JPH08129721A - NiO antiferromagnetic film manufacturing method, magnetoresistive effect element manufacturing method and element thereof - Google Patents

Abstract

PURPOSE: To obtain a method to directly produce NiO from a Ni-based alloy target having a magnetoresistance effect by forming a two-layer thin film of NiFe/NiO having an exchange interaction from one target by RF sputtering. CONSTITUTION: A NiO antiferromagnetic film can be easily formed by RF sputtering of a Ni-based alloy target having >75at% Ni content and having a magnetoresistance effect in Ar plasma containing oxygen. First, a magnetoresistance effect film is formed by RF sputtering in Ar plasma and then the same target is successively used for RF sputtering in Ar plasma containing oxygen to form an antiferromagnetic NiO film. By this method, stable magnetic exchange interaction is obtd. for 200Å to 500Å film thickness of the NiO film so that the element can be significantly made thin compared to a conventional one. Thus, a magnetoresistance effect element having a NiFe/ NiO two-layer structure or NiFe/Cu/NiFe/NiO four-layer structure without Barkhausen noise can be obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an element for manufacturing a magnetoresistive effect element used in a magnetic disk device or a magnetic encoder device, and directly to a magnetic field from a Ni-based alloy target having a composition having a magnetoresistive effect. By obtaining the antiferromagnetic alloy NiO film which is the magnetic domain control film of the resistance effect element, the manufacturing process is simplified and A
By controlling the atmosphere of RF sputtering in r plasma, for example, a NiFe / NiO two-layer film can be produced that is much thinner than the conventional one and a sufficiently stable exchange coupling magnetic field can be produced. In order to reduce Barkhausen noise, the exchange coupling magnetic field can be reduced. The present invention relates to a method of manufacturing a NiO antiferromagnetic film, a method of manufacturing a magnetoresistive effect element, and the element, which can provide a magnetoresistive effect element or the like that effectively acts.

[0002]

2. Description of the Related Art The magnetoresistive effect is the so-called permalloy (Ni
It utilizes the fact that the resistance value changes depending on the angle formed by the magnetization direction and the direction of the sense current in a thin film such as Fe). Since it senses the magnetic flux itself, it is expected to replace the conventional inductive head. There is. However, there has been a problem that so-called Barkhausen noise, which is attributed to irregular domain wall movement, occurs.

Therefore, in the conventional magnetoresistive effect element, for example, C.I. “IEEE Transaction on Magn” such as Tsang
etics, vol. 25 No. 5, 1989,
p. 3692-3694 ", an antiferromagnetic substance of FeMn is formed on a magnetoresistive effect film, and the magnetoresistive effect film is brought into a single magnetic domain state by utilizing an exchange coupling magnetic field generated at the interface thereof to cause Barkhausen noise. A method for reducing the amount has been proposed.

Further, since the magnetoresistive effect decreases as the magnetoresistive effect film becomes thinner, see, for example, “J.
Appl. Phys. , Vol. 69 no.
8, p 4774-4779 (1991) ”, Fe
Mn is used as the magnetization fixed film of the NiFe film, and non-magnetic C
There is an attempt to obtain a large magnetoresistive effect by utilizing the fact that the magnetoresistive effect changes depending on the direction of magnetization with the other free NiFe film sandwiching u.

However, the above FeMn has weak corrosion resistance, and has problems such as melting during the process and deterioration after processing. Therefore, oxides have been studied as antiferromagnetic materials having excellent corrosion resistance that generate an exchange coupling magnetic field, and NiO or the like having a relatively high Neel temperature has begun to be used.

To form an antiferromagnetic alloy NiO by RF sputtering, a NiO alloy target has low thermal conductivity and is easily cracked, and RF sputtering is difficult. Therefore, a pure Ni target is usually RF sputtered in oxygen-containing plasma. NiO is obtained by forming a film. For example, in order to form a magnetoresistive film and a magnetic domain control film, that is, to obtain a NiFe / NiO two-layer film, conventionally, ion beam sputtering is used, and a Ni-based alloy target having a magnetoresistive effect and antiferromagnetic material are used. It was necessary to prepare with two targets of an alloy NiO target, or to RF sputter a Ni-based alloy target having a magnetoresistive effect and a pure Ni target in an oxygen-containing plasma.

