Atomic simulation of homoepitaxial AlN on non-polar (11-20) plane

Abstract

ABSTRACTLarge-scale molecular dynamics vapour deposition simulations have been performed to study the homoepitaxial growth of AlN films on non-polar (11-20) AlN surfaces. The effect of growth temperature and injected N: Al flux ratio on the crystallinity and surface morphology of deposited AlN film are investigated. We find that as the growth temperature increases from 1000 K to 3000 K at injected N:Al flux ratio of 2.0, the crystallinity and surface morphology of deposited AlN film both reach the optimum at 3000 K. Increasing the growth temperature makes the adatoms more mobile to move to their ideal lattice sites. Thus, the amorphousness and defects can be effectively reduced and good crystallinity and surface morphology could be obtained. Moreover, when the N:Al flux ratio increases from 1.2 to 2.4 under the growth temperature of 2600 K, the crystallinity and surface morphology of deposited AlN film both reach the optimum at injected N: Al flux ratio of 1.6. The improved crystallinity and surface morphology can be reached by using the optimised N: Al flux ratio. Furthermore, our simulation deepens the understanding and provides guidance for the growth of AlN on the non-polar (11-20) surface in the future.