Comparison of defects in crystalline oxide semiconductor materials by electron spin resonance

Defects in crystalline InGaZnO₄ (IGZO) powder sample induced by plasma were evaluated with comparing the defects in pure constituent materials of In₂O₃, Ga₂O₃ and ZnO induced by plasma. ESR signals in IGZO observed at g = 1.939 (signal A) and g = 2.003 (signal B) were different from the g factors observed at g = 1.969 in Ga₂O₃ and at g = 1.957 in ZnO. Intensity of the ESR signal B was decreased with the annealing at 300° C in air. Origin of ESR signals induced in IGZO would be singly ionized oxygen vacancies in IGZO, and influence to the electrical properties of the semiconductor.