I have never used gold as a dry etch mask.  You are not limited to Cl2
to etch GaAs.  Simple F12 works too, but I don't know if it will attack
gold.  For very long etches I will do a Ni lift-off as a mask to protect
my resist.

Brent

Te LI wrote:
> Hi everybody,
>
> I want to do dry etching of GaAs with Gold as a mask since my special process
flow. But as I know, Gold will be etched in the Cl2, which is necessary for GaAs
etching.
>
> Can anybody give me a proper recipe for this process?
>
> Many thanks.
>
> Regards,
> Terry
>