I have worked with this material a few years ago.  Schott and Hoya
made photosensitive glass at the time.  Practical aspect ratios of 25:1
can be achieved using an HF spray etch.  The "residual" must be removed
using boiling sodium hydroxide to achieve a reasonable surface on the
etched features.  Be careful in designing your geometric requirements
for the final product to account for variations in the material from
batch to batch and process variations if you don't do the etch in two
distinct steps.  Email me if you want more details.
jaime

Message: 3
From: "Peng Jin" 
To: 
Date: Tue, 16 Jul 2002 12:59:02 +0100
Subject: [mems-talk] About the Photosensitive glass
Reply-To: [email protected]

Dear fellow MEMS Researchers,

In my experiment, I plan to use the photosensitive glass for high aspect
ratio structure. I remember that there were some informtion about it.
But I can not find it now.

Could you provide some information about the supplier of this kind of
thing. If there are somebody has done this before, could you tell which
kind equipment is necessary for it?

Any suggestion are highly appreciated.

Cheers

Peng
>=========================================
>Dr. P. Jin
>Research Associate
>School of Manufacturing and Mechanical Engineering
>The University of Birmingham
>Edgbaston, Birmingham B15 2TT
>Tel:  ++44-121-414-4256 =========================================