THIN-FILM TRANSISTOR AND METHOD OF MANUFACTURING SAME

• US 20100051937A1
• Filed: 02/08/2008
• Published: 03/04/2010
• Est. Priority Date: 02/28/2007
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Kaji, Nobuyuki, Yabuta, Hisato, Abe, Katsumi, Hayashi, Ryo
• Granted Patent: US 9,153,703 B2
• Time in Patent Office: Days
• US Class Current: 257/43
• CPC Class Codes: H01L 29/105 with vertical doping variation H01L29/7827 takes precedence
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate
• CPC Class Codes: H01L 29/78696 characterised by the structure of the channel, e.g. multichannel, transverse or longitudinal shape, length or width, doping structure, or the overlap or alignment between the channel and the gate, the source or the drain, or the contacting structure of the channel H01L29/78612 takes precedence; transistors having a drain offset region or a lightly doped drain [LDD] H01L29/78621

Abstract

There is provided a thin-film transistor including at least a substrate, a gate electrode, a gate insulating layer, an oxide semiconductor layer, a source electrode, a drain electrode and a protective layer, wherein the oxide semiconductor layer is an amorphous oxide containing at least one of the elements In, Ga and Zn, the gate electrode-side carrier density of the oxide semiconductor layer is higher than the protective layer-side carrier density thereof, and the film thickness of the oxide semiconductor layer is 30 nm±15 nm.

Claims

1. A thin-film transistor comprising at least:

a substrate;

a gate electrode;

a gate insulating layer;

an oxide semiconductor layer;

a source electrode;

a drain electrode; and

a protective layer;

wherein the oxide semiconductor layer is an amorphous oxide containing at least one of the elements In, Ga and Zn, the gate electrode-side carrier density of the oxide semiconductor layer is higher than the protective layer-side carrier density thereof, and the film thickness of the oxide semiconductor layer is 30 nm±

15 nm.

2. The thin-film transistor according to claim 1, wherein the thin-film transistor is a bottom-gate transistor.

6. A display unit comprising at least a thin-film transistor and a display device connected to the thin-film transistor through an electrode, wherein the thin-film transistor according to claim 1 is used as the thin-film transistor.

3. A method of manufacturing a thin-film transistor, comprising at least:

forming a gate electrode on a substrate;

forming a gate insulating layer;

forming an oxide semiconductor layer;

forming a source electrode and a drain electrode; and

forming a protective layer;

wherein the forming of the protective layer is performed by a sputtering method in an oxygen-containing atmosphere.

4. The method of manufacturing a thin-film transistor according to claim 3, wherein the oxygen-containing atmosphere is a mixed gas of O₂ and Ar.

5. The method of manufacturing a thin-film transistor according to claim 4, wherein the O₂/Ar mixing ratio of the mixed gas of O₂ and Ar is 20% or more and 50% or less.