Hi Xiaoyong,

I used Protek from Brewer Science about 2 years ago.  What I used to
completely strip my 10-15um Protek were O2 Plasma (with high O2 dosage at
quite a longer time) followed by SC1 clean.

You may want to try this process to see if it helps.

Regards,
Paul

Forwarded message ----------
From: Xiaoyong Liu 
To: 
Date: Fri, 2 Apr 2010 18:21:35 +0000
Subject: [mems-talk] ProteK B3 coating layer removal
Hi,
   I am using a so-called Protek B3 layer (spin coated) from Brewer Sciences
as a protecting layer for my wafer frontside during KOH wet etching. It
serves its purpose pretty well, but it is very hard to remove. I tried the
remover (Protek remover 100) they suggested as well as acetone overnight.
There is still an apparent layer there after overnight soaking in above
solutions. I also tried to use O2 plasma (as well as CF4/O2 combination),
but with no apparent effect.  I am wondering if someone has any experience
with it, and would share their insight with me. By the way, my sample is on
Si substrate coated with a thin layer of SiN. The features are just metal.

Thanks
Xiaoyong