Structural and electrical characterization of homoepitaxial (1¯02) β -Ga2O3 layers grown by halide vapor phase epitaxy using synchrotron x-ray topography and emission microscopy

This study demonstrates that (1¯02) β-Ga2O3 is a promising candidate for homoepitaxial growth via halide vapor phase epitaxy. Synchrotron x-ray rocking curve measurements confirmed a uniform full-width at half-maximum of approximately 16 arc sec across the wafer for both the substrate and the epitaxial layer. A donor concentration in the range from 7 × 1015 to 1 × 1016 cm−3 was confirmed by capacitance–voltage measurements of the Schottky barrier diodes (SBDs). Among the 35 SBDs, 32 exhibited a leakage current density lower than the detection limit under a reverse bias of −300 V, resulting in a high yield of approximately 91%. Synchrotron x-ray topography observation further identified that residual polycrystalline defects within the epitaxial film, which persist even after chemical mechanical polishing, were responsible for the reverse leakage current of the SBDs.