退火环境对非晶铟镓锌氧化物薄膜晶体管电学特性的影响

Effect of the annealing ambient on the electrical characteristics of the amorphous InGaZnO thin film transistors.

作者信息

Huang Yu-Chih, Yang Po-Yu, Huang Hau-Yuan, Wang Shui-Jinn, Cheng Huang-Chung

机构信息

Department of Electronics Engineering and Institute of Electronics, National Chiao Tung University, Hsinchu 30010, Taiwan.

出版信息

J Nanosci Nanotechnol. 2012 Jul;12(7):5625-30. doi: 10.1166/jnn.2012.6307.

DOI:10.1166/jnn.2012.6307

PMID:22966622

Abstract

The influence of the thermal annealing on the amorphous indium gallium zinc oxide (a-IGZO) thin-film transistors (TFTs) under different ambient gases has been systematically addressed. The chemical bonding states and transfer characteristics of a-IGZO TFTs show evident dependence on the annealing ambient gas. For the a-IGZO TFTs in the oxygen ambient annealing at 250 degrees C for 30 mins exhibited a maximum field effect mobility (max muFE) of 9.36 cm2/V x s, on/off current ratio of 6.12 x 10(10), and a subthreshold slope (SS) of 0.21 V/decade. Respectively, the as-deposited ones without annealing possess a max muFE of 6.61 cm2/V x s, on/off current ratio of 4.58 x 10(8), and a SS of 0.46 V/decade. In contrast, the a-IGZO TFTs annealed at 250 degrees C for 30 mins in the nitrogen ambient would be degraded to have a max muFE of 0.18 cm2/V x s, on/off current ratio of 2.22 x 10(4), and a SS of 7.37 V/decade, corresponding. It is attributed to the content of the oxygen vacancies, according the x-ray photoelectron spectroscopy (XPS) analyze of the three different samples.

摘要

系统地研究了热退火对不同环境气体下非晶铟镓锌氧化物（a-IGZO）薄膜晶体管（TFT）的影响。a-IGZO TFT的化学键合状态和转移特性明显依赖于退火环境气体。对于在250℃氧气环境中退火30分钟的a-IGZO TFT，其最大场效应迁移率（max muFE）为9.36 cm2/V·s，开/关电流比为6.12×10(10)，亚阈值斜率（SS）为0.21 V/十倍频程。相比之下，未退火的沉积态a-IGZO TFT的max muFE为6.61 cm2/V·s，开/关电流比为4.58×10(8)，SS为0.46 V/十倍频程。相反，在氮气环境中于250℃退火30分钟的a-IGZO TFT会退化，其max muFE为0.18 cm2/V·s，开/关电流比为2.22×10(4)，SS为7.37 V/十倍频程。根据对三种不同样品的X射线光电子能谱（XPS）分析，这归因于氧空位的含量。