Defect characterization of β-Ga 2 O 3 single crystals grown by vertical Bridgman method

The characteristics of structural defects observed on (100) wafers in β-Ga 2 O 3 single crystals grown by directional solidification in a vertical Bridgman furnace were studied in terms of crystal growth conditions. No high-dislocation-density regions near the wafer periphery were observed owing to the lack of adhesion between the as-grown crystal ingot surface and the crucible inner wall, and directional solidification growth in a crucible with a very low temperature gradient resulted in β-Ga 2 O 3 single crystals with a low mean dislocation density of 2.3 × 10 3 cm −2 . Line-shaped defects up to 150 µm long in the [010] direction were detected at a mean density of 0.5 × 10 2 cm −2 , which decreased with decreasing growth rate. The line-shaped defect structure and formation mechanism were discussed.