Method and structure for fabricating bonded substrate structures using thermal processing to remove oxygen species

• US 7,598,153 B2
• Filed: 03/31/2006
• Issued: 10/06/2009
• Est. Priority Date: 03/31/2006
• Status: Active Grant

• Current Assignee: Silicon Genesis
• Original Assignee: Silicon Genesis
• Inventors: Ong, Philip James, Kirk, Harry Robert, Jacy, David, Malik, Igor, Henley, Francois J., Sullivan, James Andrew, Kang, Sien Giok
• Primary Examiner(s): Dang, Phuc T
• Application Number:
  US11/394,597
• Publication Number:
  US 20070232022A1
• Time in Patent Office: 1,285 Days
• Field of Search: 438/406, 438/409, 438/419, 438/455, 438/479, 438/481, 257/E21.09, 257/E23.005
• US Class Current: 438/455
• CPC Class Codes: H01L 21/76254 with separation/delamination along an ion implanted layer, e.g. Smart-cut, Unibond

Abstract

A method for fabricating bonded substrate structures, e.g., silicon on silicon. In a specific embodiment, the method includes providing a thickness of single crystal silicon material transferred from a first silicon substrate coupled to a second silicon substrate. In a specific embodiment, the second silicon substrate has a second surface region that is joined to a first surface region from the thickness of single crystal silicon material to form of an interface region having a first characteristic including a silicon oxide material between the thickness of single crystal silicon material and the second silicon substrate. The method includes subjecting the interface region to a thermal process to cause a change to the interface region from the first characteristic to a second characteristic. In a specific embodiment, the second characteristic is free from the silicon oxide material and is an epitaxially formed silicon material provided between the thickness of single crystal silicon material and the second silicon substrate. The method includes maintaining the interface region free of multiple voids during the thermal process to form the epitaxially formed silicon material to electrically couple the thickness of single crystal silicon material to the second silicon substrate.

Claims

1. A method for fabricating bonded substrate structures, the method comprising,

providing a thickness of single crystal silicon material transferred from a first silicon substrate coupled to a second silicon substrate, the second silicon substrate having a second surface region that is joined to a first surface region from the thickness of single crystal silicon material to form of an interface region having a first characteristic including a silicon oxide material between the thickness of single crystal silicon material and the second silicon substrate;

subjecting the interface region to a thermal process to cause a change to the interface region from the first characteristic to a second characteristic, the second characteristic being free from the silicon oxide material and being an epitaxially formed silicon material provided between the thickness of single crystal silicon material and the second silicon substrate; and

maintaining the interface region free of multiple voids during the thermal process to form the epitaxially formed silicon material to electrically couple the thickness of single crystal silicon material to the second silicon substrate,

the method further comprising performing a non-contact smoothing process on a cleaved surface of the thickness of single crystal silicon.

2. The method of claim 1 wherein the first silicon substrate is a first silicon wafer and the second silicon substrate is a second silicon substrate.

3. The method of claim 1 wherein the one or more voids comprises a plurality of hydrogen species.

4. The method of claim 1 wherein the one or more voids can be provided by a diffusion process having a first rate characteristic.

5. The method of claim 1 wherein the one or more voids comprises a plurality of water species.

6. The method of claim 1 wherein the one or more voids comprises a plurality of hydroxide species.

7. The method of claim 1 wherein the second characteristic is a substantially oxygen free characteristic.

8. The method of claim 1 wherein the second characteristic comprises an epitaxially formed substantially single crystal silicon material.

9. The method of claim 1 wherein the thermal process comprises subjecting the joined thickness of single crystal silicon material and the second substrate to an argon bearing environment at a temperature greater than about 1000 Degrees Celsius.

10. The method of claim 1 wherein the thermal process comprises subjecting the joined thickness of single crystal silicon material and the second substrate to an inert gas environment at a temperature greater than about 1000 Degrees Celsius.

11. The method of claim 1 wherein the interface region having the first characteristic comprises an oxide layer of less than 10 nanometers.

12. The method of claim 1 wherein the thermal process causes one or more oxide species from the silicon oxide to diffuse from the interface region.

13. The method of claim 1 wherein the thermal process causes one or more of the oxide species from the silicon oxide to diffuse from the interface region to a region outside of the thickness of single crystal silicon material and the second silicon substrate.

14. The method of claim 1 if wherein the thermal process causes substantially all of the oxide species from the silicon oxide to diffuse from the interface region to form the epitaxial silicon material.

15. The method of claim 1 wherein the thermal process comprises subjecting the joined thickness of single crystal silicon and the second substrate to a hydrogen gas environment at a temperature greater than about 1000 Degrees Celsius.

16. The method of claim 1 wherein the non-contact smoothing process comprises an argon anneal process and/or chemical mechanical polishing process provided before the thermal treatment.

17. The method of claim 1 wherein the non-contact smoothing process comprises an epi-smoothing process, the epi-smoothing process using a HC1 gas and H2 gas species.

18. The method of claim 1 wherein the smoothing process is provided in a chamber of a cluster tool.

19. The method of claim 1 wherein the smoothing process comprises an in-situ annealing process provided in a chamber of a cluster tool.

20. The method of claim 1 further comprising forming a second layer overlying a cleaved surface of the thickness of silicon material, the second layer comprising an epitaxially formed silicon bearing material.

