Hi there,

I have been using various formulations of SU-8 which has been
made in house (although commercial mixes have also been used).
Unfortunately the structures have been suffering from an
exaggerated negative sloping sidewall problem commonly referred
to as 'T-topping'.  The latest base processing guidelines on the
MCC website blame this problem on the lower wavelength (313nm
and 334nm) output lines of mercury vapour lamps and suggest that
the problem can be eliminated by optimising the spectral
bandwidth (ie using an i-line filter).

I was just wondering if anyone had experienced this problem
and taken this step to solved the problem.

Thanks in advance,

Novak Farrington
_____________________________________

Novak Farrington
Institute of Microwaves and Photonics
School of Electronic and Electrical Engineering
University of Leeds
Leeds LS2 9JT
UK

Tel. +44 (0)113 233 2092
Fax. +44 (0)113 233 2032
email: eennf@leeds.ac.uk