JPH0610852B2 - Method of manufacturing magnetoresistive effect magnetic head - Google Patents

Description

Description: (a) Technical Field of the Invention The present invention relates to a magnetic recording device, and more particularly to a read-only magnetic head in a magnetic tape device or a magnetic disk device.

(B) Background of technology Thin film type magnetic heads are being used along with high-density recording in magnetic recording devices. Among them, magnetic heads utilizing the magnetoresistive effect have a simple structure, and Since a relatively large output signal can be obtained, it is expected to be put to practical use as a read-only head.

(C) Prior Art and Problems In a magnetoresistive effect type magnetic head, the magnetization of a ferromagnetic film formed by aligning the easy axis of magnetization in a certain direction causes an external magnetic field (for example, recorded on a magnetic recording medium) passing near it. This phenomenon utilizes a phenomenon in which the resistance of the ferromagnetic film changes depending on the magnetic signal).

In such a magnetoresistive effect magnetic head, as shown in FIG. 1, two magnetoresistive effect elements 1 made of a ferromagnetic film such as NiFe are provided on a non-magnetic substrate 3 made of glass or SiO2, for example. 2 is provided via an insulating layer 4 made of, for example, SiO2, and each magnetoresistive effect element 1 is provided.
There is a type in which a current in the same direction is made to flow in and 2, and the two magnetic resistance effect elements mutually apply a bias magnetic field by this current.

In FIG. 1, 5 and 6 are lower shield layers and upper seal layers, both of which are made of a ferromagnetic film such as NiFe, and 7 and 8 are shield layers 5 and 6 and the magnetoresistive effect element 2 and 1 is an insulating layer made of, for example, SiO2 that electrically insulates
A recording medium 9 such as a magnetic disk runs in the direction of the arrow.

In the magnetoresistive effect type magnetic head shown in FIG. 1, the directions of the bias magnetic fields applied to each other by the magnetoresistive effect elements 1 and 2 are reversed by 180 degrees as indicated by the broken line arrow in FIG.

By the way, generally, in a magnetoresistive effect element, the highest sensitivity is obtained in the vicinity of an angle of 45 degrees between the direction of magnetization and the direction of current flowing in the magnetoresistive effect element. Therefore, in FIG. 2, the operating point, that is, the angle formed by the magnetization direction with respect to the direction of the current flowing through the magnetoresistive effect element as described above is appropriately selected by appropriately selecting the current i flowing through the magnetoresistive effect elements 1 and 2. The magnetoresistive effect element can be set to around +45 degrees and the other magnetoresistive effect element can be set to around -45 degrees.

In this way, in this type of magnetoresistive head, a bias magnetic field from the outside is unnecessary. Further, as shown in FIG. 3 (A), the output signal R1 of the first magnetoresistive effect element 2 and the output signal R2 of the second magnetoresistive effect element 1 with respect to the external magnetic signal S have opposite polarities, If a difference is taken by a differential amplifier, as shown in FIG. 3 (B), an output signal R larger than that when there is one magnetoresistive effect element is provided.
Is obtained.

Note that, in FIG. 3 (A), the relationship between the resistivity (ρ) of the curve C magnetoresistive effect element and the angle (θ) formed by the direction of the magnetization with respect to the direction of the current is shown, and Δρm is the change in resistivity. It is the maximum value.

In the case of manufacturing the magnetoresistive effect type magnetic head as described above, conventionally, a ferromagnetic material for forming the shield layer 5, the insulating layer 7, and the first magnetoresistive effect element 2 on the substrate is used. After sequentially forming a film and the film, the ferromagnetic film is etched by photoetching to form a first magnetoresistive element 2 having a pattern as shown in FIG. After that, the insulating layer 4 and a ferromagnetic film for forming the second magnetoresistive effect element 1 are formed thereon, and a second film having the same shape as the magnetoresistive effect element 2 is formed by photoetching.
The magnetoresistive effect element 1 is formed.

