ORGANIC LIGHT EMITTING DISPLAY AND MANUFACTURING METHOD THEREOF

• US 20090206421A1
• Filed: 10/08/2008
• Published: 08/20/2009
• Est. Priority Date: 02/20/2008
• Status: Abandoned Application

• Current Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Original Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Inventors: Choi, Joon-Hoo, Yoon, Young-Soo, Chai, Chong-Chul, GOH, Joon-Chul
• Application Number:
  US12/247,964
• Publication Number:
  US 20090206421A1
• Time in Patent Office: Days
• US Class Current: 257/412
• CPC Class Codes: H01L 27/1214 comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
• CPC Class Codes: H01L 27/1251 comprising TFTs having a different architecture, e.g. top- and bottom gate TFTs
• CPC Class Codes: H10K 59/1213 the pixel elements being TFTs

Abstract

Disclosed are an organic light emitting display and a manufacturing method thereof. The organic light emitting display includes an organic light emitting section that generates a light, a first thin film transistor that drives the organic light emitting section and includes a first polysilicon layer and a first gate electrode formed below the first polysilicon layer, and a second thin film transistor connected to the first thin film transistor and includes a second polysilicon layer and a second gate electrode formed above the second polysilicon layer. The first and second polysilicon layers are formed on the same layer.

Claims

1. An organic light emitting display comprising:

an organic light emitting section that generates a light;

a first thin film transistor that drives the organic light emitting section and comprises a first polysilicon layer and a first gate electrode formed below the first polysilicon layer; and

a second thin film transistor connected to the first thin film transistor and comprises a second polysilicon layer and a second gate electrode formed above the second polysilicon layer, and

wherein the first and second polysilicon layers are formed on a same layer.

2. The organic light emitting display as claimed in claim 1, wherein the first thin film transistor further comprises a first source electrode and a first drain electrode formed on the first polysilicon layer, and the second thin film transistor further comprises a second source electrode and a second drain electrode formed on the second polysilicon layer.

3. The organic light emitting display as claimed in claim 2, wherein the first thin film transistor further comprises a first insulating layer interposed between the first polysilicon layer and the first gate electrode.

4. The organic light emitting display as claimed in claim 2, wherein the second thin film transistor further comprises a second insulating layer interposed between the second polysilicon layer and the second gate electrode.

5. The organic light emitting display as claimed in claim 2, wherein the second polysilicon layer comprises a channel area overlapping the second gate electrode, a doping area overlapping the second source electrode and the second drain electrode, and an offset area interposed between the channel area and the doping area.

6. The organic light emitting display as claimed in claim 2, wherein the offset area has a width of about 2 μ

m to about 5 μ

m.

7. The organic light emitting display as claimed in claim 2, further comprising a protective layer formed on the first and the second thin film transistor and a connection electrode formed on the protective layer,

wherein the first thin film transistor is electrically connected to the second thin film transistor through the connection electrode.

8. The organic light emitting display as claimed in claim 2, wherein the first gate electrode is connected to the second drain electrode so that the first thin film transistor is electrically connected to the second thin film transistor.

9. The organic light emitting display as claimed in claim 1, wherein the first gate electrode overlaps the second polysilicon layer to block a light incident onto a bottom thereof.

10. The organic light emitting display as claimed in claim 1, wherein the organic light emitting section comprises a hole injection electrode, an electron injection electrode and an organic light emitting layer.

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

forming a first gate pattern comprising a first gate electrode on a substrate;

forming first and second polysilicon layers on the first gate pattern;

forming data patterns comprising first and second source electrodes and first and second drain electrodes on first and second polysilicon layers, respectively;

forming a second gate pattern comprising a second gate electrode on the data pattern;

forming a protective layer on the second gate pattern; and

forming an organic light emitting section on the protective layer.

12. The method as claimed in claim 11, further comprising forming a first insulating layer between the first gate pattern and the first polysilicon layer and between the first gate pattern and the second polysilicon layer.

13. The method as claimed in claim 12, further comprising forming a second insulating layer between the second gate pattern and the first polysilicon layer and between the second gate pattern and the second polysilicon layer.

14. The method as claimed in claim 11, wherein the forming of the first and second polysilicon layers comprises:

forming amorphous silicon layer;

implanting impurities into the amorphous silicon layer; and

crystallizing the amorphous silicon layer.

15. The method as claimed in claim 14, wherein the second polysilicon layer is divided into a channel area, an offset area and a doping area.

16. The method as claimed in claim 15, wherein the second gate electrode overlaps the channel area of the second polysilicon layer.

17. The method as claimed in claim 11, wherein, when forming the data pattern, a contact hole is formed through the first insulating layer so that the second drain electrode is connected to the first gate electrode through the contact hole.

18. The method as claimed in claim 11, wherein the forming of the organic light emitting section comprises:

forming a hole injection electrode connected to the first drain electrode on the protective layer;

forming a pixel definition layer on the protective layer such that the hole injection electrode is partially exposed;

forming an organic light emitting layer on the hole injection electrode; and

forming an electron injection electrode on the pixel definition layer and the organic light emitting layer.

19. The method as claimed in claim 18, wherein the forming of the hole injection electrode comprises forming a connection electrode to connect the first gate electrode to the second drain electrode.

20. The method as claimed in claim 19, wherein, when forming the protective layer, a contact hole is formed to partially expose the first drain electrode, the first gate electrode and the second drain electrode.