US4944805A
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Method of heat treatment amorphous soft magnetic film layers to reduce magnetic anisotropy
Assignee: Fujifilm Holdings Corp
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Filing: 1988-09-12
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Granted: 1990-07-31
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Expires: 2008-09-12
Abstract
Abstract A method of heat treating an amorphous soft magnetic (ASM) film for use in a device that utilizes magnetism and is fabricated by depositing two or more layers of an ASM film, and an associated oxide film and conductive metal film, on a substrate. Typically, the substrate is made of an oxide. More specifically, the method involves: performing a heat treatment after each layer of the ASM film has been deposited, at a temperature lower than the crystallization temperature and the Curie point of the ASM film in a static magnetic filed applied either in a direction generally perpendicular to the direction in which a high magnetic permeability for high frequency is to be finally attained in the ASM film or in the principal direction in which the high permeability for high frequency is desired; performing a heat final treatment, after all of the layers of the ASM film have been deposited, at a temperature equal to or lower than the temperature for the previous heat treatment in a static magnetic field applied either in the principal direction or in a direction generally perpendicular thereto, the magnitude of the uniaxial magnetic anisotropy to be imparted to the ASM film being controlled by the temperature and duration of the final heat treatment.
Inventors
- 👤 Kanji Nakanishi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 02:56
CPC Classifications
C; C21; C21D; C21D1/00; C21D1/04; B; B82; B82Y; B82Y25/00; G; G11; G11B; G11B5/00; G11B5/127; G11B5/31; G11B5/3163; H; H01; H01F; H01F10/00; H01F10/32; H01F10/3204; H01F41/00; H01F41/32
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
205 words
In a method of heat treating an amorphous soft magnetic film fabricated by depositing various layers of material on a substrate including at least two layers of amorphous soft magnetic film, the improvement in combination therewith comprising the steps of: performing a heat treatment, after each layer of said amorphous soft magnetic film has been deposited, at a temperature lower than the crystallization temperature and the Curie point of said amorphous soft magnetic film, while applying a static magnetic field in a first direction generally perpendicular to a second direction in which a high permeability for high frequency is desired in said amorphous soft magnetic film of said fabricated device relative to the permeability for high frequency in said first direction; performing a final heat treatment, after all of the layers of said amorphous soft magnetic film have been deposited, at a temperature equal to or lower than the temperature for the heat treatment previous to the final heat treatment, while applying a static magnetic field in said second direction, and controlling at least one of the temperature and duration of the final heat treatment so as to control the magnitude of a uniaxial magnetic anisotropy to be imparted to said amorphous soft magnetic film.
Claim 2
Dependent Claim
205 words
In a method of heat treating an amorphous soft magnetic film fabricated by depositing various layers of material on a substrate including at least two layers of amorphous soft magnetic film, the improvement in combination therewith comprising the steps of: performing a heat treatment, after each layer of said amorphous soft magnetic film has been deposited, at a temperature lower than the crystallization temperature and the Curie point of said amorphous soft magnetic film, while applying a static magnetic field in a first direction generally perpendicular to a second direction in which a high permeability for high frequency is desired in said amorphous soft magnetic film of said fabricated device relative to the permeability for high frequency in said first direction; performing a final heat treatment, after all of the layers of said amorphous soft magnetic film have been deposited, at a temperature equal to or lower than the temperature for the heat treatment previous to the final heat treatment, while applying a static magnetic field in said second direction, and controlling at least one of the temperature and duration of the final heat treatment so as to control the magnitude of a uniaxial magnetic anisotropy to be imparted to said amorphous soft magnetic film.
Claim 3
Dependent Claim
43 words
The improvement according to claim 1, wherein the static magnetic field applied during the heat treatments is greater than the diamagnetic field that develops in said amorphous soft magnetic film and has a sufficient strength to fully magnetize said amorphous soft magnetic film.
Claim 4
Dependent Claim
18 words
The improvement according to claim 1, wherein said amorphous soft magnetic film is prepared by a sputtering process.
Claim 5
Dependent Claim
36 words
The improvement according to claim 1, wherein said various layers of material include an oxide film and a conductive film deposited on each said amorphous soft magnetic film and said substrate is formed of an oxide.
