US5308661A
Expired / Lapsed
US
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Pretreatment process for forming a smooth surface diamond film on a carbon-coated substrate
Assignee: University of California
•
Filing: 1993-03-03
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Granted: 1994-05-03
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Expires: 2013-03-03
Abstract
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.
Inventors
- 👤 Zhu Feng
- 👤 Marilee Brewer
- 👤 Ian Brown
- 👤 Kyriakos Komvopoulos
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 03:10
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/22; C23C16/26; C23C16/27; C23C16/274; C23C16/02; C23C16/0272; C23C16/277; Y; Y10; Y10S; Y10S427/00; Y10S427/102; Y10T; Y10T428/00; Y10T428/30
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
103 words
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° C. to about 600° C. during said pretreatment; and then depositing said continuous layer of diamond on the pretreated substrate.
Claim 2
Dependent Claim
103 words
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° C. to about 600° C. during said pretreatment; and then depositing said continuous layer of diamond on the pretreated substrate.
Claim 3
Dependent Claim
20 words
The process of claim 1 wherein said pretreatment is carried out for a period of at least about 10 minutes.
Claim 4
Dependent Claim
23 words
The process of claim 1 wherein said pretreatment is carried out for a period of from about 10 minutes to about 2 hours.
Claim 5
Dependent Claim
27 words
The process of claim 1 wherein said pretreatment is carried out while maintaining the pressure within a range of from about 10 Torr to about 25 Torr.
Claim 6
Dependent Claim
19 words
The process of claim 1 wherein said pretreatment is carried out while maintaining said pressure at about 20 Torr.
Claim 7
Dependent Claim
31 words
The process of claim 1 wherein said pretreatment is carried out while maintaining said methane concentration in said methane/hydrogen gas mixture within a range of from about 4% to about 10%.
Claim 8
Dependent Claim
28 words
The process of claim 6 wherein said pretreatment is carried out while maintaining a methane concentration of from about 5% to about 10% in said methane/hydrogen gas mixture.
Claim 9
Dependent Claim
109 words
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° C. to about 600° C.; and then depositing said continuous layer of diamond on the pretreated substrate.
Claim 10
Dependent Claim
109 words
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° C. to about 600° C.; and then depositing said continuous layer of diamond on the pretreated substrate.
Claim 11
Dependent Claim
25 words
The process of claim 8 wherein said substrate is maintained at a temperature of from about 550° C. to about 600° C. during said pretreatment.
Claim 12
Dependent Claim
130 words
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° C. to about 600° C.; and (c) depositing said continuous layer of diamond on the pretreated substrate.
Claim 13
Dependent Claim
130 words
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° C. to about 600° C.; and (c) depositing said continuous layer of diamond on the pretreated substrate.
Claim 14
Dependent Claim
27 words
The process of claim 10 wherein said pretreatment is carried out while maintaining the pressure within a range of from about 10 Torr to about 25 Torr.
Claim 15
Dependent Claim
19 words
The process of claim 11 wherein said pretreatment is carried out while maintaining said pressure at about 20 Torr.
Claim 16
Dependent Claim
28 words
The process of claim 10 wherein said pretreatment is carried out while maintaining a methane concentration of from about 5% to about 10% in said methane/hydrogen gas mixture.
References Cited (Backward Citations)
US5169676A
Cited
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