Why do you need it that thin? Are you using it as a spacer? Maybe you could
use a developable barc (Brewer Science has some)

1. Coat with BARC
2. Coat with photoresist
3. Pattern photoresist and develop
4. Strip photoresist with PGMEA

This would leave a patterned BARC. You should be able to get a BARC that
thin.

But it depends on why you need it that thin in the 1st place.

Robert



-----Original Message-----
From: mems-talk-bounces@memsnet.org [mailto:mems-talk-bounces@memsnet.org]
On Behalf Of Daniel Figura
Sent: Tuesday, February 09, 2010 2:25 PM
To: Michael.Cooke@uk-cpi.com; 'General MEMS discussion'
Subject: Re: [mems-talk] 50 nm resist

Hello Mike,

You may try to dilute standard positive resist with its solvent (e.g. AZ
1505 with PGMEA (AZ EBR Solvent)) to achieve such low thickness. I am not
sure how good the film quality and coverage is but you may try it.

Best regards,

Daniel Figura