Hi

The two main players in deep silicon etching are STS and Plasmatherm.  STS
probably have the larger installed user base, but Plasmatherm are generally
cheaper.  I have heard mixed reports on user satisfaction for both
manufacturers.  Both of these systems use the Bosch patented deep silicon
etch process, which relies on switching between deposition of passivating
layers and etching using enough bias to remove the passivation from
horizontal surfaces.  Alcatel have also recently obtained a license to sell
machines for the Bosch process.  STS and Plasmatherm are currently involved
in an advertising mud-slinging match, claiming that the process wrecks
turbo-pumps, etc.

The alternative is to use cryogenic wafer cooling with SF6/O2 chemistry
(non-switched).  Alcatel sell such a system, as do Oxford Plasma Technology
(my own employer - I don't pretend to be impartial!).  There has been a
recent paper published in the Journal of Micromechanics and Microengineering
(sorry, I'm not sure which volume) with the title "The Black Silicon Method
VIII: A study of the performance of etching silicon using SF6/O2-based
chemistry with cryogenical wafer cooling and a high density ICP source",
authors Jansen, deBoer, Wensink, Kloeck and Elwenspoek from the MESA
Research Institute, University of Twente, The Netherlands.

Hope this helps.  You could also visit our website, at
http://www.oxfordplasma.com.

Martin Walker
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Plasma Technology, Oxford Instruments
North End, Yatton
Bristol, BS49 4AP, England
Tel: +44 (0)1934 833851 Fax: +44 (0)1934 834918
URL http://www.oxfordplasma.com/
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