Tribological characteristics of bulk (-201) β-Ga2O3 substrate crystals grown by EFG

The tribological and mechanical tests of bulk substate crystals of gallium oxide β-polymorph grown by the EFG technique were carried out. The correlation of coefficient of friction and wear coefficient with hardness is discussed. It is shown that the smooth, epi-ready surface of (-201) Ga₂O₃ samples has an extremely low resistance to abrasion by a sapphire ball. At the same time, the surface of the β-Ga₂O₃ wafer that has not undergone a complete post-growth processing cycle has high mechanical properties. It is pointed out that this difference can be due to deformation defects, which are entered into the subsurface layers during the mechanical impact on the semiconductor material.