[mems-talk] a question about KOH etch back

[shay at mizur.com]

Hi
can be done. you have to get good control over the rate so you know when to
stop. if you do a whole wafer, have ready something to 'fish' it with from
the koh and transfter to DI water for rinsing. also, you should float it on
IPA after rinsing so it wouldn't stick and let dry over a piece of paper.
id you do only 1mm islands in a wafer there is no problem. you can go down
to 0.5u for this size.

shay

Original Message:
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From: Chin-Jen Chiang chinjen_chiang at yahoo.com.tw
Date: Tue, 6 Nov 2007 02:33:50 +0800 (CST)
To: mems-talk at memsnet.org
Subject: [mems-talk] a question about KOH etch back


Hi guys,
 
I am trying to etch back a Si bulk with KOH to remain a ~10 um thick
membrace wirh an area of 0.5mm x 0.5mm. I am concerned if such a thin
membrance with such a big area is very fragile and if it is achievable.
Someone told me such a thin Si layer is not flexible as a thin nitride
layer. Is that true? I appreciate your advices.
 
Lawrence