PMMA is notch sensitive, in addition to freezing try scribing the
reverse surface of your PMMA substrate (presuming you're not already).

-----Original Message-----
From: mems-talk-bounces@memsnet.org
[mailto:mems-talk-bounces@memsnet.org] On Behalf Of Hunter, Luke L

I've found that freezing the sample in LN2 before cleaving helps.  It's
still not perfect and PMMA doesn't like to break cleanly but it breaks
more than tears when I do this.

-----Original Message-----
From: mems-talk-bounces@memsnet.org
[mailto:mems-talk-bounces@memsnet.org] On Behalf Of Jeff Kettle


  I have been patterning structures into PMMA using an Electron beam
lithography system. I was wondering if anyone had any advice on
capturing an image of the cross section for the patterned structure
(post-development) using an SEM.