Uniform wafer-scale MOCVD homoepitaxy of β-Ga ₂ O ₃ on 2-inch (010) substrates

Abstract The (010) orientation of β -Ga 2 O 3 is a highly promising platform for next-generation lateral power electronics due to its superior theoretical transport properties. However, progress has been impeded by the unavailability of large-area substrates, limiting studies to small-scale samples. Leveraging the recent emergence of 2-inch wafers, we report the first demonstration of homoepitaxial growth on a 2-inch, Fe-doped semi-insulating (010) β -Ga 2 O 3 substrate by metal–organic chemical vapor deposition (MOCVD). A systematic, wafer-scale characterization reveals the successful growth of a high-quality epitaxial film. High-resolution x-ray diffraction shows an excellent crystalline structure, with a rocking curve full-width ranging from 21.0 arcsec to 103.0 arcsec. Atomic force microscopy confirms an atomically smooth surface with a root-mean-square roughness below 1.53 nm, displaying a distinct step-flow growth mode across the wafer. Furthermore, mercury-probe capacitance–voltage mapping indicates a well-controlled carrier concentration of ∼2 × 10 18 cm −3 with a RSD of 5.12%. This work provides the first comprehensive assessment of 2-inch (010) Ga 2 O 3 epitaxial wafers, validating a critical material platform for the development and future manufacturing of high-performance power devices.