The impact of plasma-enhanced atomic layer deposited ZrSiOx insulators on low voltage operated In-Sn-Zn-O thin film transistors

Abstract

We deposited Zr silicate by plasma-enhanced atomic layer deposition (PEALD) and investigated its gate insulator performance in indium-tin-zinc oxide (ITZO) thin film transistors (TFTs). Deposited Zr silicate had the desired characteristics of both ZrO₂, a high-k dielectric, and SiO₂. The drawbacks of ZrO₂ thin film can be compensated by employing Zr silicate thin film because the latter has a moderate dielectric constant of 8.4, stoichiometric chemistry, smooth surface, and a low leakage current. Zr silicates as gate insulators may play important roles to reduce coulomb scattering and decrease charge trap density, resulting in high electrical performance and appropriate device stability when used in ITZO TFTs.