Thin film transistor and display device comprising the same

Patent metadata

Field	Value
Publication number	US-12426446-B2
Application number	US-202217969499-A
Country	US
Kind code	B2
Filing date	Oct 19, 2022
Priority date	Oct 29, 2021
Publication date	Sep 23, 2025
Grant date	Sep 23, 2025

Abstract

A thin film transistor and a display device comprising the same is disclosed. The thin film transistor comprises an active layer on a substrate, and a first gate electrode at least partially overlapped with the active layer, wherein the active layer includes a channel portion, a first connection portion that is in contact with one side of the channel portion, and a second connection portion that is in contact with the other side of the channel portion, and an effective gate voltage applied to a first area of the channel portion, which is in contact with the first connection portion, is greater than that applied to a second area of the channel portion, which is in contact with the second connection portion.

First claim

What is claimed is:

1. A thin film transistor comprising:
an active layer on a substrate, the active layer including:
a channel portion;
a first connection portion that is in contact with a first side of the channel portion; and
a second connection portion that is in contact with a second side of the channel portion,
wherein a first area of the channel portion is in contact with the first connection portion, and a second area of the channel portion is in contact with the second connection portion,

a first gate electrode at least partially overlapping the active layer;
a conductive material layer between the substrate and the active layer, the conductive material layer overlapping the second area of the channel portion without overlapping the first area of the channel portion, and the conductive material layer is connected to the second connection portion, and
a second gate electrode between the first gate electrode and the active layer, the second gate electrode overlapping the first area of the channel portion, and
wherein the second gate electrode is non-overlapping with the second area of the channel portion.

2. The thin film transistor of claim 1 , wherein the conductive material layer comprises a material having light shielding characteristics.

3. The thin film transistor of claim 1 , further comprising:
a second gate electrode between the first gate electrode and the active layer, the second gate electrode overlapping the first area of the channel portion and non-overlapping with the second area of the channel portion.

4. The thin film transistor of claim 1 , wherein at least a portion of the second gate electrode overlaps the first gate electrode, and at least a portion of the second gate electrode is non-overlapping with the first gate electrode.

5. The thin film transistor of claim 1 , wherein a same voltage is applied to the first gate electrode and the second gate electrode.

6. The thin film transistor of claim 1 , wherein an effective gate voltage applied to a first area of the channel portion is greater than an effective gate voltage applied to a second area of the channel portion.

7. A display device comprising the thin film transistor of claim 1 .

8. The thin film transistor of claim 1 , wherein the active layer includes an oxide semiconductor material.

9. The thin film transistor of claim 8 , wherein the oxide semiconductor material includes at least one of an IZO(InZnO)-based, IGO (InGaO)-based, ITO (InSnO)-based, IGZO (InGaZnO)-based, IGZTO (InGaZnSnO)-based, GZTO (GaZnSnO)-based, GZO (GaZnO)-based, ITZO (InSnZnO)-based or FIZO(FeInZnO)-based oxide semiconductor material.

10. The thin film transistor of claim 1 , wherein the active layer includes:
a first oxide semiconductor layer; and
a second oxide semiconductor layer on the first oxide semiconductor layer.

11. The thin film transistor of claim 10 , wherein the active layer further includes a third oxide semiconductor layer on the second oxide semiconductor layer.

Assignees

• Lg Display Co Ltd

Inventors

• Ko Younghyun
• Jang Jaeman
• CHOI Seungchan
• Kang Min-Gu
• Choi Sungju

Classifications

• H10D86/423 Primary

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

• H10D86/60

  wherein the TFTs are in active matrices · CPC title

• H10D30/6755

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

• H10D30/6733

  Multi-gate TFTs · CPC title

• H10D30/6723

  having light shields · CPC title