[0007]

There is a problem that a great number of steps are required for forming the magnetoresistive effect film and the magnetic domain control film described above, and simplification of the steps is strongly demanded, but the magnetoresistive effect is obtained. Since the Ni-based alloy target contains elements such as Fe and Co that are more easily oxidized than Ni under normal conditions, there has been no movement to directly manufacture NiO from such an alloy target.

Further, in forming the magnetoresistive film and the magnetic domain control film, two targets of NiFe and NiO are sputtered to form a NiFe / NiO two-layer film to realize magnetic exchange coupling. In order to stably develop the magnetic exchange coupling, for example, as shown in an embodiment of a magnetoresistive head for a magnetic disk proposed in Japanese Patent Laid-Open No. 5-303724, a NiO film of a magnetoresistive effect element is shown. There is a problem that the element thickness becomes thicker, for example, the thickness is 1000Å, the NiFe film thickness is 400Å, and the NiO film thickness needs to be 500Å or more.

Also, in the magnetoresistive effect element having a laminated structure having a four-layered film of magnetoresistive effect film / Cu / magnetoresistive effect film / magnetization fixed film as a basic structure, NiO is similarly used as the magnetization fixed film. If the above spin valve can be easily manufactured by RF sputtering, there is a great merit in simplifying the manufacturing process.

In view of the simplification of the above conventional film forming process, the present invention produces a thin NiFe / NiO two-layer film having exchange interaction from a single target by film formation by RF sputtering. Aiming to provide a method for directly producing NiO from a Ni-based alloy target having a resistance effect, further, a magnetoresistive effect film / a two-layer film of an antiferromagnetic material or a magnetoresistive effect film / Cu / magnetoresistive effect film / magnetization It is an object of the present invention to provide a laminated magnetoresistive effect element having a four-layer film of a fixed film as a basic structure and a manufacturing method capable of easily manufacturing the element.

[0011]

In order to solve the above problems, the inventor has conducted various studies on the composition and sputtering conditions of a Ni-based alloy target capable of RF sputtering, and as a result, has found that the Ni-based alloy having a composition having a magnetoresistive effect is used. In the alloy target, when the Ni content is 75 at% or more and the input power is 1 kW, the oxygen content is 30 vol% or more.
It was found that a NiO antiferromagnetic film can be easily formed by RF sputtering in r plasma.
As a result of examining the conditions for forming a two-layered film of Ni / NiO, the above Ni-based alloy target is RF sputtered in Ar plasma to form a magnetoresistive film, and then the same target is continuously containing oxygen. When RF sputtering is performed in Ar plasma and an antiferromagnetic NiO film is formed to form a two-layer film having exchange interaction from one target, magnetic exchange interaction is stable at NiO film thickness of 200Å to 500Å The present invention has been completed by discovering that it acts on.

The inventor has also found that N having a magnetoresistive effect.
When an i-based alloy target is RF-sputtered in Ar plasma to form a magnetoresistive film, a Cu film is formed thereafter, and a Ni-based alloy target having a magnetoresistive effect is RF-sputtered in Ar plasma, anti-strength It was found that a film containing magnetic NiO as a main component was obtained, and the magnetoresistive film in contact with the film was magnetized and a spin valve could be formed. We have found that it is possible to ensure the interaction with the magnetoresistive film in contact with the magnetization fixed film by annealing in a magnetic field at a temperature above the point, and completed the present invention.

That is, according to the present invention, the Ni content is 7
A method for manufacturing a NiO antiferromagnetic film, which comprises depositing a Ni-based alloy target having a magnetoresistive effect of 5 at% or more by RF sputtering in Ar plasma containing oxygen.

Further, according to the present invention, in a method of manufacturing a laminated magnetoresistive effect element having a basic structure of a two-layered film of magnetoresistive effect film / antiferromagnetic material, the magnetoresistive effect having a Ni content of 75 at% or more. After sputtering a Ni-based alloy target having Ar to form a magnetoresistive effect film,
A method for manufacturing a magnetoresistive effect element in which a NiO antiferromagnetic film is formed by sputtering a target of the Ni-based alloy in Ar plasma containing oxygen to form a two-layer film, and the Ni content is 7
A magnetoresistive effect film formed by sputtering a Ni-based alloy target having a magnetoresistive effect of 5 at% or more in Ar plasma, and a film formed by further sputtering the Ni-based alloy target in Ar plasma containing oxygen. The present invention also proposes a magnetoresistive effect element having a two-layer film composed of the above NiO antiferromagnetic film, and the NiO antiferromagnetic film having a thickness of 200Å to 500Å.

