Hi,
I am going to use LPCVD silicon nitride as the mask to throughly etch my
SOI wafer, which is about 500 microns. I once used 0.3 micron PECVD silicon
nitride, but for some unknown reason the top layer cannot hold for through
etching, although the back side layer could. I plan to use 1500 Angstrom
LPCVD this time. But I am not sure if this is enough. Any sugestion will be
appreciated.
Thanks!

Peng Yao
DOEs lab
Electrical Engineering Dept.
Univeristy of delaware
Newark D.E 19716