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US4954232A
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Magneto-optical recording element and method for fabrication thereof
Assignee: Kyocera Corp
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Filing: 1989-05-26
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Granted: 1990-09-04
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Expires: 2009-05-26
Abstract
Abstract In a magneto-optical recording element comprising a substrate, a magnetic layer and a dielectric layer, the dielectric layer is formed by deposition of a composition comprising Si 3 N 4 and a refractive index-improving agent such as Al 2 O 3 or Y 2 O 3 . This dielectric layer has a high refractive index and the enhancement effect is improved. Moreover, this dielectric layer is excellent in the adhesion and resistance characteristics.
Inventors
- 👤 Takashi Yamada
- 👤 Hisao Arimune
- 👤 Takashi Maeda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 12:48
CPC Classifications
G; G03; G03G; G03G5/00; G03G5/16; G11; G11B; G11B11/00; G11B11/10; G11B11/105; G11B11/10582; G11B11/10586; G11B11/10589; G11B11/10591; G11B5/00; G11B5/62; G11B5/73; G11B5/7368; G11B5/739; G11B5/73923; G11B5/72; G11B5/726; G11B5/7262
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
127 words
A method for the fabrication of a magneto-optical recording element, which comprises maintaining a substrate on which a film is to be formed, a first target composed of a sintered composition comprising (a) silicon nitride and (b) at least one additive selected from the group consisting of single elements, oxides, nitrides, sulfides and silicides of elements of the groups IIIa, IVa, IIb, IIIb, IVb and VIb of the Periodic Table and a second target composed of a magnetic layer-forming metal in an inert gas atmosphere maintained at 1×10 -3 to 50×10 -3 Torr and forming a magnetic layer and a dielectric layer alternately on the substrate by sputtering, wherein said additive (b) is contained in the first target in an amount of 4 to 20 mole %.
Claim 2
Independent Claim
127 words
A method for the fabrication of a magneto-optical recording element, which comprises maintaining a substrate on which a film is to be formed, a first target composed of a sintered composition comprising (a) silicon nitride and (b) at least one additive selected from the group consisting of single elements, oxides, nitrides, sulfides and silicides of elements of the groups IIIa, IVa, IIb, IIIb, IVb and VIb of the Periodic Table and a second target composed of a magnetic layer-forming metal in an inert gas atmosphere maintained at 1×10 -3 to 50×10 -3 Torr and forming a magnetic layer and a dielectric layer alternately on the substrate by sputtering, wherein said additive (b) is contained in the first target in an amount of 4 to 20 mole %.
Claim 3
Dependent Claim
39 words
The method of claim 1 wherein at least the substrate and first target are exposed to a vacuum of less than 1×10 -5 Torr, prior to maintaining said substrate, first target and second target in an inert gas atmosphere.
Claim 4
Independent Claim
172 words
A method for fabrication of a magneto-optical recording element, the sequential steps of the method comprising: (a) providing a substrate on which a film is to be formed, a first target composed of a sintered composition comprising (i) silicon nitride and (ii) at least one additive selected from the group consisting of single elements, oxides, nitrides, sulfides, and silicides of elements of the groups IIIa, IVa, VIa, IIb, IIIb, IVb and VIb of the Periodic Table and a second target composed of a magnetic layer-forming metal, said additive (b) being contained in the first target in an amount of 4 to 20 mole %; (b) maintaining the substrate, the first target and the second target in an inert gas atmosphere maintained at 1×10 -3 to 50×10 -3 Torr; (c) applying a high-frequency electric power or direct current between the first target and the substrate to form a first dielectric layer; and (d) applying a high-frequency or direct current electric power between the second target and the substrate to form a magnetic layer.
Claim 5
Independent Claim
172 words
A method for fabrication of a magneto-optical recording element, the sequential steps of the method comprising: (a) providing a substrate on which a film is to be formed, a first target composed of a sintered composition comprising (i) silicon nitride and (ii) at least one additive selected from the group consisting of single elements, oxides, nitrides, sulfides, and silicides of elements of the groups IIIa, IVa, VIa, IIb, IIIb, IVb and VIb of the Periodic Table and a second target composed of a magnetic layer-forming metal, said additive (b) being contained in the first target in an amount of 4 to 20 mole %; (b) maintaining the substrate, the first target and the second target in an inert gas atmosphere maintained at 1×10 -3 to 50×10 -3 Torr; (c) applying a high-frequency electric power or direct current between the first target and the substrate to form a first dielectric layer; and (d) applying a high-frequency or direct current electric power between the second target and the substrate to form a magnetic layer.
Claim 6
Dependent Claim
39 words
The method of claim 3 wherein at least the substrate and first target are exposed to a vacuum of less than 1×10 -5 Torr, prior to maintaining said substrate, first target and second target is an inert gas atmosphere.
Claim 7
Dependent Claim
33 words
The method of claim 3, further comprising the step of (b) applying a high frequency or direct current electric power between the first target and the substrate to form a second dielectric layer.
Claim 8
Dependent Claim
19 words
The method of claim 3 wherein the inert gas atmosphere is maintained at 3×10 -3 to 20×10 -3 Torr.
Claim 9
Dependent Claim
28 words
The method of claim 3 wherein the additive is present in the first target in an amount of 0.5 to 8.0 mole percent based on the first target.
Claim 10
Dependent Claim
11 words
The method of claim 3 wherein the sputtering is high-frequency sputtering.
Claim 11
Dependent Claim
36 words
The method of claim 3 wherein the first target comprises 0.1 to 5.0 mole % of alumina or aluminum nitride and 0.1 to 3.0 mole % of an oxide or nitride of a rare earth element.
Claim 12
Dependent Claim
14 words
The method of claim 3 wherein the substrate is composed of transparent plastic material.
Claim 13
Dependent Claim
17 words
The method of claim 3 wherein the magnetic layer is composed of an amorphous alloy magnetic material.
Claim 14
Dependent Claim
77 words
The method of claim 3 wherein the additive is at least one member selected from the group consisting of Al, Ti, Si, Ge, Al 2 O 3 , Y 2 O 3 , La 2 O 3 , CeO 2 , Bi 2 O 3 , GeO 2 , ZrO 2 , CdO, Cr 2 O 3 , SnO 2 , PbO, AlN, TiN, YN, ZnS, Sb 2 S 3 , TiSi 2 and YSi 2 .
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-09-03 | 1994-03-05 | 1994-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-09-03 | 1998-03-05 | 1998-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-09-03 | 2002-03-05 | 2002-09-04 | $7700.00 | Window Closed / Lapsed |