Semiconductor device and manufacturing method thereof

• US 8,617,920 B2
• Filed: 02/08/2011
• Issued: 12/31/2013
• Est. Priority Date: 02/12/2010
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei
• Primary Examiner(s): Maldonado, Julio J
• Assistant Examiner(s): SHOOK, DANIEL P
• Application Number:
  US13/022,865
• Publication Number:
  US 20110198594A1
• Time in Patent Office: 1,057 Days
• Field of Search: 257/43, 257/E21.46, 257/E21.477, 257/E29.296, 438/104
• US Class Current: 438/104
• 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 29/66969 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 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate

Abstract

It is an object to provide a semiconductor device having excellent electric characteristics or high reliability, or a manufacturing method thereof. A semiconductor device including a gate electrode, an oxide semiconductor layer overlapping with the gate electrode, a source electrode and a drain electrode in contact with the oxide semiconductor layer, and a gate insulating layer provided between the gate electrode and the oxide semiconductor layer is provided. The oxide semiconductor layer is formed by a facing target sputtering method. The carrier concentration of the oxide semiconductor is less than 1×10¹²/cm³.

Claims

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

forming a gate electrode over a substrate;

forming a gate insulating layer over the gate electrode; and

forming an oxide semiconductor layer over the gate insulating layer,

wherein the oxide semiconductor layer is formed by a sputtering method in which a pair of targets provided to face each other is used, and

wherein a concentration of hydrogen in the oxide semiconductor layer is reduced by a first heat treatment after the oxide semiconductor layer is formed, and oxygen is supplied to the oxide semiconductor layer by a second heat treatment after the first heat treatment.

2. The manufacturing method of the semiconductor device according to claim 1, wherein the gate insulating layer is formed by a sputtering method in which a pair of targets provided to face each other is used.

3. The manufacturing method of the semiconductor device according to claim 1, wherein an insulating layer in contact with the oxide semiconductor layer is formed by a sputtering method in which a pair of targets provided to face each other is used.

4. The manufacturing method of the semiconductor device according to claim 1, wherein a carrier concentration of the oxide semiconductor layer is less than 1×

10¹²/cm³.

5. A semiconductor device manufactured by using the method according to claim 1.

6. A semiconductor device according to claim 5, wherein the semiconductor device is one selected from the group consisting of a laptop computer, a portable information terminal, an e-book reader, a mobile phone and a digital camera.

7. The manufacturing method of the semiconductor device according to claim 1, further comprising a step of forming a source electrode and a drain electrode electrically connected to the oxide semiconductor layer.

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

forming an oxide semiconductor layer over a substrate;

forming a gate insulating layer in contact with at least a channel formation region of the oxide semiconductor layer; and

forming a gate electrode over the gate insulating layer,

wherein the oxide semiconductor layer is formed by a sputtering method in which a pair of targets provided to face each other is used, and

wherein a concentration of hydrogen in the oxide semiconductor layer is reduced by a first heat treatment after the oxide semiconductor layer is formed, and oxygen is supplied to the oxide semiconductor layer by a second heat treatment after the first heat treatment.

9. The manufacturing method of the semiconductor device according to claim 8, wherein the gate insulating layer is formed by a sputtering method in which a pair of targets provided to face each other is used.

10. The manufacturing method of the semiconductor device according to claim 8, wherein an insulating layer in contact with the oxide semiconductor layer is formed by a sputtering method in which a pair of targets provided to face each other is used.

11. The manufacturing method of the semiconductor device according to claim 8, wherein a carrier concentration of the oxide semiconductor layer is less than 1×

10¹²/cm³.

12. A semiconductor device manufactured by using the method according to claim 8.

13. A semiconductor device according to claim 12, wherein the semiconductor device is one selected from the group consisting of a laptop computer, a portable information terminal, an e-book reader, a mobile phone and a digital camera.

14. The manufacturing method of the semiconductor device according to claim 8, further comprising a step of forming a source electrode and a drain electrode electrically connected to the oxide semiconductor layer.