Pressure-driven growth mechanisms and uniformity analysis of β-Ga2O3/4H-SiC heteroepitaxy

Abstract

During the heteroepitaxial growth of β-Ga₂O₃, chamber pressure plays a critical role in determining epitaxial quality and uniformity. This study explores the heteroepitaxial growth of β-Ga₂O₃ on 4H-SiC substrates by two-step low pressure chemical vapor deposition. Results reveal a linear correlation between the thickness, surface roughness, and crystal structure of the epitaxial layer and the substrate-to-source distance. Optical interference analysis enables effective thickness estimation based on color, using in confirming growth uniformity. Pressure-driven growth mechanisms was revealed that high pressure promotes β-Ga₂O₃ nucleation, while low pressure enhances preferential growth during the epitaxial stage. Phase and elemental analysis indicate significant pressure effects on oxygen vacancies, and the X-ray diffraction confirms high crystallinity with a narrow X-ray diffraction peak of 0.34° for the (-202) plane. The β-Ga₂O₃/4H-SiC heterojunction diode demonstrates strong rectifying behavior, supporting the application in photodetectors and high-power devices.