>I'm looking for a method to produce circular membranes etched
>from Si. The membrane itself can be made of any material eg
>Si3N4 or SiO2 or Si itself. Can anyone help?

Look at the paper by Vdovin (also spelled Vdovine) from delft on the
circular membranes he created using KOH etching of silicon.
Justin Mansell  |       "Only a risk tests the reality of a belief"
Ginzton Laboratory      |                       - C. S. Lewis
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