Slopes in positive resist are easy. +22 degrees to -22 degrees from the
vertical, flood exposure allows perfect control of angle, using image reversal.
I have personally done 40 microns thick positive resist.  Thicker is possible
but would need experiments.  Bill Moffat.

________________________________

From: mems-talk-bounces+bmoffat=yieldengineering.com@memsnet.org on behalf of
Kevin Nichols
Sent: Mon 2/28/2011 10:53 AM
To: Tsoll Doiiu; General MEMS discussion
Subject: Re: [mems-talk] Sloped microchannel



What you want to read up on is "grayscale" lithography. There's quite
a bit of literature out there on the subject specifically for SU-8.
You can achieve beautiful sloping microstructures in SU-8 with this.

However, that's a relatively advanced technique, and if you're new to
the field, consider simply doing multiple exposures of SU-8 on top of
each other to achieve "steps" similar to your desired characteristics.
If you don't need to it be smooth, that's much more likely to succeed.
I'd start with 5 or 6 layers of SU-8 on top of each other, exposed and
developed sequentially to achieve such a pattern.

- Kevin