The present invention also relates to a magnetoresistive film / Cu.
In the method of manufacturing a laminated magnetoresistive effect element having a four-layered film of / magnetoresistance effect film / magnetization fixed film as a basic structure, after the magnetoresistive effect film and the Cu film are formed, the Ni content is 75 at
% Of a Ni-based alloy target having a magnetoresistive effect is sputtered in Ar plasma to form a magnetoresistive film, and then the Ni-based alloy target is sputtered in Ar plasma containing oxygen as a magnetization fixed film. A method of manufacturing a magnetoresistive effect element in which a NiO antiferromagnetic film is formed, and a laminated magnetoresistive effect element having a four-layered film of magnetoresistive effect film / Cu / magnetoresistive effect film / magnetization fixed film as a basic structure. In the manufacturing method, the content of Ni is 75 at% as the magnetization fixed film.
The Ni-based alloy target having the above magnetoresistive effect is sputtered in Ar plasma containing oxygen to form a NiO antiferromagnetic film, and then the Ni-based alloy target is sputtered in Ar plasma to produce the magnetoresistive effect. A method of manufacturing a magnetoresistive effect element is also proposed, in which a film is formed, a Cu film and a magnetoresistive effect film are then formed, and then heat treatment is performed in a magnetic field at a temperature equal to or higher than the NeO Neel point.

Further, the present invention comprises a magnetoresistive film,
A Cu film, a magnetoresistive film formed by sputtering a Ni-based alloy target having a magnetoresistive effect with a Ni content of 75 at% or more in Ar plasma, and the Ni film.
The NiO antiferromagnetic film has a thickness of 200 and a four-layer film including a magnetization fixed film made of a NiO antiferromagnetic film formed by sputtering a base alloy target in Ar plasma containing oxygen.
We also propose a magnetoresistive effect element characterized by being Å to 500Å.

[0017]

In the present invention, Ni having a magnetoresistive effect is used.
The base alloy target is a NiFe or NiFeCo alloy target. When the Ni base alloy target is RF sputtered in Ar plasma containing oxygen, as shown in FIG. 1, when the oxygen amount exceeds 30 vol%, the magnetization almost disappears. Since antiferromagnetic NiO is generated, it is possible to directly form NiO from a Ni-based alloy target having a magnetoresistive effect. Regarding the Ni content,
If the content of i is less than 75 at%, the Neel point, which is the magnetic transformation point of the antiferromagnetic alloy, is lowered, which is not practical, and if it exceeds 85 at%, the anisotropic magnetoresistive effect is Ni.
The higher the content of Ni, the higher the magnetic properties of the spin valve element, the higher the coercive force, the lower the sensitivity, and the lower the magnetic properties of NiFe. , 85 at% or less is preferable. More preferably, it is 79 at% to 81 at%.

The amount of oxygen during sputtering is 1
To produce a NiO antiferromagnetic film for an input power of kW, 30 vol% oxygen is required, but 40 vol%
If it exceeds, the oxide film formation rate will decrease, so 30 vol
% To 40 vol% is desirable.

In the present invention, the reason for limiting the sputtering method to RF sputtering is that RF sputtering is effective in industrial production, and in the case of IBS, the NiO composition may shift and is not stable.

In the method for producing a NiFe / NiO bilayer film according to the present invention, a Ni-based alloy target having a magnetoresistive effect with a Ni content of 75 at% or more is used.
A magnetoresistive film is formed by RF sputtering in Ar plasma, and then a NiO antiferromagnetic film is formed by RF sputtering the target of the Ni-based alloy in Ar plasma containing oxygen. However, it is possible to continuously form a two-layer film by changing the atmosphere in the same chamber from a predetermined reduced pressure Ar atmosphere to an Ar atmosphere in which a predetermined amount of oxygen is introduced by using a known RF sputtering apparatus. .

