Manufacturing method of semiconductor device

• US 8,685,787 B2
• Filed: 08/17/2011
• Issued: 04/01/2014
• Est. Priority Date: 08/25/2010
• 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:
  US13/211,504
• Publication Number:
  US 20120052624A1
• Time in Patent Office: 958 Days
• Field of Search: 438/104, 438/149, 438/785, 257/103, 257/E21.459
• US Class Current: 438/104
• 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 21/02694 Controlling the interface between substrate and epitaxial layer, e.g. by ion implantation followed by annealing
• CPC Class Codes: H01L 29/26 including, apart from doping materials or other impurities, elements provided for in two or more of the groups H01L29/16, H01L29/18, H01L29/20, H01L29/22, H01L29/24 , e.g. alloys
• CPC Class Codes: H01L 29/4908 for thin film semiconductor, e.g. gate of TFT
• CPC Class Codes: H01L 29/66742 Thin film unipolar transistors
• 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 29/78606 with supplementary region or layer in the thin film or in the insulated bulk substrate supporting it for controlling or increasing the safety of the device H01L29/78642, H01L29/78645 take 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

One object is to have stable electrical characteristics and high reliability and to manufacture a semiconductor device including a semi-conductive oxide film. Film formation is performed by a sputtering method using a target in which gallium oxide is added to a material that is easy to volatilize compared to gallium when the material is heated at 400° C. to 700° C. like zinc, and a formed film is heated at 400° C. to 700° C., whereby the added material is segregated in the vicinity of a surface of the film and the oxide is crystallized. Further, a semi-conductive oxide film is deposited thereover, whereby a semi-conductive oxide having a crystal which succeeds a crystal structure of the oxide that is crystallized by heat treatment is formed.

Claims

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

forming a first film that contains an oxide including at least a first metal element and a second metal element, over a substrate;

heating the first film to form a first layer that contains a crystal of an oxide including the first metal element as a main metal component and a second layer that is on a side closer to the substrate than the first layer and contains an oxide including the second metal element as a main metal component;

forming a second film that is in contact with the first layer and contains an oxide; and

heating the first layer and the second film.

2. The manufacturing method of a semiconductor device, according to claim 1, wherein the second film is a semi-conductive oxide film.

3. The manufacturing method of a semiconductor device, according to claim 1, wherein a ratio of the second metal element to a metal element in the second film is greater than or equal to 0.2.

4. The manufacturing method of a semiconductor device, according to claim 1, wherein the first film is formed by a DC sputtering method.

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

forming a first film that contains an oxide including at least a first metal element and a second metal element, over a substrate;

heating the first film to form a first layer that contains a crystal of an oxide including the first metal element as a main metal component and a second layer that is on a side closer to the substrate than the first layer and contains an oxide including the second metal element as a main metal component;

forming a second film that is in contact with the first layer and contains an oxide; and

forming a third film from the first layer and the second film by heating the first layer and the second film.

6. The manufacturing method of a semiconductor device, according to claim 5, wherein the second film is a semi-conductive oxide film.

7. The manufacturing method of a semiconductor device, according to claim 5, wherein a ratio of the second metal element to a metal element in the second film is greater than or equal to 0.2.

8. The manufacturing method of a semiconductor device, according to claim 5, wherein the first film is formed by a DC sputtering method.

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

forming a first film that contains an oxide including at least a first metal element and a second metal element, over a substrate;

heating the first film to form a first layer that contains a crystal of an oxide including the first metal element as a main metal component and a second layer that is on a side closer to the substrate than the first layer and contains an oxide including the second metal element as a main metal component;

forming a second film that is in contact with the first layer and contains an oxide;

forming a third film from the first layer and the second film by heating the first layer and the second film; and

etching the third film and the second layer.

10. The manufacturing method of a semiconductor device, according to claim 9, wherein the second film is a semi-conductive oxide film.

11. The manufacturing method of a semiconductor device, according to claim 9, wherein a ratio of the second metal element to a metal element in the second film is greater than or equal to 0.2.

12. The manufacturing method of a semiconductor device, according to claim 9, wherein the first film is formed by a DC sputtering method.