Hello, Kamlesh, I experienced that before, and I think the volume decrease is due to too much loss of solvent during soft-bake. Try to turn your soft-bake temperature down or cut down the baking time. It should be working. On Tue, Mar 31, 2009 at 3:54 PM,wrote: > hi all > i am spin coating SU8 2050 on piranha cleaned silicon wafer but > during prebake it is shrinking and coming into the center of the > wafer. What could be the possible cause ? > -- > Kamlesh Pawar -- Best Regards, 郑瑞麟 Ruilin Zheng Address: Pen-Tung Sah MEMS Research Center, Xiamen University, Xiamen,361005, P.R.China