Due to reflection from the Silicon dioxide layer, your features could be
worst.If you decrease the first expose time and also flood expose time
(Approximate FloodExposeTime = FirstExposeTime x 4 ) it should be done.
But i have a question, your exposure power 120mJ/cm2. Is it very high for
your process?
...

Tolga YELBOGA
Project Engineer
Nanotechnology Researh Center
Bilkent University
Bilkent, Ankara 06800 TURKEY
Voice: 90-312-290-1020
http://www.nanointurkey.com
http://www.nanotam.bilkent.edu.tr


-----Original Message-----
From: jpt sharma [mailto:jptsharma@yahoo.com]
Sent: Wednesday, December 17, 2008 12:45 AM
To: mems-talk@memsnet.org
Subject: [mems-talk] Az 5412 image reversal receipe

Hi all
I am trying to use Az5412 for image reversal purpose. When I use Si wafer
with only native oxide (~1.5nm) the following recipe works fairly good.

Spin PR : 5000 rpm for 30 sec
bake : 110 C for 60 sec
Exposure : 7 sec 17 mW/cm2 using MA6 aligner
Bake : 110 for 120 sec
Flood exposure for 35 sec
Develop

But when I am trying to make pattern on Si wafer with 100 nm SiO2 deposited
using PECVD I wasn't able to use the same recipe, but wasn't able to develop
the feature less than 10 um. I tried to change the exposure time like 5 sec,
8 sec, 10 sec with 30 sec, 45 sec, 55 sec flood exposure.

No Luck!

Do you have any suggestions?

Thanks
J Sharma