Structural and electrical characteristics of thin film transistor employing an oriented crystalline InGaZnO channel

Abstract

In this study, we investigate the impact of orientated crystalline InGaZnO (IGZO) thin film transistor. To evaluate interface thermodynamic stability of temperature-sensitive IGZO film, the film-structural stabilities of high-and low-indium-content InGaZnO were studied. With increasing annealing temperature up to 700 °C, the crystallinity becomes more pronounced while device electrical characteristics are further improved. We find that the apparently reduced off-state current can be attributed to the formation of c-axis-orientated crystalline located at the X-ray diffraction peak of ð0; 0; 16Þ. The performance improvements include a very low turn-on voltage close to zero voltage, a small subthreshold swing of 130 mV/dec, and a low off-state current of 2.4 ' 10 %14 A/µm at a low operating voltage of 4 V.