Operation Procedure for Phillips XL30 ESEM

Transcription

1 Operation Procedure for Phillips XL30 ESEM The ESEM will be left in the ON state when not in use. The chamber will be at high vacuum, filament on, stage at home position, VAC and HT buttons lit, and monitor turned off. If these conditions are not met, make note of it in the log book. NOTE: When operating the ESEM, if you see any type of error message, make a not of it in the log book. There are many errors that will cause the system to turn off the diffusion pump, so check the VAC button whenever you see an error. If it is not lit then the diffusion pump is off. After making a note of the error message and clicking OK, if the error does not appear again (system returned to its normal state) you may turn on the pump by pressing the VAC button. You will need to wait for the diffusion pump to reheat to operating temperature. Before turning on the beam you will also need to press the HT button to enable high voltage. Important: the SEM computer hard drive should not be considered a back up storage space for your SEM images. Always make your own back ups and then delete all old images on the SEM computer. Go to the end of the procedure to see the Step by Step Operation Guide High Vacuum Operation: 1. Begin your entry in the log book by entering the date, your name, your PI or company name, the Operate current and the SEM session start time. 2. Swipe in to the SEM Start Card reader. 3. Open the Microscope Control software, Mctrl from the desktop. 4. Open the image database software, XL Docu from the desktop. a. Delete all old images in your XL Docu database. b. Click on the light bulb in the Always on top tool bar to toggle between Microscope Control and XL Docu. 5. In Mctrl click on VENT to vent the chamber. The chamber will fill with nitrogen. If the nitrogen cylinder is empty you may change the regulator over to the back up cylinder using the wrench on the cylinder rack. Always mark the empty cylinder with an X on the UCSD Storehouse ID tag and make a note that you changed the N2 in the log book. 6. Open the chamber door and load your samples. Make a mental note of where your samples are, how they are oriented and consider what areas you would like to examine. Remember, the chamber door will be to the left when viewing the SEM image on the screen. 7. If you plan to use the EDS detector, make sure you are aware of its position relative to your samples and make sure that the region of interest is not is not shadowed or blocked from EDS detector by some other part of your sample. 8. If you plan to use the BSE detector, slide it onto the bullet at the end of the pole piece and make sure that it is properly centered. Otherwise it will block the beam.

2 9. Close the chamber door (make sure it s all the way closed!!) and click on Pump. When closing the chamber door, be sure not to slam it shut. 10. When the chamber pressure reaches 1.3e-4mbar the vacuum status will read Vac OK. 11. The default microscope settings are: 10KV beam energy, SE detector, spot 3, TV scan rate averaging 8 frames. If necessary, choose the appropriate detector, beam energy, spot size and scan speed. These parameters can be changed after the beam is already on. 12. Select the desired navigation mode. a. Get mode will use the stage motor to move the scan frame location below 10KX. Above 10KX Get mode will shift the beam to move the scan frame location. When using get mode above 10KX, you may be prompted to allow automatic reset of the beam shift if it has reached its limit. b. Shift mode will shift the beam to move the scan frame and not use the stage motor. Shift mode is best used at magnifications above 30KX since the beam shift range is small. At low magnifications you will reach the beam shift limit almost immediately. You will here a beeping sound when the shift limit has been reached. c. Track mode will use the stage motor to move the scan frame and will not shift the beam. Track mode is best used at low magnifications since at high magnifications the stage motor steps become visible and are comparable or larger than the scan frame size. 13. To change the control panel on the right side of the screen click on Settings. The resulting drop down list shows the control panel display options. Within each control panel display option there are different sections which may also be expanded to access more functions and parameters. Do not press the Filament OFF button!! 14. In the settings control panel, turn on the beam by clicking the button that displays the beam voltage in the Beam portion of the settings panel on the right side of the screen. If the screen is too dark, increase the contrast and/or brightness until you see an image. 15. When you turn on the beam, the Confirm microscope focus pop up window will appear. Do not click OK until you have completed focus confirmation! The system does not know the height of the samples which are loaded in the chamber so, in order to avoid crashing your samples into the pole piece while adjusting the stage height, we must tell the system the maximum height of the samples that have been loaded. We do this by confirming focus at the tallest point of the sample: a. Drive to the tallest point of the samples you have loaded b. Press the right click button of the mouse and drag to the left and right to adjust the focus until the image is clear. c. Increase the magnification to 3000X or higher by pressing the + key on the number pad or selecting a magnification value from the drop down menu. Readjust the focus until the image is clear. d. Now the focal point of the beam is at the sample surface. The system knows the distance from the pole piece to the focal point of the beam and this is indicated on the databar as the working distance (WD), measured in millimeters.

