2-inch diameter (010) principal-face β-Ga₂O₃ single crystals grown by EFG method

The (010)-oriented substrates of β -Ga 2 O 3 are endowed with the maximum thermal conductivity and fastest homoepitaxial rate, which is the preferred substrate direction for high-power devices. However, the size of (010) plane wafer is critically limited by die in the commercial edge-defined film-fed growth (EFG) method. It is difficult to grow the β -Ga 2 O 3 crystal with (010) principal face due to the (100) and (001) are cleavage planes. Here, the 2-inch diameter (010) principal-face β -Ga 2 O 3 single crystal is successfully designed and grown by improved EFG method. Unlike previous reported techniques, the single crystals are pulled with [001] direction, and in this way the (010) wafers can be obtained from the principal face. In our experiments, tree-like defects (TLDs) in (010) principal-face bulk crystals are easy to generate. The relationship between stability of growth interface and origin of TLDs are thoroughly discussed. The TLDs are successfully eliminated by optimizing growth conditions. The high crystalline quality of (010)-oriented substrates are comprehensive demonstrated by full width at half maximum (FWHM) with 50.4 arcsec, consistent orientation arrangement of (010) plane, respectively. This work shows that the (010)-oriented substrates can be obtained by EFG method, predicting the commercial prospects of large-scale (010)-oriented β -Ga 2 O 3 substrates.