[mems-talk] PMMA thermal decomposition

[Sebastian Sosin]

       I am using PMMA (950 and 495, Anisole) for temporary bonding. The
process is simple: spin coat (1000 rpm/45 sec) on thermal Si oxide, bake
180C for 90 sec, cooling, bonding at 250C applying small weights.
       Bonding strength is ok but when I try to debond the wafers at 300C I
do not get good results: partial debonding, rebonding after removal from
oven. How long should I leave the wafers at 300C?
       I have also tried with wafers with spin coated PMMA (not bonded) but
I didn't get any significant results after 30-40 minutes in the oven. The
layer was still there.


Regards,
Sebastian Sosin