Title :
Effects of over-etching time on the characteristics of amorphous IGZO thin-film transistors with back-channel-etch structure
Author :
Guoying Wang ; Zhen Song ; Xiang Xiao ; Shengdong Zhang
Author_Institution :
Sch. of Electron. & Comput. Eng., Peking Univ., Shenzhen, China
Abstract :
Dry-etch for patterning Mo source/drain electrodes directly on amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistors (TFTs) with back-channel-etch (BCE) structure was investigated. The over-etching time of reactive ion etching (RIE) had a great influence on the performance of the BCE a-IGZO TFTs. The a-IGZO TFTs with an appropriate over-etching time, such as 20s, was observed with a field effect mobility (μFE) of 6.51 cm2/V·s, a threshold voltage (VTH) of 0.38 V, a subthreshold swing (SS) of 0.39 V/Dec and an Ion/Ioff current ratio of 109 even when the channel length L decreased to as small as 5 μm. The BCE a-IGZO TFT also showed a good electrical stability with VTH shift of 1.09V and -0.77V under positive and negative gate bias stress, respectively.
Keywords :
amorphous semiconductors; electrochemical electrodes; gallium compounds; indium compounds; molybdenum; sputter etching; thin film transistors; InGaZnO; Mo; Mo source-drain electrode patterning; RIE; amorphous IGZO thin-film transistors; back-channel-etch structure; channel length; dry-etch; electrical stability; field effect mobility; indium-gallium-zinc-oxide; negative gate bias stress; over-etching time effects; positive gate bias stress; reactive ion etching; voltage 0.38 V; Atmosphere; Electrodes; Iron; Logic gates; Stress; Sulfur hexafluoride; Thin film transistors;
Conference_Titel :
Active-Matrix Flatpanel Displays and Devices (AM-FPD), 2015 22nd International Workshop on
Conference_Location :
Kyoto
DOI :
10.1109/AM-FPD.2015.7173211