Scanning force microscopy of polyimide surfaces

Abstract

Scanning force microscopy was used to study several polyimide surfaces. The effects of r.f.-sputtering in argon and nitrogen atmospheres on the surface morphology of poly-[4,4′-oxydiphenylenepyromellitimide] (PMDA-ODA) and the polyimide (PI) based on the monomers 3,3′,4,4′-biphenyl tetracarboxylic dianhydride (BPDA) and p-phenylene diamine (PDA) were investigated. PI surfaces treated with r.f.-sputtering in nitrogen exhibited morphological features due to redeposited metal from the walls of the sputtering chamber, while no significant morphological change was observed when an argon atmosphere was used, for the same duration of sputtering treatment. It was shown that the enhancement of adhesion of metals on PI surfaces that have been treated with r.f.-sputtering in Ar, is not due to mechanical interlocking but rather due to chemical modification of the surface. The effect of different heat treatments on the surface morphology of co-deposited films of oxydipthalic dianhydride (ODPA) and 1,3-bis-[3-aminophenoxyl]benzene (APB), prepared by molecular beam deposition (MBD), was also studied. Such MBD films exhibited a strong dependence of morphology on the annealing process and environment.