Characterization of ion-beam modified polyimide layers

Thin chemically modified polyimide films are widely used as functional layers for new microelectronic sensors. Modification of the chemistry of these polymers can lead to different mechanical, optical and electrical properties. Ion implantation is a preferred method to modify polyimide structures. In this work the ion-induced changes of chemical structures of three polyimides were analyzed by attenuated total reflection. Fourier transform infrared spectroscopy (ATR-FTIR); X-ray photoelectron spectroscopy (XPS); Raman spectroscopy; and spectroscopic ellipsometry and atomic force microscopy (AFM). The results indicate that during the implantation process the imide structures were partly destroyed. Carbon-rich, graphite-similar and amorphous structures were formed in the surface-near area of the polyimide layers. The changes in molecular structures especially depend on the dose of implanted boron ions.