Organic light emitting display and method of fabricating the same

• US 20080284327A1
• Filed: 06/02/2008
• Published: 11/20/2008
• Est. Priority Date: 09/08/2004
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Mobile Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Lee, Kwan-Hee, Kang, Tae-Wook
• Granted Patent: US 7,914,354 B2
• Time in Patent Office: Days
• US Class Current: 313/504
• CPC Class Codes: H10K 2102/3026 Top emission
• CPC Class Codes: H10K 50/818 Reflective anodes, e.g. ITO combined with thick metallic layers
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/124 Insulating layers formed between TFT elements and OLED elements
• CPC Class Codes: H10K 59/80518 Reflective anodes, e.g. ITO combined with thick metallic layers
• CPC Class Codes: H10K 71/00 Manufacture or treatment specially adapted for the organic devices covered by this subclass
• CPC Class Codes: H10K 71/233 by photolithographic etching

Abstract

An OLED and a method of fabricating the same are provided, in which, when a reflective layer pattern is formed, a thin layer for a pixel electrode is opened at an edge of an emission region to form the pixel electrode without additional photolithography and etching processes by forming an undercut under the edge of the reflective layer pattern, i.e., under the edge of the emission region by over-etching, thereby simplifying the process and increasing the yield.

Claims

1-8. -8. (canceled)

9. A method of fabricating an organic light emitting display, comprising:

forming a thin-film transistor on a substrate to form a first structure, the thin-film transistor comprising a gate electrode, a source electrode and a drain electrode;

forming an insulating layer on the first structure to form a second structure, the insulating layer having a via-contact hole that exposes one of the source electrode and the drain electrode;

forming a reflective layer on the second structure, the reflective layer being connected to one of the source electrode and the drain electrode through the via-contact hole;

forming a reflective layer pattern protruding in a horizontal direction by etching the reflective layer and removing the insulating layer disposed under an edge of the reflective layer pattern to form an undercut under the edge of the reflective layer pattern;

forming a first electrode by forming a thin layer for a first electrode on the resultant structure, the first electrode being patterned by the undercut formed under the edge of the reflective layer pattern;

forming an organic layer having at least an emission layer on the first electrode; and

forming a second electrode on the organic layer.

10. The method according to claim 9, wherein the reflective layer is etched by using photolithography.

11. The method according to claim 9, wherein the insulating layer is formed by laminating a passivation layer and a planarization layer.

12. The method according to claim 9, wherein the reflective layer is formed of a metal having a reflectivity of 50% or more.

13. The method according to claim 12, wherein the reflective layer is formed of one selected from a group consisting of Al, Mo, Ti, Au, Ag, Pd, and an alloy thereof.

14. The method according to claim 9, wherein the step of forming the reflective pattern comprises over-etching the reflective layer to remove the insulating layer disposed under the edge of the reflective layer pattern to form the undercut.

15. The method according to claim 9, wherein the step of forming the reflective pattern comprises wet-etching the reflective layer and dry-etching the reflective layer for removing the insulating layer disposed under the edge of the reflective layer pattern to form the undercut.

16. The method according to claim 9, wherein the step of forming the reflective pattern comprises dry-etching the reflective layer to form the reflective layer pattern and over-etching the reflective layer for removing the insulating layer disposed under the edge of the reflective layer pattern to form the undercut.

17. The method according to claim 9, wherein the undercut is formed to a depth of at least twice as great as the thickness of the first electrode.

18. The method according to claim 9, wherein the second electrode is formed of a transparent electrode.

20. A display fabricated according to claim 9, wherein:

the depth of the undercut is at least twice as great as the thickness of the first electrode;

the first electrode is a pixel electrode; and

the second electrode is a transparent electrode.

19. (canceled)