The apparent TMAH etch rate is strongly influenced by the native oxide
on the silicon the Si/SiO2 etch selectivity is about 10,000/1.

-----Original Message-----
From: Kvel Bergtatt [mailto:vacmitun@gmail.com]
Sent: Tuesday, July 08, 2008 12:58 PM
To: General MEMS discussion
Subject: [mems-talk] TMAH solution photosensitivity

Hi all!

i'm wondering if somebody can lead me to the right point where i can
find
evidence, if any of TMAH solutions affected by light. i have observed
different etch rates on poly Si and wondering if light could affect
quaternary amines ability to etch Si.