I am facing a strange problem while working with SU-8 50. I am using a transparency mask with 50 micron line structures but after the whole process I am getting a line which is about 100 micron in width. For detail, shining part of transparency mask (mask pasted on glass) is in contact with PR. Exposure = 19 sec (266mJ/cm2) to 60 Sec (840mJ/cm2)for 30-32 micro thick film of SU-8 50. Is it due to the UV light used in not i-line but a broad range UV light (not T top at all)? I shall be thankful for any suggestion or advice to solve this problem.