Preparation and electrical characteristics of N-doped In-Zn-Sn-O thin film transistors by radio frequency magnetron sputtering

Abstract

Bottom-gate top-contact thin film transistors (TFTs) with an active layer of N-doped Indium-Zinc-Tin-Oxide (IZTO:N) were prepared and their electrical properties were studied in this paper. The IZTO:N film was deposited on SiO2/Si substrate by radio frequency (RF) magnetron sputtering at room temperature. The transmittance of the IZTO:N film was over 80% in the visible range. Secondary ion mass spectrometry (SIMS) result showed all the species (In, Zn, Sn, O and N) were uniformly distributed in the film. X-ray diffraction (XRD) patterns revealed that the film was amorphous structure. The obtained IZTO:N TFT operating in the enhancement mode exhibited promising electrical performance with a high saturation mobility of 35.1 cm2/V·s, a high on/off current ratio of 7.2 × 107 and a threshold voltage of 0.4 V.