p-Type β-Ga2O3 Homoepitaxial Films with Superior Electrical Transport Properties

Abstract

This work reports high structural quality and exceptional electrical transport properties of homoepitaxial β-Ga2O3 thin films grown by Metal–Organic Chemical Vapor Deposition (MOCVD) on (010)- and (–201)-oriented substrates. (010) β-Ga2O3 samples exhibit mobility of up to 69.4 cm2 (V·s)−1 and stable hole concentrations ≈2.4 × 1017 cm−3 from 370 to 700 K. Structural and morphological studies, including XRD, AFM, and STEM, confirm high epitaxial quality, absence of extended defects and minimal strain. (–201) β-Ga2O3 layer, which is simultaneously grown, exhibits typical p-Ga2O3 behavior with observed deep level defects. The hole mobility ranging from 26 to 36 cm2 V−1·s−1 is measured between 420 and 700 K. Comparison of (010) and (–201) orientations reveals distinct anisotropic electrical properties. The findings emphasize the free motion of holes in β-Ga2O3 and the critical role of crystallographic orientation.