Thin film transistor

Patent metadata

Field	Value
Publication number	US-9324882-B2
Application number	US-201514721779-A
Country	US
Kind code	B2
Filing date	May 26, 2015
Priority date	Jun 6, 2012
Publication date	Apr 26, 2016
Grant date	Apr 26, 2016

Abstract

A thin film transistor containing at least, a gate electrode, a gate insulating film, an oxide semiconductor layer, source-drain electrode and a passivation film, in this order on a substrate. The oxide semiconductor layer is a laminate containing a first oxide semiconductor layer (IGZTO) and a second oxide semiconductor layer (IZTO). The second oxide semiconductor layer is formed on the gate insulating film, and the first oxide semiconductor layer is formed between the second oxide semiconductor layer and the passivation film. The contents of respective metal elements relative to the total amount of all the metal elements other than oxygen in the first oxide semiconductor layer are as follows; Ga: 8% or more and 30% or less; In: 25% or less, excluding 0%; Zn: 35% or more to 65% or less; and Sn: 5% or more to 30% or less.

First claim

The invention claimed is:

1. A thin film transistor, comprising;
a gate electrode, a gate insulating film, an oxide semiconductor layer, an etch stopper layer, a source-drain electrode, and a passivation film configured to protect the source-drain electrode, on a substrate in this order,
wherein the oxide semiconductor layer is a laminate comprising:
a first oxide semiconductor layer consisting of In, Ga, Zn, Sn, and O; and
a second oxide semiconductor layer consisting of In, Zn, Sn, and O,
wherein
the contents of respective metal elements relative to the total amount of all the metal elements other than oxygen in the first oxide semiconductor layer are:
In: smaller than or equal to 25 atomic %, excluding 0 atomic %;
Ga: larger than or equal to 8.0 atomic % and smaller than or equal to 30 atomic %;
Zn: larger than or equal ton 30.0 atomic % and smaller than or equal to 65 atomic %; and
Sn: larger than or equal to 5 atomic % and smaller than or equal to 30 atomic %.

2. The thin film transistor according to claim 1 , wherein
the contents of respective metal elements relative to the total amount of all the metal elements other than oxygen in the first oxide semiconductor layer are:
In: smaller than or equal to 20 atomic %, excluding 0 atomic %;
Ga: larger than or equal to 15 atomic % and smaller than or equal to 30 atomic %;
Zn: larger than or equal to 35 atomic % and smaller than or equal to 65 atomic %; and
Sn: larger than or equal to 8 atomic % and smaller than or equal to 30 atomic %.

3. The thin film transistor according to claim 1 , wherein
a thickness of the second oxide semiconductor layer is larger than or equal to 0.5 nm.

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

5. The thin film transistor according to claim 2 , wherein
the second oxide semiconductor layer is formed on the gate insulating film; and
the first oxide semiconductor layer is formed between the second oxide semiconductor layer and the etch stopper layer.

6. The thin film transistor according to claim 2 , wherein
a thickness of the second oxide semiconductor layer is larger than or equal to 0.5 nm.

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

8. The thin film transistor according to claim 1 , wherein
the second oxide semiconductor layer is formed on the gate insulating film; and
the first oxide semiconductor layer is formed between the second oxide semiconductor layer and the etch stopper layer.

Assignees

• Kobe Steel Ltd
• Samsung Display Co Ltd
• Samsung Display Co Ltd

Inventors

• Goto Hiroshi
• Miki Aya
• Kishi Tomoya
• Hirose Kenta
• Morita Shinya
• Kugimiya Toshihiro
• Ahn Byung Du
• Kim Gun Hee
• Kim Yeon Hong

Classifications

• H10P14/3434

  being oxide semiconductor materials (Group IIB-VIA semiconductor materials H10P14/3424) · CPC title

• H10P14/3426

  Oxides · CPC title

• H10P14/22

  using physical deposition, e.g. vacuum deposition or sputtering · CPC title

• H10D30/6713

  characterised by the properties of the source or drain regions, e.g. compositions or sectional shapes · CPC title

• H10D30/6755 Primary

  Oxide semiconductors, e.g. zinc oxide, copper aluminium oxide or cadmium stannate · CPC title