Effect of HfO<sub>2</sub>-Based Multi-Dielectrics on Electrical Properties of Amorphous In-Ga-Zn-O Thin Film Transistors

We report the fabrication of bottom gate a-IGZO TFTs based on HfO<sub>2</sub> stacked dielectrics with decent electrical characteristics and bias stability. The microscopic, electrical, and optical properties of room temperature deposited a-IGZO film with varied oxygen content were explo...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Ruozheng Wang, Qiang Wei, Jie Li, Jiao Fu, Yiwei Liu, Tianfei Zhu, Cui Yu, Gang Niu, Shengli Wu, Hongxing Wang
Formato: article
Lenguaje:EN
Publicado: MDPI AG 2021
Materias:
Acceso en línea:https://doaj.org/article/939dc7e05e9c4b57aacc3df576f81f19
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
id oai:doaj.org-article:939dc7e05e9c4b57aacc3df576f81f19
record_format dspace
spelling oai:doaj.org-article:939dc7e05e9c4b57aacc3df576f81f192021-11-25T17:16:40ZEffect of HfO<sub>2</sub>-Based Multi-Dielectrics on Electrical Properties of Amorphous In-Ga-Zn-O Thin Film Transistors10.3390/coatings111113812079-6412https://doaj.org/article/939dc7e05e9c4b57aacc3df576f81f192021-11-01T00:00:00Zhttps://www.mdpi.com/2079-6412/11/11/1381https://doaj.org/toc/2079-6412We report the fabrication of bottom gate a-IGZO TFTs based on HfO<sub>2</sub> stacked dielectrics with decent electrical characteristics and bias stability. The microscopic, electrical, and optical properties of room temperature deposited a-IGZO film with varied oxygen content were explored. In order to suppress the bulk defects in the HfO<sub>2</sub> thin film and hence maximize the quality, surface modification of the SiN<sub>x</sub> film was investigated so as to achieve a more uniform layer. The root mean square (RMS) roughness of SiN<sub>x</sub>/HfO<sub>2</sub>/SiN<sub>x</sub> (SHS) stacked dielectrics was only 0.66 nm, which was reduced by 35% compared with HfO<sub>2</sub> single film (1.04 nm). The basic electrical characteristics of SHS-based a-IGZO TFT were as follows: <i>V</i><sub>th</sub> is 2.4 V, <i>μ</i><sub>sat</sub> is 21.1 cm<sup>2</sup> V<sup>−1</sup> s<sup>−1</sup>, <i>I</i><sub>on</sub>/<i>I</i><sub>off</sub> of 3.3 × 10<sup>7</sup>, <i>I</i><sub>off</sub> is 10<sup>−11</sup> A, and <i>SS</i> is 0.22 V/dec. Zr-doped HfO<sub>2</sub> could form a more stable surface, which will decrease the bulk defect states so that the stability of device can be improved. It was found that the electrical characteristics were improved after Zr doping, with a <i>V</i><sub>th</sub> of 1.4 V, <i>I</i><sub>on</sub>/<i>I</i><sub>off</sub> of 10<sup>8</sup>, <i>μ</i><sub>sat</sub> of 19.5 cm<sup>2</sup> V<sup>−1</sup> s<sup>−1</sup>, <i>I</i><sub>off</sub> of 10<sup>−12</sup> A, <i>SS</i> of 0.18 V/dec. After positive gate bias stress of 10<sup>4</sup> s, the Δ<i>V</i><sub>th</sub> was decreased from 0.43 V (without Zr doping) to 0.09 V (with Zr doping), the Δ<i>SS</i> was decreased from 0.19 V/dec to 0.057 V/dec, respectively, which shows a meaningful impact to realize the long-term working stability of TFT devices.Ruozheng WangQiang WeiJie LiJiao FuYiwei LiuTianfei ZhuCui YuGang NiuShengli WuHongxing WangMDPI AGarticlethin-film transistorsamorphous IGZOmulti-dielectricsannealingbias stabilityEngineering (General). Civil engineering (General)TA1-2040ENCoatings, Vol 11, Iss 1381, p 1381 (2021)
institution DOAJ
collection DOAJ
language EN
topic thin-film transistors
amorphous IGZO
multi-dielectrics
annealing
bias stability
Engineering (General). Civil engineering (General)
TA1-2040
spellingShingle thin-film transistors
amorphous IGZO
multi-dielectrics
annealing
bias stability
Engineering (General). Civil engineering (General)
TA1-2040
Ruozheng Wang
Qiang Wei
Jie Li
Jiao Fu
Yiwei Liu
Tianfei Zhu
Cui Yu
Gang Niu
Shengli Wu
Hongxing Wang
Effect of HfO<sub>2</sub>-Based Multi-Dielectrics on Electrical Properties of Amorphous In-Ga-Zn-O Thin Film Transistors
