Process for producing a light emitting device

• US 20020110940A1
• Filed: 01/17/2002
• Published: 08/15/2002
• Est. Priority Date: 01/18/2001
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Ikeda, Hisao, Ono, Koji, Miyagi, Noriko, Arao, Tatsuya, Adachi, Yoshimi, Yamagata, Hirokazu
• Granted Patent: US 6,893,887 B2
• Time in Patent Office: Days
• US Class Current: 438/22
• CPC Class Codes: H10K 50/81 Anodes
• CPC Class Codes: H10K 50/844 Encapsulations
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/122 Pixel-defining structures or layers, e.g. banks
• CPC Class Codes: H10K 59/123 Connection of the pixel electrodes to the thin film transistors [TFT]
• CPC Class Codes: H10K 59/124 Insulating layers formed between TFT elements and OLED elements
• CPC Class Codes: H10K 59/8051 Anodes
• CPC Class Codes: H10K 59/873 Encapsulations

Abstract

The surface of an anode is made flat by wiping/cleaning of the present invention. Thereafter, an organic compound layer and a cathode are formed to produce a light emitting element. In this way, the distance between the anode and the cathode becomes constant. Therefore, when an electric field is applied to the light emitting element, the current density in the organic compound layer becomes uniform. Thus, it is possible to prevent the deterioration of the organic compound layer and improve the element characteristic thereof.

Claims

1. A process for producing a light emitting device comprising the steps of:

forming an anode;

wiping/cleaning the surface of the anode with a wiping/cleaning material,

forming an organic compound layer on the anode after wiping/cleaning the surface of thereof; and

forming a cathode on the organic compound layer.

2. The process for producing the light emitting device according to claim 1, wherein the anode is composed of a transparent conductive film.

3. The process for producing the light emitting device according to claim 1, wherein the surface is made flat by the wiping/cleaning.

4. The process for producing the light emitting device according to claim 1, wherein the wiping/cleaning material is a PVA-based porous body.

5. The process for producing the light emitting, device according to claim 1, wherein the surface is wiped/cleaned with the wiping/cleaning material and a washing liquid.

6. The process for producing the light emitting device according to claim 1, wherein the surface is scrubbed with the wiping/cleaning material.

7. The process for producing the light emitting device according to claim 1, wherein when contact angle to the anode surface is smaller than 90% before the wiping/cleaning, the contact angle after the wiping/cleaning is larger than the contact angle before the wiping/cleaning and is smaller than 90°

.

8. A process for producing an active matrix type light emitting device comprising the steps of:

forming TFTs over a substrate;

forming a first insulating film comprising organic resin material over the TFTs;

forming a second insulating film comprising inorganic insulating material on the first insulating film;

forming a transparent conductive film on the second insulating film; and

wiping/cleaning the surface of the transparent conductive film with a wiping/cleaning material.

10. The process for producing the light emitting device according to claim 8, wherein the surface of the transparent conductive film is made flat by the wiping/cleaning.

11. The process for producing the light emitting device according to claim 8, wherein the organic resin material is selected form the group consisting of polyacrylate, polyimide and polyamide.

12. The process for producing the light emitting device according to claim 8, wherein the inorganic insulating material is selected from the group consisting of silicon oxide, silicon nitride, silicon oxide nitride, silicon nitride oxide, aluminum nitride, aluminum nitride oxide and aluminum oxide nitride.

13. The process for producing the light emitting device according to claim 8, wherein the wiping/cleaning material is a PVA-based porous body.

14. The process for producing the light emitting device according to claim 8, wherein the transparent conductive film is wiped/cleaned with the wiping/cleaning material and a washing liquid.

15. The process for producing the light emitting device according to claim 8, wherein the surface of the transparent conductive film is scrubbed with the wiping/cleaning material.

16. The process for producing the light emitting device according to claim 8, wherein when contact angle to the surface of the transparent conductive film is smaller than 90°

before the wiping/cleaning, the contact angle after the wiping/cleaning is larger than the contact angle before the wiping/cleaning and is smaller than 90°

.

19. The process for producing the light emitting device according to claim 17, wherein the surface of the insulating film is made flat by the wiping/cleaning.

20. The process for producing the light emitting device according to claim 17, wherein the wiping/cleaning material is a PVA-based porous body.

21. The process for producing the light emitting device according to claim 17, wherein the surface of the insulating film is wiped/cleaned with the wiping/cleaning material and a washing liquid.

