Nanogrinding induced surface and deformation mechanism of single crystal β-Ga2O3

Surface and deformation characteristics of single crystal β-Ga2O3 under nanogrinding were investigated using nanoindentation and transmission electron microscopy. Nanocrystals, stacking faults, twins and dislocations were the main deformation patterns found in the grinding of this semiconductor crystal. An amorphous phase was found when the specific grinding energy was significantly high, which was initiated behind the occurrence of other defects. The occurrence sequence of defects is somehow different from that of other semiconductors such as silicon, germanium and gallium arsenide. The hardness of grinding-induced deformed layer was higher than that of the perfect β-Ga2O3 crystal. The thickness and hardness of the defect layer were both reduced when a finer grit size was used. The mechanism responsible for deformation was found to be related to the intrinsic stacking fault energy of β-Ga2O3 and the specific grinding energy being used.