IR Thermal Microscope (QFI) - Standard Operating Procedure (HotSpot/ThermalEmission)

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Operating Procedure for Hotspot and Thermal Emission modes. Thermal Emission mode measures an actual temeperature, whereas HotSpot just shows the pixels with heat, without temperature calculation, and is simpler to run. 

Danger: DO NOT damage the probe needles nor microscope objectives.  If you are not careful, you can easily crash the microscope objective into the probe needles!

The microscope objectives may be impossible to replace, and the probe needles are setup for Very low spacing between the microscope objectives, needles and sample stage.

It is better if you can practice how to use a Probe Station in your own lab, or in the NanoFab before using this system. 

If you think the needles got bumped or damaged, please notify staff ASAP so we can take a look and replace them.
  1. Contact staff for filling the Liquid Nitrogen ("LN2") dewar the day before your planned usage.
  2. Use the small ~2 Liter container to fill LN2 for the MWIR microscope
    1. You can tell when it's full when LN2 droplets spill out from the sides of the funnel's foam insert.
  3. Turn on the Temperature Controller power and the System Controller (turning the key to 1 and press the red Power button)
  4. Turn on the computer by clicking on the rocker switch once, behind the right-side panel. Ensure computer monitor is on. Motion Control will open automatically. Note the Z (focus) setting at Maximum speed 100%! Reduce to 25-50%.
  5. Set up the electrical connection for the probes through the BNC cables according to your device, and turn on the Keithley power supply/SMU.
  6. Move the stage all the way forward with the front-most knob, put the sample on the stage, then move the stage back under the backmost microscope. ENSURE no probe needles are down, nor collide during this process! Do not touch the probe needles with your sample or tweezers.
  7. Move the probe manipulators to the right position to contact the device. CAREFUL - the magnetic bases can be hard to move, ensure nothing collides when making large movements.
  8. Keep the temperature range the same, at "Low" (highest sensitivity).
  9. on the Turret tab: NIR is visible camera. MWIR is IR camera.  Start on 1X Macro. Hit Go to switch to the Macro camera
    1. Takes a few minutes while the system changes motorized objectives, lenses and cameras.
  10. Once done, click on the Video button.
  11. Go to the Light tab, to adjust illumination intensity.
  12. Find the probe & device in the microscope, then center it by double-clicking on it.  
    1. Move the stage to put the Device under the Probe needle.
    2. Move the camera with "Motion Control" or double-clicking on the screen.
  13. Hit Stop, it will freeze the image.
  14. Switch to the 5X NIR (visible) on the Turret tab and click on Go to switch the microscope and the lenses.
  15. Hit Video and go to the Light tab, change the illumination to a proper power. Don't Saturate the camera (white).
  16. Move the z up first and observe the stage to check for collisions/safety. Then set a slow speed for Z movement 25%. Slowly move the z down until see the probe in the center. Then continue moving down until sample is in focus. KEEP watching the stage/objectives to ensure nothing collides.
  17. Put the probe needles down to make electrical contact to your device and check it with the Keithley by looking at the current with the safe low voltage. Then turn off the Keithley output.
    1. Do not adjust the stage position now that the probe needles are down!
  18. Switch the turret to MWIR (2x or 5x) and start imaging again use Focus IR to look for the hotspot.
  19. If using ThermalEmission: Click "Background" and watch the stage carefully to ensure the Shutter doesn't collide.
  20. Turn on and off the Keithley output to look for bright pixels.
    1. You may need to adjust your electrical drive and microscope position with Motion Control. NOTE the motion speed setting, 25-50% is safe.
  21. When you are ready to acquire a Hotspot image:
  22. Set Max Averages to 20.
  23. Turn on Reference imaging with Keithley output off.
  24. Press Average [OFF] button to start acquiring the reference image. When it’s done
  25. Click Thermal Emission, turn on Keithley output, click the Average button to acquire the thermal image.
    1. This is a difference image, subtracting the Live image from the Reference Image, which assumed to be 40°C.
  26. Adjust the threshold on the image to alter the transparent pixels. Also, under Analyze, look at histogram, or look at LineTrace by drawing a line, and click LinerTrace again.
  27. For saving data: Hit the [Printscreen] button on the keyboard. Then open Paint.exe on the Start Bar. Then go to EDIT and Paste the screenshot to save it.
  28. Save the file in your Nanofiles folder.
  29. In HotSpot/ThermalEmission: Go to FILE and Save image or Text file of the temperature date, or for region of interest (ROI, eg. LineTrace etc).

Ending your Session

  1. Go to file and quit.
  2. Unload the sample:
    1. lift the probes.
    2. Move the stage all the way forward, after passing the probes.
  3. Turn off the Lamp inside the dark box.
  4. Please keep supplies and tweezers inside the dark box.
  5. Sync the data with the "Nanofiles Sync" program on the desktop.
    1. Optionally check that the data is available on your laptop.
  6. Turn off the computer before you leave (Start > Shutdown).
  7. For System Controller, Turn the key to 0 to turn it off.
  8. For Temperature Controller, turn off the power switch.
  9. Close the dark box.
Author: Demis D. John, 2025.  Thanks to Tongxin Han for assistance.
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