Polyimide Spinning Notes
- Prepare spinner/vacuum pump set up.
- Dehydrate wafer at 105 degrees C by placing on a hot plate (one side okay). To set hotplate press: Set, Plate Temp, 1, 0, 5, Enter/Set.
- Place wafer on spinner. Apply adhesion promoter generously, and reseal. Set timer for 2 minutes, spin at 500 rpm for ~30 seconds, then take it up to 4000 rpm.
- Wafer is done when it stops changing colors.
- Put back on the hot plate for 10-20 minutes at 300 degrees C. (Check the Hitachi data sheets on this.)
- Cool down to 105 degrees C before spinning on polyimide.
- Place wafer on spinner. Set timer to 65 seconds. Pour on a half dollar of polyimide. Preset speed to 500 rpm, then after 30 seconds, ramp up to 2500 rpm for a 5 micron layer.
- After the first layer of polyimide, cure for 20 minutes at 180 degrees C, then spin on the second layer.
- Initial post-bake 1 minute at 105 degrees C.
- Bake for 20 minutes at 200 degrees C then 1 hour at 350 degrees C. DO this in CIS.
pruitt@cdr.stanford.edu
allisono@cdr.stanford.edu