Hello Maryla

With that thin a membrane you need something very gentle and dry. Using xenon
difluoride gas to etch a away the silicon might work. If you would like to try
it, XACTIX is the overwhelming leading supplier of xenon difluoride silicon etch
tools and we could run a sample in our demo lab.

Best Regards
David Springer
XACTIX, Inc.
2403 Sidney St.
Suite 265
Pittsburgh, PA 15203
+1 412 381 3195
davids@xactix.com
www.xactix.com


>>  Hi
 >>  I am trying to etch silicon wafer in KOH to create 50 nm thick silicon
 >>  nitride membranes. I am using 20% KOH at various tempretures. the
 >>  membranes I am getting  often easily break in the process. Can anyone give
 >>  some advice how to proceed?. Which type of nitrade is the best for this
 >>  application?

 >>  Also, I would be grateful if someone could suggest a good and not very
 >>  expensive
 >>  vendor
 >>  who could provide me with the 4" silicon wafers ( preferably 300 mic
 >>  thick) with 100nm  low stress LPCVD silicon nitride layer.
 >>  Our in-house facilities produce  a very porous silicon nitrade films.
 >>  Please reply directly to me at

 >>  rmk111@rsphysse.anu.edu.au

 >>  Thanks in advance

 >>  Maryla Krolikowska
 >>  Australian National University

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