Materials, Devices, and Circuits of Transparent Amorphous-Oxide Semiconductor

Hideya Kumomi, Seiichiro Yaginuma, Hideyuki Omura, Amita Goyal, Ayumu Sato, Masaya Watanabe, Mikio Shimada, Nobuyuki Kaji, Kenji Takahashi, Masato Ofuji, Tomohiro Watanabe, Naho Itagaki, Hisae Shimizu, Katsumi Abe, Yoshinori Tateishi, Hisato Yabuta, Tatsuya Iwasaki, Ryo Hayashi, Toshiaki Aiba, Masafumi Sano

Research output: Contribution to journalArticle

60 Citations (Scopus)

Abstract

This paper presents the following recent investigations of transparent amorphous-oxide semiconductors (TAOS) from materials to devices and circuits. 1) Composition of metals in TAOS are widely explored with the aim of seeking semiconductors suitable for the channel layers of thin-film transistors (TFTs) composing backplanes for flat-panel displays. It is found in combinatorial approaches to the materials exploration that indium-based ternary TAOS (In-X-O) and their TFTs show the properties and the performance as good as those of the most popular material of amorphous In-Ga-Zn-O (α-IGZO) when X = Zn or Ge. 2) Defects and impurities in TAOS are investigated by theoretical approaches. The first-principle calculation of the electron states reveals that charge-neutral oxygen vacancy or interstitial forms the density of states around mid-gap level and does not generate carriers directly, while hydrogen impurity raises the Fermi level beyond the conduction-band minimum and acts as a donor in TAOS. 3) Device structures of TAOS-TFTs are also investigated extensively for better performance and stability. It is found in channel-etch type TFTs with bottom-gate inverse-stagger structures that the TFT characteristics and stability are significantly improved by chemically removing the back-channel layer in a wet-etching process. Coplanar homojunction (CH) structure is proposed as a novel device structure where conductive -IGZO regions work as the source and drain electrodes to the channel region of semiconductor α-IGZO. The CH TFTs show excellent characteristics and stability, with low series resistance without any difficulty in making good electrical contact between metals and TAOS. 4) Circuits using TAOS-TFTs are demonstrated. A ring oscillator composed of fifteen-stage inverters with a buffer circuit operates as designed by circuit simulation with a TFT model for hydrogenated amorphous Si TFTs. Pixel circuits composed of three TFTs and one transparent capacitor successfully drive organic light-emission diode cells without a planarization layer on a 2-in diagonal panel having 176 × 144 × 3 pixels.

Original languageEnglish
Pages (from-to)531-540
Number of pages10
JournalIEEE/OSA Journal of Display Technology
Volume5
Issue number12
DOIs
Publication statusPublished - Jan 1 2009
Externally publishedYes

Fingerprint

Amorphous semiconductors
Thin film transistors
transistors
oxides
Networks (circuits)
thin films
homojunctions
Buffer circuits
Pixels
Metals
pixels
Oxide semiconductors
Impurities
Semiconductor materials
Gates (transistor)
impurities
inverters
Flat panel displays
Indium
flat panel displays

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering

Cite this

Kumomi, H., Yaginuma, S., Omura, H., Goyal, A., Sato, A., Watanabe, M., ... Sano, M. (2009). Materials, Devices, and Circuits of Transparent Amorphous-Oxide Semiconductor. IEEE/OSA Journal of Display Technology, 5(12), 531-540. https://doi.org/10.1109/JDT.2009.2025521

Materials, Devices, and Circuits of Transparent Amorphous-Oxide Semiconductor. / Kumomi, Hideya; Yaginuma, Seiichiro; Omura, Hideyuki; Goyal, Amita; Sato, Ayumu; Watanabe, Masaya; Shimada, Mikio; Kaji, Nobuyuki; Takahashi, Kenji; Ofuji, Masato; Watanabe, Tomohiro; Itagaki, Naho; Shimizu, Hisae; Abe, Katsumi; Tateishi, Yoshinori; Yabuta, Hisato; Iwasaki, Tatsuya; Hayashi, Ryo; Aiba, Toshiaki; Sano, Masafumi.

In: IEEE/OSA Journal of Display Technology, Vol. 5, No. 12, 01.01.2009, p. 531-540.

