Hi, It will be nice if you can measure the thickness of the resist stack. Typically, this kind of problems will happen if your resist is relatively thin compared to Metal thickness. If you are aiming for 100nm Al, you should have a resist thickness around 300nm. (which is quite easy if you use PMMA950/EL9 comb). Also you can try Al evaporation rather than sputtering. (but both works fine for me). I think it will work for you. regards, sangeeth On Mon, May 23, 2011 at 6:01 PM, 崔林wrote: > Hi, > > I am using the e-beam to pattern my sample, > the resulotion is not very high, just around 500nm, and my > sample is 10nm aluminum on sapphire. > > It is followed by sputtering 100nm metal aluminum. > After that, I use the aceton to do the lift-off. > > My problem is that the metal did not peel off as expected. I > appreciate any advice. > > Thank you! -- *Sangeeth K *