Sn의 농도와 film의 두께가 ZTO TFTs의 전기적 구조적 특징에 미치는 영향

Abstract

This thesis investigates the effect of Sn concentration and film thickness on properties of zinc tin oxide (ZTO) thin film transistors (TFTs) which were fabricated using solution process. The ZTO solution was synthesized using a zinc acetate dehydrate and tin chloride dehydrate dissolved in a solvent. This solvent composed of 2-methoxyethanol and mono-ethanolamine. The spin coating method was used to deposit the ZTO active channel films at room temperature, and the ZTO films were annealed at 300 °C for 10 min and 550 °C for 120 min. Depending on the Sn concentration and film thickness, the structure of film changed with a variation of Sn concentration, which varied the electrical parameters of ZTO TFT. Optimum Sn % and film thickness of ZTO TFT were 30% and 35 nm, respectively. The fabricated ZTO TFT exhibited an on/off ratio of 1.17×107, a carrier mobility of 17.12 cm2/Vs, a subthershold swing of 0.78 V/decade, and a threshold voltage of 4.73 V. The proposed ZTO TFT has improved electrical properties compare to conventional amorphous silicon TFTs.