Please try softbake temperature 80C and time of soft bake 20 minutes. it will work. with regards jaibir On Thu, 18 Dec 2008 Yinyan Gong wrote : >I used shipley 1813 and the spin speed is 4000rpm (thickness of photoresist is about 1.3um). After spin coating the wafer is softbaked in oven at 90C for 30min. But after the wafer is developed in MIF 319, there is always some photoresist left in the exposed area with 10um in width but the photoresist was removed in the exposed area of 100um by 100um. I tried to increase the exposure time, but the problem still exist? Could that possibly because the mask and wafer are not contacted? Thanks. > >Laura Jaibir Sharma Reasearch Scholar(PhD) Electrical Department, IIT Madras, Chennai - 36 INDIA Phone:044-22575444(off) 09445311513(home)