>Hello everybody,
>
>we tried the photoresist EPON SU-8 epoxy resin; according to
>informations in 'Micromachine Devices' and data sheets coming with the
>resist, suitable developer is XPSU8 (PGMEA). The solvent for the resin
>is GBL - gamma-butyloracton.
>>From the supplier we got no hints to the SU8-remover, but the (funny)
>advices only to lift the resist using a sacrifical thin resist layer
>underneath the SU8 - or simply to leave it on the wafer  :-(
>Fatal is the fact, that the resist, if once polymerized, cannot be
>dissolved and removed by any means (solvent, EKC270, Aceton etc.).
>
>Has anyone experience in processing SU8 and to dissolve this resist if
>polymerized??
>
>Any response is appreciated
>Tanks in advance
>Arno Steckenborn
>
>
>mail:  [email protected]
>tel:   +49-30-38624671
>fax:   +49-30-38624404
>
Dear Sir,

You have one of the most difficult problems of the SU8.

The SU8 is an epoxy and once it is polymerized, it is as all the crosslinked
epoxies, very difficult to remove. We have also tried nearly all the different
solutions and nearly nothing works. One only thing the attacts the SU8 is fuming
(100%) nitic acid. But nitric acid also attacts a lot of other material, such as
copper, nickel, aluminium, etc. In order to prevent this you have to work in a
inert atmosphere (nitrogen).

I hope this might help you. Should you have other questions about SU8 please
contact me.

Best regards

Dr Louis J. Guerin

*************************************************
Dr Louis J. Guerin
Institute for Microsystems
EPFL- Swiss Federal Institute of Technology Lausanne
CH-1015 Lausanne
tél: (+41 21) 693 5857
fax: (+41 21) 693 6670
email: [email protected]

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