LIGHT-EMITTING DEVICE AND MANUFACTURING METHOD THEREOF

• US 20110031496A1
• Filed: 08/02/2010
• Published: 02/10/2011
• Est. Priority Date: 08/07/2009
• 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 8,492,764 B2
• Time in Patent Office: Days
• US Class Current: 257/59
• 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 2102/3031 Two-side emission, e.g. transparent OLEDs [TOLED]
• CPC Class Codes: H10K 50/19 Tandem OLEDs
• CPC Class Codes: H10K 59/1213 the pixel elements being TFTs
• CPC Class Codes: H10K 59/123 Connection of the pixel electrodes to the thin film transistors [TFT]
• CPC Class Codes: H10K 59/38 comprising colour filters or colour changing media [CCM]

Abstract

A light-emitting device in which plural kinds of circuits are formed over one substrate and plural kinds of thin film transistors in accordance with characteristics of the plural kinds of circuits are included. An inverted-coplanar thin film transistor including an oxide semiconductor layer which overlaps a source and drain electrode layers is used as a thin film transistor for a pixel, a channel-stop thin film transistor is used as a thin film transistor for a driver circuit, and a color filter layer is provided between the thin film transistor for a pixel and a light-emitting element so as to overlap 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 over a substrate, and comprising;

a first thin film transistor comprising;

a gate electrode layer over the substrate;

a gate insulating layer over the gate electrode layer;

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

an oxide semiconductor layer over the gate insulating layer,

and overlapping the source and drain electrode layers,

an oxide insulating layer which is in contact with the oxide semiconductor layer;

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

a color filter layer over the oxide insulating layer;

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

a light-emitting layer over the first electrode; and

a second electrode over the light-emitting layer,

a driver circuit over the substrate, and comprising a second thin film transistor having a structure different from a structure of the first thin film transistor,

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

2. The light-emitting device according to claim 1, wherein a material of a source and drain electrode layers of the second thin film transistor is different from a material of the source and drain electrode layers of the first thin film transistor, and wherein a resistance of the material of the source and drain electrode layers of the second thin film transistor is lower than that of the first thin film transistor.

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

4. The light-emitting device according to claim 1, wherein the source and drain electrode layers of the second thin film transistor are the same materials as the connection electrode layer of the first thin film transistor.

5. The light-emitting device according to claim 1, wherein the source and drain electrode layers of the first thin film transistor are indium oxide, an alloy of indium oxide and tin oxide, an alloy of indium oxide and zinc oxide, or zinc oxide.

6. The light-emitting device according to claim 1, wherein the second thin film transistor includes an oxide semiconductor layer, the oxide insulating layer is provided over the oxide semiconductor layer, and a channel formation region of the oxide semiconductor layer and an outer edge of the oxide semiconductor layer are in contact with the oxide insulating layer.

7. 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.

8. The light-emitting device according to claim 1, wherein the second thin film transistor includes an oxide conductive layer between the oxide semiconductor layer and the source electrode layer and an oxide conductive layer between the oxide semiconductor layer and the drain electrode layer.

9. A method for manufacturing a light-emitting device, comprising the steps of:

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

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

forming a first source and drain electrode layers over the gate insulating layer so as to overlap the first gate electrode layer;

forming over the gate insulating layer, a first oxide semiconductor layer so as to overlap the first gate electrode layer, a part of the first source electrode layer, and a part of the first drain electrode layer, and a second oxide semiconductor layer so as to overlap the second gate electrode layer;

forming an oxide insulating layer so as to be in contact with a part of the second oxide semiconductor layer and with a top surface and a side surface of the second oxide semiconductor layer;

forming a second source and drain electrode layers over the second oxide semiconductor layer, and forming a connection electrode layer over the oxide insulating layer so as to be electrically connected to the first drain electrode layer;

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

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