Amorphous carbon, amorphous-carbon coated member, and process for forming amorphous carbon film

• US 20050142361A1
• Filed: 12/03/2004
• Published: 06/30/2005
• Est. Priority Date: 12/04/2003
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toyota Chuo Kenkyusho (Toyota Motor Corporation)
• Original Assignee: Kabushiki Kaisha Toyota Chuo Kenkyusho (Toyota Motor Corporation)
• Inventors: Iseki, Takashi, Hasegawa, Hideo, Mori, Hiroyuki, Matsui, Munehisa, Nakanishi, Kazuyuki, Tachikawa, Hideo, Oshima, Tadashi
• Granted Patent: US 7,455,824 B2
• Time in Patent Office: Days
• US Class Current: 428/408
• CPC Class Codes: C23C 16/26 Deposition of carbon only
• CPC Class Codes: Y10T 428/30 Self-sustaining carbon mass or layer with impregnant or other layer

Abstract

To provide a soft amorphous carbon exhibiting a low elastic modulus, an amorphous-carbon coated member provided with a coated film comprising the amorphous carbon, and a process for forming an amorphous carbon film. The amorphous carbon comprises carbon as a major component and hydrogen in an amount of from more than 30 atomic % to 60 atomic % or less, and exhibits an elastic modulus of from 40 or more to 150 GPa or less. Moreover, the amorphous-carbon coated member comprises a conductive substrate, and a coated film fixed on at least a part of a surface of the substrate and composed of the amorphous carbon. In addition, in a process for forming the amorphous-carbon coated film, an amorphous carbon film is formed on a surface of conductive substrates by a plasma CVD method. Not only a plurality of the substrates are disposed on a substrate holder, which is disposed in a film-forming furnace and is connected with a negative electrode, in such a state that they face to each other, but also a processing gas pressure and a plasma power source are operated so as to overlap negative glows of the neighboring two substrates.

Claims

1. Amorphous carbon, comprising:

carbon as a major component; and

hydrogen in an amount of from more than 30 atomic % to 60 atomic % or less; and

exhibiting an elastic modulus of from 40 or more to 150 GPa or less.

2. The amorphous carbon set forth in claim 1, wherein

when an entire content of the carbon is taken as 100 atomic %, a content of carbon having an sp³ hybrid orbital falls in a range of from 10 atomic % or more to 85 atomic % or less.

3. The amorphous carbon set forth in claim 1 exhibiting a Vickers hardness falling in a range of from 400 or more to 1,500 Hv or less.

4. The amorphous carbon set forth in claim 1 comprising silicon in an amount of 50 atomic % or less when, the entirety is taken as 100 atomic %.

5. An amorphous-carbon coated member, comprising:

a conductive substrate; and

a coated film fixed on at least a part of a surface of the substrate;

the coated film composed of amorphous carbon comprising;

carbon as a major component; and

hydrogen in an amount of from more than 30 atomic % to 60 atomic % or less; and

exhibiting an elastic modulus of from 40 or more to 150 GPa or less.

6. The amorphous-carbon coated member set forth in claim 5, wherein

when an entire content of the carbon is taken as 100 atomic %, a content of carbon having an sp³ hybrid orbital falls in a range of from 10 atomic % or more to 85 atomic % or less.

7. The amorphous-carbon coated member set forth in claim 5, wherein the coated film exhibits a Vickers hardness falling in a range of from 400 or more to 1,500 Hv or less.

8. The amorphous-carbon coated member set forth in claim 5, wherein the coated film has a film thickness of from 0.1 or more to 200 μ

m or less.

9. The amorphous-carbon coated member set forth in claim 5, wherein the amorphous carbon comprises silicon in an amount of 50 atomic % or less when the entirety is taken as 100 atomic %.

10. A process for forming an amorphous carbon film, comprising:

disposing a plurality of conductive substrates on a substrate holder in such a state that they face to each other, the substrate holder disposed in a film-forming chamber and connected with a negative electrode;

operating a processing gas pressure and a plasma power source so as to overlap negative glows of the neighboring two substrates; and

forming an amorphous carbon film on at least a part of the substrates by a plasma CVD method.

11. The process for forming an amorphous carbon film set forth in claim 10, wherein a plasma light-emission intensity at the overlapped negative glows is 1.5 times or more intenser than a plasma light-emission intensity at overlapping-free portions.

12. The process for forming an amorphous carbon film set forth in claim 10, wherein a sheath width from the surface of the substrates to the negative glows falls in a range of from a quarter or more of an interval between oppositely facing surfaces of the two neighboring substrates to the interval between the oppositely facing surfaces or less.

13. The process for forming an amorphous carbon film set forth in claim 10, wherein the processing gas pressure falls in a range of from 13 or more to 1,330 Pa or less;

and an interval between oppositely facing surfaces of the two neighboring substrates falls in a range of from 2 or more to 60 mm or less.

14. The process for forming an amorphous carbon film set forth in claim 10, wherein one of the two neighboring substrates comprises a member exhibiting conductivity and having a plurality of through holes penetrating the opposite surfaces.

15. The process for forming an amorphous carbon film set forth in claim 14, wherein the negative glows overlap inside the through holes of the member having a plurality of through holes.

16. The process for forming an amorphous carbon film set forth in claim 10, wherein a hydrogen content of the processing gas is 60 atomic % or more, thereby forming an amorphous carbon film comprising hydrogen in an amount of from more than 30 atomic % to 60 atomic % or less.

17. The process for forming an amorphous carbon film set forth in claim 10, wherein the processing gas comprises a hydrocarbon gas, or a mixture gas composed of a hydrocarbon gas and a diluent gas comprising one or more members selected from the group consisting of hydrogen and noble gases.

18. The process for forming an amorphous carbon film set forth in claim 10, wherein the processing gas comprises a raw material gas including one or more members selected from the group consisting of hydrocarbon gases, gases containing an organic metal including silicon at least, and halide gases, or a mixture gas composed of the raw material gas and a diluent gas comprising one or more members selected from the group consisting of hydrogen and noble gases.

19. The process for forming an amorphous carbon film set forth in claim 18, wherein the gases containing an organic metal comprise tetramethylsilane or silane.

20. The process for forming an amorphous carbon film set forth in claim 18, wherein the halide gases comprise silicon tetrachloride.