Hello,
For people searching on Deep Si etched structures:
STS (http://www.stsystems.com/index.html) and Alcatel both develloped some
processes and etched some devices for us, as we were looking for an ICP
etcher. I suggest you contact them with those very specific questions. Our
experience is that a lot can be done, but that each mask pattern requires
its own fine-tuned process...

Wouter van der Wijngaart
Kungl. Tekniska Högskolan       Tel:    +46 - (0)8 - 790 66 13
S3, Elektrisk mätteknik Fax:    +46 - (0)8 - 10 08 58
100 44  Stockholm               Minicall:       +46 - (0)740 - 26 71 28
Sweden                  e-mail: [email protected]
http://www.s3.kth.se/instrlab/staff/wouterw.html