AlGaN/GaN Heterostructures Electrical Performance by Altering GaN/Sapphire Buffers Growth Pressure and Low‐Temperature GaN Interlayers Application

Abstract

In this work, the possibility of improving 2D electron gas mobility and sheet carrier concentration in AlGaN/AlN/GaN heterostructures by altering GaN/sapphire buffer growth pressure and application of low-temperature GaN interlayers in GaN buffer is investigated. Obtained results show some improvements in 2DEG resistivity reduction after the introduction of two GaN buffer sublayers grown at different pressures. It is observed that the MOVPE process pressure influences the size of GaN buffer block size visible on the scanning electron microscope images of the AlGaN/AlN/GaN surface. These data are complemented by the results of high-resolution X-ray diffraction, photoluminescence, and impedance spectroscopy of the investigated heterostructures.