SURFACE CONDUCTIVITY OF POLYIMIDE FILMS M ODIFIED BY KRF EXCIMER-LASER IRRADIATION

The surface conductivity of PI (polyimide, U-Film N) irradiated by the KrF excimer laser increased with increasing laser fluence. As the irr adiation progressed, the surface morphology changed from a relatively smooth to a granular structure. SEM analysis showed that the amplitude and spacing of the surface roughness increased with increasing laser energy. The XPS analysis of laser irradiated surface revealed the loss of oxygen and nitrogen. All the results are interpreted in terms of t he carbonization of PI, which leads to the occurrence of surface condu ctivity induced by KrF laser ablation.