Temperature dependence of point contact friction on silicon

Abstract

Point contact friction and adhesion between a silicon tip and an untreated silicon(111) wafer are measured as a function of sample temperature in ultrahigh vacuum by friction force microscopy. While the friction coefficient changes drastically in the temperature range from $50\mathrm{K}$ to room temperature, and shows a reproducible maximum near $100\mathrm{K}$ , the simultaneously recorded adhesion shows much less temperature dependence. Interestingly, the velocity dependence of friction shows a logarithmic increase below $150\mathrm{K}$ although it is nearly constant above $150\mathrm{K}$ . This peculiar behavior has profound consequences for tribological properties of devices manufactured from silicon.