For example, RF sputtering is first performed in Ar plasma using a NiFe target, and N is formed at a thickness of 300 Å.
After forming the iFe film, NiO film was continuously formed in Ar plasma having an oxygen content of 30 vol%, and the exchange coupling magnetic field (He) of the NiFe / NiO bilayer film was obtained as a function of the NiO film thickness. As shown in the graph of the relationship between the NiO antiferromagnetic film thickness and the exchange coupling magnetic field, the NiO film thickness is from 200 Å to 50
A sufficiently stable exchange coupling magnetic field occurs up to 0Å, and conversely 500
It has been found that the exchange coupling magnetic field tends to be smaller when Å is exceeded.

That is, the NiO antiferromagnetic film formed by directly depositing NiO from the Ni-based alloy target having the magnetoresistive effect according to the present invention is a NiFe / NiO two-layer film made of two conventional targets. The exchange coupling magnetic field is Ni
This indicates that the film is not stable unless the O film thickness is 500 Å or more, different from the conventional NiO target sputtered NiO film, or the interface state is different. In any case, when a magnetoresistive effect element having exchange interaction is prepared from a single target having a magnetoresistive effect, the film thickness of NiO, which is a magnetic domain control film, can be made thinner than before.

Further, in the case of manufacturing a laminated magnetoresistive effect element having a four-layer film of magnetoresistive effect film / Cu / magnetoresistive effect film / magnetization fixed film as a basic structure, a film is formed from the magnetization fixed film on a substrate. In order to ensure interaction with the magnetoresistive film in contact with the magnetization fixed film, it is necessary to anneal in a magnetic field at a temperature equal to or higher than the NiO Neel point, but the heat treatment condition is to prevent oxidation of the film surface. In vacuum (<1 x
It is preferably performed at 10 ⁻³ Torr).

[0024]

【Example】

Example 1 Using a Ni80-Fe20 (at%) target having a magnetoresistive effect, oxygen was set to 0, 5, 1 by an RF sputtering apparatus.
0,15,20,25,27,30,40,45,5
Ar in various Ar atmospheres containing 0,75,80 vol%
Sputtering was performed at a gas pressure of 1 mTorr and a power of 1 kW, magnetic properties and X-ray diffraction were performed, and the product was confirmed. FIG. 2 shows the relationship between the oxygen amount and the magnetization during NiFe sputtering. It was found that the magnetization was almost 0 when the oxygen amount was 30 vol% or more, and an oxide was formed.

FIG. 3 shows the relationship between the amount of oxygen during NiFe sputtering and the film formation rate.
When the content exceeds vol%, the amount of oxygen at the time of sputtering is preferably 30 to 40 vol% because it sharply decreases. Further, when the oxide was identified by X-ray diffraction, peaks indicating Fe oxide and Co oxide were not observed, and only the peak of NiO, which is an oxide of Ni, was detected. It was possible to directly form the Ni-based alloy target having an effect by RF sputtering.

Example 2 Ni80-Fe5-Co15 (a) having a magnetoresistive effect
t%) target and oxygen of 0,10,15,20,30,40,50,75 vol with RF sputtering equipment
%, Various Ar atmospheres were used, Ar sputtering was performed at a gas pressure of 1 mTorr and a power of 1 KW, magnetic properties and X-ray diffraction were performed, and the products were confirmed. FIG. 4 shows the relationship between the oxygen amount and the magnetization during NiFe sputtering.
At 0 vol% or more, the magnetization was almost 0, and it was found that an oxide was formed. Further, when the oxide was identified by X-ray diffraction, FeO, CoO, etc. were not observed, and it was found that the produced oxide was antiferromagnetic NiO.

Example 3 NiFe was formed to a thickness of 2 μm on an AlTiC substrate to form a lower shield. 0.12μ of Al ₂ O ₃ on this
m was formed into a lower gap. Then the track width is 6
After forming the electrode so as to have a thickness of 100 μm and using photoresist to form a device having a width of 2 μm and a length of 100 μm, CoZrMo as a soft bias film with a thickness of 200 Å and Ti as a magnetic separation film with a thickness of 100 Å , Using a Ni81Fe19at% target as a magnetoresistive film, Ar sputtering was performed in a unidirectional magnetic field with an RF sputtering apparatus to form NiFe to a thickness of 200Å, and Ar sputtering was performed with the same apparatus in an Ar atmosphere containing 30 vol% oxygen. And NiO 50, 150, 200, 2 respectively
Films of 50, 400, 500, 600, 1000Å thickness are continuously formed, and CoZrMo / Ti / NiFe / NiO 4
A layer film was created. Al ₂ O ₃ 0.15 as the upper gap
A film having a thickness of μm was formed, and NiFe was formed to a thickness of 2 μm by plating to form an upper shield. After that, a terminal portion was formed, a protective layer of Al ₂ O ₃ was formed to a thickness of 30 μm, and the wafer process was completed.

