LIGHT-EMITTING DEVICE AND METHOD FOR MANUFACTURING THE SAME

• US 20110057187A1
• Filed: 08/30/2010
• Published: 03/10/2011
• 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 8,890,166 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: 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
• CPC Class Codes: H10K 59/38 comprising colour filters or colour changing media [CCM]

Abstract

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

Claims

1. A light-emitting device comprising:

a pixel portion comprising;

a first thin film transistor comprising;

a first gate electrode layer; and

a first oxide semiconductor layer over the first gate electrode layer with a gate insulating layer between the first gate electrode layer and the first oxide semiconductor layer, the first oxide semiconductor layer comprising a first channel formation region, wherein a bottom surface of the first oxide semiconductor layer is in direct contact with a first source electrode layer and a first drain electrode layer;

a connection electrode layer over the first drain electrode layer with an oxide insulating layer between the connection electrode layer and the first drain electrode layer, the connection electrode layer being electrically connected to the first drain electrode layer;

a color filter layer over the oxide insulating layer;

a first electrode over the color filter layer, the first electrode being electrically connected to the connection electrode layer;

a light-emitting layer over the first electrode; and

a second electrode over the light-emitting layer; and

a driver circuit comprising;

a second thin film transistor comprising;

a second gate electrode layer; and

a second oxide semiconductor layer over the second gate electrode layer with the gate insulating layer between the second gate electrode layer and the second oxide semiconductor layer, the second oxide semiconductor layer comprising a second channel formation region, wherein a top surface of the second oxide semiconductor layer is in direct contact with a second source electrode layer and a second drain electrode layer, and wherein the oxide insulating layer overlaps with an end portion of the second oxide semiconductor layer,

wherein an insulating layer over the second source electrode layer, the second drain electrode layer, the connection electrode layer, the oxide insulating layer and the second oxide semiconductor layer is in direct contact with the second channel formation region between the second source electrode layer and the second drain electrode layer,

wherein the pixel portion and the driver circuit are formed over a same substrate, and

wherein each of the first gate electrode layer, the gate insulating layer, the first oxide semiconductor layer, the first source electrode layer, the first drain electrode layer, the oxide insulating layer and the first electrode has light-transmitting properties.

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

wherein a conductive material of the second gate electrode layer has a lower resistance than a conductive material of the first gate electrode layer,

wherein a conductive material of the second source electrode layer has a lower resistance than a conductive material of the first source electrode layer, and

wherein a conductive material of the second drain electrode layer has a lower resistance than a conductive material of the first drain electrode layer.

3. The light-emitting device according to claim 1, wherein the connection electrode layer is formed using a film containing an element selected from the group consisting of Al, Cr, Cu, Ta, Ti, Mo, and W as its main component, or a stacked-layer film including the film containing the element as its main component and an alloy film containing the element.

4. The light-emitting device according to claim 1, wherein each of the second source electrode layer and the second drain electrode layer contains a same material as the connection electrode layer.

5. The light-emitting device according to claim 1, wherein each of the first source electrode layer and the first drain electrode layer contains an indium oxide, an alloy of an indium oxide and a tin oxide, an alloy of an indium oxide and a zinc oxide, or a zinc oxide.

6. The light-emitting device according to claim 1, wherein the oxide insulating layer is a silicon oxide film or an aluminum oxide film formed by a sputtering method.

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

wherein a first oxide conductive layer is formed between the second oxide semiconductor layer and the second source electrode layer, and

wherein a second oxide conductive layer is formed between the second oxide semiconductor layer and the second drain electrode layer.

8. The light-emitting device according to claim 1, wherein each of the first oxide semiconductor layer and the second oxide semiconductor layer comprises In, Ga, Zn and O.

9. An electronic apparatus comprising the light-emitting device according to claim 1, wherein the electronic apparatus is selected from the group consisting of a television set, a camera, a digital photo frame, a mobile phone set, a portable game console, a portable information terminal and an audio reproducing device.

