Thin film transistor and display device

Patent metadata

Field	Value
Publication number	US-9449990-B2
Application number	US-201314423838-A
Country	US
Kind code	B2
Filing date	Aug 30, 2013
Priority date	Aug 31, 2012
Publication date	Sep 20, 2016
Grant date	Sep 20, 2016

Abstract

Provided is a thin film transistor which is provided with an oxide semiconductor thin film layer and has a threshold voltage that does not change much due to light, a bias stress or the like, thereby exhibiting excellent stress stability. A thin film transistor of the present invention is provided with a gate electrode, an oxide semiconductor layer composed of a single layer which is used as a channel layer, an etch stopper layer to protect a surface of the oxide semiconductor layer, a source-drain electrode, and a gate insulator layer arranged between the gate electrode and the channel layer. The metal elements constituting the oxide semiconductor layer comprise In, Zn and Sn. The hydrogen concentration in the gate insulator layer in direct contact with the oxide semiconductor layer is controlled to 4 atomic % or lower.

First claim

The invention claimed is:

1. A thin film transistor, comprising:
a gate electrode;
an oxide semiconductor layer comprising a single layer as a channel layer;
an etch stopper layer that protects a surface of the oxide semiconductor layer;
a source-drain electrode; and
a gate insulator layer arranged between the gate electrode and the channel layer,
wherein the oxide semiconductor layer comprises In, Zn and Sn,
wherein a hydrogen concentration in the gate insulator layer in direct contact with the oxide semiconductor layer is from 0.667 to 4 atomic %,
wherein the gate insulating layer in direct contact with the oxide semiconductor layer is a silicon oxide film, and
wherein the gate insulator layer comprises the single layer structure.

2. The thin film transistor according to claim 1 , wherein when contents (atomic %) of the respective metal elements with respect to all of metal elements excluding oxygen contained in the oxide semiconductor layer are defined as [In], [Zn] and [Sn], respectively, a relationship of
15≦[In]≦35,50≦[Zn]≦60 and 15≦[Sn]≦30

is satisfied.

3. A display device comprising the thin film transistor according to claim 1 .

4. A display device comprising the thin film transistor according to claim 2 .

5. The thin film transistor according to claim 1 , wherein the oxide semiconductor layer comprises from 15 to 20 atomic % of In.

6. The thin film transistor according to claim 1 , wherein the oxide semiconductor layer comprises from 20 to 30 atomic % of Sn.

Assignees

• Kobe Steel Ltd
• Samsung Display Co Ltd

Inventors

• Miki Aya
• Morita Shinya
• Goto Hiroshi
• Tao Hiroaki
• Kugimiya Toshihiro
• Ahn Byung Du
• Kim Gun Hee
• Park Jin Hyun
• Kim Yeon Hong

Classifications

• H10P14/69433

  the material being a silicon nitride not containing oxygen, e.g. SixNy or SixByNz · CPC title

• H10P14/69215

  the material being a silicon oxide, e.g. SiO2 · CPC title

• H10P14/6922

  the material containing Si, O and at least one of H, N, C, F or other non-metal elements, e.g. SiOC, SiOC:H or SiONC · CPC title

• H10P14/6336

  in the presence of a plasma [PECVD] · CPC title

• H10D30/6757

  characterised by the structure of the channel, e.g. transverse or longitudinal shape or doping profile (TFTs having channel structures for preventing kink or snapback effects H10D30/6708; TFTs having lightly-doped source or drain extensions H10D30/6715) · CPC title