Hi all,

I have in one of my first process steps used Au particles (roughly 80nm in
diameter) in a seeded epitaxial step to form GaAs structures. As a second
step, I need to remove the Au particles, now alloyed with Ga, preferably
with a wet etch method. I can't use our standard Au etch (KI:I2:H2O), since
KI etches GaAs.

Does anyone have any suggestion for other wet etch? I have heard that some
cyanides may be used for etching Au, but it may be tricky to get those
chemicals into the lab. As far as I know, KI is used in the Au etch to
increase the solubility of AuI-compounds that forms when I2 etches the Au.
Is there any other chemicals that may be used instead of KI to make the
solution less aggressive on GaAs? NH4I?


Best regards,

Daniel Jacobsson
PhD student