LIGHT-EMITTING DEVICE AND METHOD FOR MANUFACTURING THE SAME

• US 20110210324A1
• Filed: 08/26/2010
• Published: 09/01/2011
• Est. Priority Date: 09/04/2009
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: HOSOBA, Miyuki, AKIMOTO, Kengo, YAMAZAKI, Shunpei, OIKAWA, Yoshiaki, SAKAKURA, Masayuki, SAKATA, Junichiro, TSUBUKU, Masashi
• Granted Patent: US 8,378,344 B2
• Time in Patent Office: Days
• 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 59/38 comprising colour filters or colour changing media [CCM]

Abstract

It is an object to provide a light-emitting device in which plural kinds of circuits are formed over one substrate and plural kinds of thin film transistors corresponding to characteristics of the plural kinds of circuits are provided. An inverted coplanar thin film transistor in which an oxide semiconductor layer overlaps with a source electrode layer and a drain electrode layer is used for a pixel, and a channel-etched thin film transistor is used for a driver circuit. A color filter layer is provided between the pixel thin film transistor and a light-emitting element which is electrically connected to the pixel thin film transistor so as to overlap with the light-emitting element.

Claims

1. A light-emitting device comprising:

a pixel portion including a first thin film transistor over a substrate; and

a driver circuit including a second thin film transistor over the substrate, wherein the first thin film transistor has a different structure from the second thin film transistor,

wherein the first thin film transistor comprises;

a first gate electrode layer over the substrate;

a gate insulating layer over the first gate electrode layer;

a first source electrode layer and a first drain electrode layer over the gate insulating layer;

a first oxide semiconductor layer over the gate insulating layer, the first source electrode layer, and the first drain electrode layer;

a first oxide insulating layer in contact with the first oxide semiconductor layer; and

a connection electrode layer over the gate insulating layer, wherein the connection electrode layer is electrically connected to one of the first source electrode layer and the first drain electrode layer,

wherein the pixel portion comprises;

a color filter layer over the first oxide insulating layer;

a pixel electrode over the color filter layer, wherein the pixel electrode is electrically connected to the connection electrode layer;

a light-emitting layer over the pixel electrode; and

an electrode over the light-emitting layer,

wherein the first gate electrode layer, the gate insulating layer, the first oxide semiconductor layer, the first source electrode layer, the first drain electrode layer, and the first oxide insulating layer have a light-transmitting property.

2. The light-emitting device according to claim 1,

wherein the second thin film transistor comprises a second gate electrode layer, a second source electrode layer, and a second drain electrode layer which are formed using a material different from a material of the first gate electrode layer, the first source electrode layer, and the first drain electrode layer, and

wherein the second gate electrode layer, the second source electrode layer, and the second drain electrode layer are formed using a conductive material having lower resistance than a conductive material of the first source electrode layer, and the first drain electrode layer.

3. The light-emitting device according to claim 1,

wherein the connection electrode layer is formed using a film comprising an element selected from the group consisting of Al, Cr, Cu, Ta, Ti, Mo, and W as a main component, an alloy film comprising any of the elements, or a stacked film including the films in combination.

4. The light-emitting device according to claim 2,

wherein the second source electrode layer and the second drain electrode layer are formed using the same material as the connection electrode layer.

5. The light-emitting device according to claim 1,

wherein the first source electrode layer and the first drain electrode layer are formed using indium oxide, indium oxide-tin oxide alloy, indium oxide-zinc oxide alloy, or zinc oxide.

6. The light-emitting device according to claim 1,

wherein the second thin film transistor comprise:

an second oxide semiconductor layer; and

an second oxide insulating layer over the second oxide semiconductor layer, and

wherein a channel formation region of the second oxide semiconductor layer is in contact with the second oxide insulating layer.

7. The light-emitting device according to claim 6,

wherein the first oxide insulating layer and the second oxide insulating layer are formed using a silicon oxide film or an aluminum oxide film formed by a sputtering method.

8. The light-emitting device according to claim 1,

wherein the first oxide semiconductor layer comprises In—

Ga—

Zn—

O based oxide semiconductor.

9. The light-emitting device according to claim 1,

wherein the connection electrode layer is in contact with a top surface of the first oxide semiconductor layer, a side surface of the first oxide semiconductor layer, and a side surface of the one of the first source electrode layer and the first drain electrode layer.

