====== Eric Sundholm's Recipe ======
**WARNING: Manufacturer's recommended softbake is 115 C for 60 s on a hotplate. The manufacturer does not recommend baking inbetween exposuring/developing. Such bakes are only used for the more modern 'chemically amplified photoresists'. See Ethan for the 1800 series datasheet.**

Eric is an EE grad student who used to TA the ECE418 class on semiconductor processing & has made lots of devices in the Owen clean room.

**SiO2 Wet Etching**

  *Spin 1818 photoresist at 3000 rpm for 30 seconds (~2.5 um layer)

  *Bake at 85C for 2 minutes

  *Expose for 6-8 seconds

  *Bake at 85C for 2 minutes (//skip this step for lift off//)

  *Develop 15-25 seconds in diluted 351 developer (4 DI water : 1 developer) (//Develop 8-10 seconds for lift off//)
    *Rinse quickly & 'like crazy' afterward (important)
  *Bake at 85C for 5 minutes (//skip this step for lift off//)
    *Eric says 5 minutes may be too long. Watch for cracks in the photoresist around the edges, cracks mean the bake is too long.

===== More Advice =====
  *For liftoff, apply metal deposition layer quickly after development. Don't wait longer than a few hours.
  *When cleaning masks rinse with Acetone, then IPA & quickly blow dry with N2 gas. This leaves less residue than rinsing with IPA & then DI water.