After forming the terminals, a gold pad was formed, cut, polished, and assembled to prepare a magnetic head. A read / write characteristic was evaluated using an MR read / write tester by applying a sense current of 8 mA to this magnetic head. The results are shown in Table 1. The NiO film thickness is 50, 150, 60.
Barkhausen noise is observed at 0,1000Å,
It was confirmed that the exchange coupling magnetic field of NiO does not work effectively as the magnetic domain control film, but it works effectively at 200 Å or more and 500 Å or less.

[0029]

[Table 1]

Example 4 As shown in FIG. 5, NiFe was formed to a thickness of 2 μm on an AlTiC substrate 1 to form a lower shield 2. An Al ₂ O ₃ film having a thickness of 0.2 μm was formed thereon to form a lower gap 3.
Further, as the soft bias film 4, 200 CoZrMo is used.
With a thickness of Å, Ti is formed as a magnetic separation film 5 with a thickness of 100 Å, and then as a magnetoresistive film 6, Ni80Fe20at%
A in a one-way magnetic field with an RF sputtering device using a target
r-sputtering is performed to form a NiFe film having a thickness of 250 Å, and the same apparatus is used for Ar in an Ar atmosphere containing 30 vol% oxygen
Sputtering was performed to continuously form a NiO film 7 having a thickness of 250 Å. The 4-layer film was processed into a device shape having a width of 2 μm and a length of 100 μm by photolithography and ion milling. Further, a 250 Å NiO film was removed from the device by photolithography and ion milling by the amount corresponding to the electrode and the track width. A Cu electrode 8 was formed on the portion where the NiO film was removed. In this state, as shown in FIG. 4, there are magnetic domain control films, that is, NiO films 7 on both ends of the device.

Further, as an upper gap, Al ₂ O ₃ is 0.2
A film of 5 μm was formed, and NiFe was formed to a thickness of 2 μm by plating to form an upper shield. After that, a terminal portion is formed and Al ₂ O ₃ is formed.
A protective layer of 30 μm was deposited to complete the wafer process. After processing the terminals, form a gold pad, cut, polish,
After the assembly, a magnetic head was manufactured. A read / write characteristic was evaluated using an MR read / write tester by applying a sense current of 10 mA to this magnetic head. As a result, Barkhausen noise is not recognized in the obtained signal, and N
It was confirmed that the exchange coupling magnetic field effectively acts as a magnetic domain control film even when the iO film has the above-mentioned shape.

Example 5 A Cu electrode was formed on a glass substrate, and a four-layer spin valve element having a width of 3 μm and a length of 50 μm was formed by a lift-off process. That is, the element is first formed by Ni80Fe2.
RF sputtering was performed in a unidirectional magnetic field in Ar gas using a 0 at% target to form a NiFe film with a thickness of 60 Å and a Cu target with a purity of 99.9% with a thickness of 40 Å. After rotating the magnetic field direction by 90 degrees, a NiFe film was again formed to a thickness of 40 Å using a NiFe target, and then RF sputtering was performed in Ar containing 35 vol% oxygen to form NiO to a thickness of 250 Å. A sense current of 7 mA was applied to the laminated magnetoresistive element having a basic structure of the obtained four-layer film of NiFe / Cu / NiFe / NiO, and the MR coefficient was measured in a static magnetic field of ± 200 Oe. The results are shown in FIG. 6. An MR ratio of 6% was observed in the vicinity of the zero magnetic field, and it became clear that the NiO film exerted a sufficient exchange coupling magnetic field on the NiFe film to effectively function as a spin valve.

