Annealing temperature effects on the structural and electrical properties of N-doped In-Zn-Sn-O thin film transistors

The effects of annealing temperature on the structural and electrical properties of the N -doped In-Zn-Sn-O (IZTO:N) thin film transistors (TFTs) were investigated. X-ray diffraction (XRD) result indicates that IZTO:N thin films were amorphous. The optical transmittance of the thin films was over 80% to the visible. Atomic force microscopy (AFM) images showed that surface of thin films was smooth. With the annealing temperature increased from 175 to 375 degrees C, the saturation mobility (mu(SAT)) of IZTO:N TFTs increased while the threshold voltage (V-TH ) showed a negative shift. The IZTO:N TFT annealed at 275 degrees C showed excellent overall performances with a mu(SAT) of 37.6 cm(2)/V.s, a V-TH of 1.4 V, a subthreshold swing (SS) of 0.38 V/decade and a current on/off (I-ON/I-OFF) of 4.96 x 10(9). Under gate bias stress, there was a decreased shift in V-TH with increasing temperature due to the reduction of trap states. (C) 2019 Elsevier B.V. All rights reserved.