Magnetron-sputtered high performance Y-doped ZnO thin film transistors fabricated at room temperature

Abstract

In this report, sputtered-grown undoped ZnO and Y-doped ZnO (ZnO:Y) thin film transistors (TFTs) are presented. Both undoped ZnO and ZnO:Y thin films exhibited highly preferred c-axis oriented (002) diffraction peaks. The ZnO:Y thin film crystallinity was improved with an increase of (002) peak intensity and grain size. The electrical properties of ZnO:Y TFTs were significantly enhanced relative to undoped ZnO TFTs. ZnO:Y TFTs exhibited excellent performance with high mobility of 38.79cm2V−1s−1, small subthreshold swing of 0.15V/decade, and high Ion/Ioff current ratio of the order of 8.17 × 107. The O1s X-ray photoelectron spectra (XPS) showed oxygen vacancy-related defects present in the ZnO:Y TFTs, which contributed to enhancing the mobility of the TFTs.