[mems-talk] Lift-off method for ALD deposited Al2O3 with PMMA pattern

[Michael D Martin]

Try some ultra sonic cleaning in acetone or a surfactant.  Part of the problem may be that you have a conformal layer that you are trying to lift off.  In the event that the PMMA is hardened you might try some Nanostrip (I think aluminum oxide will be OK) or N-methyl pyrrollidone (NMP). 

Good luck, 
   Michael  

>>> "Jun Huang" <huangking1 at gmail.com> 8/29/2008 9:52 AM >>>
Hi, all,

  The structure of our device composed of silicon/Patterned PMMA(~200
nm)/ALD Al2O3 (~40 nm). I have tried to dip the device in acetone to do
lift-off but the Al2O3 layer on the entire substrate surface does not
lift-off.  It seems that either acetone can not penetrate the Al2O3 layer or
the PMMA layer is hardened.  The deposition temperature for ALD  Al2O3 is ~
150 C which  should not  be high enough to harden PMMA.

  Does anyone have any suggestions on the lift-off process?