%AModak, Sushrut%ALundh, James%AAl-Mamun, Nahid%AChernyak, Leonid%AHaque, Aman%ATu, Thieu%AKuramata, Akito%ATadjer, Marko%APearton, Stephen%BJournal Name: Journal of Vacuum Science & Technology A; Journal Volume: 40; Journal Issue: 6 %D2022%I %JJournal Name: Journal of Vacuum Science & Technology A; Journal Volume: 40; Journal Issue: 6 %K %MOSTI ID: 10378555 %PMedium: X %TGrowth and characterization of α-Ga 2 O 3 on sapphire and nanocrystalline β-Ga 2 O 3 on diamond substrates by halide vapor phase epitaxy %XHalide vapor phase epitaxial (HVPE) Ga 2 O 3 films were grown on c-plane sapphire and diamond substrates at temperatures up to 550 °C without the use of a barrier dielectric layer to protect the diamond surface. Corundum phase α-Ga 2 O 3 was grown on the sapphire substrates, whereas the growth on diamond resulted in regions of nanocrystalline β-Ga 2 O 3 (nc-β-Ga 2 O 3 ) when oxygen was present in the HVPE reactor only during film growth. X-ray diffraction confirmed the growth of α-Ga 2 O 3 on sapphire but failed to detect any β-Ga 2 O 3 reflections from the films grown on diamond. These films were further characterized via Raman spectroscopy, which revealed the β-Ga 2 O 3 phase of these films. Transmission electron microscopy demonstrated the nanocrystalline character of these films. From cathodoluminescence spectra, three emission bands, UVL′, UVL, and BL, were observed for both the α-Ga 2 O 3 /sapphire and nc-Ga 2 O 3 /diamond, and these bands were centered at approximately 3.7, 3.2, and 2.7 eV. %0Journal Article