1. Start from a clean wafer.
  2. Dehydration: 120°C baking for 10 mins.
  3. Adhesive promotor coating: Programmed HMDS coating (Program 1).
  4. Spin Coating:  Note. To ensure adhesive promotor active, start PR spin coating right after HMDS coating.
    1. Dispense sufficient amount of AZ 1512 from the center of the wafer covering 60% - 70%
      of the wafer surface.
    2. Spin at 500 rpm for 20 seconds to spread out the photoresist.
    3. Spin at 4000 rpm for 35 seconds to reach 1.3 micrometer in thickness. (+ or – 476 nm).
  5. Soft Bake: 110°C (1 min).
  6. Exposure: 2.4 seconds with expose dose 40 mJ.
  7. Develop:
    1. 50 seconds gentle agitation in AZ 300MIF solution.
    2. (Optional) Stir the wafer slightly to remove red PR residue floating on top of wafer.
  8. Rinsing: Dip into water to remove developer.
  9. Dry: Blow dry the wafer with compressed Nitrogen gun.


Result Expectation:

For pattern dimension larger or equal to 2 micrometers, single layer pattern has 75° or higher cross-sectional
angle at the silicon substrate.

Resulting photoresist pattern expected

10um squares for scale     5um profile for scale