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.
  • Power switch to On.
  • Enter BIOS Password.
  • Run LEO UIF.
  • Select user directory.
  • View -> DataZone.
  • Check vacuum.
  • No vacuum / right pulldown says At Air:
  • Vacuum in e-4 torr range:
  • 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. NOTE: This URL is only available on PS:One's internal network.
    • 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.
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