Boron-aluminum nitride coating and method of producing same

• US 5,766,783 A
• Filed: 11/30/1995
• Issued: 06/16/1998
• Est. Priority Date: 03/01/1995
• Status: Expired due to Term

• Current Assignee: Sumitomo Electric Industries Limited (Sumitomo Corporation)
• Original Assignee: Sumitomo Electric Industries Limited (Sumitomo Corporation)
• Inventors: Imai, Takahiro, Utsumi, Yoshiharu, Fujimori, Naoji
• Primary Examiner(s): SPEER, TIMOTHY M
• Application Number:
  US08/565,027
• Time in Patent Office: 929 Days
• Field of Search: 428/446, 428/697, 428/698, 428/700, 428/701, 428/702, 428/336, 428/432
• US Class Current: 428/698
• CPC Class Codes: C23C 14/0641 Nitrides C23C14/0617 takes precedence
• CPC Class Codes: C23C 14/3414 Metallurgical or chemical aspects of target preparation, e.g. casting, powder metallurgy
• CPC Class Codes: C23C 16/34 Nitrides C23C16/303 takes precedence
• CPC Class Codes: C23C 30/00 Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process C23C26/00, C23C28/00 take precedence
• CPC Class Codes: Y10T 428/265 1 mil or less

Abstract

Boron-aluminum nitride B_x Al_1-x N_y (0.001≦x≦0.70, 0.85≦y≦1.05) films having wurtzite type structure are proposed. The material has higher hardness, higher sound velocity and wider band gap than hexagonal aluminum nitride (AlN).

Claims

1. A boron-aluminum nitride coating comprising:

a substrate and

a boron-aluminum nitride film having a composition of B_x Al_1-x N_y (0.001≦

x≦

0.7, 0.85≦

y≦

1.05) forming a wurtzite type crystal structure of hexagonal symmetry and having a thickness between 10 nm and 50 μ

m.

2. A boron-aluminum nitride coating as claimed in claim 1, wherein the substrate is a molybdenum (Mo) crystal, a tungsten (W) crystal, a nickel (Ni) crystal, a tantalum (Ta) crystal, or a niobium (Nb) crystal.

3. A boron-aluminum nitride coating as claimed in claim 1, wherein the substrate is a diamond (C) crystal, a silicon (Si) crystal, a germanium (Ge) crystal, an aluminum nitride (AlN) crystal, a gallium nitride (GaN) crystal, a silicon carbide (SIC) crystal, a boron phosphide (BP) crystal or an indium nitride (InN) crystal.

4. A boron-aluminum nitride coating as claimed in claim 1, wherein the substrate is an aluminum oxide (α

-Al₂ O₃) crystal, a silicon dioxide (SiO₂) crystal, a magnesium oxide (MgO) crystal, a beryllium oxide (BeO) crystal or a silicon nitride (Si₃ N₄) crystal.

5. A boron-aluminum nitride coating as claimed in claim 1, wherein the boron-aluminum nitride film is a c-axis oriented polycrystal or a single crystal.

6. A boron-aluminum nitride coating as claimed in claim 5, wherein the substrate is a diamond (C) single crystal, a silicon (Si) single crystal, a cubic silicon carbide (c-SiC) single crystal or a magnesium oxide (MgO) single crystal.

7. A boron-aluminum nitride coating as claimed in claim 6, wherein the boron-aluminum nitride film is made on a (111) plane of a cubic single crystal.

8. A boron-aluminum nitride coating as claimed in claim 5, wherein the substrate is a sapphire (α

-Al₂ O₃) single crystal or a hexagonal silicon carbide (h-SiC) single crystal.

9. A boron-aluminum nitride coating as claimed in claim 8, wherein the boron-aluminum nitride film is made on a (0001) plane of a hexagonal single crystal substrate.

10. A boron-aluminum nitride coating comprising:

a single crystal substrate;

a single crystal intermediate layer and

a boron-aluminum nitride single crystal top layer.

11. A boron-aluminum nitride coating as claimed in claim 10, wherein the boron-aluminum nitride single crystal film has a composition of B_x Al_1-x N_y (0.001≦

x≦

0.3, 0.85≦

y≦

1.05), forms a wurtzite type crystal structure of hexagonal symmetry and has a thickness between 10 nm and 50 μ

m.

12. A boron-aluminum nitride coating as claimed in claim 10, wherein the intermediate layer is an aluminum nitride (AlN) single crystal with a thickness from 1 nm to 1 μ

m.

13. A boron-aluminum nitride coating as claimed in claim 10, wherein the substrate is a diamond (C) single crystal, a silicon (Si) single crystal, a cubic silicon carbide (c-SiC) single crystal or a magnesium oxide (MgO) single crystal.

14. A boron-aluminum nitride coating as claimed in claim 13, wherein the intermediate layer is made on (111) plane of a cubic single crystal substrate.

15. A boron-aluminum nitride coating as claimed in claim 10, wherein the substrate is a sapphire (α

-Al₂ O₃) single crystal or a hexagonal silicon carbide (h-SiC) single crystal.

