Hi Hongjun,

I do a bit of EBL, mostly on Si but I have tried on non-conducting
substrates as well.  In my experience, if there are any residuals from the
conducting film or its etch solution it can impact the results of your
pattern when you proceed to development.  It could be that the particular
metal/etch chemistry affects the underlying PMMA.  If that is the case,
another metal (such as Au) could be used instead.

Regards,

Michael Rust

-----Original Message-----
From: [email protected]
[mailto:[email protected]]On Behalf Of Hongjun-ECE
Sent: Tuesday, September 05, 2006 1:09 PM
To: 'General MEMS discussion'
Subject: [mems-talk] Washing-away problem in non-conductive substrate
EBL


Dear colleagues,

I am doing EBL on non-conductive substrate. I deposited 5-12 nm silver film
on the PMMA 495 C5. I believe the EBL was performed pretty well because I
can clearly see the latent image of the exposed patterns before and after
the silver etching. But the problem happened at the step of development: the
developer (MIBK 1:3 IPA) washed away all PMMA no matter it is exposed or
not! Did you see this phenomenon before and do you have any suggestion?