Electrical and Structural Properties of Two-Inch Diameter (0001) α-Ga2O3 Films Doped with Sn and Grown by Halide Epitaxy

Two-inch diameter alpha-Ga2O3 films with thickness similar to 4 mu m were grown on basal plane sapphire by Halide Vapor Phase Epitaxy (HVPE) and doped with Sn in the top similar to 1 mu m from the surface. These films were characterized with High-Resolution X-ray Diffraction (HRXRD), Scanning Electron Microscope (SEM) imaging in the Secondary Electron (SE) and Micro-cathodoluminescence (MCL) modes, contactless sheet resistivity mapping, capacitance-voltage, current-voltage, admittance spectra, and Deep Level Transient Spectroscopy (DLTS) measurements. The edge and screw dislocations densities estimated from HRXRD data were respectively 7.4 x 10(9 )cm(-2) and 1.5 x 10(7) cm(-2), while the films had a smooth surface with a low density (similar to 10(3 )cm(-2)) of circular openings with diameters between 10 and 100 mu m. The sheet resistivity of the films varied over the entire 2-inch diameter from 200 to 500 omega square(-1). The net donor concentration was similar to 10(18 )cm(-3) near the surface and increased to similar to 4 x 10(18) cm(-3) deeper inside the sample. The deep traps observed in admittance and DLTS spectra had levels at E-c-0.25 eV and E-c-0.35 eV, with concentration similar to 10(15 )cm(-3) and E-c-1 eV with concentration similar to 10(16 )cm(-3).

Automated summary

Two-inch diameter alpha-Ga2O3 films with a thickness of about 4 μm were successfully grown on basal plane sapphire using HVPE. The films were characterized using various techniques, revealing low dislocation densities, smooth surface, and varied sheet resistivity. Furthermore, the donor concentration and deep trap levels were also observed.