(A) study on the effect of intrinsic film stress of Mo source/drain electrodes on electrical characteristics of Al doped In-Zn-Sn-O thin film transistors

Abstract

In this research, detailed mechanism on how the intrinsic film stress of Mo source and drain (S/D) electrodes affects the electrical characteristics of Al doped InZnSnO thin film transistors (Al-IZTO TFTs) is suggested. By changing the Ar pressure during the DC sputtering, Mo films with three different film stresses were successfully deposited. Three kinds of TFTs applying these Mo as S/D electrodes were fabricated. As the film stress of S/D electrodes becomes higher, not only transfer characteristics but also stabilities of Al-IZTO TFTs were deteriorated. Both experimental approach and computational simulation were performed to investigate the effect of film stress in various perspectives. According to the results, it was revealed that oxygen deficient sites in the active layer generated by the film stress of Mo S/D electrodes induced degradation of the device characteristics.