Synergetic effect of H₂O₂ and PTA on the microscratch and indentation of GaN wafer with electricity

Understanding of the removal mechanisms for GaN-ECMP (electrochemical mechanical polishing) is of significant importance for fabricating an atomic-scale smooth surface. Herein, nanoindentation and microscratch with constant and progressive load were utilized to investigate the microscale-deformation behavior of GaN underwent the synergetic effect of H₂O₂ and purified terephthalic acid (PTA) at sliding interface with electricity. Results show that the electrochemical corrosion can further reduce the hardness of GaN with the chemical corrosion, which confirmed the advantage for the potentiation of electricity in oxidative corrosion. Interestingly, as PTA and H₂O₂ coexist, the frictional coefficient of GaN is decreased and elastic-plastic deformation is integrated into microscratch process based on the evolution of the frictional coefficient to reduce excessive wear.