21. The method of claim 20 wherein the forming of the second layer is provided within a chamber of a cluster tool.

22. The method of claim 1 wherein the thickness of silicon material comprises a silicon germanium material.

23. The method of claim 1 wherein the thickness of silicon material is in a first orientation and the second silicon substrate is in a second orientation.

24. The method of claim 1 wherein the thickness of silicon material is in a first orientation and the second silicon substrate is in a second orientation, the thickness of silicon material being characterized by one or more strained regions.

25. The method of claim 1 wherein the second silicon substrate is a silicon on insulator substrate.

26. A method for fabricating bonded substrate structures, the method comprising:

providing a thickness of single crystal silicon material transferred from a first silicon substrate coupled to a second silicon substrate, the second silicon substrate having a second surface region that is joined to a first surface region from the thickness of single crystal silicon material to form of an interface region having a first characteristic including a silicon oxide material between the thickness of single crystal silicon material and the second silicon substrate; and

subjecting the interfere region to a thermal process to cause a change to the interface region from the first characteristic to a second characteristic to electrically couple the thickness of single crystal silicon material to the second silicon substrate, the second characteristic being free from the silicon oxide material and being an epitaxially formed silicon material provided between the thickness of single crystal silicon material and the second silicon substrate,

the method further comprising performing a non-contact smoothing process on a cleaved surface of the thickness of single crystal silicon.

27. The method of claim 26 wherein the first silicon substrate is a first silicon wafer and the second silicon substrate is a second silicon substrate.

28. The method of claim 26 wherein the second characteristic is a substantially oxygen free characteristic.

29. The method of claim 26 wherein the second characteristic comprises an epitaxially formed substantially single crystal silicon material.

30. The method of claim 26 wherein the thermal process comprises subjecting the joined thickness of single crystal silicon material and the second substrate to an argon bearing environment at a temperature greater than about 1000 Degrees Celsius.

31. The method of claim 26 wherein the thermal process comprises subjecting the joined thickness of single crystal silicon material and the second substrate to an inert gas environment at a temperature greater than about 1000 Degrees Celsius.

32. The method of claim 26 wherein the interface region having the first characteristic comprises an oxide layer of less than 10 nanometers.

33. The method of claim 26 wherein the thermal process causes one or more oxide species from the silicon oxide to diffuse from the interface region.

34. The method of claim 26 wherein the thermal process causes one or more of the oxide species from the silicon oxide to diffuse from the interface region to a region outside of the thickness of single crystal silicon material and the second silicon substrate.

35. The method of claim 26 wherein the thermal process causes substantially all of the oxide species from the silicon oxide to diffuse from the interface region to form the epitaxial silicon material.

36. The method of claim 26 wherein the thermal process comprises subjecting the joined thickness of single crystal silicon and the second substrate to a hydrogen gas environment at a temperature greater than about 1000 Degrees Celsius.

37. The method of claim 26 wherein the non-contact smoothing process comprises an argon anneal process and/or chemical mechanical polishing process provided before the thermal treatment.

38. The method of claim 26 wherein the non-contact smoothing process comprises an epi-smoothing process, the epi-smoothing process using a HC1 gas and H2 gas species.

39. The method of claim 26 wherein the smoothing process is provided in a chamber of a cluster tool.

40. The method of claim 26 wherein the smoothing process comprises an in-situ annealing process provided in a chamber of a cluster tool.

41. The method of claim 26 further comprising forming a second layer overlying a cleaved surface of the thickness of silicon material, the second layer comprising an epitaxially formed silicon bearing material.

42. The method of claim 41 wherein the forming of the second layer is provided within a chamber of a cluster tool.

43. The method of claim 26 wherein the thickness of silicon material comprises a silicon germanium material.

44. The method of claim 26 wherein the thickness of silicon material is in a first orientation and the second silicon substrate is in a second orientation.

45. The method of claim 26 wherein the thickness of silicon material is in a first orientation and the second silicon substrate is in a second orientation, the thickness of silicon material being characterized by one or more strained regions.

46. The method of claim 26 wherein the second silicon substrate is a silicon on insulator substrate.

47. A method for fabricating bonded substrate structures, the method comprising:

providing a thickness of single crystal silicon material transferred from a first silicon substrate coupled to a second silicon substrate, the second silicon substrate having a second surface region that is joined to a first surface region from the thickness of single crystal silicon material to form of an interface region having a first characteristic including a silicon oxide material between the thickness of single crystal silicon material and the second silicon substrate, the thickness of single crystal silicon including a surface region having a plurality of trapping sites; and

subjecting the interface region to a thermal process to cause a change to the interface region from the first characteristic to a second characteristic to electrically couple the thickness of single crystal silicon material to the second silicon substrate, the second characteristic being free from the silicon oxide material and being an epitaxially formed silicon material provided between the thickness of single crystal silicon material and the second silicon substrate and to cause a portion of the silicon oxide material to be transferred to one or more trapping sites provided on the surface region, the method further comprising performing a non-contact smoothing process on a cleaved surface of the thickness of single crystal silicon.

48. The method of claim 47 further comprising removing the portion of the silicon oxide material provided on the surface region by at least a selective etching process and/or a chemical polishing process.