10. A light-emitting device comprising:

a first gate electrode layer over a substrate;

a second gate electrode layer over the substrate;

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

a first source electrode layer over the gate insulating layer;

a first drain electrode layer over the gate insulating layer;

a first oxide semiconductor layer comprising a first channel formation region over the first source electrode layer, the first drain electrode layer and the gate insulating layer, the first oxide semiconductor layer overlapping with the first gate electrode layer, wherein the first oxide semiconductor layer is electrically connected to the first source electrode layer and the first drain electrode layer;

a second oxide semiconductor layer comprising a second channel formation region over the gate insulating layer, the second oxide semiconductor layer overlapping with the second gate electrode layer;

an oxide insulating layer over the gate insulating layer, the first source electrode layer, the first drain electrode layer, the first oxide semiconductor layer and the second oxide semiconductor layer, the oxide insulating layer having an opening overlapping with the second channel formation region;

a second source electrode layer over the oxide insulating layer and the second oxide semiconductor layer, the second source electrode layer being electrically connected to the second oxide semiconductor layer;

a second drain electrode layer over the oxide insulating layer and the second oxide semiconductor layer, the second drain electrode layer being electrically connected to the second oxide semiconductor layer;

a connection electrode layer over the oxide insulating layer, the connection electrode layer being electrically connected to the first drain electrode layer;

an insulating layer over the second oxide semiconductor layer, the oxide insulating layer, the second source electrode layer and the second drain electrode layer, the insulating layer being in direct contact with the second channel formation region;

a color filter layer over the insulating layer;

a first electrode over the color filter layer, the first electrode being electrically connected to the connection electrode layer;

a light-emitting layer over the first electrode; and

a second electrode over the light-emitting layer,

wherein each of the first gate electrode layer, the gate insulating layer, the first oxide semiconductor layer, the first source electrode layer, the first drain electrode layer, the oxide insulating layer, the insulating layer and the first electrode has light-transmitting properties.

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

wherein a conductive material of the second gate electrode layer has a lower resistance than a conductive material of the first gate electrode layer,

wherein a conductive material of the second source electrode layer has a lower resistance than a conductive material of the first source electrode layer, and

wherein a conductive material of the second drain electrode layer has a lower resistance than a conductive material of the first drain electrode layer.

12. The light-emitting device according to claim 10, wherein the connection electrode layer is formed using a film containing an element selected from the group consisting of Al, Cr, Cu, Ta, Ti, Mo, and W as its main component, or a stacked-layer film including the film containing the element as its main component and an alloy film containing the element.

13. The light-emitting device according to claim 10, wherein each of the second source electrode layer and the second drain electrode layer contains a same material as the connection electrode layer.

14. The light-emitting device according to claim 10, wherein each of the first source electrode layer and the first drain electrode layer contains an indium oxide, an alloy of an indium oxide and a tin oxide, an alloy of an indium oxide and a zinc oxide, or a zinc oxide.

15. The light-emitting device according to claim 10, wherein the oxide insulating layer is a silicon oxide film or an aluminum oxide film formed by a sputtering method.

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

wherein a first oxide conductive layer is formed between the second oxide semiconductor layer and the second source electrode layer, and

wherein a second oxide conductive layer is formed between the second oxide semiconductor layer and the second drain electrode layer.

17. The light-emitting device according to claim 10, wherein each of the first oxide semiconductor layer and the second oxide semiconductor layer comprises In, Ga, Zn and O.

18. An electronic apparatus comprising the light-emitting device according to claim 10, wherein the electronic apparatus is selected from the group consisting of a television set, a camera, a digital photo frame, a mobile phone set, a portable game console, a portable information terminal and an audio reproducing device.

19. A manufacturing method of a light-emitting device comprising the steps of:

forming a first gate electrode layer and a second gate electrode layer over a substrate;

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 to overlap with the first gate electrode layer;

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

forming an oxide insulating layer over the gate insulating layer, the first source electrode layer, the first drain electrode layer, the first oxide semiconductor layer and the second oxide semiconductor layer, wherein the oxide insulating layer is in direct contact with a peripheral portion of the second oxide semiconductor layer and in direct contact with a top surface and a side surface of the first oxide semiconductor layer;

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

forming an insulating layer over the second source electrode layer, the second drain electrode layer, the connection electrode layer and the oxide insulating layer, wherein the insulating layer is in direct contact with a channel formation region of the second oxide semiconductor layer;

forming a color filter layer over the insulating layer overlapping with the first oxide semiconductor layer; and

forming a first electrode, a light-emitting layer and a second electrode, over the color filter layer, wherein the first electrode is electrically connected to the connection electrode layer.