Pretreatment process for forming a smooth surface diamond film on a carbon-coated substrate
AssigneeThe Regents of the University of California
InventorsZhu Feng, Marilee Brewer, Ian Brown, Kyriakos Komvopoulos
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Abstract
A process is disclosed for the pretreatment of a carbon-coated substrate to provide a uniform high density of nucleation sites thereon for the subsequent deposition of a continuous diamond film without the application of a bias voltage to the substrate. The process comprises exposing the carbon-coated substrate, in a microwave plasma enhanced chemical vapor deposition system, to a mixture of hydrogen-methane gases, having a methane gas concentration of at least about 4% (as measured by partial pressure), while maintaining the substrate at a pressure of about 10 to about 30 Torr during the pretreatment.
Claims13
A process for forming a continuous layer of diamond having a smooth surface on a carbon-coated substrate, which comprises pretreating said carbon-coated substrate, without application of an electrical bias to the substrate, with a methane/hydrogen gas mixture having a concentration of methane of at least about 4% as measured by partial pressure, in a vacuum chamber in the presence of a plasma and at a pressure not exceeding about 30 Torr, and while maintaining said substrate at a temperature of from about 500.degree. C. to about 600.degree. C. during said pretreatment;
- and then depositing said continuous layer of diamond on the pretreated substrate.
A process for forming a continuous layer of diamond having a smooth surface on a carbon-coated substrate, which comprises pretreating said carbon-coated substrate, without application of an electrical bias to the substrate, with a hydrogen/methane gas mixture having a concentration of methane ranging from about 5% to about 10%, as measured by partial pressure, in a vacuum chamber in the presence of a plasma and at a pressure of from about 10 Torr to about 25 Torr, and while maintaining said substrate at a temperature within a range of from about 500.degree. C. to about 600.degree. C.;
- and then depositing said continuous layer of diamond on the pretreated substrate.
A process for forming a continuous layer of diamond having a smooth surface on a substrate, which comprises the steps in sequence of:
- (a) forming a carbon-containing coating on said substrate;
- (b) pretreating said carbon-coated substrate, without application of an electrical bias to said substrate, for a period of at least about 10 minutes with a methane/hydrogen gas mixture having a concentration of methane of from about 4% to about 10%, as measured by partial pressure, in a vacuum chamber in the presence of a plasma and at a pressure ranging from about 10 Torr to about 30 Torr, while maintaining said substrate at a temperature within a range of from about 550.degree. C. to about 600.degree. C.;
- and
- (c) depositing said continuous layer of diamond on the pretreated substrate.
Dependencies are inferred from the claim text.