JSM 6060 LV SCANNING ELECTRON MICROSCOPE STANDARD OPERATING PROCEDURES

Transcription

1 JSM 6060 LV SCANNING ELECTRON MICROSCOPE STANDARD OPERATING PROCEDURES

2 RULES All users must go through a series of standard operation procedure training. For more information contact: Longlong Liao Teaching Assistant 206 Wilhelm Hall Ames Laboratory lliao@iastate.edu Phone: (515) All users must read and UNDERSTAND this standard operating procedure manual. All users must FILL in the logbook for every usage. No one is allowed to tamper with the safety measures, interlock or vacuum systems. ANY USER WHO SHOWS DISREGARD FOR THE SAFETY PRECAUTIONS WILL HAVE THEIR SEM PRIVILEGES REVOKED. You should reserve time prior to using instrument. To schedule a session visit: Please be advised that you must use your scheduled time. You can delete a previously scheduled period 24 hours in advance with no penalty. If you schedule an SEM session and do not attend, you ll still be charged for the scheduled time. You can check out the room key from Karen Knight (2220 Hoover Hall).

3 Don t forget to return the keys in time. After-hours privileges will only be given after the user has acquired at least 30 hours of SEM time beyond training and has demonstrated competence in operating the equipment. After-hours privileges require special permission from Scott Chumbley. Please save your pictures in your directory on the ftp server. Do not save any pictures in SEM or EDS computers. Any data saved on the SEM or EDS computers will be deleted. You can reach your saved data from The user is responsible for cleaning the sample holders and sample stages after every usage. All problems and concerns must be reported to the lab supervisor immediately. Please see the contact list for phone and information.

4 Three Options to Move the Stage 1) First Option Joystick 2) Second Option Mouse 3) Third Option Stage Tab

5 Standard Operating Procedure for JSM-6060 LV SEM -SECONDARY ELECTRON IMAGING Specimen Preparation 1. Start with wearing gloves. 2. Choose one of the main sample holders and proper inset(s) for this holder. 3. According to your specimen conditions (irregular shape, nonconductive, powder, oily and dirty specimen, etc.) you may want to use copper or double side sticky carbon tapes, liquid carbon paint, carbon paste, gold or carbon sputtering, ultrasonic cleaning methods. If you are not sure which method fits best for your specimen, contact your lab supervisor (see contacts). 4. Please prepare your specimen in the specimen preparation area (Fig.1). Under no conditions are you to remove any specimen preparation tools from the SEM laboratory. 5. If your specimen has an irregular shape, draw a schematic of its cross-section and determine the highest position of the specimen. You can put a mark (like a small portion of carbon tape) at the highest position. This will help you while you are changing the working distance.

6 Fig. 1 Specimen preparation area and drawers showing preparation tools. Login to Computer 1. Start by filling out the log book. 2. Log in to the computer (ctrl + alt + del). If this will not allow you access to the SEM computer please first hit ctrl + alt Type your user name and password; do not select dial-up connections. 4. Double click on JSM 6060 icon and login using your ISU account. You should type a correct account number. 5. Wait until you see the SEM console on the screen (This takes app. 1 minute). Loading the Specimen 1. Change your gloves. Your gloves, specimen holder and specimen should be clean and dry before you load your specimen.

7 Figure 2. Z-height adjustment knob (at lowest position). 2. Check the Z-direction (Fig.2). Make sure that the stage Z is set to its minimum position so your specimen won t hit the lens or BEI detector. If the Z was not left in this condition, please note in the logbook. 3. Press and hold the VENT button (Fig.3) for 2 seconds until the button lights. Fig. 3 VENT and EVAC buttons.

8 4. Wait until VENT light stops blinking. 5. Pull the chamber towards you. 6. Insert the specimen holder onto the stage dovetail. (The flat side of the holder should be aligned with the dovetail) (Fig.4). Fig. 4 Specimen holder in the chamber. (The flat on the specimen holder goes in first) 7. Check the distance between your specimen surface and the lens (or BEI detector). Your specimen should not touch any of them. 8. Slowly close the chamber drawer. 9. Hold the door while activating the pre-pump sequence by pressing EVAC button (Fig 3). Hold the button for 2 sec until the button lights and the pump starts. 10. Wait until the HT READY indication appears in the HT icon on the screen. Typical Operation 1. If you previously created a username, click on the user tab and chose your own username and click OK. (If not you can use the general user tab.) 2. Check the scan rate, signal, magnification, and spot size before you hit the HT

