Ruilin, could you clarify what profile you are getting?

Is is wider at the bottom, i.e. something like this:
           ___
           I    I
           I    I
           I    I
          /     \
_____/        \_____

Or is it more like this:
        _______
         \         /
          \       /
           I      I
           I      I
______I      I________

I hope my attempt at ascii art works!

On Wed, Apr 23, 2008 at 7:26 PM, Andrew Sarangan  wrote:
> I am not exactly sure what the poster meant by 'concave'. Here is a
>  photo. If the structure looks like this, then the problem is
>  under-exposure. In fact, even the exposed sidewalls are not vertical
>  because the dose is decreasing with depth.
>  http://131.238.119.245/sarangan/SU8-profile.jpg
>