Display device and manufacturing method thereof

• US 8,441,007 B2
• Filed: 12/09/2009
• Issued: 05/14/2013
• Est. Priority Date: 12/25/2008
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Arai, Yasuyuki
• Primary Examiner(s): POTTER, ROY KARL
• Application Number:
  US12/634,060
• Publication Number:
  US 20100163865A1
• Time in Patent Office: 1,252 Days
• Field of Search: 257/43, 257/59, 257/E29.296, 257/E33.019, 257/E21.459, 257/E21.414, 438/104, 438/46, 438/158
• US Class Current: 257/43
• CPC Class Codes: H01L 21/02554 Oxides
• CPC Class Codes: H01L 21/02565 Oxide semiconducting materials not being Group 12/16 materials, e.g. ternary compounds
• CPC Class Codes: H01L 21/02581 Transition metal or rare earth elements
• CPC Class Codes: H01L 21/02631 Physical deposition at reduced pressure, e.g. MBE, sputtering, evaporation
• 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 27/124 with a particular composition, shape or layout of the wiring layers specially adapted to the circuit arrangement, e.g. scanning lines in LCD pixel circuits wiring structures per se H01L23/52
• CPC Class Codes: H01L 29/45 Ohmic electrodes
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate
• CPC Class Codes: H01L 29/78696 characterised by the structure of the channel, e.g. multichannel, transverse or longitudinal shape, length or width, doping structure, or the overlap or alignment between the channel and the gate, the source or the drain, or the contacting structure of the channel H01L29/78612 takes precedence; transistors having a drain offset region or a lightly doped drain [LDD] H01L29/78621

Abstract

A display device includes a first wiring functioning as a gate electrode formed over a substrate, a gate insulating film formed over the first wiring, a second wiring and an electrode layer provided over the gate insulating film, and a high-resistance oxide semiconductor layer formed between the second wiring and the electrode layer are included. In the structure, the second wiring is formed using a stack of a low-resistance oxide semiconductor layer and a conductive layer over the low-resistance oxide semiconductor layer, and the electrode layer is formed using a stack of the low-resistance oxide semiconductor layer and the conductive layer which is stacked so that a region functioning as a pixel electrode of the low-resistance oxide semiconductor layer is exposed.

Claims

1. A display device comprising:

a gate electrode formed over a substrate;

a gate insulating film formed over the gate electrode;

a wiring and an electrode layer provided over the gate insulating film; and

a high-resistance oxide semiconductor layer formed between the wiring and the electrode layer over the gate insulating film,

wherein the wiring comprises a first low-resistance oxide semiconductor layer and a first conductive layer over the first low-resistance oxide semiconductor layer,

wherein the electrode layer comprises a second low-resistance oxide semiconductor layer and a second conductive layer covering a first portion of the second low-resistance oxide semiconductor layer, and

wherein a second portion of the second low-resistance oxide semiconductor layer is arranged to function as a pixel electrode.

9. The display device according to claim 1, wherein the display device is incorporated into an electronic apparatus.

2. A display device comprising:

a gate electrode formed over a substrate;

a gate insulating film formed over the gate electrode;

a high-resistance oxide semiconductor layer formed in an island shape over the gate insulating film; and

a wiring and an electrode layer provided over the gate insulating film and the high-resistance oxide semiconductor layer,

wherein the wiring comprises a first low-resistance oxide semiconductor layer and a first conductive layer over the first low-resistance oxide semiconductor layer,

wherein the electrode layer comprises a second low-resistance oxide semiconductor layer and a second conductive layer covering a first portion of the second low-resistance oxide semiconductor layer, and

wherein a second portion of the second low-resistance oxide semiconductor layer is arranged to function as a pixel electrode.

