Hi Rama-

I would consider trying the following basic pre-CPD process wet protocol as
a basis that you can adjust bath times as necessary:

1. BOE Etch bath [time length as per your design requirement]
2. 3 changes DIH20 [5 min each change]
3. 3 changes high purity IPA, Ethanol or Methanol(min. 99.5%+) [5 min each
change]
4. Fill CPD process chamber with sufficient IPA to cover your sample upon
transfer and initiate CPD process run.

(Note: That the above times may vary depending on material(s) and design)

Also, please note that it is mandatory to maintain your substrate in a wet
submerged liquid state from your Etch Step all the way up to the CPD process
as your delicate 3-D structure(s) are being supported via the Liquid. You
may remove your sample(s) from the liquid bath to another in an appropriate
holder, but do not linger too long in between steps as the liquid will
support your structure until your CPD system can successfully take you
through the critical point drying step.


Best Regards-
Yianni Tousimis

-----Original Message-----
From: mems-talk-bounces@memsnet.org [mailto:mems-talk-bounces@memsnet.org]
On Behalf Of Ramakrishna Kotha
Sent: Thursday, June 26, 2008 3:34 AM
To: mems-talk@memsnet.org
Subject: [mems-talk] Critical Dry

Hi,

I am performing critical dry to release a parallel plate structure, which
has SiO2 as a sacrificial layer

After removing the sacrifical layer-SiO2 with BOE, then the device is
transffered to DI Water and then to Acetone in the critical dry chamber.
After performig critical dry process using Polaron-CPD 7501 tool, all the
structures are damaged (due to stiction problem).

Can anyone, suggest me the accurate process to perform critical dry.