Patent EP0457076A2 successfully refreshed from Google Patents.
EP0457076A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method for producing synthetic diamond thin film, the thin film and device using it
Assignee: Hitachi Ltd
•
Filing: 1991-04-25
•
Granted: —
•
Expires: 2011-04-25
Abstract
Abstract The present invention provides a method for producing a synthetic diamond thin film (2) which comprises decomposing with microwave a raw material gas containing at least one compound selected from the group consisting of carbon monoxide, carbon dioxide and a hydrocarbon and hydrogen or hydrogen and oxygen to produce a plasma and contacting the plasma with the surface of a substrate (1) held outside the area irradiated with the microwave to form a diamond thin film (2) on the substrate (1). The present invention further provides an apparatus for producing a synthetic diamond thin film and a synthetic diamond thin film and devices in which the synthetic diamond thin film is used.
Inventors
- 👤 Yasushi Muranaka
- 👤 Hisao Yamashita
- 👤 Hiroshi Miyadera
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 02:55
CPC Classifications
C; C30; C30B; C30B29/00; C30B29/02; C30B29/04; C23; C23C; C23C16/00; C23C16/22; C23C16/26; C23C16/27; C23C16/274; C23C16/277
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
75 words
A method for producing a synthetic diamond thin film which comprises decomposing with microwave a raw material gas containing at least one compound selected from the group consisting of carbon monoxide, carbon dioxide and a hydrocarbon and hydrogen or hydrogen and oxygen to produce a plasma and contacting the plasma with the surface of a substrate (1) held outside the area irradiated with the microwave to form a diamond thin film (2) on the substrate.
Claim 2
Dependent Claim
26 words
A method according to Claim 1, wherein the raw material gas is selected from the group consisting of CO/O₂/H₂, CH₄/O₂/H₂, CO/CO₂/H₂, CO/CO₂/O₂/H₂, CO/CH₄/O₂/H₂, CH₄/CO₂/H₂ and CH₄/CO₂/O₂/H₂.
Claim 3
Dependent Claim
27 words
A method according to claim 1, wherein the concentration of an inert gas as an impurity in the raw material gas is at most 1 mol ppm.
Claim 4
Dependent Claim
27 words
A method according to claim 1, wherein the content of oxygen in the raw material gas is in the range of 1 mol ppm - 5 mol%.
Claim 5
Dependent Claim
27 words
A method according to claim 1, wherein the substrate (1) is held outside the area irradiated with microwave and inside the area where the plasma is produced.
Claim 6
Dependent Claim
44 words
A method according to claim 1, wherein the substrate (1) comprises a glass and surface temperature of the substrate is controlled to be lower than the softening point of the material of the substrate by 100°C or more and higher than the atmospheric temperature.
Claim 7
Dependent Claim
34 words
A method according to claim 1, wherein the substrate (1) has on the surface thereof a vapor deposited film (3) of at least one material selected from the group consisting of Cu and Ni.
Claim 8
Dependent Claim
38 words
A method according to claim 1, wherein the substrate (1) has on the surface a single crystal film (3) or an amorphous film (3) of at least one material selected from the group consisting of Cu and Ni.
Claim 9
Dependent Claim
22 words
A method according to claim 1, wherein the plasma generated by the decomposition of the raw material is a non-equilibrium microwave plasma.
Claim 10
Dependent Claim
31 words
A method according to claim 1, wherein the pressure of the plasma atmosphere of the raw material gas is in the range of 1.33·10⁻⁵ - 1.33·10² hPa (10⁻⁵ - 10² Torr).
Claim 11
Independent Claim
101 words
An apparatus for producing a synthetic diamond thin film which has a chamber (32), a means for introducing a raw material gas (35) for synthesis of diamond into the chamber, a means for generating an electromagnetic wave (36) which decomposes the raw material gas (35) to produce a non-equilibrium plasma (34), a substrate holder (38) for formation of a synthetic diamond thin film which is placed at the position where the substrate (37; 37, 37') contacts with the non-equilibrium plasma (34) outside the area irradiated with the electromagnetic wave (36), and a means for adjusting the pressure of the chamber (32).
