Any leftover oxide or even native oxide will inhibit TMAH etching. Dip in
BOE prior to etch. Make sure to rinse well to make sure no Fluorine
contaminates your TMAH.
Shay

-----Original Message-----
From: mems-talk-bounces@memsnet.org [mailto:mems-talk-bounces@memsnet.org]
On Behalf Of Muk Mei Yu
Sent: Saturday, July 26, 2008 7:18 AM
To: mems-talk@memsnet.org
Cc: muk mei yu
Subject: [mems-talk] Si Etch Initiation Failure

Hi,

Did anyone encounter 'etch initiation' failure for Si etch in TMAH solution
before? Some refer etch initiation failure as passivation of Si during
etching which prohibits etching of Si. Si presents un-etched after the whole
process. What are the casues of this phenomenon? Any measures to help
mitigate this defect?

Thanks,
Muk