Dear Judith,

You could try NMP (N-methylpyrrolidone) warm bath or just anneal the
sample in oxidative atmosphere (usually above 400 C in air). Oxygen
RIE/ICP should work too.

--
Alexander Slesarev

On Mon, Nov 7, 2011 at 11:00 AM,   wrote:
> ---------- Forwarded message ----------
> From: Judith Linacero Blanco 
> To: mems-talk@memsnet.org
> Date: Mon, 7 Nov 2011 15:49:48 +0100
> Subject: [mems-talk] cleaning e-beam litography sample
> Hello everyone,
>
> I made a lithography by e-beam with lines of 200nm separated 200nm with
> 300nm of PMMA on silicon.
>
> Once I etch the silicon with RIE, and then I try to clean the sampleacetone,
> sonicated. The problem is that I still have traces of PMMA in the sample,
> and I can't clean at all the sample.
>
> Can anyone help? How I can clean the whole sample of e-beam lithography?