In−Zn−O Thin Films with Hydrogen Flow

Amorphous In−Zn−O thin films were deposited with various hydrogen flow rates using a magnetron sputtering system. With the addition of hydrogen, the mechanical stability of the films was dramatically improved without any degradation of electrical properties and optical transmittance. The average change in the resistance of the sample deposited at a hydrogen flow rate of 0.4% was approximately six times lower than that in the sample deposited without hydrogen. Both, the compressive residual stress and absorption coefficient of the sample, decreased with hydrogen flow, indicating similar trends with the average change in the resistance. The absorption coefficient near 3.1 eV indicated that subgap state defects also decreased with increasing hydrogen flow rates. It was confirmed that the improvement in mechanical stability was derived from the suppression of subgap defects due to the hydrogen impurity. Thus, we demonstrated that hydrogen is a promising candidate for stabilizing the mechanical properties of oxide thin films.