Active matrix organic EL display device and method of forming the same

• US 6,597,121 B2
• Filed: 10/29/2001
• Issued: 07/22/2003
• Est. Priority Date: 10/27/2000
• Status: Expired due to Term

• Current Assignee: Gold Charm Limited (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: NEC Corporation
• Inventors: Imura, Hironori
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): Dinh, Trinh Vo
• Application Number:
  US09/984,303
• Publication Number:
  US 20020050795A1
• Time in Patent Office: 631 Days
• Field of Search: G09/G.310, H01/J 6.304, 315/169.3, 315/169.4, 313/500, 313/505, 313/400, 313/492, 345/36, 345/45, 345/76
• US Class Current: 315/169.3
• CPC Class Codes: H01L 29/78633 with a light shield
• CPC Class Codes: H10K 50/86 Arrangements for improving contrast, e.g. preventing reflection of ambient light
• CPC Class Codes: H10K 59/126 Shielding, e.g. light-blocking means over the TFTs
• CPC Class Codes: H10K 59/8791 Arrangements for improving contrast, e.g. preventing reflection of ambient light

Abstract

The present invention provides an active matrix organic electroluminescence display device including: a transparent substrate; a plurality of pixels aligned over the transparent substrate, wherein each of the pixels further includes: a luminescent region which exhibits a luminescence upon application of an electric field; a circuitry region including at least a circuitry; and an optical shielding structure provided between the luminescent region and the circuitry region for shielding the circuitry region from the luminescence from the luminescent region.

Claims

1. A pixel structure of an electroluminescence display device, said structure including:

a luminescent region which exhibits a luminescence upon application of an electric field;

a circuitry region including at least a circuitry; and

an optical shielding structure provided between said luminescent region and said circuitry region shielding said circuitry region from said luminescence emitted from said luminescent region,

wherein said optical shielding structure includes a shielding wall which vertically extends from a lower level than a circuitry of said circuitry region to a higher level than said circuitry.

2. The pixel structure as claimed in claim 1, wherein said optical shielding structure further includes a shielding layer which horizontally extends under said circuitry region.

3. The pixel structure as claimed in claim 2, wherein said shielding wall vertically extends from a part of an upper surface of said optical shielding structure, and a bottom of said shielding wall is in contact with said part of said upper surface of said optical shielding structure.

4. The pixel structure as claimed in claim 1, wherein said shielding wall partially surrounds said luminescent region in a plan view.

5. The pixel structure as claimed in claim 1, wherein said shielding wall completely surrounds said luminescent region in a plan view.

6. The pixel structure as claimed in claim 1, wherein said shielding wall partially surrounds said circuitry in a plan view.

7. The pixel structure as claimed in claim 1, wherein said shielding wall completely surrounds said circuitry in a plan view.

8. The pixel structure as claimed in claim 1, wherein said shielding wall has a top level which is substantially the same as a wiring layer which is electrically connected to said circuitry.

9. The pixel structure as claimed in claim 1, wherein said shielding wall has a top level which is lower than an anode layer of said luminescent region.

10. The pixel structure as claimed in claim 1, wherein said shielding wall has a top level which is higher than an anode layer of said luminescent region, and a bottom level which is lower than said anode layer.

11. The pixel structure as claimed in claim 1, wherein said shielding wall is made of a same material as a wiring layer which is electrically connected to said circuitry.

12. The pixel structure as claimed in claim 1, wherein said circuitry comprises a thin film transistor.

13. An active matrix organic electroluminescence display device including:

a transparent substrate;

a plurality of pixels aligned over said transparent substrate, each of said pixels further including;

a luminescent region which exhibits a luminescence upon application of an electric field;

a circuitry region including at least a circuitry; and

an optical shielding structure provided between said luminescent region and said circuitry region shielding said circuitry region from said luminescence emitted from said luminescent region,

wherein said optical shielding structure includes a shielding wall which vertically extends from a lower level than a circuitry of said circuitry region to a higher level than said circuitry.

14. The active matrix organic electroluminescence display device as claimed in claim 13, wherein said optical shielding structure further includes a shielding layer which horizontally extends under said circuitry region.

15. The active matrix organic electroluminescence display device as claimed in claim 13, wherein said circuitry comprises a thin film transistor.

16. The active matrix organic electroluminescence display device as claimed in claim 14, wherein said shielding wall vertically extends from a part of an upper surface of said optical shielding structure, and a bottom of said shielding wall is in contact with said part of said upper surface of said optical shielding structure.

