Hi li shifeng

AS per your process mentioned, may be the gold layer is blocking the
EBL exposure.  If you are trying for gold lift off process, you need
to pattern the PMMA first , followed by gold deposition.

OR if you need the gold layer on top of PMMA, may be increase the
Ebeam exposure energy and then try.

Wish you good luck

Dr.H.Indusekhar


________________________________

From: li shifeng [mailto:david_lee77@hotmail.com]
Sent: Tue 11/25/2008 9:42 AM
To: mems-talk@memsnet.org
Subject: [mems-talk] EBL on the glass substrate

Hi, guy

I'm trying to write some patterns on glass substrate. Here is my process:

Spin coat 500nm PMMA 950 C4,
Sputtering 5nm gold
EBL exposure
Strip gold using TFA gold etcant for 6 second
Develop in MIBK : IPA=3D 1:3 for 30 sec

The problem is I cannot find any pattern on the substrate afterwards. What a=
re the possible reasons for that?  Anyone have similar experiences on this o=
r has a working recipe to share?

Thanks!