JP2000269568A - Manufacture of magnetoresistance effect device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for obtaining a magnetoresistance effect device, exhibiting regard characteristics by forming a reguired magnetic layer and a deposited layer, such as nonmagnetic layer or the like using a single vacuum chamber or a plurality of vacuum chambers. SOLUTION: In a method for manufacturing a magnetoresistance effect device, a sputtering device, which is formed by coupling a plurality of vacuum chambers 10 and 12, is used. A substrate is transferred between the vacuum chambers 10 and 12 and reguired deposited layers such as magnetic films, nonmagnetic films are formed in sequence on the substrate in the vacuum chambers for manufacturing a magnetoresistance effect device. In this case, after deposition in one vacuum chamber 10, the substrate is vacuum transferred to the next vacuum chamber 12. For forming a film in the vacuum chamber 12, after back sputtering is applied to the surface deposition film, a deposition is further formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a magnetoresistive element used for a magnetic head or the like of a magnetic disk drive.

[0002]

2. Description of the Related Art A magnetoresistive effect element used for a magnetic head of a magnetic disk drive has a magnetic film on a ceramic substrate.
Film layers such as a non-magnetic film and a conductor film are laminated in a predetermined pattern to form a required magnetoresistance effect. These film formation layers are formed by setting a target for forming each film formation layer in a vacuum chamber and performing sputtering using each target in order.
When a multi-layered film is formed by sputtering, usually, the vacuum chamber is evacuated to vacuum each time each layer is formed, and an inert gas for sputtering such as argon gas is introduced and a required target is used. By repeatedly performing the sputtering operation.

When a large number of targets must be used as in the case of forming a multilayer film, a sputtering apparatus in which a plurality of vacuum chambers are connected is used. In the case of forming a stacked film layer by using, after sputtering in one vacuum chamber, the transfer chamber connecting the vacuum chamber and the other vacuum chamber are evacuated to vacuum, and the substrate is transferred through the transfer chamber. After vacuum transfer, sputtering is performed in another vacuum chamber.

[0004]

By the way, in the magnetoresistive effect element, a product in which a film forming layer is formed in a multilayer structure more than a conventional magnetoresistive effect element such as a GMR element has been used. The characteristics of a magnetoresistive element obtained by forming a film layer by sputtering have become a problem. That is, the magnetoresistive effect element is formed by laminating the required magnetic film, non-magnetic film, and conductor film by the above-mentioned sputtering operation. The method of sputtering a target or the method of sputtering a substrate in a vacuum chamber after vacuum-transferring a substrate between vacuum chambers cannot provide a product having required characteristics.

It is considered that such a problem in the characteristics of the magnetoresistive element is caused by the characteristics of the film formed by sputtering, that is, the method of forming the film. The present invention has been made to solve the problems in a method of manufacturing a magnetoresistive element by forming a magnetoresistive film by such sputtering, and uses a single vacuum chamber or a plurality of vacuum chambers. It is an object of the present invention to provide a method of manufacturing a magnetoresistive element capable of forming a film formation layer such as a required magnetic layer and a non-magnetic layer to obtain a magnetoresistive element having required characteristics.

[0006]

The present invention has the following configuration to achieve the above object. That is, using a sputtering apparatus in which a plurality of targets for forming required film layers such as a magnetic film and a non-magnetic film in a vacuum chamber are used, and forming a film layer such as a magnetic film and a non-magnetic film on a substrate. In a method of manufacturing a magnetoresistive element by sequentially forming and stacking films, when forming a film by switching the target, the film is formed by constantly flowing a sputtering gas in a vacuum chamber including when the target is changed. . This makes it possible to prevent contamination of the surface of the film formation layer and to obtain a magnetoresistive element having good characteristics.

[0007] Further, a substrate is transported between the vacuum chambers by using a sputtering apparatus in which a plurality of vacuum chambers are connected, and required film layers such as a magnetic film and a non-magnetic film are sequentially formed on the substrate in the vacuum chamber. In a method of manufacturing a magnetoresistive element by depositing and laminating, when a film is formed in one vacuum chamber, and when the substrate is vacuum-transferred to the next vacuum chamber to form a film in the vacuum chamber, ,
After reverse sputtering is performed on the surface layer, another layer is formed. After vacuum transport of the substrate on which the film formation layer is formed, when the film formation layer is further laminated, reverse sputtering is performed in advance, so that the surface of the film formation layer can be made a clean surface. By further laminating a film formation layer on a clean surface, a magnetoresistive element having good characteristics can be obtained.