Research output: Contribution to journalArticle

Kumomi, H, Yaginuma, S, Omura, H, Goyal, A, Sato, A, Watanabe, M, Shimada, M, Kaji, N, Takahashi, K, Ofuji, M, Watanabe, T, Itagaki, N, Shimizu, H, Abe, K, Tateishi, Y, Yabuta, H, Iwasaki, T, Hayashi, R, Aiba, T & Sano, M 2009, 'Materials, Devices, and Circuits of Transparent Amorphous-Oxide Semiconductor', IEEE/OSA Journal of Display Technology, vol. 5, no. 12, pp. 531-540. https://doi.org/10.1109/JDT.2009.2025521
Kumomi, Hideya ; Yaginuma, Seiichiro ; Omura, Hideyuki ; Goyal, Amita ; Sato, Ayumu ; Watanabe, Masaya ; Shimada, Mikio ; Kaji, Nobuyuki ; Takahashi, Kenji ; Ofuji, Masato ; Watanabe, Tomohiro ; Itagaki, Naho ; Shimizu, Hisae ; Abe, Katsumi ; Tateishi, Yoshinori ; Yabuta, Hisato ; Iwasaki, Tatsuya ; Hayashi, Ryo ; Aiba, Toshiaki ; Sano, Masafumi. / Materials, Devices, and Circuits of Transparent Amorphous-Oxide Semiconductor. In: IEEE/OSA Journal of Display Technology. 2009 ; Vol. 5, No. 12. pp. 531-540.
@article{1d7db7a136f845f0a2e3174bec55eedc,
title = "Materials, Devices, and Circuits of Transparent Amorphous-Oxide Semiconductor",
abstract = "This paper presents the following recent investigations of transparent amorphous-oxide semiconductors (TAOS) from materials to devices and circuits. 1) Composition of metals in TAOS are widely explored with the aim of seeking semiconductors suitable for the channel layers of thin-film transistors (TFTs) composing backplanes for flat-panel displays. It is found in combinatorial approaches to the materials exploration that indium-based ternary TAOS (In-X-O) and their TFTs show the properties and the performance as good as those of the most popular material of amorphous In-Ga-Zn-O (α-IGZO) when X = Zn or Ge. 2) Defects and impurities in TAOS are investigated by theoretical approaches. The first-principle calculation of the electron states reveals that charge-neutral oxygen vacancy or interstitial forms the density of states around mid-gap level and does not generate carriers directly, while hydrogen impurity raises the Fermi level beyond the conduction-band minimum and acts as a donor in TAOS. 3) Device structures of TAOS-TFTs are also investigated extensively for better performance and stability. It is found in channel-etch type TFTs with bottom-gate inverse-stagger structures that the TFT characteristics and stability are significantly improved by chemically removing the back-channel layer in a wet-etching process. Coplanar homojunction (CH) structure is proposed as a novel device structure where conductive -IGZO regions work as the source and drain electrodes to the channel region of semiconductor α-IGZO. The CH TFTs show excellent characteristics and stability, with low series resistance without any difficulty in making good electrical contact between metals and TAOS. 4) Circuits using TAOS-TFTs are demonstrated. A ring oscillator composed of fifteen-stage inverters with a buffer circuit operates as designed by circuit simulation with a TFT model for hydrogenated amorphous Si TFTs. Pixel circuits composed of three TFTs and one transparent capacitor successfully drive organic light-emission diode cells without a planarization layer on a 2-in diagonal panel having 176 × 144 × 3 pixels.",
author = "Hideya Kumomi and Seiichiro Yaginuma and Hideyuki Omura and Amita Goyal and Ayumu Sato and Masaya Watanabe and Mikio Shimada and Nobuyuki Kaji and Kenji Takahashi and Masato Ofuji and Tomohiro Watanabe and Naho Itagaki and Hisae Shimizu and Katsumi Abe and Yoshinori Tateishi and Hisato Yabuta and Tatsuya Iwasaki and Ryo Hayashi and Toshiaki Aiba and Masafumi Sano",
year = "2009",
month = "1",
day = "1",
doi = "10.1109/JDT.2009.2025521",
language = "English",
volume = "5",
pages = "531--540",
journal = "IEEE/OSA Journal of Display Technology",
issn = "1551-319X",
publisher = "IEEE Computer Society",
number = "12",

}

TY - JOUR

T1 - Materials, Devices, and Circuits of Transparent Amorphous-Oxide Semiconductor

