Dear Robert Antaki,

Have you tried patterning a circlular mask (e.g. with silicon nitride) on
your wafer and then performing a KOH etch to undercut the circular mask to
reveal the <111> crystal planes which could them be used for alignment ?

Regards,
Andy Mirza
Technology Manager

EV Group-Technology, Tel: (602) 437 9492 x 112, Fax: (602) 437 9435
E-mail: a.mirza@evgroup.com , Web
www.EVGroup.com

========================================

-----Original Message-----
From: Robert_Antaki@mitel.com [mailto:Robert_Antaki@mitel.com]
Sent: Monday, May 08, 2000 9:21 AM
To: MEMS@ISI.EDU
Subject: alignment to crystal planes


Hello to all,

I am looking for different approches to align precisely a photolithography
mask
to the crystallographic planes of silicon.
The reason is simple, I will do an anisotropic wet etch with the transfered
patterns and require them to be well aligned to the crystal structure for
the
etch to proceed properly.

I work with standard 150mm {100} silicon wafers, but comments from other
fields
are welcome.

Regards,

Robert Antaki
Implantation engineer,
Mitel S.C.C.
Bromont, Qc, Canada