Electron microscopy studies of plasma-polymerized organosilicon thin films

Plasma-polymerized thin films of hexamethylcyclotrisilazane were pyrolysed in vacuum and studied by transmission electron microscopy. Examination of the polymer film after various durations of pyrolysis revealed significant changes in their surface structure and a distinct difference in the thermal stability powder and film phases. The number of powder particles in the surface layer and their size increased with pyrolysis time. The observations showed that powder particles embedded in the film matrix were gradually exposed in the surface layer owing to a decrease in the film thickness during pyrolysis. Good agreement was obtained between the experimental and theoretical distribution curves of particle size. The identical properties of powder particles exposed in the surface of the pyrolysed film and those taken from the interelectrode region indicates that they are primarily formed in the gas phase.