In addition, a substrate is transported between the vacuum chambers by using a sputtering apparatus in which a plurality of vacuum chambers are connected, and required layers such as a magnetic film and a non-magnetic film are sequentially formed on the substrate in the vacuum chamber. In a method of manufacturing a magnetoresistive element by forming a film and stacking, when transferring a substrate between vacuum chambers, it is necessary to transfer the substrate in an inert gas atmosphere and then form a film in the vacuum chamber. Features. When transporting a substrate between vacuum chambers, the surface of the film-forming layer formed on the substrate is not contaminated by transporting the substrate in an inert gas atmosphere, and it is favorable without performing reverse sputtering in advance when forming a film. It is possible to obtain a magnetoresistive effect element having various characteristics. Even in the case of a sputtering apparatus in which a plurality of vacuum chambers are connected, when a plurality of targets for forming a required film formation layer such as a magnetic film and a non-magnetic film are provided in the vacuum chamber, the switching of the targets is performed. It is effective to form a film by constantly flowing a sputtering gas in a vacuum chamber including the above, in order to obtain a magnetoresistive element having good characteristics without contaminating the surface of the film formed layer.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. In the present embodiment, the first vacuum chamber 10 and the second vacuum chamber 12 shown in FIG.
A magnetoresistive element is formed by forming a film on the substrate by using a sputtering apparatus including a transfer chamber 14 connecting the two. The magnetoresistance effect element formed in this embodiment is a so-called GMR element, and the configuration of the magnetoresistance effect film is as follows. Ta / NiFe / CoFeB / Cu / CoFeB / PdPtMn / Ta

The magnetoresistance effect element is formed by sequentially laminating the above magnetoresistance effect films in a predetermined pattern. A method for forming a magnetoresistive element by forming a magnetoresistive effect film in a predetermined pattern is the same as a conventional method,
Hereinafter, a method of forming the magnetoresistive film will be described. Since five kinds of materials are used for the film formation layer, five kinds of targets are prepared in the vacuum chamber. The arrangement of the targets can be appropriately selected. In the present embodiment, one target 16a is installed in the first vacuum chamber 10, and
Four targets 16b in the second vacuum chamber 12,
16c, 16d and 16e were installed. The target installed in the first vacuum chamber 10 was Ta, and the targets installed in the second vacuum chamber 12 were NiFe, CoFeB, C
u, PdPtMn.

FIG. 2 shows a flow chart of a film forming process for forming a magnetoresistive element using the present apparatus. Step 100 is a step of setting a substrate on which a film formation layer is to be formed in the vacuum chamber 10 in a state where required targets are set in the vacuum chamber 10 and the vacuum chamber 12.
After setting the substrate in the vacuum chamber 10, the vacuum chamber 10 is evacuated to a vacuum (step 102). At the same time, the transfer chamber 14 and the second vacuum chamber 12 are evacuated to a vacuum.

Next, an argon gas is introduced into the vacuum chamber 10 as a sputtering gas (step 104). In this state, sputtering is performed using Ta as a target in the first vacuum chamber 10 to form a Ta film on the substrate surface (step 106). After forming a film in the first vacuum chamber 10, the second vacuum chamber 12 is transferred via the transfer chamber 14.
To transfer the substrate. From the first vacuum chamber 10 to the second
The substrate is transferred in a vacuum to the vacuum chamber 12 (step 108).

After transporting the substrate to the second vacuum chamber 12, before sputtering each target to form a film, reverse sputtering is performed on the Ta film layer on the substrate to slightly reduce the surface of the Ta film layer. (Step 11)
0). Reverse sputtering is an operation in which a sputtering gas such as an argon gas is introduced into the second vacuum chamber 12 and the voltage applied to the substrate and the target is reversed from the state of the film formation to slightly etch the surface of the film formation layer. This exposes the clean surface of the film formation surface. This reverse sputtering operation is an essential operation for forming a magnetoresistive film having required characteristics.

