Hello Lin,Yaojian maybe you can try to use H2SO4+H2O2=3:1 or Aceton with ultrasonic ,this maybe can clean you dirty mask ----- Original Message ----- From: "Lin, Yaojian"To: "'General MEMS discussion'" Sent: Thursday, July 31, 2003 11:14 PM Subject: [mems-talk] Mask Clean > Hello Friends, > > I am looking for the methods to clean the dirty mask, which may have some > polymer spots. > > Could you please give me some clue? > > With many thanks, > > Yaojian Lin > > > > >