Thin film transistor and display device comprising the same

Patent metadata

Field	Value
Publication number	US-12538526-B2
Application number	US-202217963101-A
Country	US
Kind code	B2
Filing date	Oct 10, 2022
Priority date	Oct 12, 2021
Publication date	Jan 27, 2026
Grant date	Jan 27, 2026

Abstract

A thin film transistor and a display device comprising the same are provided. The thin film transistor comprises an active layer, and a gate electrode at least partially overlapped with the active layer, wherein the active layer includes a channel portion overlapped with the gate electrode, 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, the channel portion includes a first channel area and a second channel area, each of the first channel area and the second channel area is extended from the first connection portion to the second connection portion, and a length of the first channel area is shorter than that of the second channel area.

First claim

The invention claimed is:

1 . A thin film transistor comprising:
an active layer; and a gate electrode at least partially overlapped with the active layer, wherein the active layer includes:
a channel portion overlapped with the gate electrode;
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:
the channel portion includes a first channel area and a second channel area,
each of the first channel area and the second channel area extends from the first connection portion to the second connection portion, and
a length of the first channel area is shorter than a length of the second channel area in a direction between the first connection portion and the second connection portion,
wherein the active layer includes:
a first active layer including the first channel area; and
a second active layer including the second channel area,
wherein the first active layer and the second active layer are disposed in a same layer, and are spaced apart from each other in an area overlapping the gate electrode.

2 . The thin film transistor of claim 1 , wherein the gate electrode has a width that changes in a stepwise manner at a boundary between the first channel area and the second channel area.

3 . The thin film transistor of claim 1 , wherein the gate electrode has a width that changes in stepwise manner between the first channel area and the second channel area.

4 . The thin film transistor of claim 1 , wherein the gate electrode has a width that gradually changes along a direction from the first channel area to the second channel area.

5 . The thin film transistor of claim 1 , wherein the gate electrode overlaps each of the first channel area and the second channel area, a width of the gate electrode that overlaps the first channel area smaller than a width of the gate electrode that overlaps the second channel area.

6 . The thin film transistor of claim 5 , wherein a first portion of the gate electrode overlapped with the first channel area and a second portion of the gate electrode overlapped with the second channel area are integrally formed.

7 . The thin film transistor of claim 1 , further comprising:
a vacant area in the active layer, wherein the active layer surrounds the vacant area in a plan view.

8 . The thin film transistor of claim 7 , wherein the active layer is not disposed in the vacant area.

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

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

11 . 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.

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

13 . A display device comprising:
a display element; and a pixel driving circuit for driving the display element, the pixel driving circuit includes a first thin film transistor, wherein the thin film transistor comprises:
an active layer; and
a gate electrode at least partially overlapped with the active layer,
the active layer including:
a channel portion overlapped with the gate electrode;
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,
the channel portion including a first channel area and a second channel area, each of the first channel area and the second channel area extending from the first connection portion to the second connection portion, and a length of the first channel area shorter than a length of the second channel area in a direction between the first connection portion and the second connection portion, wherein the active layer includes:
a first active layer including the first channel area; and
a second active layer including the second channel area,
wherein the first active layer and the second active layer are disposed in a same layer, and are spaced apart from each other.

14 . The display device of claim 13 , wherein the gate electrode overlaps each of the first channel area and the second channel area, a width of the gate electrode that overlaps the first channel area smaller than a width of the gate electrode that overlaps the second channel area.

15 . The display device of claim 14 , wherein a first portion of the gate electrode overlapped with the first channel area and a second portion of the gate electrode overlapped with the second channel area are integrally formed.

Assignees

• Lg Display Co Ltd

Inventors

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

Classifications

• H10K59/1213

  the pixel elements being TFTs · CPC title

• H10D86/60

  wherein the TFTs are in active matrices · CPC title

• H10D86/423

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

• H10D30/6755

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

• H10D30/6757 Primary

  characterised by the structure of the channel, e.g. transverse or longitudinal shape or doping profile (TFTs having channel structures for preventing kink or snapback effects H10D30/6708; TFTs having lightly-doped source or drain extensions H10D30/6715) · CPC title