After performing reverse sputtering, sputtering is sequentially performed in the second vacuum chamber 12 using each of the above-mentioned targets. Are sequentially formed (step 112). In the present embodiment, in this sputtering step, argon gas is flowed, that is, when a different kind of film formation layer is formed, the gas is not exhausted to a vacuum each time a film is formed, but is held while the gas is held. And When a magnetoresistance effect film is formed by laminating a plurality of film formation layers, it is effective to perform sputtering in such a gas-hold state in order to obtain a required magnetoresistance effect.

After a required film formation layer is formed in the second vacuum chamber 12, the substrate is transported to the first vacuum chamber 10 again to form the uppermost Ta film formation layer. Also in the case of transferring from the second vacuum chamber 12 to the first vacuum chamber 10, the transfer is performed by vacuum transfer as described above. Therefore, the second vacuum chamber 12, the transfer chamber 1
4. The first vacuum chamber 10 is evacuated and the transfer chamber 1 is evacuated.
The substrate is conveyed to the first vacuum chamber 10 via Step 4 (Step 114).

After transporting the substrate to the first vacuum chamber 10, a sputtering gas is again introduced into the first vacuum chamber 10 to perform reverse sputtering (step 116) to reduce the thickness of the film formed on the surface of the substrate. Then, the surface of the film formation layer is cleaned to form a clean surface, and then sputtering is performed using a Ta target to form a Ta film formation layer (step 118).
In this manner, a magnetoresistive effect film including a required film formation layer is formed. The magnetoresistive element is obtained by etching each of the above-mentioned film formation layers into a predetermined pattern and forming necessary electrodes and the like.
After the substrate is taken out of the vacuum chamber 10 (step 120), necessary processing is performed to form a magnetic head used in a magnetic disk drive.

In the above embodiment, the first vacuum chamber 1
Although the transfer of the substrate between the zero vacuum chamber 12 and the second vacuum chamber 12 was performed by vacuum transfer, when transferring the substrate between the vacuum chambers, an inert gas such as an argon gas was allowed to flow, and the transfer was performed in an inert gas atmosphere. It is also effective to transfer the substrate by using. As described above, when the substrate is transferred in an inert gas atmosphere, the substrate is transferred to a vacuum chamber, and a film is formed without performing reverse sputtering in advance to obtain a magnetoresistive element having required characteristics. Is possible.

FIG. 3 shows a flowchart of the film forming process in this case. In the case of a method of forming a film by transporting a substrate in an inert gas atmosphere, after transporting the substrate to the second vacuum chamber 12 after forming the film in the first vacuum chamber 10, a transport that is evacuated in advance is used. An argon gas is introduced into the chamber 14 and the second vacuum chamber 12, and the substrate is transferred from the first vacuum chamber 10 to the second vacuum chamber 12 while the argon gas is flowing.

When the substrate is transported in an inert gas atmosphere as described above, it is possible to prevent foreign matter from adhering to the surface of the film formation layer and contaminate the surface of the film formation layer. The film forming operation in the next step can be performed without performing the above. Of course, the same applies to the case where the substrate is transferred from the second vacuum chamber 12 to the first vacuum chamber 10. It should be noted that there is no problem in performing reverse sputtering in advance even when the wafer is transported with the argon gas flow. When the substrate is transferred, another inert gas can be used instead of the argon gas.

FIGS. 4 and 5 show the results of measuring the magnetic characteristics by forming the magnetoresistive element having the above-mentioned film-forming layer by the method of forming the film-forming layer according to the manufacturing method of the above embodiment. A to D in the figure are measurement samples. Depending on whether or not these samples were held by gas when depositing film formation layers in the vacuum chamber 12 and whether or not reverse sputtering was performed in advance when depositing films after vacuum transfer, Are classified as follows. Note that the gas hold is a method in which, when forming different kinds of film formation layers by sputtering, film formation is performed sequentially while the sputtering gas is flowing without exhausting to a vacuum each time the film is formed. Sample gas hold Reverse spatter A No No B Yes No C No Yes D Yes Yes

FIG. 4 shows, for each of the samples A to D,
It is a result of measuring a change (Δρ) in specific resistance when magnetism is applied to a sample of specific resistance ρ. When the samples A and D are compared, the specific resistance ρ is reduced by about 7 μΩcm, and Δρ is set to about 0.
It has increased by 3 μΩcm. It is preferable in terms of characteristics that the magnetoresistive element has a small specific resistance ρ and a large Δρ. In this regard, it can be seen that Samples C and D exhibit significantly better properties than Samples A and B.