In this type of magnetoresistive effect magnetic head, it is desirable that the thickness of the insulating layer 4 is as small as possible in terms of frequency characteristics and sensitivity.

However, according to the above-described conventional manufacturing process, dust is not mixed in or adhered between the etching process for forming the first magnetoresistive effect element 2 and the subsequent film forming process of the insulating layer 4. Therefore, as the thickness of the insulating layer 4 becomes smaller, defects such as dielectric breakdown are more likely to occur, and film formation of the magnetoresistive effect element 2 is caused by residues of the photoresist used in the photoetching process. At this time, unevenness is generated on the base and the edge profile of the molded magnetoresistive effect element 2 becomes non-uniform, so that the erasing of the demagnetizing field becomes insufficient and the deterioration of the magnetic characteristics is apt to occur. Further, since the magnetoresistive effect elements 2 and 1 are individually molded, there is a drawback that a pattern shift occurs between the two and the magnetic properties are likely to deteriorate similarly to the above. Ri, these also, had also become a disadvantage to raise the lowered production cost and the yield of the product.

(D) Object of the Invention It is an object of the present invention to eliminate the drawbacks of the conventional manufacturing method and to provide a method of manufacturing a magnetoresistive head having excellent frequency characteristics, sensitivity and economy.

(E) Configuration of the Invention According to the present invention, the above-mentioned object is to successively form a first insulating layer, a first magnetoresistive effect element layer, a second insulating layer, and a second magnetoresistive effect element layer on a substrate. And a step of etching a portion of the second magnetoresistive effect element layer corresponding to a terminal lead-out window position to the first magnetoresistive effect element layer, the first magnetoresistive effect element layer, the second insulating layer and the second magnetic layer. A step of etching the resistance effect element layer into a final magnetic head shape;
A magnetic layer including a step of depositing an insulating layer and etching the insulating layer and the second insulating layer to form a through hole as a terminal lead-out window in the first and second magnetoresistive effect element films. This is achieved by a method of manufacturing a resistance effect type magnetic head.

(F) Embodiments of the Invention Embodiments of the present invention will be described below with reference to the drawings.

FIG. 5 and subsequent drawings are views for explaining a preferred embodiment of the present invention, in which (A) is a plan view and (B) is a cross-sectional view of a portion indicated by a chain line in (A). In these figures, the same parts as those shown above are designated by the same reference numerals.

In FIG. 5, as an adhesion layer (a layer for increasing the adhesion strength between the lower shield layer 5 and the substrate 3 which is subsequently formed) on the substrate 3, an Al / Cu alloy layer having a thickness of 500Å and 1000
After forming a Å-thick Ti layer (all not shown),
The lower shield layer 5 made of Fe has a thickness of 2 μm and the first insulating layer 7 made of SiO 2 has a thickness of 0.3 μm.
Of the first ferromagnetic film 100, which will be the magnetoresistive element of
00Å, the second insulating layer 4 made of SiO2 has a thickness of 0.3 μm, NiFe
And the second ferromagnetic film 200 which is to be the second magnetoresistive effect element and has a thickness of 500Å.

In the steps up to this point, the insulating layers 4 and 7 made of SiO2 are generally formed by sputtering, and the other adhesion layers, the lower shield layer 5, and the ferromagnetic films 100 and 200 are formed by sputtering or vapor deposition. It is also possible to form a film without taking it out.

In FIG. 5, the ferromagnetic film 200 is shown by photoetching into the shape shown by hatching in FIG. 5A. This is the terminal of the magnetoresistive effect element 1 described later. Ferromagnetic film in advance so as to avoid the exit window
This is because 200 is removed, and a high degree of pattern accuracy is not required.

Next, the ferromagnetic films 100 and 200 and the insulating layer 4 are formed by ion milling (a dry etching method of accelerating Ar ions or the like to irradiate an object and perform processing such as cutting) 300 as shown in FIG.
Molded in the shape shown in.

