Formation of scandium nitride (ScN) layer on gallium arsenide (GaAs) substrate using a combined technique of e-beam evaporator and ammonia annealing treatment

Abstract

A demonstration on a new technique of growing ScN using electron beam (e-beam) evaporator, coupled with successive ammonia (NH3) annealing treatment is presented in this paper. The annealing temperature was varied at 750, 800, 850, 900 and 980°C in order to obtain the best ScN layer. It was found that as the annealing temperature increased, the surface morphology of the ScN layer changed and ScN grains formed abundantly on the surface. The best surface of ScN layer was found in the 900°C annealed sample. However, the roughness of the ScN increased with temperature. The photoluminescence (PL) peak of the near-to-band-edge (NBE) of ScN was observable in all samples and its intensity was the highest in the 900°C annealed sample. Note that when the annealing treatment was conducted at 980°C, the GaN PL peak is observable. Raman peaks of TO(X) of ScN were much evident at the annealing temperature above 900°C. The formation of ScN bonds was confirmed by X-ray spectroscopy (XPS) measurement. In the end of this work, we propose that the formation of ScN using the above techniques was successful, with thermal annealing at the temperature of 900°C.