Photodetector and manufacture method thereof, touch substrate and display panel

Patent metadata

Field	Value
Publication number	US-11217614-B2
Application number	US-201816321658-A
Country	US
Kind code	B2
Filing date	May 11, 2018
Priority date	Jun 2, 2017
Publication date	Jan 4, 2022
Grant date	Jan 4, 2022

Abstract

A photodetector and a manufacture method thereof, a touch substrate and a display panel are provided. The photodetector includes: a substrate; a polysilicon layer on the substrate including a first doped region and a second doped region; a transparent conductive film covering the first doped region of the polysilicon layer; and a metal electrode on the second doped region of the polysilicon layer. The conductive film, the metal electrode and the polysilicon layer constitute a photosensitive device.

First claim

What is claimed is:

1. A photodetector, comprising:
a substrate;
a polysilicon layer on the substrate, wherein the polysilicon layer comprises a first doped region and a second doped region;
a transparent conductive film, covering the first doped region of the polysilicon layer; and
a metal electrode on the second doped region of the polysilicon layer,
wherein the conductive film, the metal electrode and the polysilicon layer constitute a photosensitive device.

2. The photodetector according to claim 1 , wherein the metal electrode and the transparent conductive film form an interdigital electrode.

3. The photodetector according to claim 1 , wherein the conductive film further covers a region of the polysilicon layer between the first doped region and the second doped region.

4. The photodetector according to claim 1 , further comprises an anti-reflection layer, wherein the anti-reflection layer is disposed on a region of the polysilicon layer other than the second doped region.

5. A touch substrate, comprising:
the photodetector according to claim 1 ; and
a thin film transistor (TFT) device, a source electrode or a drain electrode of the TFT device being connected to the metal electrode, and the TFT device being configured to read a photodetection signal output by the PIN device.

6. A display panel, comprising the touch substrate according to claim 5 .

7. The photodetector according to claim 1 , wherein the photosensitive device is a PIN device.

8. The photodetector according to claim 1 , wherein the first doped region and the second doped region each is of a comb shape, and the first doped region and the second doped region interlock with each other.

9. The photodetector according to claim 4 , wherein the anti-reflection layer is between the conductive film and the polysilicon layer.

10. The photodetector according to claim 1 , further comprising a reflective metal layer between the polysilicon layer and the substrate.

11. The photodetector according to claim 10 , further comprising a buffer layer between the reflective metal layer and the polysilicon layer.

12. The photodetector according to claim 1 , wherein the polysilicon layer comprises low temperature polysilicon.

13. The photodetector according to claim 1 , wherein the metal electrode and the transparent conductive film each is of a comb shape, and the metal electrode and the transparent conductive film interlock with each other.

14. The touch substrate according to claim 5 , wherein a portion of the polysilicon layer is used as an active layer of the TFT device.

15. A manufacture method of a photodetector, comprising:
preparing a substrate;
forming a polysilicon layer on the substrate;
forming a first doped region on a first region of the polysilicon layer, and forming a second doped region on a second region of the polysilicon layer;
forming a transparent conductive film on the first doped region of the polysilicon layer; and
forming a metal electrode on the second doped region of the polysilicon layer,
wherein the conductive film, the metal electrode and the polysilicon layer constitute a PIN device.

16. The method according to claim 15 , wherein the forming of the polysilicon layer on the substrate comprises:
forming an amorphous silicon layer on the substrate; and
performing excimer laser annealing to the amorphous silicon layer to form the polysilicon layer.

17. The method according to claim 15 , wherein the forming of the first doped region and the second doped region comprises:
preparing a first mask and a second mask, wherein the first mask and the second mask each comprises a base and a plurality of mutually parallel tooth portions respectively extending from the base by a predetermined length;
injecting first ions into the first region using the first mask to form the first doped region; and
injecting second ions into the second region using the second mask to form the second doped region.

18. The method according to claim 15 , further comprising:
forming an anti-reflection layer on a region of the polysilicon layer other than the second doped region.

19. The method according to claim 16 , wherein the forming of the first doped region and the second doped region comprises:
preparing a first mask and a second mask, wherein the first mask and the second mask each comprises a base and a plurality of mutually parallel tooth portions respectively extending from the base by a predetermined length;
injecting first ions into the first region using the first mask to form the first doped region; and
injecting second ions into the second region using the second mask to form the second doped region.

20. The method according to claim 16 , further comprising:
forming an anti-reflection layer on a region of the polysilicon layer other than the second doped region.

Assignees

• Boe Technology Group Co Ltd

Inventors

• Bu Qianqian
• Ren Qingrong
• Sun Jianming

Classifications

• H10F39/80377

  characterised by the channel of the transistor, e.g. channel having a doping gradient · CPC title

• H10F39/8067

  Reflectors · CPC title

• H10F39/805

  Coatings · CPC title

• H10F39/028

  performed after manufacture of the image sensors, e.g. annealing, gettering of impurities, short-circuit elimination or recrystallisation · CPC title

• H10F39/024

  of coatings or optical elements · CPC title