MANUFACTURING METHOD OF SEMICONDUCTOR DEVICE

• US 20120225543A1
• Filed: 02/23/2012
• Published: 09/06/2012
• Est. Priority Date: 03/04/2011
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: OHNO, Shinji, SATO, Yuichi, KOEZUKA, Junichi
• Granted Patent: US 9,646,829 B2
• Time in Patent Office: Days
• US Class Current: 438/479
• 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 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate

Abstract

A method for manufacturing a highly reliable semiconductor device with less change in threshold voltage is provided. An insulating film from which oxygen can be released by heating is formed in contact with an oxide semiconductor layer, and light irradiation treatment is performed on a gate electrode or a metal layer formed in a region which overlaps with the gate electrode, so that oxygen is added into the oxide semiconductor layer in a region which overlaps with the gate electrode. Accordingly, oxygen vacancies or interface states in the oxide semiconductor layer in a region which overlaps with the gate electrode can be reduced.

Claims

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

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

forming an insulating layer from which oxygen is released by heating, over the gate electrode;

forming an oxide semiconductor layer in contact with the insulating layer; and

performing a light irradiation treatment on at least the gate electrode, whereby the oxygen is added from the insulating layer into the oxide semiconductor layer.

2. The method for manufacturing a semiconductor device according to claim 1, further comprising a step of forming an anti-oxidation layer containing at least one of molybdenum nitride, tungsten nitride, titanium nitride, tantalum nitride, and aluminum nitride on a surface of the gate electrode which is in contact with the insulating layer.

3. The method for manufacturing a semiconductor device according to claim 1, wherein the insulating layer is formed by a sputtering method using oxygen or a mixed gas of oxygen and argon.

4. The method for manufacturing a semiconductor device according to claim 1, wherein the number of oxygen vacancies and the number of interface states in the oxide semiconductor layer are reduced by adding the oxygen into the oxide semiconductor layer.

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

forming an oxide semiconductor layer over a substrate having an insulating surface;

forming an insulating layer from which oxygen is released by heating, in contact with the oxide semiconductor layer;

forming a gate electrode over the insulating layer; and

performing a light irradiation treatment on at least the gate electrode, whereby the oxygen is added from the insulating layer into the oxide semiconductor layer.

6. The method for manufacturing a semiconductor device according to claim 5, further comprising a step of forming an anti-oxidation layer containing at least one of molybdenum nitride, tungsten nitride, titanium nitride, tantalum nitride, and aluminum nitride on a surface of the gate electrode which is in contact with the insulating layer.

7. The method for manufacturing a semiconductor device according to claim 5, wherein the insulating layer is formed by a sputtering method using oxygen or a mixed gas of oxygen and argon.

8. The method for manufacturing a semiconductor device according to claim 5, wherein the number of oxygen vacancies and the number of interface states in the oxide semiconductor layer are reduced by adding the oxygen into the oxide semiconductor layer.

9. A method for manufacturing a semiconductor device, comprising the steps of:

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

forming a gate insulating layer over the substrate;

forming an oxide semiconductor layer over the gate insulating layer;

forming an insulating layer from which oxygen is released by heating, in contact with the oxide semiconductor layer so as to overlap with the gate electrode;

forming a metal layer over the insulating layer so as to overlap with the insulating layer; and

performing a light irradiation treatment on at least the metal layer, whereby the oxygen is added from the insulating layer into the oxide semiconductor layer.

10. The method for manufacturing a semiconductor device according to claim 9, wherein a layer having an optical absorptance of 60% or more in a wavelength region from 400 nm to 1000 nm both inclusive, is formed as the metal layer.

11. The method for manufacturing a semiconductor device according to claim 9, wherein the insulating layer is formed by a sputtering method using oxygen or a mixed gas of oxygen and argon.

12. The method for manufacturing a semiconductor device according to claim 9, wherein the number of oxygen vacancies and the number of interface states in the oxide semiconductor layer are reduced by adding the oxygen into the oxide semiconductor layer.

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

forming an island-shaped metal layer over a substrate having an insulating surface;

forming an insulating layer from which oxygen is released by heating, over the island-shaped metal layer;

forming an oxide semiconductor layer in contact with the insulating layer;

forming a gate insulating layer over the oxide semiconductor layer;

forming a gate electrode over the gate insulating layer so as to overlap with the island-shaped metal layer and the insulating layer; and

performing a light irradiation treatment on at least the island-shaped metal layer, whereby the oxygen is added from the insulating layer into the oxide semiconductor layer.

14. The method for manufacturing a semiconductor device according to claim 13, wherein a layer having an optical absorptance of 60% or more in a wavelength region from 400 nm to 1000 nm both inclusive, is formed as the island-shaped metal layer.

15. The method for manufacturing a semiconductor device according to claim 13, wherein the insulating layer is formed by a sputtering method using oxygen or a mixed gas of oxygen and argon.

16. The method for manufacturing a semiconductor device according to claim 13, wherein the number of oxygen vacancies and the number of interface states in the oxide semiconductor layer are reduced by adding the oxygen into the oxide semiconductor layer.