The electrical properties of transparent amorphous zinc-indium-tin oxide (a-ZITO) thin films and the characteristics of thin-film transistors (TFTs) based on these films were examined as functions of the ZITO chemical composition. The ZITO thin films were deposited by cosputtering. By adjusting the content ratio of ZnO and ITO, high-performance a-ZITO TFTs could be fabricated. The a-ZITO TFTs exhibited optimal performance when the a-ZITO film was deposited by sputtering ZnO at a power of 80 W and ITO at a power of 50 W, with the oxygen partial pressure being 4%. The chemical composition of the thin film that exhibited the optimal performance was Zn/In/Sn = 0.53:0.38:0.09. The ZITO TFTs exhibited enhanced-mode operation and a threshold voltage of 0.9 V, an on/off current ratio of 4.7×105, a subthreshold swing of 0.294 V/decade, and a field-effect mobility of 5.32 cm2 V-1 s-1.
All Science Journal Classification (ASJC) codes
- Materials Science(all)