Dear members:
I have a question about silicon trench wet etching. If etched from back side,
for example, 2um mask dimension, how wide the trench will be in the front side
with wet etching? I know this depends on the orientation of wafer and the
trench direction. According to the book, if the trench is aligned accurately,
it is possible to get a vertical side wall, thus, the width in front side will
be the same as that in back side, say, 2um.

I donot know whether it requires very high accuracy to alignment in order to
get vertical side wall. If I do the alignment manualy, generally how thin i
can get in the front side? Is there anybody has experience in this area?

thanks.

Regards,
Yilei Zhang