Method for forming thin film utilizing sputtering target

• US 8,889,477 B2
• Filed: 09/05/2012
• Issued: 11/18/2014
• Est. Priority Date: 06/08/2011
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei, Maruyama, Tetsunori, Imoto, Yuki, Sato, Hitomi, Watanabe, Masahiro, Mashiyama, Mitsuo, Okazaki, Kenichi, Shimazu, Takashi, Nakashima, Motoki
• Primary Examiner(s): Geyer, Scott B
• Application Number:
  US13/603,484
• Publication Number:
  US 20130011962A1
• Time in Patent Office: 804 Days
• Field of Search: None
• US Class Current: 438/104
• CPC Class Codes: B28B 11/243 Setting, e.g. drying, dehydrating or firing ceramic articles B28B11/242 takes precedence
• CPC Class Codes: C04B 2235/3284 Zinc oxides, zincates, cadmium oxides, cadmiates, mercury oxides, mercurates or oxide forming salts thereof
• CPC Class Codes: C04B 2235/3286 Gallium oxides, gallates, indium oxides, indates, thallium oxides, thallates or oxide forming salts thereof, e.g. zinc gallate
• CPC Class Codes: C04B 2235/76 Crystal structural characteristics, e.g. symmetry
• CPC Class Codes: C04B 35/453 based on zinc, tin, or bismuth oxides or solid solutions thereof with other oxides, e.g. zincates, stannates or bismuthates
• CPC Class Codes: C04B 35/64 Burning or sintering processes C04B33/32 takes precedence ; powder metallurgy B22F
• CPC Class Codes: C23C 14/08 Oxides C23C14/10 takes precedence
• CPC Class Codes: C23C 14/086 of zinc, germanium, cadmium, indium, tin, thallium or bismuth
• CPC Class Codes: C23C 14/3414 Metallurgical or chemical aspects of target preparation, e.g. casting, powder metallurgy
• CPC Class Codes: C23C 14/345 using substrate bias
• 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 29/24 including, apart from doping materials or other impurities, only semiconductor materials not provided for in groups H01L29/16, H01L29/18, H01L29/20, H01L29/22 including organic materials H10K99/00
• 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

A semiconductor device including a highly reliable transistor formed using an oxide semiconductor is manufactured. An oxide semiconductor film is deposited by a sputtering method, using a sputtering target including an oxide semiconductor having crystallinity, and in which the direction of the c-axis of a crystal is parallel to a normal vector of the top surface of the oxide semiconductor. The target is formed by mixing raw materials so that its composition ratio can obtain a crystal structure.

Claims

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

producing sputtered particles by cleaving a target along an a-b plane of crystals of the target, the target comprising a polycrystalline oxide semiconductor material comprising indium and zinc;

depositing the sputtered particles onto a surface over a substrate to form an oxide semiconductor film including a crystalline structure; and

heating the oxide semiconductor film to reduce a concentration of hydrogen,

wherein the crystalline structure has a c-axis being parallel to a normal vector of a surface of the oxide semiconductor film.

2. The method according to claim 1, wherein the sputtered particles maintain an original crystal state when the sputtered particles reach the surface over the substrate.

3. The method according to claim 1, wherein a crystal state of the target is transferred to the substrate by depositing the sputtered particles.

4. The method according to claim 1, wherein the sputtered particles have a flat-plate-like shape.

5. The method according to claim 1, wherein the sputtered particles have a pellet-like shape.

6. The method according to claim 1, wherein the polycrystalline oxide semiconductor material further comprises gallium.

7. The method according to claim 1, wherein the polycrystalline oxide semiconductor material further comprises at least one element selected from the group consisting of Sn, Hf, Al, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu.

8. The method according to claim 1, wherein the oxide semiconductor film is formed at a substrate temperature of 200°

C. or higher.

9. The method according to claim 1, wherein the oxide semiconductor film is formed in a gas containing oxygen at 80 vol. % or greater.

10. The method according to claim 1, further comprising a step of etching the oxide semiconductor film to form an oxide semiconductor layer including a channel of a transistor.

11. The method according to claim 1, wherein the c-axis in the crystalline structure is aligned in a direction within a range from −

5°

to 5°

to the normal vector of the surface of the oxide semiconductor film.

12. The method according to claim 1, further comprising the step of heating the oxide semiconductor film in an atmosphere comprising oxygen after the heating step.

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

producing sputtered particles by cleaving a target along an a-b plane of crystals of the target, the target comprising a polycrystalline oxide semiconductor material comprising indium and zinc; and

depositing the sputtered particles onto a surface over a substrate to form an oxide semiconductor film including a crystalline structure,

wherein the crystalline structure has a c-axis being parallel to a normal vector of a surface of the oxide semiconductor film.

14. The method according to claim 13, wherein the sputtered particles maintain an original crystal state when the sputtered particles reach the surface over the substrate.

15. The method according to claim 13, wherein a crystal state of the target is transferred to the substrate by depositing the sputtered particles.

16. The method according to claim 13, wherein the sputtered particles have a flat-plate-like shape.

17. The method according to claim 13, wherein the sputtered particles have a pellet-like shape.

18. The method according to claim 13, wherein the polycrystalline oxide semiconductor material further comprises gallium.

19. The method according to claim 13, wherein the polycrystalline oxide semiconductor material further comprises at least one element selected from the group consisting of Sn, Hf, Al, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu.

20. The method according to claim 13, wherein the oxide semiconductor film is formed at a substrate temperature of 200°

C. or higher.

21. The method according to claim 13, wherein the oxide semiconductor film is formed in a gas containing oxygen at 80 vol. % or greater.

22. The method according to claim 13, further comprising a step of etching the oxide semiconductor film to form an oxide semiconductor layer including a channel of a transistor.

23. The method according to claim 13, wherein the c-axis in the crystalline structure is aligned in a direction within a range from −

5°

to 5°

to the normal vector of the surface of the oxide semiconductor film.

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

producing sputtered particles by cleaving a target along an a-b plane of crystals of the target, the target comprising a polycrystalline oxide semiconductor material comprising indium and zinc;

depositing the sputtered particles onto a surface over a substrate to form an oxide semiconductor film including a crystalline structure; and

heating the substrate at a temperature of 100°

C. or higher while depositing the sputtered particles,

wherein the crystalline structure has a c-axis being parallel to a normal vector of a surface of the oxide semiconductor film.

25. The method according to claim 24, wherein the sputtered particles maintain an original crystal state when the sputtered particles reach the surface over the substrate.

26. The method according to claim 24, wherein a crystal state of the target is transferred to the substrate by depositing the sputtered particles.

27. The method according to claim 24, wherein the sputtered particles have a flat-plate-like shape.

28. The method according to claim 24, wherein the sputtered particles have a pellet-like shape.

29. The method according to claim 24, wherein the polycrystalline oxide semiconductor material further comprises gallium.

30. The method according to claim 24, wherein the polycrystalline oxide semiconductor material further comprises at least one element selected from the group consisting of Sn, Hf, Al, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu.

31. The method according to claim 24, wherein the oxide semiconductor film is formed in a gas containing oxygen at 80 vol. % or greater.

32. The method according to claim 24, further comprising a step of etching the oxide semiconductor film to form an oxide semiconductor layer including a channel of a transistor.

33. The method according to claim 24, wherein the c-axis in the crystalline structure is aligned in a direction within a range from −

5°

to 5°

to the normal vector of the surface of the oxide semiconductor film.