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

[email protected] 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,
>