In that case, the only other things I can think of are poor collimation
of your source (unlikely with a proper mask aligner) or that you are
getting unwanted reflections from the mask/substrate.

Abhishek Jain wrote:
> They are 50-60um at the bottom and 30um at the top, thus a positive
> slope!
> thanks
>
> On 4/3/07, Gareth Jenkins  wrote:
>> Exposure with <340nm leads to negative sidewall slopes rather than
>> postive which is the observed problem unless I misread it.
>> Abhishek, are the structures 30um at the top and 60um wide at the
>> bottom? If it's the other way round (60 at the top, 30 at the bottom)
>> then a filter could indeed be the answer.