Effects of helium annealing in low-temperature and solution-processed amorphous indium-gallium-zinc-oxide thin-film transistors

In this paper, low-temperature, solution-processed amorphous indium-gallium-zinc-oxide thin-film transistors (a-IGZO TFTs) with annealing temperatures as low as 300°C were fabricated using different annealing gases of He, N2, and O2 and their electrical characteristics and long-term stability were a...

Full description

Bibliographic Details
Main Authors: Jeongmin Kim, Ikjun Jang, Jaewook Jeong
Format: Article
Language:English
Published: AIP Publishing LLC 2019-04-01
Series:AIP Advances
Online Access:http://dx.doi.org/10.1063/1.5092642
_version_ 1818032893444751360
author Jeongmin Kim
Ikjun Jang
Jaewook Jeong
author_facet Jeongmin Kim
Ikjun Jang
Jaewook Jeong
author_sort Jeongmin Kim
collection DOAJ
description In this paper, low-temperature, solution-processed amorphous indium-gallium-zinc-oxide thin-film transistors (a-IGZO TFTs) with annealing temperatures as low as 300°C were fabricated using different annealing gases of He, N2, and O2 and their electrical characteristics and long-term stability were analyzed. The field-effect mobility was improved by nearly two times for the a-IGZO TFTs annealed in helium ambient (He sample) in comparison with those annealed in oxygen and nitrogen ambient environments. The subthreshold slope and threshold voltage were also improved for the a-IGZO TFTs annealed in the helium ambient environment due to the low defect density of states in the sub-bandgap region. However, X-ray photoelectron spectroscopy measurements indicate that the electrical characteristics of the low-temperature solution-processed a-IGZO TFTs show severe channel-length dependencies due to the oxygen vacancy variations in the active region. In addition, long-term stability measurements up to seven days reveal that due to the inherently low electron density and high defect density of states in the active region, an increase in the carrier density in the active region induces a large negative shift of the threshold voltage without changing the field-effect mobility or subthreshold slope. It is understood that low-temperature solution-processed a-IGZO TFTs strongly depend on the formation of oxygen vacancies, which can be resolved by controlling the indium mole fraction under a helium annealing condition.
first_indexed 2024-12-10T06:14:36Z
format Article
id doaj.art-2dfd4a5ca57d440188979ec4d1b1b409
institution Directory Open Access Journal
issn 2158-3226
language English
last_indexed 2024-12-10T06:14:36Z
publishDate 2019-04-01
publisher AIP Publishing LLC
record_format Article
series AIP Advances
spelling doaj.art-2dfd4a5ca57d440188979ec4d1b1b4092022-12-22T01:59:28ZengAIP Publishing LLCAIP Advances2158-32262019-04-0194045228045228-710.1063/1.5092642112904ADVEffects of helium annealing in low-temperature and solution-processed amorphous indium-gallium-zinc-oxide thin-film transistorsJeongmin Kim0Ikjun Jang1Jaewook Jeong2School of Information and Communication Engineering, Chungbuk National University, Cheongju, Chungbuk 28644, KoreaSchool of Information and Communication Engineering, Chungbuk National University, Cheongju, Chungbuk 28644, KoreaSchool of Information and Communication Engineering, Chungbuk National University, Cheongju, Chungbuk 28644, KoreaIn this paper, low-temperature, solution-processed amorphous indium-gallium-zinc-oxide thin-film transistors (a-IGZO TFTs) with annealing temperatures as low as 300°C were fabricated using different annealing gases of He, N2, and O2 and their electrical characteristics and long-term stability were analyzed. The field-effect mobility was improved by nearly two times for the a-IGZO TFTs annealed in helium ambient (He sample) in comparison with those annealed in oxygen and nitrogen ambient environments. The subthreshold slope and threshold voltage were also improved for the a-IGZO TFTs annealed in the helium ambient environment due to the low defect density of states in the sub-bandgap region. However, X-ray photoelectron spectroscopy measurements indicate that the electrical characteristics of the low-temperature solution-processed a-IGZO TFTs show severe channel-length dependencies due to the oxygen vacancy variations in the active region. In addition, long-term stability measurements up to seven days reveal that due to the inherently low electron density and high defect density of states in the active region, an increase in the carrier density in the active region induces a large negative shift of the threshold voltage without changing the field-effect mobility or subthreshold slope. It is understood that low-temperature solution-processed a-IGZO TFTs strongly depend on the formation of oxygen vacancies, which can be resolved by controlling the indium mole fraction under a helium annealing condition.http://dx.doi.org/10.1063/1.5092642
spellingShingle Jeongmin Kim
Ikjun Jang
Jaewook Jeong
Effects of helium annealing in low-temperature and solution-processed amorphous indium-gallium-zinc-oxide thin-film transistors
AIP Advances
title Effects of helium annealing in low-temperature and solution-processed amorphous indium-gallium-zinc-oxide thin-film transistors
title_full Effects of helium annealing in low-temperature and solution-processed amorphous indium-gallium-zinc-oxide thin-film transistors
title_fullStr Effects of helium annealing in low-temperature and solution-processed amorphous indium-gallium-zinc-oxide thin-film transistors
title_full_unstemmed Effects of helium annealing in low-temperature and solution-processed amorphous indium-gallium-zinc-oxide thin-film transistors
title_short Effects of helium annealing in low-temperature and solution-processed amorphous indium-gallium-zinc-oxide thin-film transistors
title_sort effects of helium annealing in low temperature and solution processed amorphous indium gallium zinc oxide thin film transistors
url http://dx.doi.org/10.1063/1.5092642
work_keys_str_mv AT jeongminkim effectsofheliumannealinginlowtemperatureandsolutionprocessedamorphousindiumgalliumzincoxidethinfilmtransistors
AT ikjunjang effectsofheliumannealinginlowtemperatureandsolutionprocessedamorphousindiumgalliumzincoxidethinfilmtransistors
AT jaewookjeong effectsofheliumannealinginlowtemperatureandsolutionprocessedamorphousindiumgalliumzincoxidethinfilmtransistors