Use a planar plasma unit with a temperature control that can be set to
switch off at a specific temperature.  Bill Moffat

-----Original Message-----
From: mems-talk-bounces+bmoffat=yieldengineering.com@memsnet.org
[mailto:mems-talk-bounces+bmoffat=yieldengineering.com@memsnet.org] On
Behalf Of Mike Whitson
Sent: Thursday, June 24, 2010 8:18 AM
To: ameya.g@gmail.com; General MEMS discussion
Subject: Re: [mems-talk] Removing hard-baked photoresist

The asher will eventually do the job, but you may have to let it run for
a very long time, and there's a good chance you will have to contend
with problems related to heating of your sample.  If you have access to
it, oxygen RIE can be much faster and more effective than a barrel
asher.  I've used a bench-top ICP-RIE to strip cross-linked PMMA with
good success.  If you want to be extra thorough, you can use piranha
much more safely after the RIE has taken out most of the organic
material - piranha can be very violent if you give it a lot of organic
matter to oxidize at once.

Even if you don't have a specific oxygen RIE, many DRIE tools have an
oxygen cycle for chamber descumming which can also be used for organic
stripping if your facility's SOP allows.

Solvent-based strippers (acetone, NMP, etc.) won't help you on
cross-linked resists, don't bother with those.

-Mike