HVPE 성장법을 이용한 고품질 베타-산화갈륨 에피택시 성장

Abstract

Gallium oxide (Ga2O3) is one of the ultra-wide-bandgap semiconductor materials and can be used as a high-power electronic material. Recently, many studies have been conducted on the β-Ga2O3, which is the most stable of the five phases of Ga2O3. In particular, various experiments have been conducted on high-quality thin film growth in order to utilize it as a high-power device, but the growth rate is low and it is difficult to adjust the doping concentration. In this study, it was attempted to suppress the pre-reaction of precursors by adding HCl flow in the growth process of Halide Vapor Phase Epitaxy (HVPE) method. The surface morphology and electrical property of the β-Ga2O3 epilayer were dynamically changed according to the flow rate of additional HCl gas. The β-Ga2O3 epitaxial growth rate increased up to 20 times, and the Si doping concentration increased linearly. As the flow rate of SiH4 gas increased, the carrier concentration was adjusted from 3.67×1017 ea/cm3 to 2.32×1019 ea/cm3. In addition, initial growth control was attempted to reduce defects inside the epitaxy, and the density of bullet-type defects was reduced to 105 ea/cm2.