Hello everyone,

I've been using O2 plasma (60 mTorr, 30 sccm, 150 W) and have seen an etch
rate of about 120 nm/min and a selectivity to resist of about 1:1. A problem
that I've been seeing is that there is considerable isotropy to the etch.
For instance, a 700 nm diameter hole in 2 um resist that I try to transfer
into 1.6 um of parylene becomes a ~3 um hole in the parylene after 15
minutes of etch. Has anyone seen a similar effect, and if so, found a way to
improve the anisotropy of the etch?

Thanks.
Keith L. Aubin, Ph.D.
Cornell University
School of Applied and Engineering Physics
212 Clark Hall, Ithaca, NY 14853
607-255-6286

-----Original Message-----
From: mems-talk-bounces@memsnet.org [mailto:mems-talk-bounces@memsnet.org]
On Behalf Of Eric Sanjuan
Sent: Wednesday, September 07, 2005 7:08 PM
To: mems-talk@memsnet.org
Subject: [mems-talk] plasma etching of parylene

Using a high density plasma you can get incredibly fast etch rates, i.e.
>2um/min - parylene-N, check this paper out, there's some fundamental
insights that will help you along your way...... BTW remember that there are
different types of parylene, and depending on which one you are etching, you
might want to optimize your feedgas chemistry. eric

JVST - Journal of Vacuum Science and Technology  "High-density plasma
patterning of low dielectric constant polymers: A comparison between
polytetrafluoroethylene, parylene-N, and poly-arylene ether)," T.E.F.M.
Standaert, P.J. Matsuo, X. Li, G.S. Oehrlein, T.-M. Lu, R.
Gutmann, C.T. Rosenmayer, J.W. Bartz, J.G. Langan, and W.R. Entley, J. Vac.
Sci. Technol. A 19, 435-446 (2001).