Comparative studies on the physical and electronic properties of reactively sputtered ZnO and ZnON semiconductors

Thin film transistors were fabricated using ZnO and ZnON semiconductors grown by DC reactive sputtering. After low vacuum annealing at 250 °C, ZnON devices exhibit superior electrical performance (µsat=56.3 cm2/Vs, Vth=−1.59 V, and SS=0.51 V/dec) in comparison with ZnO devices (µsat=0.99 cm2/Vs, Vth=3.28 V, and SS=1.22 V/dec). The physical and electronic structures in both materials were analyzed by X-ray diffraction and X-ray absorption spectroscopy, respectively. The chemical bonding states were also examined by X-ray photoelectron spectroscopy. Consequently, nitrogen incorporation in DC reactive sputtering is found to suppress crystallization and enhance electron transport by the formation of Zn–N bonds.