THIN-FILM TRANSISTOR, DISPLAY UNIT, AND ELECTRONIC APPARATUS

• US 20140346499A1
• Filed: 05/09/2014
• Published: 11/27/2014
• Est. Priority Date: 05/24/2013
• Status: Active Grant

• Current Assignee: JDI Design and Development GK
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: KATO, Yuichi
• Granted Patent: US 9,053,984 B2
• Time in Patent Office: Days
• US Class Current: 257/43
• CPC Class Codes: H01L 27/1225 with semiconductor materials not belonging to the group IV of the periodic table, e.g. InGaZnO
• CPC Class Codes: H01L 29/66969 of devices having semiconductor bodies not comprising group 14 or group 13/15 materials comprising selenium or tellurium in uncombined form other than as impurities in semiconductor bodies of other materials, comprising cuprous oxide or cuprous iodide H01L21/02365
• CPC Class Codes: H01L 29/78603 characterised by the insulating substrate or support H01L29/78657 takes precedence
• CPC Class Codes: H01L 29/78618 characterised by the drain or the source properties, e.g. the doping structure, the composition, the sectional shape or the contact structure silicide contacts, electrodes in general H01L29/458
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate

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.

Claims

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 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 provided with a display unit, the display unit being 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.