17. The active matrix organic electroluminescence display device as claimed in claim 14, wherein said shielding wall partially surrounds said luminescent region in a plan view.

18. The active matrix organic electroluminescence display device as claimed in claim 14, wherein said shielding wall completely surrounds said luminescent region in a plan view.

19. The active matrix organic electroluminescence display device as claimed in claim 14, wherein said shielding wall partially surrounds said circuitry in a plan view.

20. The active matrix organic electroluminescence display device as claimed in claim 14, wherein said shielding wall completely surrounds said circuitry in a plan view.

21. The active matrix organic electroluminescence display device as claimed in claim 14, wherein said shielding wall has a top level which is substantially the same as a wiring layer which is electrically connected to said circuitry.

22. The active matrix organic electroluminescence display device as claimed in claim 14, wherein said shielding wall has a top level which is lower than an anode layer of said luminescent region.

23. The active matrix organic electroluminescence display device as claimed in claim 14, wherein said shielding wall has a top level which is higher than an anode layer of said luminescent region, and a bottom level which is lower than said anode layer.

24. The active matrix organic electroluminescence display device as claimed in claim 14, wherein said shielding wall is made of a same material as a wiring layer which is electrically connected to said circuitry.

25. A method of forming an optical shielding structure between a luminescent region and a circuitry region in a pixel of an electroluminescence display device shielding said circuitry region from a luminescence emitted from said luminescent region, said method comprising the steps of:

selecting forming an optical shielding layer over a substrate on said circuitry region;

forming a first insulating layer over said optical shielding layer and said substrate;

forming a circuitry over said first insulating layer on said circuitry region;

forming a second insulating layer over said circuitry and said first insulating layer;

forming at least a first contact hole, which penetrates said second insulating layer and reaches a part of said circuitry, and at least a second contact hole, which penetrates said first and second insulating layers and reaches a part of said optical shielding layer;

selectively forming at least a wiring layer electrically connected through said at least first contact hole to said circuitry and also at least an optical shielding wall within said at least second contact hole, wherein said optical shielding wall is in contact with said optical shielding layer.

26. The method as claimed in claim 25, wherein said step of forming at least a wiring layer further comprises the steps of:

depositing an electrically conductive and optically shielding material over said second insulating layer and also within said at least first contact hole and said at least second contact hole; and

selectively removing said electrically conductive and optically shielding material to form at least a wiring layer electrically connected to said circuitry and also at least an optical shielding wall in contact with said optical shielding layer.

27. The method as claimed in claim 25, wherein said at least second contact hole partially surrounds said luminescent region in a plan view.

28. The method as claimed in claim 25, wherein said at least second contact hole completely surrounds said luminescent region in a plan view.

29. The method as claimed in claim 25, wherein said at least second contact hole partially surrounds said circuitry in a plan view.

30. The method as claimed in claim 29, wherein said at least first contact hole completely surrounds said circuitry in a plan view.

31. The method as claimed in claim 29, wherein said at least second contact hole completely surrounds said circuitry in a plan view.

32. A method of forming an optical shielding structure between a luminescent region and a circuitry region in a pixel of an electroluminescence display device shielding said circuitry region from a luminescence emitted from said luminescent region, said method comprising the steps of:

selectively forming an optical shielding layer over a substrate on said circuitry region;

forming a first insulating layer over said optical shielding layer and said substrate;

forming a circuitry over said first insulating layer on said circuitry region;

forming a second insulating layer over said circuitry and said first insulating layer;

forming at least a first contact hole, which penetrates said first and second insulating layers and reaches a part of said optical shielding layer;

selecting forming at least an optical shielding wall within said at least first contact hole, wherein said optical shielding wall is in contact with said optical shielding layer;

forming a third insulating layer over said at least optical shielding wall and said second insulating layer;

forming at least a second contact hole, which penetrates said second and third insulating layer and reaches a part of said circuitry; and

selectively forming at least a wiring layer electrically connected through said at least second contact hole to said circuitry.

33. The method as claimed in claim 32, wherein said at least first contact hole partially surrounds said luminescent region in a plan view.

34. The method as claimed in claim 32, wherein said at least first contact hole completely surrounds said luminescent region in a plan view.

35. The method as claimed in claim 32, wherein said at least first contact hole partially surrounds said circuitry in a plan view.