Dear Maria,

Thank you for your kindness! I actually have very little experience in using
SU8. As far as I know that SU8 3000 series (MicroChem) is less brittle than any
other SU8 series.

thanks a lot again!

James

> -----Original Message-----
> From: mems-talk-bounces@memsnet.org [SMTP:mems-talk-bounces@memsnet.org] On
Behalf Of Maria Nordström
> Sent: 09 March 2006 06:41
> To:   General MEMS discussion
> Subject:      RE: [mems-talk] Problems due to poor SU8 adhesion to metal
surface
>
> Dear James,
>
> Yes, this has been discussed before actually... :-) However, I'm quite
intrigued to see that you are working with the SU-8 3000 series! From where have
you purchased this? I have heard for a long time that MicroChem would put out a
new series of SU-8, but I have not been able to find out any more info about
it...could you fill me in? And in what way does the 3000 series differ from the
2000 series?? Have you tried any of the other series and have you so experienced
any differences?
>
> About your question: low adhesion with SU-8/metal is a problem in general. We
have done a study on it and you can find the work in Microelectronic Engineering
78-79 (2005) 152-157. There are two things you could try: (i) increase the
exposure dosage, that generally improves the adhesion or (ii) use an adhesion
layer such as Ti or Cr, about 50 Å. Good luck!