Dear MEMS community,

I am trying to lift-off the SU-8 2000 on silicon substrate, but can not. I
precoated OMNICOAT layer (microchem) on silicon ( the thickness is only about 30
nm, 1st 500rpm 5s, 2nd 3000rpm 30s), spincoated Su-8 2000 ( about 300nm in
thickness measured by ellipsometer, 500rpm 5s, 3000rpm 30s), prebaked SU-8, 5
minus at 90C, exposed by E-beam lithography, postbaked Su-8, 5 minus at 90C,
developed, then I coated (by both sputtering   system and thermal evaporator)
50nm-thick Au and Al films. I put the structures into Remover PG (microchem),
using ultrasound machine to stir for more than 1h. Still I cannot lift off the
Su-8. If anyone know how to lift-off, please let me know. Thanks,

Yongdong Liu
--------------------------------------
Researcher Associate
Dept. of Electrical & Computer Engineering
University of Utah
Tel:801-587-9462
Fax:801-5824330