Mathies:Photolithography in BNC
OAI UV Exposer
Important note: If your wafers are thicker than 700um, vacuum seal is unable to hold the vacuum for contact mode. Instead, you should manually load your wafers onto the chuck.
1. Warm up the UV-lamp for at least 30 minutes. This allows the UV power to stabilize.
2. Turn on nitrogen and vacuum pump in the service room.
3. Measure the UV power using a photometer. Calculate the required exposure time.
4. Keep the dummy mask in place and load the wafer. Be sure to lower the chuck, to prevent a collision to the mask. Turn “Substrate” switch on, hold the mask frame down and then turn “Frame” switch on. Raise the chuck until you see interference lines. Record the height number and lower the chuck.
5. Check whether you can see the same interference lines if you turn on “Contact”. If yes, you can use the Contact mode; if not, you need to manually raise the chuck to the pre-recorded height in step 4.
6. Remove the dummy mask and your wafer, and then replace your own mask. Chrome side down.
7. Load your wafer as in step 4 and align the mask using translational and rotational levers on the sides of mask frame. Turn on “Contact” or manually raise the chuck.
8. Expose with the set time on the UV lamp timer.
9. To unload your wafer, switch off “Contact”, switch on “N2 Purge”, switch off “Frame”, and lastly switch off “Substrate”.
10. Switch off “N2 Purge” after unload.
11. After use, log your time on the logbook, turn off the pump and nitrogen in the service room, and turn off the UV lamp.
- Eric Chu 15:20, 29 July 2009 (PDT):
or instead, discuss this protocol.