Claim 12
Dependent Claim
47 words
An apparatus according to claim 11, which additionally has a means (41) for generating an electric field or a magnetic field which allows the non-equilibrium plasma (34) produced by the decomposition of the raw material gas (35) to reach and contact the surface of the substrate (37;37,37').
Claim 13
Dependent Claim
45 words
A synthetic diamond thin film which has a ratio Ia/Id of less than 3 where Id indicates a Raman scattering intensity based on diamond crystal according to the Macro Raman spectroscopy and Ia indicates a Raman scattering intensity based on amorphous component other than diamond.
Claim 14
Dependent Claim
35 words
A synthetic diamond thin film in which the full width at half maximum of Raman scattering peak based on a diamond crystal according to the Macro Raman spectroscopy is in the range of 3-5 cm⁻¹.
Claim 15
Dependent Claim
50 words
A synthetic diamond thin film which has a ratio Ib/Ig of at least 2 where Ib indicates an intensity of a peak of diamond at a wavelength of 440 nm according to the cathode luminescence analysis and Ig indicates an intensity of a peak at a wavelength of 530-600 nm.
Claim 16
Dependent Claim
15 words
A synthetic diamond thin film for light emitting devices which has the Ia/Id of 0-3.
Claim 17
Dependent Claim
27 words
A synthetic diamond thin film for light emitting devices which has a full width at half maximum of the Raman scattering peak of 3 - 5 cm⁻¹.
Claim 18
Dependent Claim
18 words
A synthetic diamond thin film for light emitting devices which has the ratio Ib/Ig of at least 2.
Claim 19
Dependent Claim
48 words
A synthetic diamond thin film composite which comprises a synthetic diamond thin film (2) which has the ratio Ia/Id of less than 3 and a substrate (1) for formation of the thin film which has a lattice constant differing by 1% or less from that of the diamond.
Claim 20
Dependent Claim
32 words
A synthetic diamond thin film composite which comprises a silicon single crystal substrate (1) on which is formed a synthetic diamond thin film (2) having the ratio Ia/Id of less than 3.
Claim 21
Dependent Claim
64 words
A synthetic diamond thin film composite which comprises an insulating substrate (1), a thin film layer (3) of single crystal or polycrystal of Cu, Ni or cubic boron nitride formed on the substrate (1) and a synthetic diamond thin film (2) formed on the surface of the thin film layer (3), the synthetic diamond thin film having the ratio Ia/Id of less than 3.
Claim 22
Dependent Claim
127 words
A light emitting device which comprises an electrically insulating transparent substrate (1), a transparent electrode (5) formed on the substrate (1), a transparent insulating layer (4) formed on the transparent element electrode (5), a light emitter (10) formed on the transparent insulating layer (4), an insulating layer (4') formed on the light emitter (10), an electrode formed (5') on the insulating layer (4'), and a means (11, 12) for applying alternating voltage between the electrodes (5, 5'), at least a part of the light emitter (10) being composed of a synthetic diamond thin film (2) which has the ratio Ia/Id of less than 3, the full width at half maximum of Raman scattering peak of 3 - 5 cm⁻¹, and the ratio Ib/Ig of at least 2.
Claim 23
Dependent Claim
76 words
A Braun tube which has an electron gun, a deflection coil which deflects an electron beam emitted from the electron gun on the basis of external signal, and a shadow mask, wherein a phosphor screen formed on an inner surface of a face panel comprises a synthetic diamond thin film which has the ratio Ia/Id of less than 3 and the full width at a half maximum of Raman scattering peak of 3 - 5 cm⁻¹.
Claim 24
Dependent Claim
59 words
A field effect transistor which comprises an insulating layer (1), a semiconductor layer (21) provided on the insulating layer (1), and a gate electrode (24), a drain electrode (22) and a source electrode (23) provided on the semiconductor layer (21), wherein the semiconductor layer comprises a synthetic diamond thin film (21) having the ratio Ia/Id of 0 - 3.
Claim 25
Dependent Claim
49 words
A field effect transistor according to claim 24, wherein a vapor deposition layer (3) of at least one material selected from the group consisting of Cu and Ni is provided on the insulating layer (1) and thereon is provided the semiconductor layer comprising the synthetic diamond thin film (21).
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.