Design and Performance Analysis of Zinc Oxide Thin Film Transistor (ZnO2 TFT) with High-kk Dielectric Materials
Abstract
ZnO has been extensively used as oxide in the thin film electronics industry because of its performance advantages such as electrical and optical properties. This study represents the design and optimization of the ZnO thin film transistor (TFT). The characteristics of the device are studied using the software Silvaco TCAD ATLAS. The improvement in the performance of the device has been observed in optimizing dielectric layer thickness (ToxTox). Further SiO2 oxide layer is replaced with the high-kk dielectric to improve its performance. The use of high-kk dielectric gives the concept of equivalent oxide thickness (EOT) in which physical thickness (PT) of the dielectric layer is increased without increasing electric thickness (effective thickness), which improves the reliability of the device. The electrical parameters extracted for the low-kk SiO2 (K=3.9K=3.9) at thickness (TSiO2) 50nm are Ion=2.13×10−5Ion=2.13×10−5A, Ioff=1.41×10−12Ioff=1.41×10−12A, Ion∕Ioff=107Ion∕Ioff=107, SS=0.077SS=0.077V/decade, VTH=0.27VTH=0.27V. The high performance of the device has been achieved using Al2O3 and HfO2 as the dielectric material.