10. The display device according to claim 2, wherein the display device is incorporated into an electronic apparatus.

3. A display device comprising:

a wiring and an electrode layer over a substrate;

a high-resistance oxide semiconductor layer formed between the wiring and the electrode layer over the substrate;

a gate insulating film formed over the high-resistance oxide semiconductor layer; and

a gate electrode formed over the gate insulating film,

wherein the wiring comprises a first low-resistance oxide semiconductor layer and a first conductive layer over the first low-resistance oxide semiconductor layer,

wherein the electrode layer comprises a second low-resistance oxide semiconductor layer and a second conductive layer covering a first portion of the second low-resistance oxide semiconductor layer, and

wherein a second portion of the second low-resistance oxide semiconductor layer is arranged to function as a pixel electrode.

11. The display device according to claim 3, wherein the display device is incorporated into an electronic apparatus.

4. A display device comprising:

a high-resistance oxide semiconductor layer formed in an island shape over a substrate;

a wiring and an electrode layer over the substrate and the high-resistance oxide semiconductor layer;

a gate insulating film formed over the high-resistance oxide semiconductor layer; and

a gate electrode formed over the gate insulating film,

wherein the wiring comprises a first low-resistance oxide semiconductor layer and a first conductive layer over the first low-resistance oxide semiconductor layer,

wherein the electrode layer comprises a second low-resistance oxide semiconductor layer and a second conductive layer covering a first portion of the second low-resistance oxide semiconductor layer, and

wherein a second portion of the second low-resistance oxide semiconductor layer is arranged to function as a pixel electrode.

12. The display device according to claim 4, wherein the display device is incorporated into an electronic apparatus.

5. A method of manufacturing a display device, comprising the steps of:

forming a gate electrode over a substrate;

forming a gate insulating film over the gate electrode;

forming a wiring and an electrode layer over the gate insulating film by stacking a low-resistance oxide semiconductor layer and a conductive layer over the low-resistance oxide semiconductor layer; and

forming a high-resistance oxide semiconductor layer between the wiring and the electrode layer over the gate insulating film,

wherein a region of the conductive layer which corresponds to a region of the electrode layer functioning as a pixel electrode is etched, so that the low-resistance oxide semiconductor layer is exposed.

6. A method of manufacturing a display device, comprising the steps of:

forming a gate electrode over a substrate;

forming a gate insulating film over the gate electrode;

forming a high-resistance oxide semiconductor layer so as to have an island shape over the gate insulating film; and

forming a wiring and an electrode layer over the gate insulating film and the high-resistance oxide semiconductor layer by stacking a low-resistance oxide semiconductor layer and a conductive layer over the low-resistance oxide semiconductor layer,

wherein a region of the conductive layer which corresponds to a region of the electrode layer functioning as a pixel electrode is etched, so that the low-resistance oxide semiconductor layer is exposed.

7. A method of manufacturing a display device, comprising the steps of:

forming a wiring and an electrode layer over a substrate by stacking a low-resistance oxide semiconductor layer and a conductive layer over the low-resistance oxide semiconductor layer;

forming a high-resistance oxide semiconductor layer between the wiring and the electrode layer over the substrate;

forming a gate insulating film over the high-resistance oxide semiconductor layer; and

forming a gate electrode over the gate insulating film,

wherein a region of the conductive layer which corresponds to a region of the electrode layer functioning as a pixel electrode is etched, so that the low-resistance oxide semiconductor layer is exposed.

8. A method of manufacturing a display device, comprising the steps of:

forming a high-resistance oxide semiconductor layer so as to have an island shape over a substrate;

forming a wiring and an electrode layer over the substrate and the high-resistance oxide semiconductor layer by stacking a low-resistance oxide semiconductor layer and a conductive layer over the low-resistance oxide semiconductor layer;

forming a gate insulating film over the high-resistance oxide semiconductor layer; and

forming a gate electrode over the gate insulating film,

wherein a region of the conductive layer which corresponds to a region of the electrode layer functioning as a pixel electrode is etched, so that the low-resistance oxide semiconductor layer is exposed.