Method for manufacturing semiconductor device

• US 10,269,563 B2
• Filed: 12/22/2015
• Issued: 04/23/2019
• Est. Priority Date: 09/03/2010
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei
• Primary Examiner(s): Stark, Jarrett J
• Application Number:
  US14/978,374
• Publication Number:
  US 20160111280A1
• Time in Patent Office: 1,218 Days
• CPC Class Codes: H01L 21/02488 Insulating materials
• 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 21/02631 Physical deposition at reduced pressure, e.g. MBE, sputtering, evaporation
• CPC Class Codes: H01L 21/283 Deposition of conductive or insulating materials for electrodes conducting electric current
• 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 29/78603 characterised by the insulating substrate or support H01L29/78657 takes precedence
• 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

Electrical characteristics of transistors using an oxide semiconductor are greatly varied in a substrate, between substrates, and between lots, and the electrical characteristics are changed due to heat, bias, light, or the like in some cases. In view of the above, a semiconductor device using an oxide semiconductor with high reliability and small variation in electrical characteristics is manufactured. In a method for manufacturing a semiconductor device, hydrogen in a film and at an interface between films is removed in a transistor using an oxide semiconductor. In order to remove hydrogen at the interface between the films, the substrate is transferred under a vacuum between film formations. Further, as for a substrate having a surface exposed to the air, hydrogen on the surface of the substrate may be removed by heat treatment or plasma treatment.

Claims

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

forming an oxide semiconductor layer over a substrate while heating the substrate;

forming an island-shaped oxide semiconductor layer by patterning the oxide semiconductor layer;

forming a source electrode and a drain electrode over the island-shaped oxide semiconductor layer by etching a conductive layer;

supplying oxygen to the island-shaped oxide semiconductor layer after forming the source electrode and the drain electrode;

forming an oxide insulating layer over the island-shaped oxide semiconductor layer, the source electrode, and the drain electrode; and

forming a gate electrode over the oxide insulating layer,

wherein each of the source electrode and the drain electrode comprises a nitride of a metal element.

2. The method for manufacturing a semiconductor device according to claim 1, wherein the metal element is tantalum.

3. The method for manufacturing a semiconductor device according to claim 1,

wherein the supplying oxygen to the island-shaped oxide semiconductor layer is performed before forming the oxide insulating layer.

4. The method for manufacturing a semiconductor device according to claim 1,

wherein the island-shaped oxide semiconductor layer comprises a channel formation region, and

wherein a portion of the conductive layer over the channel formation region is etched at the step of forming the source electrode and the drain electrode.

5. The method for manufacturing a semiconductor device according to claim 1,

wherein a surface of the island-shaped oxide semiconductor layer is exposed at the step of forming the source electrode and the drain electrode.

6. The method for manufacturing a semiconductor device according to claim 1,

wherein the oxide insulating layer comprises aluminum oxide.

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

forming an oxide semiconductor layer over a substrate while heating the substrate;

forming an island-shaped oxide semiconductor layer by patterning the oxide semiconductor layer;

forming a source electrode and a drain electrode over the island-shaped oxide semiconductor layer by etching a conductive layer;

supplying oxygen to the island-shaped oxide semiconductor layer after forming the source electrode and the drain electrode;

forming an oxide insulating layer over the island-shaped oxide semiconductor layer, the source electrode, and the drain electrode;

performing a heat treatment after forming the oxide insulating layer; and

forming a gate electrode over the oxide insulating layer,

wherein each of the source electrode and the drain electrode comprises a nitride of a metal element.

8. The method for manufacturing a semiconductor device according to claim 7, wherein the metal element is tantalum.

9. The method for manufacturing a semiconductor device according to claim 7,

wherein the island-shaped oxide semiconductor layer comprises a channel formation region, and

wherein a portion of the conductive layer over the channel formation region is etched at the step of forming the source electrode and the drain electrode.

10. The method for manufacturing a semiconductor device according to claim 7,

wherein a surface of the island-shaped oxide semiconductor layer is exposed at the step of forming the source electrode and the drain electrode.

11. The method for manufacturing a semiconductor device according to claim 7,

wherein the oxide insulating layer comprises aluminum oxide.

12. The method for manufacturing a semiconductor device according to claim 7, wherein a temperature in the step of performing the heat treatment is higher than or equal to 250°

C. and lower than 350°

C.

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

forming an oxide semiconductor layer over a substrate while heating the substrate;

forming a conductive layer over the oxide semiconductor layer;

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

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

performing a heat treatment after forming the oxide insulating layer; and

forming a gate electrode over the oxide insulating layer,

wherein each of the source electrode and the drain electrode comprises a nitride of a metal element.

14. The method for manufacturing a semiconductor device according to claim 13, wherein the metal element is tantalum.

15. The method for manufacturing a semiconductor device according to claim 13,

wherein the oxide semiconductor layer comprises a channel formation region, and

wherein a portion of the conductive layer over the channel formation region is etched at the step of forming the source electrode and the drain electrode.

16. The method for manufacturing a semiconductor device according to claim 13,

wherein a surface of the oxide semiconductor layer is exposed at the step of forming the source electrode and the drain electrode.

17. The method for manufacturing a semiconductor device according to claim 13,

wherein the oxide insulating layer comprises aluminum oxide.

18. The method for manufacturing a semiconductor device according to claim 13, wherein a temperature in the step of performing the heat treatment is higher than or equal to 250°

C. and lower than 350°

C.