Sudarshan,

Your taper is a product of the chemical etch process. You may want to explore
another process method to achieve vertical walls. Look into using ultrasonic or
abrasive etch.

Regards,

Jim Quandt
Process Manager
Sycamore Glass Components
Ph # 815-895-8533

-----Original Message-----
From: hegdesudarshan@gmail.com
To: mems-talk@memsnet.org
Sent: Mon, 16 Apr 2007 10:26 AM
Subject: [mems-talk] Etching Vertical Holes in Si 110 wafer


The objective is to etch through vertical holes of 100 micron dimension in
Si wafer of 300 micron thickness.
I am using Si 110 wafer.
I have tried out a parallelogram with one of the angles equal to 70.6 and
the other as 109.4.
But each time, I am getting slanted faces which results in stopping of
etching.
Please help me regarding regarding this if at all vertical holes are
possible.