High-quality heteroepitaxy of ε-Ga2O3 films on 4H-SiC substrates grown via MOCVD

Abstract

In this study, high-quality ε-Ga₂O₃ epitaxial layers were grown on a silicon carbide (4H-SiC) substrate via metal–organic chemical vapor deposition (MOCVD) with a two-step growth method. A (004) rocking curve full width of half maximum (FWHM) of the ε-Ga₂O₃ epitaxial layer as small as 0.09° (341 arcsec) is achieved, which is currently the lowest reported value obtained using the MOCVD method. The effect of nucleation layer structure on the crystalline quality is investigated. As a result, a high-temperature nucleation layer, composed of a mixed phase (β + ε) structure with low grain density is beneficial for the growth of high-quality ε-Ga₂O₃ films. A growth model was proposed to explain the mechanism whereby high quality ε-Ga₂O₃ hetroepitaxy is achieved. This study provides valuable insight for the development of epitaxial ε-Ga₂O₃ on 4H-SiC substrates.