JEOL 7800F

The JEOL 7800F SEM is located in the basement in the room K08. The tool has a primary and a supporting Caar - Petur and Nader, respectively. The SEM is equipped with the following detectors:

• an Inlens detector, referred to as the UED (Upper electron detector)
• an SE2 detector, referred to as the LED (Lower electron detector)
• a back scattered electron detector, BSED
• an EDS (Energy dispersion X-ray detector)

The following manual is split up into three workflows:

• Loading your sample
• Beam conditioning
• Unloading your sample

Additionally, the sections are divided into basic, intermediate and advanced parts.

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Here we go:

General Notes

Before loading your sample, one needs to choose the appropriate sample holder. There are 4 sample holders, and their dimensions determine the maximum sample size, working distance, and tilting one can use.

1. 12.5mm at 15WD 70 degrees, 10WD 50
2. 25mm - Tilt Max 50
3. 12.5mm Cross Section Holder
4. 25mm Cross Section Holder

Loading the sample

• Mount your sample on the correct sample holder using carbon tape or using a clip.
• Measure the offset your sample makes above the holder. One can recess their chip into the stage to reduce the chips offset to 0mm.
• Check that there is no sample in the chamber (In the instrument schematic in the JEOL software, the white stage line should be in the unload position).
• Vent the SEM chamber by holding down the Vent button on the side of the load lock until it starts to blink (1sec).
• Release the chip holding the door in place directly after letting go of the button to allow for a smoother transition. Open the door once the Vent button has stopped blinking.
• Place sample holder in the load lock tray. With one hand on the back of the door, grip the sample holder with two fingers and slide into place. Take note that orientation matters, and the arrows on the sample holder correspond to the direction it should be loaded.

• Close the Load Lock door and latch the door shut.
• Evacuate the chamber by pressing and holding the load lock button on the side of the load lock until it starts blinking.
• Wait until the chamber has evacuated to the order of 10-2 Pa. There will be three hisses denoting the closing of the turbo pump value, opening the load lock door, and opening the turbo pump value again.
• Special care needs to be taken when loading the sample into the chamber. The loading arm is Never to be rotated or tilted to sides (only up and down directions), and the metal portion of the loading arm is never be touched.
• Begin by pulling the loading arm directly down to a horizontal position. The loading arm will be pulled into place. It has the ability to be moved up and down by a few degrees.
• The loading arm does not go into the chamber at a perfectly horizontal angle, one needs to slightly play with the angle, find the correct orientation, and push the loading arm into the chamber.
• Push the loading arm all the way in until you feel the sample is gripped by the stage.
• Pull out the loading arm all the way out. The loading arm will click twice on its journey outwards, and will be pulled out far enough when the upper portion of the loading arm extends past the two white arrows.
• Keeping tension on the loading arm pull the loading arm up into its upright position.

• Once the sample is in place, a box will prompt in the JEOL software. It will ask for you to select your sample holder and your offset you measured before. This will ensure the e-gun does not run into your sample.

Beam conditioning

• When you load your sample into the chamber, the camera will automatically take a topview photo of your sample on the stage. Navigate onto your sample by right clicking on the sample location (Take image rotation into account).
• Choose desired Voltage value.
• Choose desired probe current (higher current is advised for high tilt and high view distances)
• Enable the LDF mode, which is a large depth of field mode. This mode is useful for rough conditioning.
• Find a suitable object or the corner of your sample and use the rough focus (right click on the focus button) to get decent focus.
• Zoom in and roughly focus and stimgate.
• Switch the LDF mode off and zoom onto an object at x 10-20k. Focus and Stimagate.
• Enable the wobbler, and use the same nobs as the stigmator to correct for the aperture alignment. This is done by trying to reduce the movement of your object.
• Turn off the wobbler and refocus and stimgmate.
• Voila ́ you are ready to image

Unloading your sample

• To unload your sample click on the Specimen Exchange button in the software. This will cause the SEM to prepare the stage to be unloaded, by untilting, unrotating, moving the stage to z = 40mm, ect.
• Once this procedure is complete the Specimen Exchange button will turn green and the sample is ready to be unloaded.
• Pull the loading arm down, and gently push it into the SEM chamber. Push until you have transferred your sample onto the loading arm. Pull out your sample without rotating the arm.
• Press and hold down (2 s) the Vent button on the side of the Load Lock.
• Open the Latch on the side of the loadlock to help release the pressure.
  • This is to prevent the overpressure from popping the O-ring out of groove.
• Once the Vent button stops blinking your sample is ready to be unloaded.

Resources

Invitation to the SEM world

A guide to scanning microscope observation (JEOL)

Hitachi SEM user guide (2007)