Liquid crystal display device including transistor which includes oxide semiconductor

• US 10,095,071 B2
• Filed: 05/16/2016
• Issued: 10/09/2018
• Est. Priority Date: 12/03/2008
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Ishitani, Tetsuji, Kubota, Daisuke
• Primary Examiner(s): NGO, HUYEN LE
• Application Number:
  US15/155,094
• Publication Number:
  US 20160259217A1
• Time in Patent Office: 876 Days
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/13394 spacers regularly patterned on the cell subtrate, e.g. walls, pillars G02F1/133377 takes precedence
• CPC Class Codes: G02F 1/134309 characterised by their geometrical arrangement
• CPC Class Codes: G02F 1/134372 for fringe field switching [FFS] where the common electrode is not patterned
• CPC Class Codes: G02F 1/13439 characterised by their electrical, optical, physical properties; materials therefor; method of making
• CPC Class Codes: G02F 1/1345 Conductors connecting electrodes to cell terminals
• CPC Class Codes: G02F 1/136222 Colour filters incorporated in the active matrix substrate
• CPC Class Codes: G02F 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence

Abstract

A liquid crystal display device is provided, which includes a transistor including an oxide semiconductor layer, a resin layer, a first electrode layer, a second electrode layer having an opening, and a liquid crystal layer. One of the first electrode layer and the second electrode layer is a pixel electrode layer which is electrically connected to the transistor, and the other of the first electrode layer and the second electrode layer is a common electrode layer. The liquid crystal display device is configured to display an image by a lateral electric field mode.

Claims

1. A liquid crystal display device comprising:

a transistor over a substrate, the transistor comprising;

a gate electrode comprising a copper layer;

a first oxide semiconductor layer over the gate electrode, the first oxide semiconductor layer comprising indium, gallium, and zinc;

a second oxide semiconductor layer over the first oxide semiconductor layer; and

a source electrode layer and a drain electrode layer electrically connected to the first oxide semiconductor layer;

a first insulating film over the transistor, the first insulating film comprising a first opening;

a resin layer over the transistor, the resin layer comprising a second opening;

a first electrode layer over the resin layer, the first electrode layer being directly in contact with one of the source electrode layer and the drain electrode layer through the first opening and the second opening, and the first electrode layer not comprising a slit;

a second insulating film over the first electrode layer;

a second electrode layer over the second insulating film, the second electrode layer comprising a slit; and

a liquid crystal layer,

wherein the first oxide semiconductor layer comprises a depressed portion between the source electrode layer and the drain electrode layer,

wherein one of the first electrode layer and the second electrode layer is a pixel electrode layer which is electrically connected to the transistor, and the other of the first electrode layer and the second electrode layer is a common electrode layer, and

wherein the liquid crystal display device is configured to display an image by a lateral electric field mode.

2. The liquid crystal display device according to claim 1, wherein the gate electrode further comprises a titanium layer overlapping with the copper layer.

3. The liquid crystal display device according to claim 1, wherein the first electrode layer is positioned between the substrate and the second electrode layer.

4. The liquid crystal display device according to claim 1, wherein the first electrode layer and the second electrode layer comprise a same material.

5. The liquid crystal display device according to claim 1, wherein the lateral electric field mode is an FFS mode.

6. The liquid crystal display device according to claim 1,

wherein the resin layer is a light-transmitting chromatic-color resin layer, and

wherein the light-transmitting chromatic-color resin layer is overlapped with the pixel electrode layer and the first oxide semiconductor layer.

7. The liquid crystal display device according to claim 1, wherein the transistor further comprises a gate insulating film between the gate electrode and the first oxide semiconductor layer.