AMTEtcher for etching Silicon

Dear all,

P5000 and LAMPoly are our standard Si etchers. I was wondering,
however, if anyone has ever used AMT for etching Si. There seems to be
a recipe for doing it. If you have etched Si in AMT, I would
appreciate any information on the etch rate, and, if available, any
information on its comparison with P5000. My patterns are thin (30 nm
thick) isolated Si lines with widths ranging between 50 nm - 200 nm.

Thanks
-Rohan