The [010] tilt low angle grain boundaries in bulk β-Ga2O3 crystals grown by EFG method

High crystal quality in both the substrate and epitaxy ensures the performance and stability of semiconductor devices. However, due to its low symmetry structure, a variety of crystal defects are easily formed in β-Ga₂O₃. Specifically, low angle grain boundaries (LAGBs) can limit the single crystal size of the β-Ga₂O₃ substrate, thereby reducing the yield of single crystal substrates. In this work, [010] tilt LAGBs were observed on the surface of (010) β-Ga₂O₃ wafer following wet chemical etching, and the etching morphology of the [010] tilt LAGBs showed “bending line segment”. The orientation analysis of the (010) β-Ga₂O₃ wafer indicates that most of the [010] tilt LAGBs in β-Ga₂O₃ bulk crystals have orientation difference angles of <2°. Transmission electron microscope (TEM) results indicate the presence of edge dislocations in the vicinity of [010] tilt LAGBs. The geometric shape of [010] tilt LAGBs in β-Ga₂O₃ crystals was obtained, and the formation mechanism was explained in conjunction with the crystal growth mechanism. Furthermore, [010] tilt LAGBs can result in the appearance of double peaks in X-ray rocking curves due to their capacity to disrupt the integrity of single crystals and to cause orientation differences between grains.