Characterization of Er-doped AlN films prepared by RF magnetron sputtering

Abstract

Er-doped AlN thin film was deposited on sapphire substrates (0001) by RF magnetron sputtering at different sputtering times. The crystalline structure, surface morphology and electrical properties of the thin films have been investigated. The XRD patterns and the SEM sectional diagram indicate that Er-doped AlN thin films present the preferred orientation of C axis. The crystalline quality of the films rises first and then decreases with the increase of sputtering time and reaches best at 90 min. Piezoelectric coefficient d33 indicates maximum value of 9.53 pm/V. Correspondingly, the best surface morphology of thin film was obtained at 90 min and the surface roughness reached a minimum of 2.012 nm. In addition, the change of resistance is same with change of the crystalline quality and the resistivity reached a maximum of 4.36 ∗ 1012 Ω·cm at 90 min.