10. A light-emitting device comprising:

a pixel portion including a first thin film transistor over a substrate and;

a driver circuit including a second thin film transistor over the substrate, wherein the first thin film transistor has a different structure from the second thin film transistor,

wherein the first thin film transistor comprises;

a first gate electrode layer over the substrate;

a gate insulating layer over the first gate electrode layer;

a first source electrode layer and a first drain electrode layer over the gate insulating layer;

a first oxide semiconductor layer over the gate insulating layer, the first source electrode layer, and the first drain electrode layer;

a first oxide insulating layer in contact with the first oxide semiconductor layer; and

a connection electrode layer over the gate insulating layer, wherein the connection electrode layer is electrically connected to one of the first source electrode layer and the first drain electrode layer,

wherein the pixel portion comprises;

a color filter layer over the first oxide insulating layer;

a pixel electrode over the color filter layer, wherein the pixel electrode is electrically connected to the connection electrode layer;

a light-emitting layer over the pixel electrode; and

an electrode over the light-emitting layer,

wherein the first gate electrode layer, the gate insulating layer, the first oxide semiconductor layer, the first source electrode layer, the first drain electrode layer, and the first oxide insulating layer have a light-transmitting property, and

wherein the first oxide insulating layer is in contact with a side surface of the first oxide semiconductor layer and a side surface of the other one of the first source electrode layer and the first drain electrode layer.

11. The light-emitting device according to claim 10,

wherein the second thin film transistor comprises a second gate electrode layer, a second source electrode layer, and a second drain electrode layer which are formed using a material different from a material of the first gate electrode layer, the first source electrode layer, and the first drain electrode layer, and

wherein the second gate electrode layer, the second source electrode layer, and the second drain electrode layer are formed using a conductive material having lower resistance than a conductive material of the first source electrode layer, and the first drain electrode layer.

12. The light-emitting device according to claim 10,

wherein the connection electrode layer is formed using a film comprising an element selected from the group consisting of Al, Cr, Cu, Ta, Ti, Mo, and W as a main component, an alloy film comprising any of the elements, or a stacked film including the films in combination.

13. The light-emitting device according to claim 11,

wherein the second source electrode layer and the second drain electrode layer are formed using the same material as the connection electrode layer.

14. The light-emitting device according to claim 10,

wherein the first source electrode layer and the first drain electrode layer are formed using indium oxide, indium oxide-tin oxide alloy, indium oxide-zinc oxide alloy, or zinc oxide.

15. The light-emitting device according to claim 10,

wherein the second thin film transistor comprise:

an second oxide semiconductor layer, and

an second oxide insulating layer over the second oxide semiconductor layer, and

wherein a channel formation region of the second oxide semiconductor layer is in contact with the second oxide insulating layer.

16. The light-emitting device according to claim 15,

wherein the first oxide insulating layer and the second oxide insulating layer are formed using a silicon oxide film or an aluminum oxide film formed by a sputtering method.

17. The light-emitting device according to claim 10,

wherein the first oxide semiconductor layer comprises In—

Ga—

Zn—

O based oxide semiconductor.

18. The light-emitting device according to claim 10,

wherein the connection electrode layer is in contact with a top surface of the first oxide semiconductor layer, a side surface of the first oxide semiconductor layer, and a side surface of the one of the first source electrode layer and the first drain electrode layer.

19. A method for manufacturing a light-emitting device, comprising:

forming a first gate electrode layer and a second gate electrode layer over a substrate having an insulating surface;

forming a gate insulating layer over the first gate electrode layer and the second gate electrode layer;

forming a first source electrode layer and a first drain electrode layer over the gate insulating layer, wherein the first source electrode layer and the first drain electrode layer overlap with the first gate electrode layer;

forming a first oxide semiconductor layer over the gate insulating layer, wherein the first oxide semiconductor layer overlaps with the first gate electrode layer, a part of the first source electrode layer, and a part of the first drain electrode layer;

forming a connection electrode layer electrically connected to the first drain electrode layer, over the gate insulating layer;

forming a second oxide semiconductor layer which overlaps with the second gate electrode layer;

forming a second source electrode layer and a second drain electrode layer over the second oxide semiconductor layer,

forming an oxide insulating layer in contact with a top surface and a side surface of the first oxide semiconductor layer and a top surface of the second oxide semiconductor layer;

forming a color filter layer over the oxide insulating layer which overlaps with the first oxide semiconductor layer;

forming a pixel electrode electrically connected to the connection electrode layer, over the color filter layer;

forming a light-emitting layer over the pixel electrode; and

forming an electrode over the light-emitting layer.

20. The method for manufacturing a light-emitting device according to claim 19,

wherein the first gate electrode layer, the gate insulating layer, the first oxide semiconductor layer, the first source electrode layer, the first drain electrode layer, and the oxide insulating layer have a light-transmitting property.

21. The method for manufacturing a light-emitting device according to claim 19,

wherein the second source electrode layer and the second drain electrode layer are formed using the same material as the connection electrode layer.

22. The method for manufacturing a light-emitting device according to claim 19,

wherein the first oxide semiconductor layer comprises In—

Ga—

Zn—

O based oxide semiconductor.