3 e. Click Ok to confirm that the image is in focus. The value of the stage height Z will be replaced by the current value of WD. f. It is imperative that you focus on the highest point of the sample (+-1mm), otherwise you may crash your sample into the pole piece! 16. Set the stage height to 10mm. Now the location at which you confirmed focus will be 10mm below the pole piece. Zoom out and readjust the focus. 17. Drive to the region you wish to examine. 18. Secondary Electron Imaging techniques: a. Use TV scan rate averaging eight frames when imaging with the secondary electron detector. b. Careful attention should be given to the choice of beam acceleration voltage. Different materials will respond in different ways to the beam. Try a variety of beam energies, starting low, to see what gives the best image results. Keep in mind that the beam may damage certain materials. c. Each time you change the beam energy you may also need to adjust the other imaging parameters listed below. d. Adjust the brightness and contrast so that the image contains as many grey levels as possible. The ACB (Auto Contrast and Brightness) button may be used as a starting point. e. Increase or decrease the magnification using the + and keys on the number pad, selecting a preset magnification from the drop down menu or using the slider bar in the imaging panel. f. Adjust the focus by pressing the right click button of the mouse and dragging left or right. A good strategy is to focus the image at twice the magnification at which you intend to capture the image and then zoom back out. Once the image is in clear focus you can zoom out and the image will be in good focus at lower magnifications. g. As you adjust the focus, watch for the features of your sample surface to elongate in perpendicular directions. This indicates astigmatism. If the image simply blurs with no distortion when you adjust the focus in and out, the stigmator may not need adjustment. h. Before adjusting the stigmator you must be certain that the focus is as at the center point. You can identify the ideal position as the exact mid point between the elongation of the image features in either direction as you move the mouse left and right adjusting the focus. Use a round particle for this adjustment. i. To correct astigmatism hold the shift key, press and hold the right click button of the mouse. Green cross hairs will appear. First move the cross hairs in the horizontal (x) direction left or right. Watch for the image quality to steadily improve. If it worsens, move the other way. If you reach the edge of the screen and need further adjustment, release the right click button and while still holding the shift key, press the right click button again. This will reset the position of the cross hairs to the middle of the screen. Between each stigmator adjustment, readjust the focus as well. Repeat this procedure in the y axis. j. For magnifications above 70KX a smaller spot size such as spot 1 or 2 should be selected. At low magnifications a larger spot may be used. Try different spot

4 sizes to see which works best. When using small spot sizes slower scan speeds can increase the signal to noise ratio and make the image clearer. 19. Image capture: a. In TV scan mode the image can be noisy. To increase the signal to noise ratio and get a clear image it is necessary to use a slower scan speed. b. When you are ready to capture the image, press F2 for a single frame scan. c. To adjust the single scan rate, go to the Scan drop down menu and select Change. Select Single scan from the list of presets and set the desired line time and lines per frame. The normal settings for the single scan are 33.2ms line time and 2420 lines per frame. d. After the single scan is complete the image will be frozen. You can save the image by clicking on the file box button on the XL Docu Always on top tool bar. e. Unfreeze the image by clicking on the snowflake button to go back to TV scan and continue examining your sample. 20. End procedure: a. Turn off the beam. b. Go to the Stage drop down menu and select Home to home the stage. c. While the stage is homing, click Vent. d. While the stage is homing and the chamber is venting you can save your images to disc. Click on the light bulb in the XL Docu tool bar to toggle to XL Docu. e. Select all images captured today. f. Click on either the J to export your images as.jpeg files or the T to export your images as.tif files. g. Select the appropriate file path, click Ok. The images will be copied to the specified folder. Be sure to delete old images over time. h. Close XL Docu i. Copy your images to a USB drive. 21. Open the chamber door and unload your samples. 22. If you used the BSE detector, place it back into the holder. 23. Close the chamber door and click on Pump. 24. Close Microscope Control 25. Swipe the Finish SEM card reader 26. Finish your log book entry by entering the session end time. If you encountered any issues during your session, make a note in the log book. 27. Make sure the SEM console is not cluttered. Do not leave a mess! ESEM Step by Step Operation Guide 1. Make log book entry 2. Swipe in 3. Open Microscope Control 4. Vent the chamber 5. Load sample 6. Pump, make sure the chamber door is closed

5 7. Open your XL Docu database (.mdb file) 8. Delete old images 9. Click on the light bulb 10. Maximize Microscope Control 11. Wait for Vac OK 12. Turn on beam 13. Focus at tallest point on sample at 3000X magnification 14. Click OK to confirm focus 15. Set Z=10mm, click Go To. 16. Refocus 17. Find area of interest 18. Zoom to 30KX and find a round particle 19. Focus, stigmate 20. Zoom in to desired magnification, find smaller particle if necessary 21. Focus, stigmate 22. Press F2 for single slow scan 23. Save image with file box button on XL Docu Always on top bar 24. Unfreeze the image When finished imaging your sample: 1. Turn beam off 2. Home the stage 3. Vent 4. Click light bulb to go to XL Docu 5. Select all images 6. Choose J or T (.jpeg or.tif) to export images to your folder on the data storage computer 7. Copy images to your USB drive 8. Unload sample 9. Pump, make sure the chamber door is closed 10. Log off of SEM computer 11. Complete your log book entry with the end time of the session 12. Swipe out In case of PLCB Error: Vacuum button disabled 1. Make note of the text in the error message, ok the error. If the error does not reappear, then the system was able to reach normal configuration 2. Check the VAC and HT buttons on the front panel below the SEM chamber. If they are not lit then the pump has shut off, press the VAC button to turn the pump back on. It may take up to 45 minutes for the diffusion pump to reach operating temperature. 3. When the vacuum status reads Idle, press the HT button and the SEM is ready for use