Resist Process Information
At present, we have 4 resists available in a variety of thicknesses. We have a very limited resist budget, and all of these resists are very expensive (the latter three all cost ~ > $1000 per 100 mL !!) So please work carefully, and try to use as little resist volume as possible.
Positive Resists
PMMA Poly(methyl methacrylate). High resolution, medium contrast, poor etch resistance.
P(MMA-MAA) Copolymer, a variant of PMMA, lower contrast but lower dose, usually used for multi-layer resist structures for liftoff.
ZEP-520A high resolution (some say better than PMMA, some say worse), medium contrast (somewhat higher than PMMA, although some report somewhat worse), somewhat better etch resistance
Negative Resists
ma-N 2400 high resolution, high contrast, decent etch resistance
HSQ very high resolution, very low sensitivity (=high dose), inorganic - forms SiO2 when exposed