JPH02130880A - Magnetoresistance element and manufacture thereof - Google Patents

Abstract

PURPOSE:To scarcely generate hysteresis in a magnet-resistance element by providing stripe pattern of INC phase, Z phase and ABS phase in a thin ferromagnetic film having magnetoresistance effect, forming the directions of induction magnetic anisotropy of the INC phase, Z phase and ABS phase in parallel with the direction of the pattern. CONSTITUTION:Permanent magnets 1, 2 are disposed at both positions of a substrate on which a ferromagnetic material (e.g., Permalloy 83Ni-17Fe) having magnetoresistance effect is deposited in a thin film state, and a magnetic field is operated in a direction parallel to INC phase and Z phase for forming a stripe pattern later. A part corresponding to the ABS phase for forming a stripe pattern later is masked with a mask 3. Ferromagnetic material is deposited in a thin film state on the substrate, and induction magnetic anisotropy is provided in a direction operated by the magnet at the thin film 4. The parts corresponding to the deposited INC phase and Z phase are similarly masked, the ferromagnetic material is deposited on the part corresponding to the ABS phase to form a thin film 5. Pattern of the INC phase 6, Z phase 7 and ABS phase 8 are formed at predetermined positions of the films 4, 5.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a magnetoresistive element used in a magnetic encoder or the like to detect a magnetic signal using a ferromagnetic magnetoresistive effect, and a method for manufacturing the same.

"Prior Art" Conventionally, when manufacturing a magnetoresistive element, a ferromagnetic material having a magnetoresistive effect is deposited in the form of a thin film, and stripes of INC phase, Z phase, and ABS phase are formed on the thin film as shown in FIG. forming a pattern. Furthermore, when depositing a ferromagnetic material, permanent magnets are placed on both sides of the substrate, so that the entire thin film has induced magnetic anisotropy in the direction of the magnetic field. Therefore, in the conventional magnetoresistive element, the direction of induced magnetic anisotropy is the same in each of the INC phase, Z phase, and ABS phase.

``Problem to be solved by the invention'' If a magnetic field is applied to the entire ferromagnetic thin film in the same direction as the stripe pattern of the INC phase and the Z phase, as in the past,
The BS phase is subjected to induced magnetic anisotropy in a direction perpendicular to the stripe pattern. Therefore, in the ABS phase, the magnetic domain structure becomes triaxial and hysteresis is likely to occur.
There was a problem in that an error occurred in the detected value of the magnetoresistive element.

Therefore, in the present invention, similar to the INC phase, induced magnetic anisotropy is applied to the ABS phase in parallel to the stripe pattern, thereby preventing hysteresis from occurring in the magnetoresistive element and preventing deterioration due to external stress. The purpose is to

"Means for Solving the Problems" The method for manufacturing a magnetoresistive element of the present invention includes, when depositing a ferromagnetic material in the form of a thin film, depositing it on the INC phase and Z phase portions;
vapor deposition on parts of the ABS phase separately, and
When depositing on the NC phase and Z phase parts, the ABS phase is masked and a magnetic field is applied in the same direction as the stripe pattern of the INC phase and Z phase. When depositing on the ABS phase part, the INC phase and the two A magnetic field is applied in the same direction as the stripe pattern of the ABS phase by masking the part with the phase.

After the above vapor deposition is completed, a magnetoresistive element is obtained by providing a stripe pattern of INC phase, Z phase, and ABS phase at predetermined positions in the thin film.

In the magnetoresistive element of the present invention, a stripe pattern of INC phase, Z phase, and ABS phase is provided on a thin film of a ferromagnetic material having a magnetoresistive effect, and induced magnetic differences in each part of INC phase, Z phase, and ABS phase are provided. A magnetoresistive element characterized in that the direction of orientation is parallel to the direction of each stripe pattern.

