Surface analytical studies of ion-implanted uni-directionally aligned silicon nitride for tribological applications

Abstract

Uni-directionally aligned silicon nitride, which exhibits both high strength and high toughness, was implanted with B +, N +, Si + and Ti + ions at a fluence of 2 × 10 17 ions/cm 2 and an energy of 200 keV. The effect of ion implantation on the surface structure of the uni-directionally aligned silicon nitride has been studied, in terms of surface analyses such as atomic force microscopy (AFM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), secondary ion mass spectroscopy (SIMS) and X-ray absorption near edge structure (XANES). It was clarified that the ion-implanted layer was amorphized and the implantation profile showed good agreement with that estimated from a TRIM simulation. It was found that BN and TiN were formed in B +- and Ti +-implanted Si 3N 4, respectively. There was a slight difference in ion implantation depth among different structures of Si 3N 4, considered to be due to differences in ion channeling.