Example 6 As shown in FIG. 7, NiFe was formed to a thickness of 2 μm on an AlTiC substrate 10 to form a lower shield 11. Lower gap 1 with Al ₂ O ₃ 0.2 μm thick formed on this
And 2. Ni80Fe20at having magnetoresistive effect
After processing the element as a magnetoresistive effect film 13 by an RF sputtering apparatus using a% target, NiFe was deposited to a thickness of 60 Å in a magnetic field oriented in the longitudinal direction. Next, the purity is 99.9.
% Cu target to form a Cu film 14 with a thickness of 30Å, the magnetic field direction is rotated 90 degrees, and a Ni80Fe20at% target having a magnetoresistive effect is used.
As No. 5, NiFe was deposited to a thickness of 60 Å, and then Ar sputtering containing 30 vol% of oxygen was further performed in the same apparatus to continuously deposit NiO as a magnetization fixed film 16 to a thickness of 250 Å. The four-layer film was processed into a device shape having a width of 2 μm and a length of 50 μm by photolithography and ion milling. Further, in order to form an electrode, the NiO film of 250 Å thickness was removed from the required position of the element by photolithography and ion milling. The Cu electrode 17 is formed on the portion where the NiO film is removed.
Was formed.

Further, although not shown, the upper gap is A
1 ₂ O ₃ was formed into a film with a thickness of 0.25 μm, and Ni was formed by plating.
Fe was formed to a thickness of 2 μm to form an upper shield. After that, a terminal portion was formed, a protective layer of Al ₂ O ₃ was formed to a thickness of 30 μm, and the wafer process was completed. After the terminal processing, a gold pad was formed, cut, polished, and assembled to prepare a magnetic head. A sense current of 8 mA is passed through this magnetic head, and M
The read / write characteristics were evaluated using an R read / write tester. As a result, the obtained signal intensity was about twice as high as the signal intensity of the conventional NiFe film, and it was confirmed that NiO acted as the magnetization fixed film and effectively acted as the spin valve.

Example 7 A 4-layer film having a width of 2 μm and a length of 50 μm was formed on a glass substrate by a lift-off process. That is, for the formation of the element, first, a Ni80Fe20at% target is used, RF sputtering is performed in Ar containing 35 vol% of oxygen, NiO is formed as a magnetization fixed film to a thickness of 250 Å, and then oxygen is contained in the same apparatus. RF sputtering was performed in Ar without Ar to form a NiFe film as a magnetoresistive film with a thickness of 70Å. Then, using a 99.9% pure Cu target, C
The u film is formed in 30Å, and the NiFe film is used as the magnetoresistive film again in 40Å using the Ni80Fe20at% target.
A film was formed to a thickness and a Cu electrode was formed in a required pattern. Further, the obtained device was heat-treated at a temperature of 220 ° C. in a unidirectional magnetic field in the device width direction to form a spin valve. A sense current of 10 mA is applied to the device according to the present invention, and 60 H
A magnetic field of ± 50 Oe was applied at z and the MR curve was measured.
The result is shown in FIG. 8. An MR ratio of 5% was observed, and N
The iO film exerts a sufficient exchange coupling magnetic field on the NiFe film,
It became clear that it works effectively as a spin valve.

[0036]

According to the present invention, the Ni content is 75 at%.
The Ni-based alloy target having the above-described composition having the magnetoresistive effect was used to supply oxygen at 30 vo at an input power of 1 kW.
It has been found that a NiO antiferromagnetic film can be easily formed by RF sputtering in Ar plasma containing 1% or more. First, the Ni-based alloy target is RF-sputtered in Ar plasma to produce a magnetoresistive effect. A film is formed, and then the same target is continuously RF sputtered in Ar plasma containing oxygen to form an antiferromagnetic NiO film to form a two-layer film having exchange interaction from one target. By doing so, the two-layer film can be formed in an extremely simplified process.

The magnetic exchange interaction in the NiFe / NiO two-layer film according to the present invention has a NiO film thickness of 20.
Since it operates stably from 0Å to 500Å, it can be made much thinner than before and has a Barkhausen noise free magnetoresistive film / antiferromagnetic two-layer film as a basic structure. An effective element can be provided. Furthermore, a spin valve element using NiO as a magnetization fixed film and exhibiting a high magnetoresistive effect, that is, a magnetoresistive effect film /
It is possible to easily provide a laminated magnetoresistive effect element having a four-layer film of Cu / magnetoresistance effect film / magnetization fixed film as a basic structure.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between the NiO antiferromagnetic film thickness and the exchange coupling magnetic field.

