If positive resist is okay, and your only limitation is film thickness, there
are several other candidates:

Rohm & Haas SPR220 (4.5 or 7.0)
AZ Electronic Materials AZ9260 or AZ9245

All of these materials can easily be coated in excess of 5 µm (for the thicker
films, up to 65µm is possible in a single coat with specialized coating
equipment).

If you need even thicker, there is AZ50XT from AZ Electronic Materials, and
SIPR7123M20 from Shin Etsu.

Best Regards,
Chad Brubaker

EV Group       invent * innovate * implement
Technology - Tel:  480.727.9635, Fax:  480.727.9700  e-mail:
[email protected], www.EVGroup.com

-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of D. Zhou
Sent: Monday, July 31, 2006 9:06 AM
To: General MEMS discussion
Subject: Re: [mems-talk] Patterning SU-8 for DRIE process

Hi Florian,

Thanks very much for your message. Actually I know nothing about SU-8 at
all. The reason why I am considering SU-8 as a candidate for the DRIE mask
is that it could be thick. I tried S1828 (the thickest positive resist
available in our group) with low spin speed but still could not reach the
required thickness. Silcon dioxide is the perfect mask but our facility
broke down and will not be ready in September. According to your
suggestion, what negative resist can I use for this purpose? How thick can
it be? And how to pattern it?