Heteroepitaxial growth and electric properties of (110)-oriented scandium nitride films

ScN films were grown on MgO(110) substrates and alpha-Al2O3(10 (1) over bar0) substrates by a molecular beam epitaxy method, and their crystalline orientation, crystallinity, and electric properties were examined. Mg (110)-oriented ScN films were epitaxially grown on MgO(110) substrates with the same crystal orientations, and ScN films with an orientation relationship (110) ScN || (10 (1) over bar0) alpha-Al2O3 and [001] ScN || [1210]alpha-Al2O3 were epitaxially grown on alpha-Al2O3(10 (1) over bar0) substrates. Remarkably, electric-resistivity anisotropy was observed for ScN films grown on MgO(110) substrates, and the anisotropy depended on the growth temperature. The carrier concentration and Hall mobility of the ScN films grown on alpha-Al2O3(10 (1) over bar0) substrates ranged from 10(19)- 10(21) cm(-3) and 10-150cm(2) V-1 s(-1), respectively. The crystallinity, crystallineorientation anisotropy, and electric properties of the films were strongly affected by growth conditions. For the growth of ScN films with high mobility on alpha-Al2O3(1010) substrates, a high temperature and an appropriate ratio of source materials were necessary. (C) 2017 Elsevier B.V. All rights reserved.