I think you can do KOH etching. See
http://www.ee.byu.edu/cleanroom/KOH.phtml
The setup is easy, KOH solution, agitation (microwave or magnetic bar. I
think the latter is better.), and wather bath.
Etching rate is 1~2um / min. No limitation on size. :)

HTao


On 12/13/2005 5:36 PM, Mac McReynolds wrote:

>Does any one have a source for deep silicon etching on 200mm wafers??  I'm
looking for depths in the range of 100-200µ, large (50µ plus)
features.  Please feel free to contact me directly.