SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THEREOF

• US 20100304529A1
• Filed: 05/26/2010
• Published: 12/02/2010
• Est. Priority Date: 05/29/2009
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: SASAKI, Toshinari, SAKATA, Junichiro, OHARA, Hiroki
• Granted Patent: US 8,796,078 B2
• Time in Patent Office: Days
• US Class Current: 438/104
• CPC Class Codes: H01L 21/02164 the material being a silicon oxide, e.g. SiO2
• CPC Class Codes: H01L 21/02565 Oxide semiconducting materials not being Group 12/16 materials, e.g. ternary compounds
• CPC Class Codes: H01L 21/30604 Chemical etching
• CPC Class Codes: H01L 29/45 Ohmic electrodes
• CPC Class Codes: H01L 29/66969 of devices having semiconductor bodies not comprising group 14 or group 13/15 materials comprising selenium or tellurium in uncombined form other than as impurities in semiconductor bodies of other materials, comprising cuprous oxide or cuprous iodide H01L21/02365
• CPC Class Codes: H01L 29/78618 characterised by the drain or the source properties, e.g. the doping structure, the composition, the sectional shape or the contact structure silicide contacts, electrodes in general H01L29/458
• 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

An object is to provide a highly reliable semiconductor device including a thin film transistor having stable electric characteristics. In addition, another object is to manufacture a highly reliable semiconductor device at low cost with high productivity. In a method for manufacturing a semiconductor device including a thin film transistor including an oxide semiconductor layer as a channel formation region, the oxide semiconductor layer is heated under a nitrogen atmosphere to lower its resistance, thereby forming a low-resistance oxide semiconductor layer. Further, resistance of a region of the low-resistance oxide semiconductor layer, which is overlapped with a gate electrode layer, is selectively increased, thereby forming a high-resistance oxide semiconductor layer. Resistance of the oxide semiconductor layer is increased by forming a silicon oxide film in contact with the oxide semiconductor layer by a sputtering method.

Claims

1. A method for manufacturing a semiconductor device, comprising:

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

forming a gate insulating layer over the gate electrode layer;

forming an oxide semiconductor layer over the gate insulating layer;

heating the oxide semiconductor layer under a nitrogen atmosphere;

forming a source electrode layer and a drain electrode layer over the oxide semiconductor layer after the heating step; and

forming a silicon oxide film by a sputtering method over the gate insulating layer, the oxide semiconductor layer, the source electrode layer, and the drain electrode layer so that the silicon oxide film is in contact with part of the oxide semiconductor layer.

4. The method for manufacturing a semiconductor device according to any one of claims 1 to 3, wherein the oxide semiconductor layer is heated at 200°

C. or higher under a nitrogen atmosphere.

5. The method for manufacturing a semiconductor device according to any one of claims 1 to 3, wherein the oxide semiconductor layer is formed by a sputtering method under an oxygen atmosphere, an argon atmosphere, or an atmosphere containing oxygen and argon.

11. The method for manufacturing a semiconductor device according to any one of claims 1 to 3 and 6 to 8, wherein the silicon oxide film is formed by a sputtering method under an oxygen atmosphere, an argon atmosphere, or an atmosphere containing oxygen and argon.

12. The method for manufacturing a semiconductor device according to any one of claims 1 to 3 and 6 to 8, wherein the heating step is performed at 300°

C. or less under an air atmosphere or a nitrogen atmosphere after the silicon oxide film is formed.

13. The method for manufacturing a semiconductor device according to any one of claims 1 to 3 and 6 to 8, wherein the semiconductor device is incorporated in one selected from the group consisting of a poster, an advertisement, an electronic book, a television set, a digital photo frame, an amusement machine, a computer, and a wristwatch.

2. A method for manufacturing a semiconductor device, comprising:

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

forming a gate insulating layer over the gate electrode layer;

forming an oxide semiconductor layer over the gate insulating layer;

forming a source electrode layer and a drain electrode layer over the oxide semiconductor layer;

heating the oxide semiconductor layer, the source electrode layer, and the drain electrode layer under a nitrogen atmosphere; and

forming a silicon oxide film by a sputtering method over the gate insulating layer, the oxide semiconductor layer, the source electrode layer, and the drain electrode layer after the heating step so that the silicon oxide film is in contact with part of the oxide semiconductor layer.

3. A method for manufacturing a semiconductor device, comprising:

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

forming a gate insulating layer over the gate electrode layer;

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

forming an oxide semiconductor layer over the source electrode layer and the drain electrode layer;

heating the oxide semiconductor layer under a nitrogen atmosphere; and

forming a silicon oxide film by a sputtering method over the gate insulating layer, the source electrode layer, the drain electrode layer, and the oxide semiconductor layer after the heating step so that the silicon oxide film is in contact with the oxide semiconductor layer.

6. A method for manufacturing a semiconductor device, comprising:

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

forming a gate insulating layer over the gate electrode layer;

forming a first oxide semiconductor layer over the gate insulating layer;

heating the first oxide semiconductor layer under a nitrogen atmosphere to reduce its resistance, so that a second oxide semiconductor layer is formed;

forming a conductive film over the second oxide semiconductor layer;

selectively etching the conductive film to expose part of the second oxide semiconductor layer overlapped with the gate electrode layer, and to form a source electrode layer and a drain electrode layer; and

forming a silicon oxide film by a sputtering method over the second oxide semiconductor layer, the source electrode layer, and the drain electrode layer so that a region of the second oxide semiconductor layer in contact with the silicon oxide film has a higher resistance than the second oxide semiconductor layer.

9. The method for manufacturing a semiconductor device according to any one of claims 6 to 8, wherein the first oxide semiconductor layer is heated at 200°

C. or higher under a nitrogen atmosphere.

10. The method for manufacturing a semiconductor device according to any one of claims 6 to 8, wherein the first oxide semiconductor layer is formed by a sputtering method under an oxygen atmosphere, an argon atmosphere, or an atmosphere containing oxygen and argon.

7. A method for manufacturing a semiconductor device, comprising:

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

forming a gate insulating layer over the gate electrode layer;

forming a first oxide semiconductor layer over the gate insulating layer;

forming a conductive film over the first oxide semiconductor layer;

selectively etching the conductive film to expose part of the first oxide semiconductor layer overlapped with the gate electrode layer, and to form a source electrode layer and a drain electrode layer;

heating the first oxide semiconductor layer, the source electrode layer, and the drain electrode layer under a nitrogen atmosphere to reduce a resistance of the first oxide semiconductor layer, so that a second oxide semiconductor layer is formed; and

forming a silicon oxide film by a sputtering method over the second oxide semiconductor layer, the source electrode layer, and the drain electrode layer so that a region of the second oxide semiconductor layer in contact with the silicon oxide film has a higher resistance than the second oxide semiconductor layer.

8. A method for manufacturing a semiconductor device, comprising:

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

forming a gate insulating layer over the gate electrode layer;

forming a conductive film over the gate insulating layer;

selectively etching the conductive film to form a source electrode layer and a drain electrode layer;

forming a first oxide semiconductor layer over the source electrode layer and the drain electrode layer;

heating the first oxide semiconductor layer under a nitrogen atmosphere to reduce its resistance, so that a second oxide semiconductor layer is formed; and

forming a silicon oxide film by a sputtering method over the second oxide semiconductor layer so that a region of the second oxide semiconductor layer in contact with the silicon oxide film has a higher resistance than the second oxide semiconductor layer.