Investigation of the crack extending downward along the seed of the β-Ga2O3 crystal grown by the EFG method

Abstract

A crack extending downward along the seed of a beta-gallium oxide (β-Ga₂O₃) crystal grown using the edge-defined film-fed growth (EFG) method severely affects the efficiency of crystal slicing. In this study, the influence of the crack on the structural, electronic, and optical properties, as well as the defects in the β-Ga₂O₃ crystal, was investigated. The causes of the crack were also discussed in this study. Compared with the low crystalline crystal on the right side of the crack, the single crystal on the left side exhibits superior crystalline quality, according to the high-resolution X-ray diffraction and Raman scattering spectra. The Hall data and optical transmission spectra reveal that the crack has a negligible effect on the carrier concentration and optical bandgap. The PL results indicate that the right crystal has more defects caused by oxygen vacancies than the left crystal. Rugby-ball-shaped dislocation etch pits were discovered using a chemical etching approach. The average dislocation densities on the left and right sides of the crack were 9 × 10³ cm⁻² and 3 × 10⁴ cm⁻², respectively.