Display device including anode electrode that includes first, second and third anode electrode layers, and method of manufacturing the same

Patent metadata

Field	Value
Publication number	US-12144193-B2
Application number	US-202117556799-A
Country	US
Kind code	B2
Filing date	Dec 20, 2021
Priority date	Dec 23, 2020
Publication date	Nov 12, 2024
Grant date	Nov 12, 2024

Abstract

An embodiment of a display device comprises a base substrate; an anode electrode disposed on the base substrate; a cathode electrode facing the anode electrode; and an organic light emitting layer disposed between the anode electrode and the cathode electrode, wherein the anode electrode includes: a first anode electrode disposed between the base substrate and the organic light emitting layer, a second anode electrode disposed between the first anode electrode and the organic light emitting layer, and a third anode electrode disposed between the second anode electrode and the organic light emitting layer, wherein a width of the first anode electrode is equal to or greater than a width of the second anode electrode.

First claim

What is claimed is:

1. A display device comprising:
a base substrate;
an anode electrode disposed on the base substrate;
a cathode electrode facing the anode electrode; and
an organic light emitting layer disposed between the anode electrode and the cathode electrode,
wherein the anode electrode includes:
a first anode electrode disposed between the base substrate and the organic light emitting layer,
a second anode electrode disposed between the first anode electrode and the organic light emitting layer, and
a third anode electrode disposed between the second anode electrode and the organic light emitting layer,

wherein a width of the first anode electrode is equal to or greater than a width of the second anode electrode,
wherein the second anode electrode has a second side surface including a second upper side surface connected to a top surface of the second anode electrode and a second lower side surface connected to a bottom surface of the second anode electrode, and
wherein the second upper side surface and the second lower side surface form a protrusion that extends outward from the top surface and the bottom surface of the second anode electrode.

2. The display device of claim 1 , wherein an end of the first anode electrode is aligned in a thickness direction with an end of the second anode electrode, or protrudes outward.

3. The display device of claim 2 , wherein the first anode electrode has a first side surface, and
the first side surface is aligned with an intersection of the second upper side surface and the second lower side surface, or protrudes outward.

4. The display device of claim 2 , wherein the end of the first anode electrode protrudes outward from the end of the second anode electrode by a distance within a range of and including 0 to 0.05 μm.

5. The display device of claim 1 , wherein a material of the first anode electrode and a material of the third anode electrode are different from each other.

6. The display device of claim 5 , wherein the material of the first anode electrode includes Indium-Zinc-Oxide (IZO), and the material of the third anode electrode includes Indium-Tin-Oxide (ITO).

7. The display device of claim 6 , wherein a material of the second anode electrode includes a reflective metal, and the material of the second anode electrode includes silver (Ag).

8. The display device of claim 6 , wherein the material of the first anode electrode has an alloy ratio in which a relative ratio of indium to zinc (In:Zn) is within a range and including 9:1 to 8:2.

9. The display device of claim 5 , further comprising a via layer disposed between the first anode electrode and the base substrate,
wherein the via layer includes an organic insulating material, and the first anode electrode functions to increase an adhesive force between the anode electrode and the via layer.

10. The display device of claim 5 , wherein the third anode electrode has a high work function compared to the second anode electrode, and functions to prevent aggregation of the second anode electrode.

11. The display device of claim 1 , wherein the first anode electrode has an etching rate within a range of and including 1.25 Å/sec to 2.5 Å/sec with respect to a non-phosphoric acid-based etchant.

12. The display device of claim 11 , wherein the first anode electrode and the second anode electrode are etched in a continuous process using the non-phosphoric acid-based etchant.

13. The display device of claim 12 , wherein the etching of the first anode electrode and the second anode electrode with respect to the non-phosphoric acid-based etchant is completed within 60 seconds.

14. A method of manufacturing a display device, comprising:
forming an active layer on a display area of a base substrate in which the display area and a pad area located around the display area are defined;
forming a gate insulating layer on the active layer;
forming a first conductive layer on the gate insulating layer, the first conductive layer including a gate electrode on the display area and a first pad electrode on the pad area;
forming an interlayer insulating layer on the first conductive layer;
forming a second conductive layer on the interlayer insulating layer, the second conductive layer including a source electrode and a drain electrode connected to the active layer on the display area, and a second pad electrode connected to the first pad electrode on the pad area;
forming a via layer on the display area except the pad area on the second conductive layer;
forming a first anode electrode layer over the display area and the pad area on the via layer;
forming a second anode electrode layer over the display area and the pad area on the first anode electrode layer;
forming a third anode electrode layer over the display area and the pad area on the second anode electrode layer;
arranging a photoresist on the third anode electrode layer in the display area after the forming the third anode electrode layer;
forming a third anode electrode by etching the third anode electrode layer using a first etchant while using the photoresist as a mask;
forming a second anode electrode by etching the second anode electrode layer using a second etchant different from the first etchant while using the photoresist as a mask after the forming of the third anode electrode; and
forming a first anode electrode by etching the first anode electrode layer using the second etchant while using the photoresist as a mask in a continuous step with the forming of the second anode electrode,
wherein the forming the second anode electrode and the first anode electrode produces:
a side surface of the second anode electrode having an upper side surface connected to a top surface of the second anode electrode and a lower side surface connected to a bottom surface of the second anode electrode, and
the upper side surface and the lower side of the second anode electrode form a protrusion that extends outward from the top surface and the bottom surface of the second anode electrode.

15. The method of claim 14 , wherein the second etchant includes a non-phosphoric acid-based etchant, and
the first etchant includes a phosphoric acid-based etchant.

16. The method of claim 15 , wherein the first anode electrode layer has an etching rate within a range of and including 1.25 Å/sec to 2.5 Å/sec with respect to the non-phosphoric acid-based etchant.

17. The method of claim 15 , wherein the first anode electrode layer and the second anode electrode layer are etched in a continuous process using the non-phosphoric acid-based etchant.

18. The method of claim 17 , wherein the forming of the second anode electrode layer and the forming of the first anode electrode layer are completed within 60 seconds using the non-phosphoric acid-based etchant.

19. The method of claim 14 , wherein a material of the first anode electrode layer and a material of the third anode electrode layer are different from each other,
the material of the third anode electrode layer includes Indium-Tin-Oxide (ITO),
the material of the first anode electrode layer includes Indium-Zinc-Oxide (IZO), and
the material of the first anode electrode layer has an alloy ratio in which a relative ratio of indium to zinc (In:Zn) within a range and including 9:1 to 8:2.

Assignees

• Samsung Display Co Ltd

Inventors

• Park Jong Hee
• Kim Hyoung Sik

Classifications

• H10K59/80515

  characterised by their shape · CPC title

• H10K71/621

  Providing a shape to conductive layers, e.g. patterning or selective deposition · CPC title

• H10K59/131

  Interconnections, e.g. wiring lines or terminals · CPC title

• H10K50/813 Primary

  characterised by their shape · CPC title

• H10K59/80518 Primary

  Reflective anodes, e.g. ITO combined with thick metallic layers · CPC title