FIG. 2 is a graph showing the relationship between the amount of oxygen and the magnetization during NiFe sputtering.

FIG. 3 is a graph showing the relationship between the amount of oxygen and the film formation rate during NiFe sputtering.

FIG. 4 is a graph showing the relationship between the amount of oxygen and magnetization during NiFe sputtering.

FIG. 5 is a vertical cross-sectional explanatory view of an example of a magnetoresistive effect element according to the present invention.

FIG. 6 is a graph showing an MR curve in a static magnetic field of ± 200 Oe in the example of the present invention.

FIG. 7 is a vertical cross-sectional explanatory view of another embodiment of the magnetoresistive effect element according to the present invention.

FIG. 8: 60 Hz, ± 50 O in the embodiment of the present invention
It is a graph which shows the MR curve in the magnetic field of e.

[Explanation of symbols]

 1,10 AlTiC substrate 2,11 Lower shield 3,12 Lower gap 4 Soft bias film 5 Magnetic separation film 6,13,15 Magnetoresistive film 7 NiO film 8,17 Cu electrode 14 Cu film 16 Magnetization fixed film

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location H01F 41/18 H01L 43/08 Z 43/12

Claims (6)

[Claims] 1. A Ni-based alloy target having a magnetoresistive effect having a Ni content of 75 at% or more is converted into an oxygen-containing A target.
A method for producing a NiO antiferromagnetic film, characterized by forming the film by RF sputtering in r plasma. 2. A method for manufacturing a laminated magnetoresistive element having a basic structure of a magnetoresistive film / antiferromagnetic two-layer film, wherein a Ni content having a magnetoresistive effect of 75 at% or more is present. After the alloy target is sputtered in Ar plasma to form a magnetoresistive film, the Ni-based alloy target is sputtered in Ar plasma containing oxygen to form a NiO antiferromagnetic film to form a two-layer film. A method of manufacturing a magnetoresistive effect element, comprising: 3. A method for manufacturing a laminated magnetoresistive element having a four-layered structure of magnetoresistive film / Cu / magnetoresistive film / magnetization fixed film as a basic structure, wherein the magnetoresistive film and Cu are used.
After the film is formed, a Ni-based alloy target having a magnetoresistive effect with a Ni content of 75 at% or more is sputtered in Ar plasma to form a magnetoresistive effect film. Ar alloy target containing oxygen
A method of manufacturing a magnetoresistive effect element, characterized by forming a NiO antiferromagnetic film by sputtering in plasma. 4. In a method of manufacturing a laminated magnetoresistive element having a four-layered film of magnetoresistive film / Cu / magnetoresistive film / magnetization pinned film as a basic structure, the magnetization pinned film is Ni.
With a magnetic content of 75 at% or more and having a magnetoresistive effect
The base alloy target is sputtered in Ar plasma containing oxygen to form a NiO antiferromagnetic film, and then the Ni base alloy target is sputtered in Ar plasma to form a magnetoresistive film, and then Cu A method of manufacturing a magnetoresistive effect element, comprising forming a film and a magnetoresistive effect film, and further performing heat treatment in a magnetic field at a temperature equal to or higher than a NeO Neel point. 5. A magnetoresistive effect film formed by sputtering a Ni-based alloy target having a magnetoresistive effect with a Ni content of 75 at% or more in Ar plasma, and further, using a target of the Ni-based alloy with oxygen. The NiO antiferromagnetic film has a two-layer film consisting of a NiO antiferromagnetic film formed by sputtering in an Ar plasma containing ArN and has a thickness of 200Å to 500
Magnetoresistive element characterized by being Å. 6. A magnetoresistive effect film, a Cu film, and a magnetoresistive effect film formed by sputtering a Ni-based alloy target having a magnetoresistive effect with a Ni content of 75 at% or more in Ar plasma. Further, the N-based alloy target was sputtered in Ar plasma containing oxygen to form an N film.
A magnetoresistive effect element having a four-layer film including a magnetization fixed film made of an iO antiferromagnetic film, wherein the NiO antiferromagnetic film has a thickness of 200Å to 500Å.