9 button. You can select a fast scan (Scan 2), SEI signal, low magnification (X30 or lower), and spot size for starting. 3. Hit the HT Ready button. 4. If the screen is all dark or white, first try the ACB (Auto Contrast and Brightness) button to set a proper level of contrast and brightness. 5. Use coarse/fine focus to focus your sample. 6. If you are authorized to change the Z stage level, find the highest position of your specimen using your drawing and/or marker. Focus on this spot before changing Z. Be mindful of the actual distance between this spot and the lens at all times. If you are not authorized to change Z-stage level, consult the instructor. 7. Take a picture on Scan 2 or Scan 3 by clicking the FREEZE button. (Scan 4 automatically freezes). Use the SAVE button to save your picture in your folder. If Necessary 1. If the image shows directionality of focus (Fig. 5), you should correct astigmatism. This is only apparent if you are at a high magnification (> 3000x). Fig. 5 (a) Astigmatism corrected, b) Directionality seen by going over focus.

10 2. Using the FOCUS control (mouse or knob), go over and under focus while looking for directionality in the image at high magnification (> 3000x). 3. Obtain the best focus. (The image may not be sharp but has no directionality). 4. Adjust the STIGX and STIGY controls (mouse or knobs), as if they were focusing controls. Try to obtain a sharp image. 5. Check the focus and repeat steps 2-5 if necessary. If Necessary 1. If the image shifts while focusing (Fig. 6), you should align the Objective Aperture. Fig. 6 (a) in focus image with Objective Aperture is aligned well, (b) over focus image with bad Objective Aperture alignment showing a slight image shift.

11 2. Set spot size to ~30 and center a feature with good contrast on the screen. 3. Increase your magnification to ~10,000X. 4. Adjust Contrast and Brightness, and Focus your image. 5. Turn on the OL Wobbler (Under Tools menu). 6. If the image moves back and forth, adjust OL aperture knobs (Fig.7) to minimize image shift. These knobs are sensitive. Only small adjustments are necessary. Fig. 7 OL Wobbler knobs 7. Turn off the OL Wobbler. Shut Down 1. Check the scan rate, signal, magnification, and spot size before you hit the HT button. You should select Scan 2, SEI signal, low magnification (X30 or lower), and spot size.

12 2. If you changed the Z-direction stage, find the highest position of your specimen. (Use your drawing and/or marker to determine it properly). Focus on this spot and carefully decrease the Z-stage to its minimum position (Fig.2). 3. Press HT button to turn off high tension. 4. Hit EXIT to close the software. 5. Wear your gloves. 6. Press and hold the VENT button (Fig.3) for about 2 seconds until it lights. 7. Pull the chamber towards you. Check the distance between your specimen surface and the lens (or BEI detector). Your specimen should not touch any of them. 8. Slowly close the chamber drawer. 9. Hold the door while activating the pre-pump sequence by pressing the EVAC button (Fig 3) until it lights and begins blinking. 10. Log out from the computer. 11. Finish writing your logbook entries. 12. DO NOT LEAVE the lab until EVAC light stays lit. Specimen chamber should be kept under vacuum. 13. Clean up your mess and put any specimen preparation tools in order.

13 Low Vacuum Mode 1. Set your working distance to 8 mm 12 mm for imaging. If you are not authorized to change Z-stage level, consult the supervisor. Be mindful of the actual distance between this spot and the lens at all times. 2. Press LV button. Low Vacuum Control tab (Fig.11) will appear on the screen. Fig.10 Vacuum Control Buttons 3. Click on the target pressure you want to reach. (133 Pascal = 1 Torr) (Fig.11) Fig.11 Low Vacuum Control 4. In low vacuum mode image will only be BEI. Use SHADOW mode to emphasize topography.

14 If charging occurs: 5. (a) Adjust air to determine the optimum pressure when charging stops. Too much air may result in too little signal. (b) Adjust the probe current (spot size). Too low a probe current may result in too little a signal (c) Adjust your accelerating voltage. Too low a kv may result in too little a signal. Fig.12 JEOL digital control panel at LV mode Shut Down 1. Switch your vacuum back to High Vacuum.. 2. Check the scan rate, magnification, and spot size before you hit the HT button. You should select Scan 2, low magnification (X30 or lower), and spot size. 3. Follow normal sample removal procedure (See Secondary Electron Imaging Mode).