Thanks Edward and Andrea for the reply!
I need to remove the top ~ 0.1 um of Si with diffusion 'cause I am
suspecting my top surface is rich with defects due to the saturating
concentration of dopants right at the surface.

About surface roughness: I think you don't get rougher than 0.1um when you
are etching 0.1um off. And my requirement for surface roughness is very
lenient. 0.1um will do. But uniformity is the problem.

I have a small RIE (Plastherm 790) but it doesn't give me much uniformity
over 3" wafer.

right now I am thinking about using low temperature UV oxidation to create
some oxide and then remove them by HF.

More suggestions?

On Dec 19, 2007 12:57 PM, Andrea Mazzolari  wrote:

> Hello Dave,
> which is the thickness you need to remove ? Which is wafer orientation ?
> Which is surface rougness you can accept ?
>
> Andrea