Semiconductor device including oxide semiconductor and manufacturing method thereof

Patent metadata

Field	Value
Publication number	US-9425045-B2
Application number	US-201113107283-A
Country	US
Kind code	B2
Filing date	May 13, 2011
Priority date	May 21, 2010
Publication date	Aug 23, 2016
Grant date	Aug 23, 2016

Abstract

It is an object to provide a semiconductor device including an oxide semiconductor, which has stable electric characteristics and high reliability. An oxide semiconductor film serving as a channel formation region of a transistor is formed by a sputtering method at a temperature higher than 200° C., so that the number of water molecules eliminated from the oxide semiconductor film can be 0.5/nm 3 or less according to thermal desorption spectroscopy. A substance including a hydrogen atom such as hydrogen, water, a hydroxyl group, or hydride which causes variation in the electric characteristics of a transistor including an oxide semiconductor is prevented from entering the oxide semiconductor film, whereby the oxide semiconductor film can be highly purified and made to be an electrically i-type (intrinsic) semiconductor.

First claim

The invention claimed is:

1. A method for manufacturing a semiconductor device comprising the step of:
forming an oxide semiconductor film serving as a channel formation region of a transistor by a sputtering method at a temperature higher than 300° C. and lower than or equal to 500° C. so that the number of water molecules eliminated from the oxide semiconductor film is 0.5/nm 3 or less according to thermal desorption spectroscopy and a carrier density of the oxide semiconductor film is less than 1×10 12 /cm 3 ,
wherein the number of water molecules is calculated by comparing a first value of integral of a TDS spectrum of water molecules in the oxide semiconductor film with a second value of integral of a TDS spectrum of hydrogen molecules in a reference sample,
wherein the first value of integral and the second value of integral are calculated within a temperature range of higher than or equal to 150° C. and lower than or equal to 400° C., and
wherein the reference sample is a silicon wafer.

2. The method for manufacturing a semiconductor device according to claim 1 , wherein the oxide semiconductor film includes at least one of In, Ga, and Zn.

3. The method for manufacturing a semiconductor device according to claim 1 , wherein a formation atmosphere of the oxide semiconductor film is a rare gas atmosphere, an oxygen atmosphere, or a mixed atmosphere of a rare gas and oxygen.

4. The method for manufacturing a semiconductor device according to claim 1 , wherein the transistor is formed over a glass substrate.

5. The method for manufacturing a semiconductor device according to claim 1 , wherein the silicon wafer contains hydrogen atoms at 1×10 16 atoms/cm 3 .

6. The method for manufacturing a semiconductor device according to claim 1 , wherein the number of water molecules eliminated from the oxide semiconductor film is 0.1/nm 3 or less according to thermal desorption spectroscopy.

7. The method for manufacturing a semiconductor device according to claim 1 , further comprising the steps of:
forming a source electrode and a drain electrode which are in contact with the oxide semiconductor film;
forming a gate insulating film over the source electrode and the drain electrode; and
forming a gate electrode over the gate insulating film.

8. A method for manufacturing a semiconductor device comprising the step of:
forming an oxide semiconductor film serving as a channel formation region of a transistor by a sputtering method at a temperature higher than 300° C. and lower than or equal to 500° C. so that the number of water molecules eliminated from the oxide semiconductor film is 0.5/nm 3 or less according to thermal desorption spectroscopy and a carrier density of the oxide semiconductor film is less than 1×10 12 /cm 3 ,
wherein the number of water molecules is calculated by comparing a first value of integral of a TDS spectrum of water molecules in the oxide semiconductor film with a second value of integral of a TDS spectrum of hydrogen molecules in a reference sample,
wherein the first value of integral and the second value of integral are calculated within a temperature range of higher than or equal to 150° C. and lower than or equal to 400° C.,
wherein the reference sample is a silicon wafer, and
wherein the oxide semiconductor film is an i-type oxide semiconductor film.

