Research on Nano-Mechanical and Micro-Tribological Behaviors of C+- Implanted Silicon

Abstract

The knowledge of tribological properties of silicon is important due to its potential application for micromechanical devices. Single crystal silicon wafers were implanted by carbon ion with an energy of 80 keV and different implantation doses of 2×1015 ions/cm2 and 2×1016 ions/cm2, respectively. The nanohardness and elastic modulus of silicon wafers before and after C+ implantation were studied on the nano-mechanical testing system. The micro sliding tests on silicon wafers before and after C+ implantation were performed on the UMT-2 Micro-tribometer to investigate the coefficient of friction and wear volume. The results demonstrate that the nanohardness and elastic modulus of silicon wafer at the implantation dose of 2×1015 ions/cm2 decrease and those of 2×1016 ions/cm2 have little change. C+ implantation improves friction-reducing effect of silicon wafers and the coefficient of friction decreases to a great extent. But when the load reaches a certain value, the coefficient of friction increases sharply and the worn trace occurs on the silicon surface. Adhesive and abrasive wear are the main mechanisms at light loads and micro fatigue is the main mechanism at heavy loads.