GaAs etching in PQuest

Hi labmembers,

I am preparing a new process which involves etching features into GaAs. I haven't worked much with GaAs in the past, and was hoping to benefit from the existing expertise. I was planning to use P Quest, and was wondering if anybody has experience etching GaAs in this machine recently, and might be able to share recipes/etch rates (including selectivity for mask materials). I would like to etch on the order of 1 micron deep features. Also, if you recommend any surface cleaning/pre-treatments before the etch, it would be greatly appreciated.

Thank you,
Neil Dasgupta
Prinz Group