Thin-film transistor, display unit, and electronic apparatus

Patent metadata

Field	Value
Publication number	US-9053984-B2
Application number	US-201414273847-A
Country	US
Kind code	B2
Filing date	May 9, 2014
Priority date	May 24, 2013
Publication date	Jun 9, 2015
Grant date	Jun 9, 2015

Abstract

Provided is a thin-film transistor that includes: a substrate; a first barrier film formed on the substrate; a second barrier film formed in a selective region on the first barrier film, and having a barrier property against hydrogen; an oxide semiconductor layer including a first part formed on the second barrier film and a second part formed on the first barrier film, in which the first part functions as an active layer, and the second part has lower electrical resistance than the first part; a gate electrode formed on the first part of the oxide semiconductor layer with a gate insulating film therebetween; and a source electrode or drain electrode electrically connected to the second part of the oxide semiconductor layer. The first barrier film has a barrier property against an impurity from the substrate and a property of chemically reducing the oxide semiconductor layer.

First claim

The invention is claimed as follows:

1. A thin-film transistor comprising:
a substrate;
a first barrier film formed on the substrate;
a second barrier film formed in a selective region on the first barrier film, and having a barrier property against hydrogen;
an oxide semiconductor layer including a first part formed on the second barrier film and a second part formed on the first barrier film, the first part functioning as an active layer, and the second part having lower electrical resistance than the first part;
a gate electrode formed on the first part of the oxide semiconductor layer with a gate insulating film therebetween; and
a source electrode or drain electrode electrically connected to the second part of the oxide semiconductor layer,
the first barrier film having a barrier property against an impurity from the substrate and a property of chemically reducing the oxide semiconductor layer.

2. The thin-film transistor according to claim 1 , wherein
the first barrier film contains one or both of silicon nitride and silicon oxynitride, and
the second barrier film is a single-layered film or a stacked film that contains one or more of oxide silicon, silicon oxynitride, aluminum oxide, and titanium oxide.

3. The thin-film transistor according to claim 1 , wherein the substrate is made of a flexible resin material.

4. The thin-film transistor according to claim 1 , wherein the second part of the oxide semiconductor layer is formed in contact with the first barrier film.

5. The thin-film transistor according to claim 1 , wherein the gate electrode and the gate insulating film are patterned into same shape as one another.

6. The thin-film transistor according to claim 1 , wherein the second part of the oxide semiconductor layer is utilized to form a retention capacity.

7. The thin-film transistor according to claim 1 , wherein the source electrode or drain electrode is provided to oppose a portion of the second part of the oxide semiconductor layer.

8. A display unit comprising:
a display region provided with a plurality of pixels, each of the pixels being provided with a thin-film transistor, each of the thin-film transistors comprising:
a substrate;
a first barrier film formed on the substrate;
a second barrier film formed in a selective region on the first barrier film, and having a barrier property against hydrogen;
an oxide semiconductor layer including a first part formed on the second barrier film and a second part formed on the first barrier film, the first part functioning as an active layer, and the second part having lower electrical resistance than the first part;
a gate electrode formed on the first part of the oxide semiconductor layer with a gate insulating film therebetween; and
a source electrode or drain electrode electrically connected to the second part of the oxide semiconductor layer, the first barrier film having a barrier property against an impurity from the substrate and a property of chemically reducing the oxide semiconductor layer.

9. The display unit according to claim 8 , wherein the display unit is an organic electroluminescence display unit.

10. An electronic apparatus comprising:
a display unit, the display unit including a display region, the display region being provided with a plurality of pixels arranged in a matrix, each of the pixels being provided with a thin-film transistor, each of the thin-film transistors comprising:
a substrate;
a first barrier film formed on the substrate;
a second barrier film formed in a selective region on the first barrier film, and having a barrier property against hydrogen;
an oxide semiconductor layer including a first part formed on the second barrier film and a second part formed on the first barrier film, the first part functioning as an active layer, and the second part having lower electrical resistance than the first part;
a gate electrode formed on the first part of the oxide semiconductor layer with a gate insulating film therebetween; and
a source electrode or drain electrode electrically connected to the second part of the oxide semiconductor layer, the first barrier film having a barrier property against an impurity from the substrate and a property of chemically reducing the oxide semiconductor layer.

Assignees

• Sony Corp

Inventors

• Kato Yuichi

Classifications

• H10D99/00 Primary

  Subject matter not provided for in other groups of this subclass · CPC title

• H10D30/6758

  characterised by the insulating substrates · CPC title

• H10D30/6755

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

• H10D30/6713

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

• H10D86/423 Primary

  comprising semiconductor materials not belonging to the Group IV, e.g. InGaZnO · CPC title