Achar,

It would seem to me that you might be better off if after your last HF
etch you did an RCA clean to leave a very thin oxide that would render the
wafer hydrophilic.  The pin holes could be from that final HF and the
inability to dry that wafer surface blemish free. Might be worth a try, let
us know how you make out. Gary

Gary Hillman
S-Cubed
PO Box 365
9 Mars Ct.
Montville, NJ 07045
phone 973-263-0640 ex 35
fax 973-263-8888
Check out our web site and Twitter at www.s-cubed.com


-----Original Message-----
From: mems-talk-bounces+garyh=s-cubed.com@memsnet.org
[mailto:mems-talk-bounces+garyh=s-cubed.com@memsnet.org]On Behalf Of
Felix Lu
Sent: Sunday, January 22, 2012 7:33 PM
To: hvbachar@smail.iitm.ac.in; General MEMS discussion
Subject: Re: [mems-talk] Pin holes in thermal oxide


Hi,

    Can you explain the purpose of the dry-wet-dry oxidation steps? If this
is for some gate oxide, does it show comparable results to a plain dry oxide
of similar thickness?

One thing I might try is to do an initial solvent, BOE, RCA1 (and RCA2
depending on if metal contamination would affect your results), BOE clean.

Best of luck.

Felix