Through the steps up to this point, the ferromagnetic films 100 and 200 are formed into almost final shapes as the magnetoresistive effect elements 1 and 2, respectively.

Continuing from the above, excess portions of the lower shield layer 5 and the insulating layer 7 are removed by ion milling as shown in FIG. As shown in FIG. 8, a third insulating layer 8 made of SiO 2 is formed on the entire surface to a thickness of 0.3 μm, and a part of the surface is covered with an upper shield layer 6 made of NiFe.
Is formed into a strip shape with a thickness of 2 μm.

Further, as shown in FIG. 9, a protective layer 10 made of SiO2
After forming a film over the entire surface to a thickness of μm, the terminal extraction window 11
The insulating layers of the portions 12 and 12 are removed by photoetching to expose the terminal portions of the magnetoresistive effect elements 1 and 2.

The terminal layers 13, 14 and 15 made of Al or the like are provided so as to be electrically connected to the terminal portions of the magnetoresistive effect elements 1 and 2 through the terminal lead-out windows 11 and 12 provided as described above.
Provide as shown. The terminal layer 15 is a common terminal commonly connected to one terminal portion of each of the magnetoresistive effect elements 1 and 2.

Finally, the magnetoresistive effect element 1 is cut by cutting along the line XX in FIG. 10 and polishing the cut surface.
And 2 are molded into the final shape shown in FIG. 4, and the magnetoresistive effect magnetic head is completed.

Needless to say, if a magnetic substrate such as ferrite is used instead of the non-magnetic substrate 3 in the above, the formation of the lower shield layer 5 can be omitted and the process can be simplified.

(G) Effect of the Invention According to the present invention, the thickness of the insulating layer between the two magnetoresistive effect elements can be made smaller than the thickness in the case of the conventional manufacturing method, which is about 0.5 μm. Further, it is possible to make the edge profile of these magnetoresistive elements uniform and to eliminate the misalignment between these elements, which makes it possible to provide a magnetoresistive magnetic head having a large reproduction output and excellent frequency characteristics. effective.

In addition, the yield of products can be improved and the number of steps can be reduced as compared with the conventional method, which has the effect of providing a low-cost magnetic head.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing the basic structure of a magnetoresistive effect magnetic head provided with two magnetoresistive effect elements, and FIGS. 2 and 3 are operations of the magnetoresistive effect magnetic head having the structure shown in FIG. 4 is a schematic diagram showing an example of the shape of a magnetoresistive effect element in the magnetoresistive effect type magnetic head shown in FIG. 1, and FIGS. 5 to 10 relate to the present invention. FIG. 7 is a schematic diagram for explaining a manufacturing process of a magnetoresistive effect magnetic head. In the figure, 1 and 2 are magnetoresistive elements, 3 is a substrate, 4, 7 and 8 are insulating layers, 5 is a lower shield layer, and 6
Is an upper shield layer, 9 is a recording medium, 10 is a protective insulating layer, 11
And 12 are terminal exit windows, 13, 14 and 15 are terminal layers, 100
Reference numerals 200 and 200 are ferromagnetic films, and 300 is a shape of the magnetoresistive effect element molded together.

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Fumio Kume 1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Fujitsu Limited (56) References JP-A-52-58515 (JP, A) JP-A-57-86124 (JP, A)

Claims (1)

[Claims] 1. A step of sequentially forming a first insulating layer, a first magnetoresistive effect element layer, a second insulating layer, and a second magnetoresistive effect element layer on a substrate, and a second magnetoresistive effect. In the element layer, a step of etching a portion corresponding to the terminal lead-out window position to the first magnetoresistive effect element layer, the first magnetoresistive effect element layer, the second insulating layer, and the second magnetoresistive effect element layer as final magnetic The step of etching into a head shape, the third insulating layer is deposited, and the insulating layer and the second insulating layer are etched to form the first insulating layer.
And a step of forming a through hole as a terminal lead-out window in the second magnetoresistive effect element film.