Single-crystal material on non-single-crystalline substrate

• US 6,328,796 B1
• Filed: 02/01/1999
• Issued: 12/11/2001
• Est. Priority Date: 02/01/1999
• Status: Expired due to Term

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Kub, Francis J., Hobart, Karl D.
• Primary Examiner(s): KUNEMUND, ROBERT M
• Application Number:
  US09/243,182
• Time in Patent Office: 1,044 Days
• Field of Search: 117/915, 117/94, 117/97, 438/455, 216/2, 216/95
• US Class Current: 117/94
• CPC Class Codes: C30B 25/02 Epitaxial-layer growth
• CPC Class Codes: C30B 25/18 characterised by the substrate
• CPC Class Codes: C30B 29/36 Carbides
• CPC Class Codes: C30B 29/40 AIIIBV compounds wherein A is B, Al, Ga, In or Tl and B is N, P, As, Sb or Bi
• CPC Class Codes: C30B 29/403 AIII-nitrides
• CPC Class Codes: C30B 29/406 Gallium nitride
• CPC Class Codes: Y10S 117/915 Separating from substrate

Abstract

A method for making a multilayered structure with a single crystal film bonded to a polycrystalline substrate has the steps of:

bonding a single crystal film to a polycrystalline substrate; and

growing an epitaxial layer on said single crystal film bonded to said polycrystalline substrate.

Claims

1. A method for making a multilayered device with an epitaxial layer grown on a single-crystal film bonded to a non-single crystalline substrate, comprising the steps of:

a. wafer bonding a single-crystal film, consisting of one or more single-crystal layers, to a non-single crystalline substrate, wherein said substrate has a thermal coefficient of expansion; and

b. growing a first epitaxial layer on said single-crystal film, wherein said first epitaxial layer has a thermal coefficient of expansion, and wherein said thermal coefficient of expansion for said substrate and said epitaxial layer are closely matched.

2. The method of claim 1, wherein said polycrystalline substrate is a ceramic substrate.

3. The method of claim 1, wherein said single crystal film is a compliant single crystal film.

4. The method of claim 1, wherein said single crystal film is a semiconductor.

5. The method of claim 1, wherein said single crystal film is selected from the group consisting of MgO, Si, SiC, InP, GaSb, GaAs, and CaF₂.

6. The method of claim 1, wherein said substrate is electrically insulating.

7. The method of claim 1, wherein said substrate is electrically conducting.

8. The method of claim 1, wherein said substrate has a high thermal conductivity.

9. The method of claim 1, wherein said substrate is optically transparent.

10. The method of claim 1, wherein said substrate is selected from the group consisting of SiC, graphite, diamond, and AlN.

11. The method of claim 1, wherein said epitaxial layer is selected from the group consisting of SiC, AlN, GaN, InGaN, diamond, and AlGaN.

12. The method of claim 1, further comprising:

growing at least one additional epitaxial layer on said epitaxial layer on said single crystal film bonded to said polycrystalline substrate.

15. The method of claim 12, further comprising:

prior to said step of bonding said single crystal etch stop layer to a polycrystalline second substrate, implanting hydrogen into said first substrate to a selected depth below said single crystal etch stop layer; and

after said step of bonding said single crystal etch stop layer to a polycrystalline second substrate, heating said first substrate, to split said first substrate at the preselected depth of said implanted hydrogen.

16. The method of claim 12, wherein said single crystal etch stop layer is selected from the group consisting of Si, GaAs, CaF₂.

17. The method of claim 12, wherein said etchable first substrate is a ceramic substrate.

18. The method of claim 12, wherein said etchable first substrate is selected from the group consisting of SiC and GaN.

19. The method of claim 12, wherein said single crystal film is a compliant single crystal film.

20. The method of claim 12, wherein said substrate is electrically insulating.

21. The method of claim 12, wherein said substrate is electrically conducting.

22. The method of claim 12, wherein said substrate has a high thermal conductivity.

24. The method of claim 22, wherein said thermal conductivity is greater than 10 W/mK at room temperature.

25. The method of claim 22, wherein said substrate is an amorphous substrate.

26. The method of claim 22, wherein said substrate has a strain point temperature greater than 1140°

C.

27. The method of claim 2, wherein said polycrystalline substrate is silicon carbide.

28. The method of claim 2, wherein said ceramic substrate is aluminum nitride.

29. The method of claim 1, further including a bond interface between said substrate and said single-crystal film and wherein said bond interface is electrically conducting.

30. The method of claim 11, wherein said first epitaxial layer is GaN.

31. The product of claim 1.

32. The method of claim 1, wherein said substrate is polysilicon carbide, said single-crystal film is silicon (111) and said epitaxial layer is GaN.

33. The method of claim 1, further including an AlN buffer layer between said single-crystal film and said epitaxial layer.

34. The method of claim 33, wherein said AlN buffer layer is between said single-crystal silicon (111) film and said epitaxial GAN layer.

35. The method of claim 1, wherein said substrate is poly-AlN, said single-crystal film is silicon (111) and said epitaxial layer is GaN.

13. A method for making a multilayered device, comprising the steps of:

a. growing a single-crystal etch stop layer, consisting of one or more single-crystal layers, on an etchable first substrate;

b. wafer bonding said single-crystal etch stop layer to a second non-single crystalline substrate having a thermal coefficient of expansion;

c. etching said etchable first substrate to expose said single-crystal etch stop layer; and

d. growing an epitaxial layer having a thermal coefficient of expansion on said single-crystal etch stop layer and wherein said second non-single crystalline substrate and said epitaxial layer have closely matched coefficients of thermal expansion.

14. The method of claim 13, wherein said epitaxial layer is selected from the group consisting of SiC, AlN, GaN, InGaN, diamond, and AlGaN.

36. The product of claim 13.

23. A method of making a multilayered device, comprising the steps of:

a. wafer bonding a single-crystal film to a non-single crystalline substrate, wherein said non-single crystalline substrate has a thermal conductivity greater than 1.5 W/mK at room temperature; and

b. fabricating said device at a temperature greater than 300°

C.

37. The product of claim 23.