Gate insulator for high mobility oxide TFT

Abstract

We adopted SiO2 film by means of plasma enhanced atomic layer deposition (PEALD) as the first gate insulator of top gate IGZO TFT. TFT post-annealed at 300°C shows mobility, Vth, and S.S of 39.9 cm2/V.s, -1V, and 0.32 V/dec., respectively. We investigated the effect of H in the gate insulator during the annealing with the comparison of bottom gate coplanar TFT with ALD grown alumina film as the gate insulator.