Dynamic magnetic information storage or retrieval – Head – Magnetoresistive reproducing head
Reexamination Certificate
1999-11-03
2001-10-09
Ometz, David L. (Department: 2652)
Dynamic magnetic information storage or retrieval
Head
Magnetoresistive reproducing head
C360S319000, C360S125330
Reexamination Certificate
active
06301086
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a structure for supporting a thin-film magnetic head element, a thin-film magnetic head, and a method for manufacturing the supporting structure.
2. Description of Related Art
A magnetoresistive (MR) head comprises a supporting structure with an insulating film such as an alumina film deposited on a ceramic substrate. The ceramic substrate may be made of alumina titanium carbide. In an MR head of this type, a magnetic shield film is deposited on the insulating film. An MR element, a recording head element and so on are formed on the magnetic shield film. The magnetic shield film may be made of a soft magnetic material such as: a permalloy; a Co-based amorphous alloy like a Co—Nb—Zr or Co—Fe—B—Si alloy; and an FeAlSi alloy.
An MR head converts electric variations into magnetic ones, and vice versa, by taking advantage of magnetoresistance unlike an MIG head utilizing electromagnetic induction. Thus, an MR head can reproduce a large voltage without depending on a relative velocity between the head and a recording medium. In recent years, MR heads have been more and more often applied to hard disk drives (HDD) with a large capacity for computers to increase the recording density thereof.
A magnetic shield film for an MR head is required to increase the magnetic permeability thereof at radio frequencies. Specifically, the magnetic shield film needs to exhibit high magnetic permeability at frequencies within a range from about 100 MHz to about 300 MHz. To improve the magnetic permeability of the magnetic shield film, a technique of controlling and uniformizing the in-plane uniaxial magnetic anisotropy thereof over a wide area on a substrate should be developed.
If an FeAlSi alloy film such as a sendust film is used as a magnetic shield film and deposited directly on an insulating film like an alumina film, however, it is possible that the FeAlSi alloy film poorly adheres to the insulating film. In addition, it is difficult to control and uniformize the magnetic anisotropy of the FeAlSi alloy film over a wide area.
SUMMARY OF THE INVENTION
An object of the present invention is providing a thin-film magnetic head supporting structure with an FeAlSi alloy film exhibiting enhanced adhesiveness to a ceramic substrate and well-controlled magnetic anisotropy.
Another object of the present invention is providing a thin-film magnetic head comprising such a supporting structure.
Still another object of the present invention is providing a method for manufacturing the thin-film magnetic head supporting structure.
A thin-film magnetic head supporting structure according to the present invention includes: an FeAlSi alloy film; a ceramic substrate used for structural support of the FeAlSi alloy film; and an intermediate multilayer structure disposed between the FeAlSi alloy film and the ceramic substrate. The intermediate multilayer structure includes a Cr film and an Fe film, which are stacked in this order over the ceramic substrate.
In one embodiment of the present invention, the Fe film is preferably in direct contact with the FeAlSi alloy film and the Cr film, and the thickness of the Fe film is preferably in the range from 20 nm to 500 nm, both inclusive.
In another embodiment, the supporting structure preferably further includes an insulating film between the ceramic substrate and the Cr film.
In still another embodiment, the thickness of the Cr film is preferably in the range from 5 nm to 100 nm, both inclusive.
Another thin-film magnetic head supporting structure according to the present invention includes: an FeAlSi alloy film; a ceramic substrate used for structural support of the FeAlSi alloy film; an insulating film formed on the surface of the ceramic substrate; and an intermediate multilayer structure disposed between the insulating film and the FeAlSi alloy film. The intermediate multilayer structure includes: a metal layer, which is formed in contact with the FeAlSi alloy film for controlling in-plane uniaxial magnetic anisotropy of the FeAlSi alloy film; and an adhesive layer, which is formed between the insulating film and the metal layer and is adhesive to the insulating film more strongly than the metal layer is.
In one embodiment of the present invention, the metal layer is preferably so thick as not to be substantially affected by the adhesive layer on the surface thereof.
A thin-film magnetic head according to the present invention includes: the thin-film magnetic head supporting structure of the present invention; and a magnetoresistive device formed on the supporting structure.
A method according to the present invention is applicable to manufacturing a thin-film magnetic head supporting structure including an FeAlSi alloy film and a ceramic substrate used for structural support of the FeAlSi alloy film. The method includes the steps of: depositing an intermediate multilayer structure on the ceramic substrate; and depositing the FeAlSi alloy film on the intermediate multilayer structure. The step of depositing the intermediate multilayer structure includes: depositing a Cr film on the ceramic substrate; and depositing an Fe film on the Cr film.
In one embodiment of the present invention, the Fe film is preferably deposited to a thickness from 20 nm to 500 nm, both inclusive.
In another embodiment of the present invention, a conductive ceramic substrate with an insulating film formed thereon is preferably used as the ceramic substrate.
In still another embodiment, the Fe film is preferably deposited by sputtering.
REFERENCES:
patent: 4953051 (1990-08-01), Wada et al.
patent: 5673163 (1997-09-01), Cohen
patent: 5756201 (1998-05-01), Kadono et al.
patent: 5795663 (1998-08-01), Koike et al.
patent: 6147843 (2000-11-01), Yamamoto et al.
patent: 4-105309 (1992-04-01), None
Costellia Jeffrey L.
Nixon & Peabody LLP
Ometz David L.
Sumitomo Special Metals Co. Ltd.
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