Adhesion, friction, and wear of plasma-deposited thin silicon nitride films at temperatures to 700 °C

Abstract

An investigation examined the adhesion, friction and wear behavior of silicon nitride films deposited by low and high frequency plasmas (30 kHz and 13.56 MHz) at various temperatures up to 700 °C in vacuum. The results of the investigation indicated that the Si/N ratios were much greater for the films deposited at 13.56 MHz than for those deposited at 30 kHz. Amorphous silicon was present in both low and high frequency plasma-deposited silicon nitride films. However, more amorphous silicon occurred in the films deposited at 13.56 MHz than in those deposited at 30 kHz. Temperature significantly influenced adhesion, friction and wear of the silicon nitride films. Wear occurred in the contact area at high temperature. The wear correlated with the increase in adhesion and friction for the low and high frequency plasma-deposited films above 600 °C and 500 °C respectively. The low and high frequency plasma-deposited thin silicon nitride films exhibited a capability for lubrication (low adhesion and friction) in vacuum at temperatures to 500 °C and 400 °C respectively.