ACTIVE MATRIX SUBSTRATE, METHOD OF MANUFACTURING ACTIVE MATRIX SUBSTRATE, AND DISPLAY DEVICE

• US 20170363926A1
• Filed: 06/07/2017
• Published: 12/21/2017
• Est. Priority Date: 06/15/2016
• Status: Active Grant

• Current Assignee: JDI Design and Development GK
• Original Assignee: JOLED Inc.
• Inventors: MATSUO, Eri, KINOSHITA, Tomoatsu, TOYOTA, Motohiro, HIROMASU, Yasunobu
• Granted Patent: US 10,551,704 B2
• Time in Patent Office: Days
• CPC Class Codes: G02F 1/136286 Wiring, e.g. gate line, drain line
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: H01L 24/24 of an individual high density interconnect connector
• CPC Class Codes: H01L 24/82 by forming build-up interconnects at chip-level, e.g. for high density interconnects [HDI] interconnection structure between a plurality of semiconductor chips H01L23/5389
• CPC Class Codes: H01L 24/83 using a layer connector
• 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 27/124 with a particular composition, shape or layout of the wiring layers specially adapted to the circuit arrangement, e.g. scanning lines in LCD pixel circuits wiring structures per se H01L23/52
• CPC Class Codes: H01L 27/1255 integrated with passive devices, e.g. auxiliary capacitors
• CPC Class Codes: H01L 27/1262 with a particular formation, treatment or coating of the substrate

Abstract

Provided is an active matrix substrate that includes a substrate, a thin film transistor, an electrode layer, and a second insulating film. The thin film transistor is provided on the substrate and includes an oxide semiconductor layer, a gate electrode, and source and drain electrodes. The oxide semiconductor layer includes a first region as a channel region. The electrode layer is level with the gate electrode, is provided in a different region from the thin film transistor, and includes a first end. The second insulating film is provided between the substrate and the electrode layer and includes a second end at a more retreated position than the first end of the electrode layer. The oxide semiconductor layer further includes a second region having lower resistance than the first region. The electrode layer is electrically coupled, at the first end, to the second region of the oxide semiconductor layer.

Claims

1. An active matrix substrate, comprising:

a substrate;

a thin film transistor that is provided on the substrate and includes an oxide semiconductor layer, a gate electrode, and source and drain electrodes, the oxide semiconductor layer including a first region as a channel region, the gate electrode being disposed in confronted relation with the first region of the oxide semiconductor layer with a first insulating film in between, and the source and drain electrodes being electrically coupled to the oxide semiconductor layer;

an electrode layer that is level with the gate electrode, is provided in a different region from the thin film transistor, and includes a first end; and

a second insulating film that is provided between the substrate and the electrode layer and includes a second end at a more retreated position than the first end of the electrode layer,

the oxide semiconductor layer further including a second region having lower resistance than the first region, and

the electrode layer being electrically coupled, at the first end, to the second region of the oxide semiconductor layer.

2. The active matrix substrate according to claim 1, wherein

the electrode layer is provided in overlapping relation with the oxide semiconductor layer.

3. The active matrix substrate according to claim 2, wherein

the oxide semiconductor layer includes the second region in adjacent relation to the first region, and

the second region includes, at an opposite end to the first region, an overlap part in which the second region overlaps with the electrode layer.

4. The active matrix substrate according to claim 1, further comprising a high-resistance film that includes a metal oxide and covers respective upper surfaces of the gate electrode, the electrode layer, and the second region of the oxide semiconductor layer.

5. The active matrix substrate according to claim 1, wherein

in the thin film transistor, the gate electrode and the first insulating film have a same shape in plan view.

6. The active matrix substrate according to claim 1, further comprising a capacitor, the capacitor including:

a first electrode layer that is level with the oxide semiconductor layer of the thin film transistor; and

a second electrode layer that is provided on the first electrode layer with the second insulating film in between and serves as the electrode layer.

7. The active matrix substrate according to claim 6, wherein

the first electrode layer includes a same oxide semiconductor as the oxide semiconductor layer, and

the second electrode layer includes a same material as the gate electrode.

8. A method of manufacturing an active matrix substrate, the method comprising:

forming a thin film transistor on a substrate, the thin film transistor including an oxide semiconductor layer, a gate electrode, and source and drain electrodes, the oxide semiconductor layer including a first region as a channel region, the gate electrode being disposed in confronted relation with the first region of the oxide semiconductor layer with a first insulating film in between, and the source and drain electrodes being electrically coupled to the oxide semiconductor layer;

forming, in a different region from the thin film transistor, an electrode layer that is level with the gate electrode and includes a first end; and

forming a second insulating film between the substrate and the electrode layer, the second insulating film including a second end at a more retreated position than the first end of the electrode layer,

the oxide semiconductor layer further including a second region having lower resistance than the first region, and

the electrode layer being electrically coupled, at the first end, to the second region of the oxide semiconductor layer.

9. The method of manufacturing the active matrix substrate according to claim 8, wherein

the electrode layer is formed in overlapping relation with the oxide semiconductor layer.

10. The method of manufacturing the active matrix substrate according to claim 9, wherein

after the electrode layer and the gate electrode are formed, a metal film is formed and heat treatment is performed, to form the second region.

11. The method of manufacturing the active matrix substrate according to claim 8, wherein

in the forming of the thin film transistor, the gate electrode and the first insulating film are successively processed in a same process.

12. A display device provided with an active matrix substrate, the active matrix substrate comprising:

a substrate;

a thin film transistor that is provided on the substrate and includes an oxide semiconductor layer, a gate electrode, and source and drain electrodes, the oxide semiconductor layer including a first region as a channel region, the gate electrode being disposed in confronted relation with the first region of the oxide semiconductor layer with a first insulating film in between, and the source and drain electrodes being electrically coupled to the oxide semiconductor layer;

an electrode layer that is level with the gate electrode, is provided in a different region from the thin film transistor, and includes a first end; and

a second insulating film that is provided between the substrate and the electrode layer and includes a second end at a more retreated position than the first end of the electrode layer,

the oxide semiconductor layer further including a second region having lower resistance than the first region, and

the electrode layer being electrically coupled, at the first end, to the second region of the oxide semiconductor layer.