Hi,
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I am new in the field of microfabrication and I am experiencing issues =
with Su8 that does not adhere correctly on the silicon wafer...
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I am currently using Su8-2035 in order to achieve structures of 50 =
microns high. I am basically following the instructions given by the =
supplier (microchem) to perform the lithography. Also, I ve been told to =
dehydrate the wafer for 1 hour at 200 C before spining the resist.
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Anyway, my design involves turns, curves and some larger features. =
Looking under a microscope, i can see lots of micro-cracks in the resist =
especially concentrated on larger features and angles. Also, after I =
cure PDMS on the top of it, some Su8 structures actually come off of the =
wafer and stay embeded in the PDMS.
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Another intringing observation is the fact that the "color" of the =
larger features does not seem to be homogeneous. Some of it looks =
transparent while some other parts seem to have a darker color...
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Any suggestion would be greatly appreciated, thanks -
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- Marc =20