AU - Kumomi, Hideya

AU - Yaginuma, Seiichiro

AU - Omura, Hideyuki

AU - Goyal, Amita

AU - Sato, Ayumu

AU - Watanabe, Masaya

AU - Shimada, Mikio

AU - Kaji, Nobuyuki

AU - Takahashi, Kenji

AU - Ofuji, Masato

AU - Watanabe, Tomohiro

AU - Itagaki, Naho

AU - Shimizu, Hisae

AU - Abe, Katsumi

AU - Tateishi, Yoshinori

AU - Yabuta, Hisato

AU - Iwasaki, Tatsuya

AU - Hayashi, Ryo

AU - Aiba, Toshiaki

AU - Sano, Masafumi

PY - 2009/1/1

Y1 - 2009/1/1

N2 - This paper presents the following recent investigations of transparent amorphous-oxide semiconductors (TAOS) from materials to devices and circuits. 1) Composition of metals in TAOS are widely explored with the aim of seeking semiconductors suitable for the channel layers of thin-film transistors (TFTs) composing backplanes for flat-panel displays. It is found in combinatorial approaches to the materials exploration that indium-based ternary TAOS (In-X-O) and their TFTs show the properties and the performance as good as those of the most popular material of amorphous In-Ga-Zn-O (α-IGZO) when X = Zn or Ge. 2) Defects and impurities in TAOS are investigated by theoretical approaches. The first-principle calculation of the electron states reveals that charge-neutral oxygen vacancy or interstitial forms the density of states around mid-gap level and does not generate carriers directly, while hydrogen impurity raises the Fermi level beyond the conduction-band minimum and acts as a donor in TAOS. 3) Device structures of TAOS-TFTs are also investigated extensively for better performance and stability. It is found in channel-etch type TFTs with bottom-gate inverse-stagger structures that the TFT characteristics and stability are significantly improved by chemically removing the back-channel layer in a wet-etching process. Coplanar homojunction (CH) structure is proposed as a novel device structure where conductive -IGZO regions work as the source and drain electrodes to the channel region of semiconductor α-IGZO. The CH TFTs show excellent characteristics and stability, with low series resistance without any difficulty in making good electrical contact between metals and TAOS. 4) Circuits using TAOS-TFTs are demonstrated. A ring oscillator composed of fifteen-stage inverters with a buffer circuit operates as designed by circuit simulation with a TFT model for hydrogenated amorphous Si TFTs. Pixel circuits composed of three TFTs and one transparent capacitor successfully drive organic light-emission diode cells without a planarization layer on a 2-in diagonal panel having 176 × 144 × 3 pixels.

AB - This paper presents the following recent investigations of transparent amorphous-oxide semiconductors (TAOS) from materials to devices and circuits. 1) Composition of metals in TAOS are widely explored with the aim of seeking semiconductors suitable for the channel layers of thin-film transistors (TFTs) composing backplanes for flat-panel displays. It is found in combinatorial approaches to the materials exploration that indium-based ternary TAOS (In-X-O) and their TFTs show the properties and the performance as good as those of the most popular material of amorphous In-Ga-Zn-O (α-IGZO) when X = Zn or Ge. 2) Defects and impurities in TAOS are investigated by theoretical approaches. The first-principle calculation of the electron states reveals that charge-neutral oxygen vacancy or interstitial forms the density of states around mid-gap level and does not generate carriers directly, while hydrogen impurity raises the Fermi level beyond the conduction-band minimum and acts as a donor in TAOS. 3) Device structures of TAOS-TFTs are also investigated extensively for better performance and stability. It is found in channel-etch type TFTs with bottom-gate inverse-stagger structures that the TFT characteristics and stability are significantly improved by chemically removing the back-channel layer in a wet-etching process. Coplanar homojunction (CH) structure is proposed as a novel device structure where conductive -IGZO regions work as the source and drain electrodes to the channel region of semiconductor α-IGZO. The CH TFTs show excellent characteristics and stability, with low series resistance without any difficulty in making good electrical contact between metals and TAOS. 4) Circuits using TAOS-TFTs are demonstrated. A ring oscillator composed of fifteen-stage inverters with a buffer circuit operates as designed by circuit simulation with a TFT model for hydrogenated amorphous Si TFTs. Pixel circuits composed of three TFTs and one transparent capacitor successfully drive organic light-emission diode cells without a planarization layer on a 2-in diagonal panel having 176 × 144 × 3 pixels.

UR - http://www.scopus.com/inward/record.url?scp=85008054158&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85008054158&partnerID=8YFLogxK

U2 - 10.1109/JDT.2009.2025521

DO - 10.1109/JDT.2009.2025521

M3 - Article

VL - 5

SP - 531

EP - 540

JO - IEEE/OSA Journal of Display Technology

JF - IEEE/OSA Journal of Display Technology

SN - 1551-319X

IS - 12

ER -