I used SF6 RIE for semi-anisotropic etch of Si with PR mask.
The etched surface was rough and there was excessive white
Polymeric deposition on it. I found out that this "polymer"
can be removed with short isotropic Si etch such as XeF2.
And it is obviousely inorganic becuae oxygen plasma doesn't
work.

I've used inductively coupled plasma for SF6 isotropic etch
and observed no such phenomena. I read from Pister paper that
XeF2 etch could create white -(SF2)- composite if the sample
is not well dehydrated. However, I have not heard of such
complaint against SF6 chemistry.

The surface roughness could be due to strong capacitive power.
But can anyone suggest a clue for the white deposition?

Thanks
ShuTing