Investigation of the effects of deposition parameters on indium-free transparent amorphous oxide semiconductor thin-film transistors fabricated at low temperatures for flexible electronic applications

摘要

Low temperature gallium tin zinc oxide (GSZO) based thin film transistors fabricated on silicon has been investigated as a potential indium free transparent amorphous oxide semiconductor thin film transistor (TAOS TFT) with potential device applications on plastic substrates. A comprehensive and detailed study on the performance of GSZO TFTs has been carried out by studying the effects of processing parameters such as deposition temperature and annealing temperature/duration, as well as the channel thickness with all temperatures held below 150 °C. Variety of characterization techniques, namely Rutherford backscattering (RBS), x-ray photoelectron spectroscopy (XPS) and x-ray reflectivity (XRR) in addition to Ⅰ-Ⅴ and C-V measurements were employed to determine the effects of the above parameters on the composition and quality of the channel. Optimized TFT characteristics of I_D=3×10~(-7) A, I_(ON/OFF) =2×10~6, V_(ON) ～ -2 V, SS ～ 1 V/dec and μ_(FE) = 0.14 cm~2/V• s with a ΔV_(ON) of 3.3 V under 3 hours electrical stress were produced.