16. A boron-aluminum nitride coating as claimed in claim 15, wherein the intermediate layer is made on a (0001) plane of a hexagonal single crystal substrate.

17. A boron-aluminum nitride coating comprising:

a single crystal substrate;

a boron-aluminum nitride single crystal intermediate layer with sublayers of gradient B/Al compositions changing stepwise or continually and

a boron-aluminum nitride top layer.

18. A boron-aluminum nitride coating as claimed in claim 17, wherein the sublayers of the intermediate boron-aluminum nitride single crystal layer have compositions of B_x Al_1-x N_y (0.0001≦

x_m ≦

x≦

x_n ≦

x₀, 0.85≦

y≦

1.05) changing stepwise or continually from x=x_m to x=x_n, have a thickness from 1 nm to 1 μ

m and form a wurtzite type crystal structure of hexagonal symmetry, and the boron-aluminum nitride single crystal top film has a composition of B_x0 Al_1-x0 N_y (0.001≦

x₀ ≦

0.70, 0.85≦

y≦

1.05), has a thickness between 10 nm and 50 μ

m and forms a wurtzite type crystal structure of hexagonal symmetry.

19. A boron-aluminum nitride coating as claimed in claim 18, wherein the substrate is a diamond single crystal, a silicon (Si) single crystal, a cubic silicon carbide (c-SiC) single crystal or a magnesium oxide (MgO) single crystal.

20. A boron-aluminum nitride coating as claimed in claim 19, wherein the intermediate layer is made on a (111) plane of the single crystal substrate.

21. A boron-aluminum nitride coating as claimed in claim 20, wherein the substrate is a sapphire (α

-Al₂ O₃) single crystal or a hexagonal silicon carbide (h-SiC) single crystal.

22. A boron-aluminum nitride coating as claimed in claim 21, wherein the intermediate layer is made on a (0001) plane of the single crystal substrate.

23. A boron-aluminum nitride coating comprising:

a single crystal substrate;

an aluminum nitride (AlN) single crystal first intermediate layer;

a boron-aluminum nitride single crystal second intermediate layer with sublayers of gradient B/Al compositions changing stepwise or continually and

a boron-aluminum nitride single crystal top layer.

24. A boron-aluminum nitride coating as claimed in claim 23, wherein the sublayers of the intermediate boron-aluminum single crystal layer have compositions of B_x Al_1-x N_y (0.0001≦

x_m ≦

x≦

x_n ≦

x₀, 0.85≦

y≦

1.05) changing stepwise or continually from x=x_m to x=x_n, have a thickness from 1 nm to 1 μ

m and form a wurtzite type crystal structure of hexagonal symmetry, and the boron-aluminum nitride single crystal top film has a composition of B_x0 Al_1-x0 N_y (0.001≦

x₀ ≦

0.70, 0.85≦

y≦

1.05), has a thickness between 10 nm and 50 μ

m and forms a wurtzite type crystal structure of hexagonal symmetry, the top film having a thickness between 10 nm and 50 μ

m.

25. A boron-aluminum nitride coating as claimed in claim 24, wherein the substrate is a diamond single crystal, a silicon (Si) single crystal, a cubic silicon carbide (c-SiC) single crystal or a magnesium oxide (MgO) single crystal.

26. A boron-aluminum nitride coating as claimed in claim 25, wherein the intermediate layer is made on a (111) plane of the single crystal substrate.

27. A boron-aluminum nitride coating as claimed in claim 26, wherein the substrate is a sapphire (α

-Al₂ O₃) single crystal or a hexagonal silicon carbide (h-SiC) single crystal.

28. A boron-aluminum nitride coating as claimed in claim 27, wherein the intermediate layer is made on a (0001) plane of the single crystal substrate.

29. A boron-aluminum nitride film having a composition of B_x Al_1-x N_y (0.001≦

x≦

0.55, 0.85≦

y≦

1.05), forming a wurtzite type crystal structure or hexagonal symmetry and having a thickness between 1 nm and 50 μ

m.

30. A boron-aluminum nitride coated member comprising:

a hard substrate member;

hard films deposited on the substrate member, having a composition of B_x Al_1-x N_y (0.0001≦

x≦

0.55, 0.85≦

y≦

1.05), forming a wurtzite type crystal structure of hexagonal symmetry, each film having a thickness between 1 nm and 50 μ

m, a sum of the thickness of all films ranging from 0.5 μ

m to 50 μ

m.

31. A boron-aluminum nitride coated member as claimed in claim 30, wherein the substrate member has at least one intermediate layer comprising a carbide, a nitride, an oxide, boride, diamond or a solid-solution of a carbide, a nitride, a boride or diamond between the substrate member itself and the hard films.

32. A boron-aluminum nitride coated member as claimed in claim 31, wherein at least one said intermediate layer is aluminum nitride (AlN), aluminum oxide (Al₂ O₃), silicon nitride (Si₃ N₄) or silicon carbide (SiC).

33. A boron-aluminum nitride coated member as claimed in claim 30, wherein the substrate member comprises a nitride, a carbide, an oxide, a boride of a transition metal belonging to the periodic table group IVa, Va or VIa, a solid solution thereof or diamond.