Process and apparatus for producing diamond film

• US 5,217,700 A
• Filed: 12/13/1991
• Issued: 06/08/1993
• Est. Priority Date: 12/15/1990
• Status: Expired due to Term

• Current Assignee: TRLI Incorporated
• Original Assignee: Fujitsu Limited
• Inventors: Kurihara, Kazuaki, Sasaki, Kenichi, Kawarada, Motonobu
• Primary Examiner(s): Straub, Gary P.
• Assistant Examiner(s): Kalinchak, Stephen G.
• Application Number:
  US07/806,246
• Time in Patent Office: 543 Days
• Field of Search: 423/446, 156/DIG. 68, 427/249, 427/34, 427/39, 427/450, 427/577, 204/157.47
• US Class Current: 423/446
• CPC Class Codes: C23C 16/27 Diamond only
• CPC Class Codes: C23C 16/30 Deposition of compounds, mixtures or solid solutions, e.g. borides, carbides, nitrides
• CPC Class Codes: C23C 16/453 passing the reaction gases through burners or torches, e.g. atmospheric pressure CVD C23C16/513 takes precedence; for flame or plasma spraying of coating material in the molten state C23C4/00
• CPC Class Codes: C23C 4/04 characterised by the coating material
• CPC Class Codes: C23C 4/12 characterised by the method of spraying

Abstract

A process and apparatus for producing a diamond film from a gas phase, in which a fuel gas is burnt by oxygen gas in a torch, to thereby provide a gas flame jet having a high temperature and high speed sufficient to form a high quality diamond film on a substrate, by an unlimited use of various kinds of combustible carbon compound gases as the fuel gas. A process and apparatus for producing a diamond film from a gas phase, in which a thermal spray material is fed to a combustion flame to thereby form an intermediate layer of a mixture of the thermal spray material and diamond between a substrate and a diamond film, to thereby provide a high purity diamond film having an improved adhesion to the substrate.

Claims

1. A process for producing a diamond film, comprising the steps of:

supplying oxygen gas and a fuel gas containing a combustible carbon compound to a combustion chamber of a torch at a ratio such that a gaseous mixture is formed having an atomic ratio of carbon greater than the atomic ratio of oxygen;

burning said gaseous mixture in said combustion chamber to thereby generate a carbon-rich combustion gas having reducing properties in said chamber;

ejecting said combustion gas from said combustion chamber through a nozzle of said torch to thereby form a gas flame jet;

applying said gas flame jet to a substrate while maintaining the substrate at a temperature of from 500°

C. to 1200°

C. to thereby form a diamond film on said substrate.

2. A process according to claim 1, wherein said fuel gas is mainly composed of a carbon compound gas.

3. A process according to claim 1, wherein said fuel gas is mainly composed of a mixture of a carbon compound gas and hydrogen gas.

4. A process according to claim 1, wherein said carbon compound is a hydrocarbon.

5. A process according to claim 1, wherein said combustion gas is ejected from said combustion chamber through said nozzle of said torch into an atmosphere having a reduced pressure, to thereby form said gas flame jet, and the gas flame jet is applied to said substrate while said substrate is held in said atmosphere.

6. A process according to claim 1, wherein said fuel gas comprises acetylene, propane, propylene, methylacetylene, or a mixture of hydrogen gas and a hydrocarbon gas.

7. A process according to claim 1, said process comprising the further steps of:

feeding a thermal spray material to said gas flame jet; and

varying the feed amount of said thermal spray material to thereby form an intermediate layer of a mixture of said thermal spray material and diamond between said substrate and said diamond film.

8. A process according to claim 7, wherein said thermal spray material is fed in the form of a powder gas comprising a powder of said thermal spray material mixed with and carried by a carrier gas.

9. A process according to claim 7, wherein said thermal spray material is fed in the form of a wire.

10. A process according to claim 7, wherein said process is carried out in an atmosphere having a reduced pressure.

11. A process according to claim 7, wherein the feed amount of said thermal spray material is varied to thereby form said intermediate layer in which a content of said thermal spray material is decreased continuously with respect to the direction from said substrate towards said diamond film.