You need to make sure that there is no SiO2 or mask material on the
silicon.

Rick


-----Original Message-----
From: mems-talk-bounces+rmorrison=draper.com@memsnet.org
[mailto:mems-talk-bounces+rmorrison=draper.com@memsnet.org] On Behalf Of
???
Sent: Wednesday, July 06, 2011 5:31 AM
To: mems-talk@memsnet.org
Subject: [mems-talk] TMAH doesn't attack some of (100) silicon wafers

Hi, all,

While etching  (100) silicon wafers,  most of wafers were etched
normally.
But few of (100) silicon wafers of the same batch were not etched at the
initial time. It seems that the initial reaction just didn't take place.


Has anyone had this experience?

Thanks!