Dear all

I'm having a lot of trouble with the dry etching GaAs. Using a CL2 @ 15
sccm, Ar @ 4 sccm, 4 mTorr pressure, Power RF @ 200W, ICP @ 200W, and a
de-oxidised silicon wafer on a quartz platter. The surface is very rough
and etch rate seems to diminish with etch time. The GaAs is de-oxidised in
HCl and were using Ti as a mask (600nm) for the etch. I need to etch about
30um.

Any suggestions?

Regards
Greg Chance
Physics Department
Bath University UK