High thickness uniformity of 2-in. wafer-scale β-Ga2O3 films grown by MOCVD and photoelectrical properties

In this study, 2-in. wafer-scale large-area β-Ga2O3 epitaxial films were fabricated on c-plane sapphire substrates via metal-organic chemical vapor deposition. X-ray diffraction, atomic force microscopy, field-emission scanning electron microscope, and photoelectric properties were carried out to disclose the material uniformity of large-scale β-Ga2O3 epitaxial films. Even with film thickness as thick as 1.5  μm, the grown β-Ga2O3 epitaxial films demonstrated high crystal quality with an average FWHM of 1.71° and a standard deviation (SD) of 0.035, smooth surface morphology with an average root-mean-square of 5.45 nm and a slight deviation of 0.09 nm, outstanding thickness uniformity with an average film thickness of 1.55  μm and SD value of only 28 nm. Furthermore, each β-Ga2O3 photodetector on epitaxial wafer expressed uniform stability of the photoelectric performance distribution. High material uniformity of our fabricated large-scale β-Ga2O3 epitaxial films lays a solid foundation for its future mass production of Ga2O3-based devices.