Have you tried soaking in water?  Metal chlorides tend to be soluble in
water, particularly GaClx.  Presumably, you are using chlorine for the
etch,   Is this correct?

Also, oxygen is not a good choice for the cleaning of metal
chlorides.  Oxidized metal chlorides tend to be much less soluble in water
than the chlorides and are generally much more difficult to remove.

Robert

On Thu, Sep 30, 2010 at 5:43 AM, Zetao MA  wrote:

> Hello,
>  Our RIE 800 chamber cover is extremely dirty (for GaN etching), and we
> soak it for a few days with Acetone. but the Acetone does not rinse the
> coated materials at all. The Oxygen cleaning does not work either.
>  Please give any advice to cleaning the Chamber cover, especially the
> sidewall.
>
> --
> BR.
> Dept. of EEE., CYC712,
> University of Hong Kong.