22. The process for producing the light emitting device according to claim 17, wherein the surface of the insulating film is scrubbed with the wiping/cleaning material.

23. The process for producing the light emitting device according to claim 17, wherein when contact angle to the insulating film is smaller than 90°

before the wiping/cleaning, the contact angle after the wiping/cleaning is larger than the contact angle before the wiping/cleaning and is smaller than 90°

.

24. The process for producing the light emitting device according to claim 17, wherein the insulating film is formed to have a film thickness of 1 to 50 nm.

25. The process for producing the light emitting device according to claim 17, wherein the insulating film comprises a material selected from the group consisting of polyacrylate, polyimide or polyamide.

28. The process for producing the light emitting device according to claim 26, wherein the surface of the third insulating film is made flat by the wiping/cleaning.

29. The process for producing the light emitting device according to claim 26, wherein the organic resin material is selected from the group consisting of polyacrylate, polyimide and polyamide.

30. The process for producing the light emitting device according to claim 26, wherein the inorganic insulating material is selected from the group consisting of silicon oxide, silicon nitride, silicon oxide nitride, silicon nitride oxide, aluminum nitride, aluminum nitride oxide and aluminum oxide nitride.

31. The process for producing the light emitting device according to claim 26, wherein the wiping/cleaning material is a PVA-based porous body.

32. The process for producing the light emitting device according to claim 26, wherein the transparent conductive film is wiped/cleaned with the wiping/cleaning material and a washing liquid.

33. The process for producing the light emitting device according to claim 26, wherein the surface of the third insulating film is scrubbed with the wiping/cleaning, material.

34. The process for producing the light emitting, device according to claim 26, wherein the third insulating film is formed to have a film thickness of 1 to 50 nm.

35. The process for producing the light emitting device according to claim 26, wherein the third insulating film is made of polyacrylate, polyimide or polyamide.

36. The process for producing the light emitting device according to claim 26, wherein when contact angle to the surface of the third insulating film is smaller than 90°

before the wiping/cleaning, the contact angle after the wiping/cleaning is larger than the contact angle before the wiping/cleaning and is smaller than 90°

.

37. The process for producing the light emitting device according to claim 26, wherein the TFT is manufactured by following steps:

first step of forming a semiconductor layer over the substrate;

second step of forming an insulating film on the semiconductor layer;

third step of forming a conductive layer on the insulating film;

fourth step of selectively etching the conductive layer to form a first conductive layer having a first tapered shape;

fifth step of introducing an impurity element into the semiconductor layer;

sixth step of selectively etching the first conductive layer to form a second conductive layer having a second tapered shape; and

seventh step of introducing the impurity element into the semiconductor layer,

wherein the concentration of the impurity element introduced in the seventh step is lower than that introduced in the fifth step.

9. A process for producing an active matrix type light emitting device comprising the steps of:

forming the TFTs over a substrate;

forming a first insulating film comprising organic resin material over the TFTs;

forming a second insulating film comprising inorganic insulating material on the first insulating film;

forming an anode on the second insulating film; and

wiping/cleaning the surface of the anode with a wiping/cleaning material.

17. A process for producing a light emitting device comprising the steps of:

forming a transparent conductive film;

forming an insulating film comprising an organic resin material on the transparent conductive film; and

wiping/cleaning the surface of the insulating film with a wiping/cleaning material.

18. A process for producing a light emitting device comprising the steps of:

forming an anode;

forming an insulating film comprising an organic resin material on the anode; and

wiping/cleaning the surface of the insulating film with a wiping/cleaning material.

26. A process for producing an active matrix type light emitting device comprising the steps of:

forming TFTs over a substrate;

forming a first insulating film comprising an organic resin material over the TFTs;

forming a second insulating film comprising an inorganic insulating material on the first insulating film;

forming a transparent conductive film on the second insulating film;

forming a third insulating film comprising an organic resin material on the transparent conductive film; and

wiping/cleaning the surface of the third insulating film with a wiping/cleaning material.

27. A process for producing an active matrix type light emitting device comprising the steps of:

forming TFTs over a substrate;

forming a first insulating film comprising an organic resin material over the TFTs;

forming a second insulating film comprising an inorganic insulating material on the first insulating film;

forming an anode on the second insulating film;

forming a third insulating film comprising an organic resin material on the anode; and

wiping/cleaning the surface of the third insulating film with a wiping/cleaning material.