

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.
• 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.