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Title: Abnormal positive bias stress instability of In–Ga–Zn–O thin-film transistors with low-temperature Al{sub 2}O{sub 3} gate dielectric

Abstract

Low-temperature atomic layer deposition (ALD) was employed to deposit Al{sub 2}O{sub 3} as a gate dielectric in amorphous In–Ga–Zn–O thin-film transistors fabricated at temperatures below 120 °C. The devices exhibited a negligible threshold voltage shift (ΔV{sub T}) during negative bias stress, but a more pronounced ΔV{sub T} under positive bias stress with a characteristic turnaround behavior from a positive ΔV{sub T} to a negative ΔV{sub T}. This abnormal positive bias instability is explained using a two-process model, including both electron trapping and hydrogen release and migration. Electron trapping induces the initial positive ΔV{sub T}, which can be fitted using the stretched exponential function. The breakage of residual AlO-H bonds in low-temperature ALD Al{sub 2}O{sub 3} is triggered by the energetic channel electrons. The hydrogen atoms then diffuse toward the In–Ga–Zn–O channel and induce the negative ΔV{sub T} through electron doping with power-law time dependence. A rapid partial recovery of the negative ΔV{sub T} after stress is also observed during relaxation.

Authors:
; ; ; ;  [1]
  1. Department of Electronics Engineering and Institute of Electronics, National Chiao Tung University, Hsinchu, Taiwan (China)
Publication Date:
OSTI Identifier:
22489332
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 108; Journal Issue: 3; Other Information: (c) 2016 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ALUMINIUM OXIDES; ATOMS; DIELECTRIC MATERIALS; HYDROGEN; INSTABILITY; RELAXATION; STRESSES; THIN FILMS; TRANSISTORS; TRAPPING

Citation Formats

Chang, Yu-Hong, Yu, Ming-Jiue, Lin, Ruei-Ping, Hsu, Chih-Pin, and Hou, Tuo-Hung, E-mail: thhou@mail.nctu.edu.tw. Abnormal positive bias stress instability of In–Ga–Zn–O thin-film transistors with low-temperature Al{sub 2}O{sub 3} gate dielectric. United States: N. p., 2016. Web. doi:10.1063/1.4939905.
Chang, Yu-Hong, Yu, Ming-Jiue, Lin, Ruei-Ping, Hsu, Chih-Pin, & Hou, Tuo-Hung, E-mail: thhou@mail.nctu.edu.tw. Abnormal positive bias stress instability of In–Ga–Zn–O thin-film transistors with low-temperature Al{sub 2}O{sub 3} gate dielectric. United States. doi:10.1063/1.4939905.
Chang, Yu-Hong, Yu, Ming-Jiue, Lin, Ruei-Ping, Hsu, Chih-Pin, and Hou, Tuo-Hung, E-mail: thhou@mail.nctu.edu.tw. Mon . "Abnormal positive bias stress instability of In–Ga–Zn–O thin-film transistors with low-temperature Al{sub 2}O{sub 3} gate dielectric". United States. doi:10.1063/1.4939905.
@article{osti_22489332,
title = {Abnormal positive bias stress instability of In–Ga–Zn–O thin-film transistors with low-temperature Al{sub 2}O{sub 3} gate dielectric},
author = {Chang, Yu-Hong and Yu, Ming-Jiue and Lin, Ruei-Ping and Hsu, Chih-Pin and Hou, Tuo-Hung, E-mail: thhou@mail.nctu.edu.tw},
abstractNote = {Low-temperature atomic layer deposition (ALD) was employed to deposit Al{sub 2}O{sub 3} as a gate dielectric in amorphous In–Ga–Zn–O thin-film transistors fabricated at temperatures below 120 °C. The devices exhibited a negligible threshold voltage shift (ΔV{sub T}) during negative bias stress, but a more pronounced ΔV{sub T} under positive bias stress with a characteristic turnaround behavior from a positive ΔV{sub T} to a negative ΔV{sub T}. This abnormal positive bias instability is explained using a two-process model, including both electron trapping and hydrogen release and migration. Electron trapping induces the initial positive ΔV{sub T}, which can be fitted using the stretched exponential function. The breakage of residual AlO-H bonds in low-temperature ALD Al{sub 2}O{sub 3} is triggered by the energetic channel electrons. The hydrogen atoms then diffuse toward the In–Ga–Zn–O channel and induce the negative ΔV{sub T} through electron doping with power-law time dependence. A rapid partial recovery of the negative ΔV{sub T} after stress is also observed during relaxation.},
doi = {10.1063/1.4939905},
journal = {Applied Physics Letters},
number = 3,
volume = 108,
place = {United States},
year = {Mon Jan 18 00:00:00 EST 2016},
month = {Mon Jan 18 00:00:00 EST 2016}
}