Adhesion and friction forces on silicon wafers with dual surface modifications at nano-scale

Abstract

Surfaces of silicon wafers were topographically and chemically modified. As the first step, nanochannels were fabricated on silicon wafers using MEMS fabrication process. Next, the nano-channeled surfaces were coated with DLC thin film (20 nm thickness). Adhesion and friction forces on these surfaces were measured using an AFM. Results showed that the chemical and topographical modifications reduced the surface forces. Further, a combination of both the kinds of modifications was even more effective in decreasing the surface forces, owing to the combined effects of reduced real area of contact and lower interfacial energies. It is proposed that the combined surface modification is a potential route to enhance the tribological performance of elements of MEMS devices.