Electrical performance of ZnO thin film transistors having different active layer thickness

Abstract

In this work, ZnO based thin film transistors (TFTs) were fabricated by sol–gel spin-coating method. We report the changes in ZnO TFTs performance according to the thickness of active layer. As the thickness of channel layer increases, it was observed an increase in the field effect mobility up to 0.34 cm²v^-1s^-1 for 65 nm and a decrease in the leakage current. But the maximum I_on/I_off ratio was obtained for 50 nm thickness of ZnO-TFT. This improvement can be attributed to the reduction of channel resistance and enhancement of average grain size.