From yyao at intpax.com  Wed Sep  5 20:04:31 2001
From: yyao at intpax.com (Yahong Yao)
Date: Wed, 05 Sep 2001 22:04:31 -0500
Subject: etch rate of program 3
Message-ID: <3B96E7BF.58E819CC@intpax.com>

Hello All,

After watching emails about amtetcher, I think I should bring your
attention or at least ask about this question.  It is about drytek2.

On 08/24/01 (Friday), I did an etch using program #3 (Nitride etch) for
35mins.  The mask was standard 1.6um PR.  The films were 6000A Nitride
and 1000A PolySi.  They were on wafer backside therefore were not in
good quality due to the roughness.  The pattern size was really big
(3mm*3mm).  According to the etch rate on the manual, 1.6um PR should
sustain at least 45mins.  But what left after 35mins were only Si
features.  The PR, Nit and polySi were all go.  Only a small portion
around wafer edge had films on.

Q:  What's wrong in this process?  For the PR treatment, I only did two
mins postbake on the svgdev.  Could this be the reason?  No experience
of long etch on the drytek2, any suggestion is highly appreciated.
Thanks in advance.

Yahong