Organic light emitting display and method of manufacturing the same

• US 8,158,979 B2
• Filed: 07/09/2010
• Issued: 04/17/2012
• Est. Priority Date: 11/04/2009
• 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: Kang, Ki-Nyeng, Pyo, Young-Shin, Jin, Dong-Un
• Primary Examiner(s): Nguyen, Dao H
• Assistant Examiner(s): Nguyen, Tram H
• Application Number:
  US12/833,785
• Publication Number:
  US 20110101330A1
• Time in Patent Office: 648 Days
• Field of Search: 257/43, 257/72, 257/66, 257/223, 257/227, 257/291, 257/292, 257/439, 257/443, 257/655, 257/E21.7, 257/E27.1, 257/E27.125, 257/E27.112, 257/E29.117, 257/E29.145, 257/E29.147, 257/E29.151, 257/E29.182, 257/E29.202, 257E29273-E29299, 257/E29.314, 257/E29.32, 257/E23.016, 257/E21.094, 257/E21.401, 257/E21.121, 257/E21.372, 257E21411-E21416, 257/E33.053, 257/E29.094, 257/59, 257/E33.022, 257/E33.068, 257/E29.003, 438/149, 438/163
• US Class Current: 257/43
• CPC Class Codes: H01L 27/1225 with semiconductor materials not belonging to the group IV of the periodic table, e.g. InGaZnO
• CPC Class Codes: H10K 59/1213 the pixel elements being TFTs
• CPC Class Codes: H10K 59/124 Insulating layers formed between TFT elements and OLED elements

Abstract

An organic light emitting display is disclosed. The display comprises a transistor with an active layer comprising an oxide semiconductor material. The oxide semiconductor material has conductivity suitable for the transistor because of a diffusion path allowing hydrogen to escape from the active layer.

Claims

1. An organic light emitting display comprising:

a substrate;

a gate electrode formed on the substrate;

a first insulating layer on the gate electrode;

an active layer comprising an oxide semiconductor material on the first insulating layer and the gate electrode;

a second insulating layer on the active layer;

source and drain electrodes on the second insulating layer coupled to the active layer;

a third insulating layer comprising an organic material on the source and drain electrodes and on the second insulator;

an anode electrode on the third insulating layer electrically coupled to the source or drain electrode;

a pixel defining layer on the anode electrode and the third insulator patterned so that the anode electrode in an emission region is exposed;

an organic light emitting layer formed on the exposed anode electrode; and

a cathode electrode formed on the organic light emitting layer,

wherein the anode electrode does not overlap the active layer.

2. The organic light emitting display as claimed in claim 1, wherein the oxide semiconductor material comprises ZnO.

3. The organic light emitting display as claimed in claim 2, wherein the oxide semiconductor material is doped with at least one of Ga, In, and Sn.

4. The organic light emitting display as claimed in claim 1, wherein the organic material comprises acrylic or polyimide.

5. A method of manufacturing an organic light emitting display, the method comprising:

forming a gate electrode on a substrate;

forming a first insulating layer over the gate electrode;

forming an active layer comprising an oxide semiconductor material on the first insulating layer and the gate electrode;

forming a second insulating layer over the active layer;

forming source and drain electrodes coupled to the active layer over the second insulating layer;

forming a third insulating layer comprising an organic material over the source and drain electrodes;

patterning the third insulating layer to expose the source or drain electrode;

bathing the third insulating layer and the exposed source or drain electrode;

forming a first electrode over the third insulating layer, the first electrode being coupled to the exposed source or drain electrode, wherein the first electrode does not to overlap the active layer;

forming a pixel defining layer over third insulating layer and the first electrode, wherein the pixel defining layer exposes the first electrode in an emission region;

forming an organic light emitting layer over the exposed first electrode; and

forming a second electrode on the organic light emitting layer.

6. The method as claimed in claim 5, wherein the oxide semiconductor material comprises ZnO.

7. The method as claimed in claim 6, wherein the oxide semiconductor material is doped with at least one of Ga, In, Hf, and Sn.

8. The method as claimed in claim 5, wherein the organic material comprises acrylic or polyimide.

9. The method as claimed in claim 5, wherein H₂O is used in the bathing.

10. The method as claimed in claim 9, wherein H diffuses into the third insulating layer during the bathing.

11. The method as claimed in claim 10, wherein H diffuses out of the third insulating layer over the active layer after the bathing.

12. The method as claimed in claim 11, wherein H is prevented by the first electrode from diffusing out of the third insulating layer in an area not over the active area.

13. The method as claimed in claim 5, further comprising forming a diffusion path for H from the active area through the second and third insulating layers, the diffusion path being substantially perpendicular to a plane defined by the substrate.

14. The method as claimed in claim 5, further comprising planarizing the third insulating layer.

15. The method as claimed in claim 5, further comprising performing a heat treatment after forming the pixel defining layer.