Study of InGaZnO Thin Film Transistors With Dual Treatment of Pre-Oxidation ZrO2 High-κ Dielectric and Post-Oxidation InGaZnO Channel by Neutral Beam System

Abstract

With better field-effect mobility (>10 cm2/V·S), smaller subthreshold swing (S.S), and other electrical characteristics, amorphous IGZO thin film transistors (a-IGZO TFTs) has been studied extensively for its promising applications, such as liquid crystal displays and flat-panel displays. In this investigation, TFT devices are experimented to enhance the electrical characteristics. Atmosphere Pressure-PECVD (AP-PECVD) is used to deposit a-IGZO, which is designed as device channel layer. In order to maintain enough gate control ability with thinner effective oxide thickness (EOT), high-κ material ZrO2 is used as dielectric, lowering the gate leaking current. With post dual neutral beams O2 plasma treated on both a-IGZO channel layer 400 W and ZrO2 dielectric 100 W, the best result for experimental devices show that the a-IGZO TFT has electrical characteristics of field-effect mobility of 22.22 cm2/V·S, threshold voltage (VT) of 2.86 V, S.S of 74 mV/decade, and Ion/Ioff ratio of 8.2×105. Keywor