I have also seen a porous texture in SU-8 when doing low intensity
exposures (for greyscale lithography). This occurred in regions which
received a very low exposure dose.
How are you exposing it? Sounds like there may be some diffraction,
reflection or other effect which is slightly exposing the region close
to the wall
csh@u.washington.edu wrote:
> Hello all,
>
> Recently I have been working on the SU8 50 and SU8 2050.
> I noticed that the sidewalls exhibit porous-like texture.
> The SU8 50 was expired a year ago but the SU8 2050 is fresh. I am
> wondering is there anyone notice about this? Is it the nature of SU8
> or some process steps I can do to eliminate this problem?
> Thanks,
>