description We report the fabrication of bottom gate a-IGZO TFTs based on HfO<sub>2</sub> stacked dielectrics with decent electrical characteristics and bias stability. The microscopic, electrical, and optical properties of room temperature deposited a-IGZO film with varied oxygen content were explored. In order to suppress the bulk defects in the HfO<sub>2</sub> thin film and hence maximize the quality, surface modification of the SiN<sub>x</sub> film was investigated so as to achieve a more uniform layer. The root mean square (RMS) roughness of SiN<sub>x</sub>/HfO<sub>2</sub>/SiN<sub>x</sub> (SHS) stacked dielectrics was only 0.66 nm, which was reduced by 35% compared with HfO<sub>2</sub> single film (1.04 nm). The basic electrical characteristics of SHS-based a-IGZO TFT were as follows: <i>V</i><sub>th</sub> is 2.4 V, <i>μ</i><sub>sat</sub> is 21.1 cm<sup>2</sup> V<sup>−1</sup> s<sup>−1</sup>, <i>I</i><sub>on</sub>/<i>I</i><sub>off</sub> of 3.3 × 10<sup>7</sup>, <i>I</i><sub>off</sub> is 10<sup>−11</sup> A, and <i>SS</i> is 0.22 V/dec. Zr-doped HfO<sub>2</sub> could form a more stable surface, which will decrease the bulk defect states so that the stability of device can be improved. It was found that the electrical characteristics were improved after Zr doping, with a <i>V</i><sub>th</sub> of 1.4 V, <i>I</i><sub>on</sub>/<i>I</i><sub>off</sub> of 10<sup>8</sup>, <i>μ</i><sub>sat</sub> of 19.5 cm<sup>2</sup> V<sup>−1</sup> s<sup>−1</sup>, <i>I</i><sub>off</sub> of 10<sup>−12</sup> A, <i>SS</i> of 0.18 V/dec. After positive gate bias stress of 10<sup>4</sup> s, the Δ<i>V</i><sub>th</sub> was decreased from 0.43 V (without Zr doping) to 0.09 V (with Zr doping), the Δ<i>SS</i> was decreased from 0.19 V/dec to 0.057 V/dec, respectively, which shows a meaningful impact to realize the long-term working stability of TFT devices.
format article
author Ruozheng Wang
Qiang Wei
Jie Li
Jiao Fu
Yiwei Liu
Tianfei Zhu
Cui Yu
Gang Niu
Shengli Wu
Hongxing Wang
author_facet Ruozheng Wang
Qiang Wei
Jie Li
Jiao Fu
Yiwei Liu
Tianfei Zhu
Cui Yu
Gang Niu
Shengli Wu
Hongxing Wang
author_sort Ruozheng Wang
title Effect of HfO<sub>2</sub>-Based Multi-Dielectrics on Electrical Properties of Amorphous In-Ga-Zn-O Thin Film Transistors
title_short Effect of HfO<sub>2</sub>-Based Multi-Dielectrics on Electrical Properties of Amorphous In-Ga-Zn-O Thin Film Transistors
title_full Effect of HfO<sub>2</sub>-Based Multi-Dielectrics on Electrical Properties of Amorphous In-Ga-Zn-O Thin Film Transistors
title_fullStr Effect of HfO<sub>2</sub>-Based Multi-Dielectrics on Electrical Properties of Amorphous In-Ga-Zn-O Thin Film Transistors
title_full_unstemmed Effect of HfO<sub>2</sub>-Based Multi-Dielectrics on Electrical Properties of Amorphous In-Ga-Zn-O Thin Film Transistors
title_sort effect of hfo<sub>2</sub>-based multi-dielectrics on electrical properties of amorphous in-ga-zn-o thin film transistors
publisher MDPI AG
publishDate 2021
url https://doaj.org/article/939dc7e05e9c4b57aacc3df576f81f19
work_keys_str_mv AT ruozhengwang effectofhfosub2subbasedmultidielectricsonelectricalpropertiesofamorphousingaznothinfilmtransistors
AT qiangwei effectofhfosub2subbasedmultidielectricsonelectricalpropertiesofamorphousingaznothinfilmtransistors
AT jieli effectofhfosub2subbasedmultidielectricsonelectricalpropertiesofamorphousingaznothinfilmtransistors
AT jiaofu effectofhfosub2subbasedmultidielectricsonelectricalpropertiesofamorphousingaznothinfilmtransistors
AT yiweiliu effectofhfosub2subbasedmultidielectricsonelectricalpropertiesofamorphousingaznothinfilmtransistors
AT tianfeizhu effectofhfosub2subbasedmultidielectricsonelectricalpropertiesofamorphousingaznothinfilmtransistors
AT cuiyu effectofhfosub2subbasedmultidielectricsonelectricalpropertiesofamorphousingaznothinfilmtransistors
AT gangniu effectofhfosub2subbasedmultidielectricsonelectricalpropertiesofamorphousingaznothinfilmtransistors
AT shengliwu effectofhfosub2subbasedmultidielectricsonelectricalpropertiesofamorphousingaznothinfilmtransistors
AT hongxingwang effectofhfosub2subbasedmultidielectricsonelectricalpropertiesofamorphousingaznothinfilmtransistors
_version_ 1718412545419640832