Hi all,

Thanks for your help.

For me, what I have done is
I had a 6'' silicon wafer and I coated it with negative photo resist
(Arch Chemicals HNR80), 1 micron in thickness, I think.  It was
exposed under UV light, and then developed.  After this, I evaporated
a thin aluminum film onto the wafer, one micron thick.  Then I need to
do the lift off process to pattern the aluminum.  However, I got
failed in doing so.  It seems like that, the acetone can not etch the
negative PR, which works well in removing positive PR.
So I need to figure out another way or find out another solvent to do
this.  Could you give me some suggestion?

Thanks very much.

Duan