The Effect of Tip Materials on the Nanotribology with Atomic Force Microscope Technique

Abstract

The effect of tip materials on the friction properties of silicon substrate was investigated by using atomic force microcopy (AFM). The roughness of the silicon wafer surface was characterized with silicon tip at tapping mode, and then the relationship between the friction force and normal force was obtained by silicon tip and silicon nitride tip at contact mode. The experimental results show that when the load exceeds a critical value, the friction coefficient with silicon tip increases from 0.17 to 0.37, which is due to the wear of the silicon tip; the friction coefficient with a hard silicon nitride tip increases from 0.25 to 0.5, which can only be attributed to the plastic deformation of silicon substrate. And the roughness of the silicon substrate can lead to an incomplete contact, which can influence the real contact area between the silicon nitride tip and silicon substrate.