III-V Lithography BayK. Suss - #579
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| ***** *****Description: Mask Aligner *****Compatible Materials: No Restrictions *****Incompatible Materials: |
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| 1. Log on to the tool using the LabAccess terminal. 2. Check if both of the power supply of the mask aligner and UV-lamp are on. If not, record what was happened on the logbook and send email to the maintenance ASAP. 3. Check if the microscope lamp is on. If not, try to contact the mask aligner super-user and ask him to change the light bulb. Do not set the microscope power supply over “5” for long time period otherwise the light bulb will break. 4. There are three different wafer chucks to use. Select proper chuck for your wafer. If the wafer chuck is not clean, wipe it with Acetone and IPA, then rinse it with DI water and blow it dry. Keep the wafer chuck clean at any time for good alignment and exposure. 5. There are two types of mask holders for different mask dimensions. Select the proper one for your exposure. Clean the holder if it is not clean. Put your maskplate on the holder with Cr face up. Turn on the vacuum and make sure that the mask has been sucked firmly. 6. Load the mask holder to the aligner, and hold the mask holder on the mask aligner firmly by tightening two knobs on the mask aligner. |
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| 7. Load your wafer on to the wafer chuck, and load the chuck to the right place. 8. While raising up the wafer chuck for alignment, check the wafer surface from side ways to make sure that the wafer surface is close but has not contact the maskplate surface. 9. Make sure that the contact switch has been set to the right place and the contact indicator is ON. 10. While watching through the microscope objectives, raise the wafer chuck up gently by slowly turning the chucking-raising knob in the front side of the mask aligner. 11. Align the wafer to the photomask by turning the X-Y positioner, then make the wafer close contact to the mask. 12. Set the exposure time to the timer on the right side of the mask aligner. 13. Push the exposure button and start the exposure. 14. After exposure, unload the wafer and start over from STEP 6 to 12 until all the wafers have been properly exposed. 15. Unload maskplate from the mask holder. 16. Put everything to the original place. Turn off the microscope lamp power supply. 16. Fill out the logbook, comment on the logbook if you find anything abnormal and send email to the maintenance. 17. Log off of the tool using the LabAccess terminal. NOTES: DO NOT attempt to change the bulb by yourself. The mask aligner housing and lamp are very fragile and hard for one person to deal with. The lamp itself is also very dangerous if handled improperly as it is under very high pressure (50-70 atmosphere). |
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