Claim 6
Dependent Claim
18 words
The improvement according to claim 1, wherein said high frequency is greater than or equal to 1 MHz.
Claim 7
Dependent Claim
22 words
The improvement according to claim 1, wherein each said head treatment is applied in one of a non-oxidizing atmosphere and a vacuum.
Claim 8
Dependent Claim
25 words
The improvement according to claim 1, wherein the temperature of said final heat treatment is the same as the temperature of said previous heat treatment.
Claim 9
Dependent Claim
22 words
The improvement according to claim 1, wherein prior to said final heat treatment, a step of cooling to room temperature is performed.
Claim 10
Dependent Claim
19 words
The improvement according to claim 1, wherein said final heat treatment is performed immediately following said previous heat treatment.
Claim 11
Dependent Claim
199 words
In a method of heat treating an amorphous soft magnetic film fabricated by depositing various layers of material including at least two layers of an amorphous soft magnetic film on a substrate, the improvement in combination therewith comprising: performing a heat treatment, after each layer of said amorphous soft magnetic film has been deposited, at a temperature lower than the crystallization temperature and the Curie point of said amorphous soft magnetic film, while applying a static magnetic field in a first direction in which a high permeability for high frequency is desired in said soft magnetic film of said fabricated device relative to the permeability for high frequency in said first direction; performing a final heat treatment, after all of the layers of said amorphous soft magnetic film have been deposited, at a temperature equal to or lower than the temperature for the heat treatment previous to the final heat treatment, while applying a static magnetic field in a second direction generally perpendicular to said first direction, the magnitude of the uniaxial magnetic anisotropy to be imparted to said amorphous soft magnetic film being controlled by the temperature utilized in said final heat treatment and by the duration thereof.
Claim 12
Dependent Claim
199 words
In a method of heat treating an amorphous soft magnetic film fabricated by depositing various layers of material including at least two layers of an amorphous soft magnetic film on a substrate, the improvement in combination therewith comprising: performing a heat treatment, after each layer of said amorphous soft magnetic film has been deposited, at a temperature lower than the crystallization temperature and the Curie point of said amorphous soft magnetic film, while applying a static magnetic field in a first direction in which a high permeability for high frequency is desired in said soft magnetic film of said fabricated device relative to the permeability for high frequency in said first direction; performing a final heat treatment, after all of the layers of said amorphous soft magnetic film have been deposited, at a temperature equal to or lower than the temperature for the heat treatment previous to the final heat treatment, while applying a static magnetic field in a second direction generally perpendicular to said first direction, the magnitude of the uniaxial magnetic anisotropy to be imparted to said amorphous soft magnetic film being controlled by the temperature utilized in said final heat treatment and by the duration thereof.
Claim 13
Dependent Claim
43 words
The improvement according to claim 10, wherein said static magnetic field applied during said heat treatments is greater than the diamagnetic field that develops in said amorphous soft magnetic film and has a sufficient strength to fully magnetize said amorphous soft magnetic film.
Claim 14
Dependent Claim
18 words
The improvement according to claim 10, wherein said amorphous soft magnetic film is prepared by a sputtering process.
Claim 15
Dependent Claim
36 words
The improvement according to claim 10, wherein said various layers of material include an oxide film and a conductive film deposited on each said amorphous soft magnetic film and said substrate is formed of an oxide.
Claim 16
Dependent Claim
18 words
The improvement according to claim 10, wherein said high frequency is greater than or equal to 1 MHz.
Claim 17
Dependent Claim
22 words
The improvement according to claim 10, wherein each said heat treatment is applied in one of a non-oxidizing atmosphere and a vacuum.
Claim 18
Dependent Claim
25 words
The improvement according to claim 10, wherein the temperature of said final heat treatment is the same as the temperature of said previous heat treatment.
Claim 19
Dependent Claim
22 words
The improvement according to claim 10, wherein prior to said final heat treatment, a step of cooling to room temperature is performed.
Claim 20
Dependent Claim
19 words
The improvement according to claim 10, wherein said final heat treatment is performed immediately following said previous heat treatment.
References Cited (Backward Citations)
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