Thin film transistor, array substrate, methods for fabricating the same, and display device

• US 10,204,934 B2
• Filed: 10/21/2016
• Issued: 02/12/2019
• Est. Priority Date: 01/05/2016
• Status: Active Grant

• Current Assignee: BOE Technology Group Co., Ltd.
• Original Assignee: BOE Technology Group Co., Ltd.
• Inventors: Tian, Hongwei, Niu, Yanan, Tang, Liang, Zhang, Chaobo, Chuo, Luopeng
• Primary Examiner(s): Ahmed, Selim
• Application Number:
  US15/522,811
• Publication Number:
  US 20180090521A1
• Time in Patent Office: 844 Days
• CPC Class Codes: H01L 27/1248 with a particular composition or shape of the interlayer dielectric specially adapted to the circuit arrangement
• CPC Class Codes: H01L 27/1255 integrated with passive devices, e.g. auxiliary capacitors
• CPC Class Codes: H01L 27/1259 Multistep manufacturing methods
• CPC Class Codes: H01L 27/1262 with a particular formation, treatment or coating of the substrate
• CPC Class Codes: H01L 29/66757 Lateral single gate single channel transistors with non-inverted structure, i.e. the channel layer is formed before the gate
• CPC Class Codes: H01L 29/78633 with a light shield
• CPC Class Codes: H01L 29/78675 with normal-type structure, e.g. with top gate
• CPC Class Codes: H10K 59/126 Shielding, e.g. light-blocking means over the TFTs

Abstract

The embodiments of the present disclosure relate to an array substrate, a thin film transistor, methods for fabricating the same, and a display device. The method for fabricating the array substrate provided by the embodiments of the present disclosure comprises: forming an active layer on a substrate; forming a gate on the active layer; forming a first insulation layer on the gate; forming a light blocking portion on the first insulation layer, the light blocking portion being arranged above an edge portion of the gate, so that the light blocking portion blocks light entering the active layer from the edge portion of the gate.

Claims

1. A thin film transistor comprising:

a substrate;

an active layer positioned on the substrate;

a gate positioned on the active layer, the gate including one or more edge portions;

a first insulation layer positioned on the gate; and

a light blocking portion positioned on the first insulation layer, the light blocking portion being arranged only above the one or more edge portions of the gate to block light from entering the active layer from the one or more edge portions of the gate.

2. The thin film transistor according to claim 1, wherein a projection of the light blocking portion onto the active layer is partially overlapped with a projection of the gate onto the active layer.

3. The thin film transistor according to claim 2, wherein the projection of the light blocking portion onto the active layer has a width no less than 4 μ

m and no more than 20 μ

m.

4. The thin film transistor according to claim 3, wherein a portion of the projection of the light blocking portion onto the active layer, which is not overlapped with the projection of the gate onto the active layer, has a width no less than 3 μ

m.

5. The thin film transistor according to claim 1, wherein the active layer is a polycrystalline silicon layer.

6. An array substrate comprising one or more conductive layers and the thin film transistor according to claim 1.

7. The array substrate according to claim 6, further comprising a second insulation layer and a first conductive layer positioned on the second-insulation layer, the first conductive layer having a first portion, wherein the first portion forms the gate.

8. The array substrate according to claim 7, further comprising a second conductive layer having a second portion, wherein the second portion forms the light blocking portion.

9. A display device, comprising the array substrate according to claim 6.

10. An array substrate comprising one or more conductive layers and a thin film transistor, the thin film transistor including a substrate, an active layer positioned on the substrate, a gate positioned on the active layer, a first insulation layer positioned on the gate, a light blocking portion positioned on the first insulation layer, a second insulation layer, a first conductive layer positioned on the second insulation layer and having a first portion and a third portion, and a second conductive layer having a second portion and a fourth portion, the light blocking portion being arranged above an edge portion of the gate to block light from entering the active layer from the edge portion of the gate, wherein the first portion forms the gate, wherein the second portion forms the light blocking portion, wherein the third portion is spaced apart from the first portion, wherein the fourth portion is spaced apart from the second portion, and wherein the third portion and the fourth portion are at least partially overlapped with each other in a vertical direction to form a capacitor.

11. The array substrate according to claim 10, wherein the second conductive layer includes a fifth portion spaced apart from the second portion and the fourth portion.

12. A method for fabricating an array substrate, the method comprising:

forming an active layer on a substrate;

forming a gate on the active layer;

forming a first insulation layer on the gate; and

forming a light blocking portion on the first insulation layer so that the light blocking portion is arranged only above one or more edge portions of the gate to block light from entering the active layer from the one or more edge portions of the gate.

13. The method according to claim 12, wherein forming the light blocking portion on the first insulation layer comprises forming the light blocking portion on the first insulation layer so that a projection of the light blocking portion onto the active layer partially overlaps a projection of the gate onto the active layer.

14. The method according to claim 12, wherein forming the gate on the active layer comprises:

forming a second insulation layer on the active layer; and

forming a first conductive layer on the second insulation layer, wherein the first conductive layer has a first portion that forms the gate.

15. The method according to claim 14, wherein forming the light blocking portion on the first insulation layer comprises:

forming a second conductive layer on the first insulation layer, wherein the second conductive layer has a second portion that forms the light blocking portion.

16. The method according to claim 15, wherein forming the first conductive layer on the second insulation layer comprises forming the first conductive layer so that a third portion of the first conductive layer is spaced apart from the first portion, and wherein forming the second conductive layer on the first insulation layer comprises forming the second conductive layer so that a fourth portion of the second conductive layer is spaced apart from the second portion, the method further comprising at least partially overlapping the third portion and the fourth portion with each other in a vertical direction to form a capacitor.

17. The method according to claim 12, wherein the active layer is a polycrystalline silicon layer, and wherein forming the active layer comprises:

forming an amorphous silicon layer on the substrate; and

converting the amorphous silicon layer into the polycrystalline silicon layer.