FIG. 5 shows the coercive force (Hce) in the easy axis direction and the anisotropic magnetic field (Hk) in the direction perpendicular to the easy axis for the samples A to D.
h) is the measurement result. It is preferable that the values of Hce and Hkh are smaller values as characteristics of the magnetoresistive element. The measurement results are shown for samples A and B
It can be seen that Sample C is superior to Sample C, and Sample D is further superior to Sample C.

From the above measurement results, it was clearly recognized that the reverse sputtering and the gas hold had an effective function and effect in the method of manufacturing the magnetoresistive film. That is, GM
The method of the present invention in a method of manufacturing a magnetoresistive element such as an R element can be used as a very effective method for manufacturing an element exhibiting a required magnetoresistive effect.

In the above embodiment, the first chamber 1
Although the description has been given of the example of the sputtering apparatus including the zero chamber and the second chamber 12, the operation by the gas hold and the reverse sputtering is similarly effective for the sputtering apparatus having a single vacuum chamber. Further, in the above embodiment, an example in which a film is formed for a GMR element has been described, but the configuration and the number of stacked layers are not limited to those having the film composition of the above embodiment. When a plurality of vacuum chambers are used, the type and number of targets to be installed in each vacuum chamber can be appropriately selected.

[0025]

According to the method of manufacturing a magnetoresistive element according to the present invention, it is possible to obtain a magnetoresistive element having required characteristics as described above. Further, the method of the present invention has an advantage that a film can be formed using a conventional apparatus as it is.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a schematic configuration of a sputtering apparatus used for manufacturing a magnetoresistance effect element according to the present invention.

FIG. 2 is a flowchart showing a film forming process for forming a magnetoresistive element.

FIG. 3 is a flowchart showing another film forming process for forming a magnetoresistive element.

FIG. 4 is a graph showing a result of measuring a characteristic of a specific resistance of the magnetoresistance effect element.

FIG. 5 is a graph showing a result of measuring magnetic characteristics of a magnetoresistive element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 1st vacuum chamber 12 2nd vacuum chamber 14 Transfer chamber 16a, 16b, 16c, 16d, 16e Target 46 Solder plating film 50 Solder ball

Claims (4)

[Claims] 1. A sputtering apparatus in which a plurality of targets for forming required film layers such as a magnetic film and a non-magnetic film are installed in a vacuum chamber, and a magnetic film and a non-magnetic film are formed on a substrate. In a method of manufacturing a magnetoresistive effect element by sequentially forming and stacking film layers, when a film is formed by switching the target, a sputtering gas is always flowed in a vacuum chamber including when the target is switched. A method of manufacturing a magnetoresistive element, comprising forming a film. 2. A sputtering apparatus in which a plurality of vacuum chambers are connected to each other to transfer a substrate between the vacuum chambers and sequentially form required film layers such as a magnetic film and a non-magnetic film on the substrate in the vacuum chamber. In a method of manufacturing a magnetoresistive element by forming a film and stacking, when forming a film in one vacuum chamber, and then carrying a substrate in a vacuum to the next vacuum chamber and forming a film in the vacuum chamber, A method of manufacturing a magnetoresistive element, comprising: performing reverse sputtering on a film formation layer on the surface, and further forming a film. 3. Using a sputtering apparatus in which a plurality of vacuum chambers are connected, a substrate is transported between the vacuum chambers, and necessary film layers such as a magnetic film and a non-magnetic film are sequentially formed on the substrate in the vacuum chamber. In a method of manufacturing a magnetoresistive element by forming a film and stacking, when transferring a substrate between vacuum chambers, it is necessary to transfer the substrate in an inert gas atmosphere and then form a film in the vacuum chamber. A method for manufacturing a magnetoresistive element, which is characterized in that: 4. A plurality of targets for forming required film-forming layers such as a magnetic film and a non-magnetic film are provided in the vacuum chamber, and when the target is switched to form a film, 4. The method for manufacturing a magnetoresistive element according to claim 2, wherein a film is formed by constantly flowing a sputtering gas in a vacuum chamber.