Realization of 4-inch diameter and thick β-Ga2O3 single crystals using the vertical Bridgman method

Abstract

Gallium oxide (β-Ga₂O₃) is an ultra-wide-bandgap semiconductor with properties promising for next-generation power and optoelectronic devices. Here, 4-inch diameter, (100) oriented β-Ga₂O₃ bulk single crystals with a thickness exceeding 30 mm were successfully grown using a modified vertical Bridgman method. Active numerical simulations were employed to accelerate the iterative optimization of the crystal growth process. The resulting crystals exhibited high crystalline quality, confirmed by high-resolution X-ray diffraction (HRXRD), with a narrow full width at half maximum of 64.8 arcsec. Impurity analysis identified rhodium (Rh) as the primary metallic contaminant (63 ppm), contributing to electrical resistivity exceeding 10¹⁰ Ω cm. Our work demonstrates a pathway toward low-cost, scalable production of large, high-quality β-Ga₂O₃ crystals, advancing their prospects for high-performance device applications.