Semiconductor device including oxide semiconductor and manufacturing method thereof

• US 9,425,045 B2
• Filed: 05/13/2011
• Issued: 08/23/2016
• Est. Priority Date: 05/21/2010
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei, Sasaki, Toshinari, Noda, Kosei
• Primary Examiner(s): Dulka, John P
• Application Number:
  US13/107,283
• Publication Number:
  US 20110284839A1
• Time in Patent Office: 1,929 Days
• Field of Search: 438/104
• US Class Current: 1/1
• 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 21/385 using diffusion into or out of a solid from or into a solid phase, e.g. a doped oxide layer
• CPC Class Codes: H01L 27/1225 with semiconductor materials not belonging to the group IV of the periodic table, e.g. InGaZnO
• 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 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/nm³ 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.

Claims

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/nm³ or less according to thermal desorption spectroscopy and a carrier density of the oxide semiconductor film is less than 1×

10¹²/cm³,

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×

10¹⁶ atoms/cm³.

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/nm³ 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/nm³ or less according to thermal desorption spectroscopy and a carrier density of the oxide semiconductor film is less than 1×

10¹²/cm³,

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×

10¹⁶ atoms/cm³.

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/nm³ 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/nm³ or less according to thermal desorption spectroscopy and a carrier density of the oxide semiconductor film is less than 1×

10¹²/cm³, 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×

10¹⁶ atoms/cm³.

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/nm³ 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.