Micro-orientation control of silicon polymer thin films on graphite modified by heteroatom doping

Shimoyama, Iwao   ; Baba, Yuji  ; Hirao, Norie*

Polysilane has one-dimensional semiconducting electronic structure. Although the electronic property of polysilane thin film depends on orientation structure, the micro-orientation control method has not been established. We attempted orientation control for polydimethylsilane (PDMS) thin films by surface modification of graphite substrate using ion beam irradiation. Whereas PDMS thin film had flat-lying orientation on non irradiated graphite, random orientation was formed on Ar-irradiated graphite. And, we found that PDMS thin film had standing orientation on N-irradiated graphite using near edge X-ray absorption fine structure spectroscopy. Furthermore, we deposited PDMS thin film on a graphite substrate which was irradiated by N ion beam through a grid with of 25m periodicity and observed that the orientation structure of the PDMS thin film depended on the irradiated pattern using photoelectron emission microscopy. Based on these results, we concluded our method is available for micro-orientation control of polysilane films.