Unless otherwise specified, chemical concentrations are as follows: * Acetone: concentrated * H2O2: 3% solution in water * HCl: 37% solution in water * HF: 3% solution in water * NaOH: 1% solution in water * KOH: 30% solution in water # metals ## Aluminum (evaporated) Copper etches should work but etch rates will be slightly different ## Chromium (evaporated) Copper etches should work but etch rates will be slightly different # Other materials

Material	Etch	Suggested masks	Temperature	Approximate etch rate
Copper (evaporated)	1 HCl : 6 H2O2	photoresist	room temperature	3500-4000 nm/min
Copper (evaporated)	1 HCl : 5 H2O2 : 50 H2O	photoresist	room temperature	350-400 nm/min
Silicon (\<100\> plane)	KOH	thermal SiO2 (slowly attacked), Ta2O5 (deep etches)	80C	TODO
Silicon (\<110\> plane)	KOH	thermal SiO2 (slowly attacked), Ta2O5 (deep etches)	80C	TODO
Silicon dioxide (thermal)	1 HF : 5 H2O	photoresist	room temperature	TODO
Silicon dioxide (sol-gel)	1 HF : 5 H2O	photoresist	room temperature	1200 - 1800 nm/min
Tantalum oxide (sol-gel)	HF	Cu with Cr adhesion layer	80C	5-20 nm/min (rough number)

# missing * silicon (isotropic)