9. The method for manufacturing a semiconductor device according to claim 8 , wherein the oxide semiconductor film includes at least one of In, Ga, and Zn.

10. The method for manufacturing a semiconductor device according to claim 8 , wherein a formation atmosphere of the oxide semiconductor film is a rare gas atmosphere, an oxygen atmosphere, or a mixed atmosphere of a rare gas and oxygen.

11. The method for manufacturing a semiconductor device according to claim 8 , wherein the transistor is formed over a glass substrate.

12. The method for manufacturing a semiconductor device according to claim 8 , wherein the silicon wafer contains hydrogen atoms at 1×10 16 atoms/cm 3 .

13. The method for manufacturing a semiconductor device according to claim 8 , wherein the number of water molecules eliminated from the oxide semiconductor film is 0.1/nm 3 or less according to thermal desorption spectroscopy.

14. The method for manufacturing a semiconductor device according to claim 8 , further comprising the steps of:
forming a source electrode and a drain electrode which are in contact with the oxide semiconductor film;
forming a gate insulating film over the source electrode and the drain electrode; and
forming a gate electrode over the gate insulating film.

15. A method for manufacturing a semiconductor device comprising the steps of:
forming an oxide semiconductor film serving as a channel formation region of a transistor by a sputtering method at a temperature higher than 300° C. and lower than or equal to 500° C. so that the number of water molecules eliminated from the oxide semiconductor film is 0.5/nm 3 or less according to thermal desorption spectroscopy and a carrier density of the oxide semiconductor film is less than 1×10 12 /cm 3 , and
performing an oxygen doping treatment on the oxide semiconductor film,
wherein the number of water molecules is calculated by comparing a first value of integral of a TDS spectrum of water molecules in the oxide semiconductor film with a second value of integral of a TDS spectrum of hydrogen molecules in a reference sample,
wherein the first value of integral and the second value of integral are calculated within a temperature range of higher than or equal to 150° C. and lower than or equal to 400° C., and
wherein the reference sample is a silicon wafer.

16. The method for manufacturing a semiconductor device according to claim 15 , wherein the oxide semiconductor film includes at least one of In, Ga, and Zn.

17. The method for manufacturing a semiconductor device according to claim 15 , wherein a formation atmosphere of the oxide semiconductor film is a rare gas atmosphere, an oxygen atmosphere, or a mixed atmosphere of a rare gas and oxygen.

18. The method for manufacturing a semiconductor device according to claim 15 , wherein the transistor is formed over a glass substrate.

19. The method for manufacturing a semiconductor device according to claim 15 , wherein the silicon wafer contains hydrogen atoms at 1×10 16 atoms/cm 3 .

20. The method for manufacturing a semiconductor device according to claim 15 , wherein the number of water molecules eliminated from the oxide semiconductor film is 0.1/nm 3 or less according to thermal desorption spectroscopy.

21. The method for manufacturing a semiconductor device according to claim 15 , further comprising the steps of:
forming a source electrode and a drain electrode which are in contact with the oxide semiconductor film;
forming a gate insulating film over the source electrode and the drain electrode; and
forming a gate electrode over the gate insulating film.

Assignees

• Yamazaki Shunpei
• Sasaki Toshinari
• Noda Kosei
• Semiconductor Energy Lab

Inventors

• Yamazaki Shunpei
• Sasaki Toshinari
• Noda Kosei

Classifications

• H10P32/17

  characterised by the semiconductor material · CPC title

• H10P32/14

  within a single semiconductor body or layer in a solid phase; between different semiconductor bodies or layers, both in a solid phase · CPC title

• H10P14/3434

  being oxide semiconductor materials (Group IIB-VIA semiconductor materials H10P14/3424) · CPC title

• H10P14/3426 Primary

  Oxides · CPC title

• H10P14/22

  using physical deposition, e.g. vacuum deposition or sputtering · CPC title