Effect of substrate temperature and bias voltage on the properties in DC magnetron sputtered AlN films on glass substrates

Abstract

AlN films have been deposited on glass substrates at various growth conditions by DC reactive magnetron sputtering. The AlN film deposited at 300 °C shows a strongly c-axis preferred orientation with a high thermal conductivity of 12.5 W/mk. The evolution of c-axis preferential orientation, morphology, growth rate and residual stress as well as thermal conductivity of the synthesized films are investigated as a function of sputtering parameters. The crystalline quality of the films gradually improves to highly c-axis orientation as the substrate temperature increased to 300 °C. The deposition rate enhances with the substrate temperature increased or the negative bias voltage was applied. The surface roughness of the AlN films would be reduced due to the moderately increased substrate temperature or enhanced N2/Ar ratio. Moreover, it is found that high temperature and high negative bias voltage are able to grow AlN films with compressive residual stress, and the thermal conductivity of the films are improved with the increase of film thickness.