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US 4,382,100 AGranted
Application of a layer of carbonaceous material to a surface
AssigneeNational Research Development Corporation
InventorLeslie A. Holland
Life of this patent
Estimating the term…
Abstract
A layer of a carbonaceous material is applied to a surface by connecting the surface through capacitive means to a radio frequency source, and simultaneously exposing the surface to a plasma generated in a hydrocarbon gas.
Claims10
A method of applying a non-crystalline carbonaceous material to a surface consisting of the steps of:
- (1) placing the surface in a single enclosure;
- (2) evacuating the single enclosure;
- (3) supplying to the enclosure a gas consisting essentially of carbon and hydrogen to a pressure sufficient to sustain a plasma, and
- simultaneously:
- generating a plasma in the gas in said single enclosure, while
- applying the surface through capacitive means an electrical potential which changes sign cyclically at time intervals of between 5.times.10.sup.-9 and 10.sup.-6 seconds,
- whereby the surface is maintained at a net negative potential with respect to the plasma so that positive ions are attracted to the surface during a part of each electrical potential cycle solely by the provision on the surface of the net negative potential resulting in a carbonaceous material being deposited on the surface.
4 more elements
A method of applying a carbonaceous material to a surface consisting of the steps of:
- (1) placing the surface in an enclosure containing a gas at less than atmospheric pressure, the gas consisting essentially of carbon and hydrogen;
- and
- (2) connecting the surface through capacitive means to one terminal of a source of electromagnetic radiation at a frequency of between 0.5 and 100 megahertz, and connecting the other terminal of the source to an electrode spaced from the surface,
- whereby simultaneously a plasma is generated in the gas and a net negative bias potential is maintained on the surface with respect to the plasma so that positive ions are attracted to the surface during a part of each electrical potential cycle solely by the provision on the surface of the net negative potential resulting in a carbonaceous material being deposited on the surface.
1 more element
A method of applying a carbonaceous material to two spaced surfaces, said method consisting of the steps of:
- (1) placing the two surfaces in an enclosure containing a gas at less than atmospheric pressure, the gas consisting essentially of carbon and hydrogen;
- and
- (2) connecting each surface through respective capacitive means to a different terminal of a source of electromagnetic radiation at a frequency of between 0.5 and 100 megahertz,
- whereby simultaneously a plasma is generated in the gas and a net negative bias potential is maintained on each surface with respect to the plasma, so that positive ions are attracted to the surface during a part of each electrical potential cycle solely by the provision on the surface of the net negative potential resulting in a carbonaceous material being deposited on the surface.
1 more element
A method of applying a carbonaceous material to a surface consisting of the steps of:
- (1) placing the surface in an enclosure containing a gas at less than atmospheric pressure, the gas consisting essentially of carbon and hydrogen;
- (2) connecting the surface through capacitive means to one terminal of a first source of electromagnetic radiation at a frequency of between 0.5 and 100 megahertz;
- (3) connecting the other terminal of the source to an electrode spaced from the surface, whereby a net negative bias potential is maintained on the surface;
- and
- (4) simultaneously generating a plasma in the gas by means of a conducting coil surrounding the surface and connected to a second source of electromagnetic radiation at a radio frequency.
2 more elements
A method of applying a carbonaceous material to a surface consisting of the steps of:
- (1) placing the surface in an enclosure containing a gas at less than atmospheric pressure, the gas consisting essentially of carbon and hydrogen;
- (2) connecting the surface through capacitive means to one terminal of a source of electromagnetic radiation at a frequency of between 0.5 and 100 megahertz;
- (3) connecting the other terminal of the source to an electrode spaced from the surface, whereby a net negative bias potential is maintained on the surface;
- and simultaneously generating a plasma in the gas by means of a heated filament and a spaced further electrode and a net negative bias potential is maintained on the surface with respect to the plasma so that positive ions are attracted to the surface during a part of each electrical potential cycle solely by the provision on the surface of the net negative potential resulting in a carbonaceous material being deposited on the surface.
1 more element
Dependencies are inferred from the claim text.