If bt negative angle you mean overhang for lift off.  You can not
achieve it by using negative resist.  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 caozijian.cn@gmail.com
Sent: Wednesday, February 23, 2011 3:48 PM
To: Xiaohui Lin; General MEMS discussion
Subject: Re: [mems-talk] Image Reversal resist

Maybe you can choose SU-8 2005?

I think that if you choose any negative resist, you can perform negative
angle.