Effect of the Bias Voltage on the Polycrystalline a-axis Oriented AlN Thin Films by RF Sputtering

In this study, a polycrystalline AlN thin films with a dominant peak of (100) plane under the sputtering parameters of 150 W with 2 hours deposition time are investigated. The study analyzes the effect of different negative bias voltages applied to the substrate holder of the sputtering system. The crystal structure analyzed by x-ray diffraction (XRD) shows that the AlN films is a hexagonal wurtzite structure. Sputtering the AlN films with higher negative bias voltage does increase the nitrogen atomic percentage. It was noticed that the AlN films deposited without any bias voltage resulted in close to stoichiometric of Al and N. It is also observed that the surface roughness of the AlN thin films does not change much with the increases of negative bias voltage.