"Operation" In the magnetoresistive element manufactured by the above method, the INC phase and the Z
Induced magnetic anisotropy is applied not only to the phase but also to the ABS phase in the same direction as the strub pattern direction. Therefore, hysteresis is less likely to occur in the magnetoresistive element. In addition, due to its induced magnetic anisotropy, the magnetoresistive element has no parts that are vulnerable to external stress, and deterioration of characteristics can be prevented.

Although the vapor deposition is performed in two parts, the thin film deposited first is masked during the subsequent vapor deposition, and the substrate temperature during vapor deposition is low, so there is no possibility that the characteristics of the first thin film will change. do not have.

"Example" Embodiments of the present invention will be described with reference to FIGS. 1 to 3.

First, permanent magnets 1 and 2 are placed on both sides of the substrate on which a thin film of ferromagnetic material (e.g. permalloy 83Ni-17Fe) having a magnetoresistive effect is deposited (Fig. 1), and later a stripe pattern is created using INC. A magnetic field is applied in a direction parallel to the phase and the Z phase. Further, a mask 3 is used to mask a portion corresponding to the ABS phase in which a stripe pattern will be created later. Mo is suitable as a mask material because it has a small coefficient of thermal expansion. In this state, a ferromagnetic material is deposited in a thin film on the substrate other than the masked part, and the thin film 4
has induced magnetic anisotropy in the direction acted on by the permanent magnet.

Next, the mask 3 is removed and the permanent magnet l is removed.

2, leave it as it is or change only the spacing, turn the substrate with the above vapor deposition 90 degrees and place it between the permanent magnets 1.2 (Figure 2). In this state, it is parallel to the stripe pattern of the ABS phase. The above-mentioned evaporation film is subjected to a magnetic field.
Masking the parts corresponding to the C phase and Z phase in the same manner as above,
A thin film 5 was created by depositing a ferromagnetic material on a portion corresponding to the ABS phase.

After the two vapor depositions are completed, patterns of an INC phase 6, a Z phase 7, and an ABS phase 8 are created at predetermined positions on the thin film 4.5 (FIG. 3).

In the above embodiments, the portion corresponding to the ABS phase was deposited later, but it may be deposited first. Further, the method of applying a magnetic field is not limited to the use of permanent magnets, and a method using a coil may also be used.

"Effects of the Invention" In the magnetoresistive element of the present invention or the magnetoresistive element produced by the manufacturing method of the present invention, the induced magnetic anisotropy acts in parallel not only on the INC phase and the Z phase but also on the ABS phase. It is resistant to external stress because hysteresis is less likely to occur, and there is no part where induced magnetic anisotropy acts in the vertical direction.
Therefore, deterioration of characteristics can be prevented.

[Brief explanation of the drawing]

1 and 2 are explanatory diagrams showing the manufacturing process of the magnetoresistive element of the present invention, FIG. 3 is a plan view of a thin film obtained by vapor deposition with a stripe pattern such as an INC phase, and FIG.
The figure is an explanatory diagram showing a conventional method for manufacturing a magnetoresistive element. 3: Mask 4: Thin film 6: INC phase 7: Z phase 8: ABS phase Applicant: Hitachi Metals, Ltd.

Claims (2)

[Claims] (1) INC
In addition, when vapor deposition is carried out on the INC phase and Z phase parts, the ABS phase is masked and the INC phase and Z phase are vapor deposited separately.
Apply a magnetic field in the same direction as the stripe pattern with the phase,
A method for manufacturing a magnetoresistive element, characterized in that when depositing on the ABS phase part, the INC phase and Z phase parts are masked and a magnetic field is applied in the same direction as the stripe pattern of the ABS phase. (2) In a magnetoresistive element in which a stripe pattern of an INC phase, a Z phase, and an ABS phase is provided on a thin film obtained by vapor-depositing a ferromagnetic material having a magnetoresistive effect, the INC phase, Z phase,
A magnetoresistive element characterized in that the magnetic field direction of each part of the ABS phase is parallel to the direction of each stripe pattern.