Investigations of Solution-Processed BaTiO3 Thin Films with UV-Ozone Treatment and Its Applications as the Dielectric Layers of Indium Gallium Zinc Oxide Thin Film Transistors

摘要

In recent years the optoelectronics industry has been well developed Thin film transistors (TFTs) are particularly important in the development of active-matrix organic light-emitting diode (AM-OLED) displays Amorphous oxide semiconductors (AOSs) such as indium gallium zinc oxide (IGZO) have emerged as potential materials as channel of TFTs Instead of improving the electrical characteristics of the channel layer of TFTs an alternative way is to use high dielectric-constant (high-k) materials as the gate dielectrics for high capacitance and low leakage current Besides the conventional dielectrics finding a more suitable material for TFTs is also a critical issue to be investigated BaTiO3 (BTO) an oxide with a perovskite structure that could be used as ferroelectric materials has ever applied for dielectric layer of organic thin film transistors (OTFTs) and exhibits good insulator property without high process temperature Nevertheless BTO films applied for AOS-TFTs have rarely been investigated In this study sol-gel method is used to fabricate BTO thin films with different UV-ozone illumination time at low-temperature process In the first part of this thesis the detailed investigation of BTO thin films including material and electrical characteristics is presented In the second part of this thesis the proposed BTO thin films after suitable UV-ozone treatment are applied for the dielectric layers of IGZO-TFTs The electrical characteristic and stability test of the devices via bias or illumination are also examined With UV-ozone treatment BTO/IGZO-TFTs show an on/off current ratio of 1 66 × 107 a saturation mobility of 0 29 cm2/Vs and an subthreshold swing of 0 069 V/dec closed to the theoretical minimum value

獎項日期	2015 8月 4
原文	English
監督員	Sheng-Yuan Chu (Supervisor)