SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THEREOF

• US 20090186437A1
• Filed: 03/26/2009
• Published: 07/23/2009
• Est. Priority Date: 11/15/2005
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Akimoto, Kengo
• Granted Patent: US 8,158,464 B2
• Time in Patent Office: Days
• US Class Current: 438/30
• CPC Class Codes: H01L 27/1214 comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
• 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 27/1255 integrated with passive devices, e.g. auxiliary capacitors
• CPC Class Codes: H01L 29/41733 for thin film transistors with insulated gate
• CPC Class Codes: H01L 29/45 Ohmic electrodes
• CPC Class Codes: H01L 29/4908 for thin film semiconductor, e.g. gate of TFT
• CPC Class Codes: H01L 29/78621 with LDD structure or an extension or an offset region or characterised by the doping profile
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate

Abstract

To provide a semiconductor device in which a defect or fault is not generated and a manufacturing method thereof even if a ZnO semiconductor film is used and a ZnO film to which an n-type or p-type impurity is added is used for a source electrode and a drain electrode. The semiconductor device includes a gate insulating film formed by using a silicon oxide film or a silicon oxynitride film over a gate electrode, an Al film or an Al alloy film over the gate insulating film, a ZnO film to which an n-type or p-type impurity is added over the Al film or the Al alloy film, and a ZnO semiconductor film over the ZnO film to which an n-type or p-type impurity is added and the gate insulating film.

Claims

1. A method of manufacturing a liquid crystal display device comprising:

forming an active matrix portion on a first substrate;

wherein the active matrix portion comprises at least one thin film transistor comprising a semiconductor film containing zinc oxide as a channel formation region;

forming a closed pattern of a sealant around the active matrix portion;

dropping liquid crystal composition in the closed pattern; and

attaching the first substrate and a second substrate to each other after dropping the liquid crystal composition.

2. A method of manufacturing a liquid crystal display device comprising:

forming a thin film transistor over a first substrate, the thin film transistor comprising;

a semiconductor film comprising zinc oxide;

a conductive film comprising an oxide in contact with the semiconductor film;

a metal film in contact with the conductive film; and

a gate electrode adjacent to the semiconductor film with a gate insulating film interposed therebetween,

wherein the conductive film is between the semiconductor film and the metal film.

forming a pixel electrode over the first substrate wherein the pixel electrode is electrically connected to the thin film transistor;

forming a closed pattern of a sealant over the first substrate;

dropping liquid crystal composition over the pixel electrode in the closed pattern; and

attaching a second substrate to the first substrate with the liquid crystal composition between the first substrate and the second substrate.

5. A method of manufacturing a liquid crystal display device according to claim 2, wherein the metal film is aluminum film or aluminum alloy film.

7. A method of manufacturing a liquid crystal display device according to claim 2, wherein the conductive film comprises zinc oxide.

9. A method of manufacturing a liquid crystal display device according to claim 2, wherein the metal film is a Ti film.

11. A method of manufacturing a liquid crystal display device according to claim 2, wherein the metal film includes a first metal layer comprising aluminum and a second metal layer comprising titanium wherein the second metal layer is in contact with the conductive film.

3. A method of manufacturing a liquid crystal display device comprising:

forming a thin film transistor over a first substrate, the thin film transistor comprising;

a gate electrode;

a gate insulating film formed over the gate electrode; and

a semiconductor film comprising zinc oxide over the gate electrode with the gate insulating film interposed therebetween;

forming an insulating film comprising a resin material on the semiconductor film;

forming a pixel electrode over the insulating film wherein the pixel electrode is electrically connected to the thin film transistor through a contact hole of the insulating film;

forming a closed pattern of a sealant over the first substrate;

dropping liquid crystal composition over the pixel electrode in the closed pattern; and

attaching a second substrate to the first substrate with the liquid crystal composition between the first substrate and the second substrate.

4. A method of manufacturing a liquid crystal display device comprising:

forming a thin film transistor over a first substrate, the thin film transistor comprising;

a gate electrode formed over the first substrate;

a gate insulating film formed over the gate electrode;

a metal film formed over the substrate;

a conductive film comprising an oxide formed on and in contact with the metal film; and

a semiconductor film comprising zinc oxide formed on and in contact with the conductive film and the gate insulating film;

forming an insulating film on the semiconductor film;

forming a pixel electrode over the insulating film wherein the pixel electrode is in contact with the conductive film through a contact hole of the insulating film;

forming a closed pattern of a sealant over the first substrate;

dropping liquid crystal composition over the pixel electrode in the closed pattern; and

attaching a second substrate to the first substrate with the liquid crystal composition between the first substrate and the second substrate.

6. A method of manufacturing a liquid crystal display device according to claim 4, wherein the metal film is aluminum film or aluminum alloy film.

8. A method of manufacturing a liquid crystal display device according to claim 4, wherein the conductive film comprises zinc oxide.

10. A method of manufacturing a liquid crystal display device according to claim 4, wherein the metal film is a Ti film.

12. A method of manufacturing a liquid crystal display device according to claim 4, wherein the metal film includes a first metal layer comprising aluminum and a second metal layer comprising titanium wherein the second metal layer is in contact with the conductive film.

13. A method of manufacturing a liquid crystal display device according to claim 4, wherein the insulating film comprises a resin.