EP0049032A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Coating insulating materials by glow discharge
Assignee: BTG International Ltd
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Filing: 1981-07-21
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Granted: —
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Expires: 2001-07-21
Abstract
Abstract Coatings of hard carbon, silicon, or germanium are applied to electrically insulating materials in a D.C. glow discharge chamber. Initiation and maintenance of a glow discharge is ensured by using a cathode of larger area than the material to be coated. For example the cathode 7 may be twice the diameter of the material 8 to be coated. Materials capable of being coated include zinc sulphide, zinc selenide, silica, and glass. The gases used are hydrocarbon e.g. butane, methane etc. for carbon coatings; silane for silicon coatings; and germane for germanium coatings.
Inventors
- 👤 Geoffrey William Green
- 👤 Alan Harold Lettington
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 23:39
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/44; C23C16/50; C23C16/503
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
54 words
A method of depositing coatings on an electrically insulating material substrate in a glow discharge chamber supplied with D.C. electrical power wherein the substrate is mounted on a cathode of larger area than the substrate whereby the exposed area of the cathode serves to maintain a glow discharge and dark space above the substrate.
Claim 2
Independent Claim
54 words
A method of depositing coatings on an electrically insulating material substrate in a glow discharge chamber supplied with D.C. electrical power wherein the substrate is mounted on a cathode of larger area than the substrate whereby the exposed area of the cathode serves to maintain a glow discharge and dark space above the substrate.
Claim 3
Dependent Claim
19 words
The method of claim 1 wherein the coating is infra red transparent hard carbon deposited from a hydrocarbon gas.
Claim 4
Dependent Claim
14 words
The method of claim 1 wherein the coating is silicon deposited from silane gas.
Claim 5
Dependent Claim
14 words
The method of claim 1 wherein the coating is germanium deposited from germane gas.
Claim 6
Dependent Claim
15 words
The method of claim 1 wherein the substrate is heated prior to depositing the coating.
Claim 7
Dependent Claim
18 words
The method of claim 1 wherein the substrate is cleaned by ion bombardment prior to depositing the coating.
Claim 8
Dependent Claim
18 words
The method of claim 1 wherein at least two layers of different materials are deposited on the substrate.
Claim 9
Dependent Claim
89 words
Apparatus for carrying out the method of claim 1 comprising, a vacuum chamber including an anode, means for providing vacuum condition in the chamber, means for supplying D.C. electrical power, means for supplying a gas into the chamber, and a cathode structure for carrying a substrate to be coated, the cathode having a substantially larger area than the substrate so that exposed areas of the cathode maintain a glow discharge and a dark space above the substrate whilst the D.C. power is applied to the anode & cathode structure.
Claim 10
Dependent Claim
16 words
Apparatus as claimed in claim 8 wherein the cathode structure is recessed to receive the substrate.
Claim 11
Dependent Claim
16 words
Apparatus as claimed in claim 8 wherein the cathode structure includes means for controlling its temperature.
Claim 12
Dependent Claim
19 words
Apparatus as claimed in claim 8 wherein an earthed shield surrounds the cathode structure to confine the glow discharge.
Claim 13
Dependent Claim
9 words
A substrate coated by the method of claim 1.
Claim 14
Dependent Claim
17 words
A substrate as claimed in claim 12 coated with a layer of infra red transparent hard carbon.
Claim 15
Dependent Claim
25 words
A substrate as claimed in claim 13 wherein a thin bonding layer of silicon is applied to the substrate before deposition of the hard carbon.
Claim 16
Dependent Claim
14 words
A substrate as claimed in claim 12 wherein the substrate material is zinc sulphide.
Claim 17
Dependent Claim
14 words
A substrate as claimed in claim 12 wherein the substrate material is zinc selenide.
References Cited (Backward Citations)
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