Stable and High-Performance Flexible ZnO Thin-Film Transistors by Atomic Layer Deposition
Journal
ACS Applied Materials and Interfaces
Journal Volume
7
Journal Issue
40
Pages
22610-22617
Date Issued
2015
Author(s)
Abstract
Passivation is a challenging issue for the oxide thin-film transistor (TFT) technologies because it requires prolonged high-temperature annealing treatments to remedy defects produced in the process, which greatly limits its manufacturability as well as its compatibility with temperature-sensitive materials such as flexible plastic substrates. This study investigates the defect-formation mechanisms incurred by atomic layer deposition (ALD) passivation processes on ZnO TFTs, based on which we demonstrate for the first time degradation-free passivation of ZnO TFTs by a TiO2/Al2O3 nanolaminated (TAO) film deposited by a low-temperature (110 °C) ALD process. By combining the TAO passivation film with ALD dielectric and channel layers into an integrated low-temperature ALD process, we successfully fabricate flexible ZnO TFTs on plastics. Thanks to the exceptional gas-barrier property of the TAO film (water vapor transmission rate (WVTR)20 cm2 V(-1) s(-1), subthreshold swing10,000 s), air-storage (>1200 h), and bending (1.3 cm radius for 1000 times).
Type
journal article