JPH06251978A - Soft magnetic thin film and manufacture thereof - Google Patents

Abstract

PURPOSE:To stably provide a soft magnetic thin film which is low in coercive force, high in saturation magnetic flux density, excellent in resistance to corrosion, and low in characteristics dispersion. CONSTITUTION:A soft magnetic thin film whose main components are Co, Fe, and Cu is formed through a wet plating method, wherein organic acid ion- containing plating bath and/or CE ion-substantially free plating bath is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a soft magnetic thin film using a wet plating method and a soft magnetic thin film.

[0002]

2. Description of the Related Art Magnetic thin films for thin film magnetic heads and thin film transformers are required to have excellent soft magnetic characteristics such as low coercive force and high saturation magnetic flux density, and at the same time, high corrosion resistance for improving reliability. To be done. Such a magnetic thin film is generally formed by a vapor phase film forming method such as a sputtering method or a liquid phase film forming method such as a plating method, but the plating method can easily form a large area film. Moreover, there is an advantage that a highly uniform film can be obtained, and the number of steps is small and the equipment is inexpensive.

The increase in the recording density in recent years is largely due to the increase in the coercive force of the recording medium. In order to sufficiently write on a recording medium having a large coercive force, it is necessary to generate a stronger magnetic field from the recording head. Further, for the magnetic material of the shield layer of the MR inductive composite head, a high saturation magnetic flux density material which can be expected to have a desired shield effect with a thinner film is required for high density recording. For this reason,
There is a demand for a high saturation magnetic flux density material that is more than the Ni-Fe alloy (permalloy) that has been widely used in the past.

As one of the soft magnetic plating films satisfying such requirements for magnetic characteristics, a Co--Fe based alloy can be mentioned. For example, Japanese Patent Application No. 3-122515 discloses a CoFe soft magnetic film obtained by co-depositing S using naphthalenetrisulfonic acid and propynol. This CoFe
In soft magnetic films, grain refinement has been realized, and coercive force values of 1 Oe or less have been reported.

The International Electrochemical Society (ISE) PROC
EEDINGS OF THE SYMPOSIUM ON MAGNETIC MATERIALS, PRO
Fe is 10 in CESSES AND DEVICES, 90-8,361 (1990)
It has been reported that the crystal structure, magnetic properties, and deterioration of magnetic properties due to heat treatment of a CoFe alloy of up to 14% by weight. In this report, the minimum coercive force (about 3 Oe) is obtained in the vicinity of 11.5 wt% Fe.

However, the CoFe alloy is a Ni-F which is a relatively low saturation magnetic flux density material which has been widely used in the past.
The corrosion resistance was inferior to that of the e alloy. Further, since the composition system has a large crystal magnetic anisotropy, it is difficult to make the particles fine for imparting the desired uniaxial magnetic anisotropy.

The addition of the third element is effective for improving the corrosion resistance. For example, when Rh is added, the corrosion resistance can be improved while maintaining high characteristics (Japanese Patent Application No. 4-41).
92), but Rh is extremely expensive.

By the way, Cu on the CoFe alloy plating film
It is effective to reduce coercive force by the addition of PROCEEDINGS OF THE SYMPOSIUM ON MAGN of the International Electrochemical Society (ISE).
Reported in ETIC MATERIALS, PROCESSES AND DEVICES, 91-2, p579. In this report, a coercive force of 0.6 Oe and a saturation magnetic flux density twice as high as that of permalloy are obtained when the Fe content is 10.5% by weight. CoFe in this report
The Cu alloy plated film has a structure in which the fcc phase and the bcc phase are mixed. The composition range of low coercive force is mainly F
The content of Fe is controlled by the content of e, and the content of Fe is 10 to 1
The coercive force is less than 1 Oe only in a narrow range of 2% by weight. On the other hand, regarding Cu, the coercive force becomes low if it is contained in an amount of 2% by weight or more, and it is disclosed that the addition amount is determined for controlling Hk.

However, since the deposition potentials of Co, Fe, and Cu are greatly different from each other, stable film formation is difficult. Particularly, the composition greatly changes depending on the pH of the plating bath. Change is a problem.
Further, in the above report, high characteristics were obtained in the mixed phase of bcc and fcc, but it is considered that the characteristics are likely to change when the abundance ratio of these phases changes.

[0010]

The present invention has been made under such circumstances, and provides a soft magnetic thin film having a low coercive force, a high saturation magnetic flux density and a high corrosion resistance, stably suppressing variations in characteristics. The purpose is to do.

[0011]

The above objects are achieved by the present invention described in (1) to (10) below. (1) A method for producing a soft magnetic thin film containing Co, Fe and Cu as main components by a wet plating method, which uses a plating bath containing an organic acid ion in addition to Co ion, Fe ion and Cu ion. A method for manufacturing a soft magnetic thin film, comprising: (2) The organic acid ion is at least 1 selected from succinate ion, citrate ion, malonate ion, maleate ion, gluconate ion and tartrate ion.
The method for producing a soft magnetic thin film according to (1) above, which is a seed. (3) The method for producing a soft magnetic thin film according to (2) above, wherein tartrate ions are used as the organic acid ions. (4) The concentration of the organic acid ion in the plating bath is 0.01
~ 1.0 mol / liter above (1) to (3)
1. A method for manufacturing a soft magnetic thin film according to any one of 1. (5) A method for producing a soft magnetic thin film containing Co, Fe and Cu as main components by a wet plating method, characterized in that a plating bath containing substantially no Cl ions is used. Manufacturing method. (6) Co ions, Fe ions and Cu in the plating bath
The method for producing a soft magnetic thin film according to (5) above, wherein sulfate is used as a source of ions. (7) The method for producing a soft magnetic thin film according to (5) or (6), wherein the plating bath according to any one of (1) to (4) is used as the plating bath. (8) The method for producing a soft magnetic thin film according to any one of (1) to (7) above, which comprises performing annealing in a magnetic field after forming the soft magnetic thin film. (9) Cu content of 4 to 30 wt% and Fe content of 2
13% by weight, the balance being substantially Co, the above (1)
A soft magnetic thin film formed by the method according to any one of (1) to (8). (10) A soft magnetic thin film containing Co, Fe and Cu as main components, which is composed of an fcc phase and has a coercive force of 1 Oe or less.

[0012]

In the present invention, since the plating bath containing organic acid ions such as tartrate ion is used, the stability of the plating bath, particularly the pH stability is good, and the soft magnetic thin film having high characteristics can be stably produced. can do.

Further, when continuous film formation is performed, the pH of the plating bath is
Tends to be high, and at this time the coercive force of the formed film is high. However, in the present invention, by using a plating bath that does not substantially contain Cl ions, even when the pH of the plating bath becomes high. A soft magnetic thin film having a low coercive force can be formed. Further, in this case, since a soft magnetic thin film with a small internal stress can be formed, a low coercive force can be obtained even when the thickness is 4 μm or more, and a soft magnetic thin film extremely suitable for the core of a thin film magnetic head or a thin film transformer can be obtained. To be

Since the soft magnetic thin film of the present invention contains Cu, it has good corrosion resistance, has little change in magnetic characteristics over time, and has high reliability. Specifically, when a silver / silver chloride electrode is used as a reference electrode in a 0.1N-HCl solution, a value of -100 mV or more is obtained as a spontaneous potential. It has corrosion resistance equal to or higher than that of permalloy. Further, a low coercive force of 2 Oe or less, and further 1 Oe or less can be easily obtained. In the mixed phase of the fcc phase and the bcc phase, the ratio of each phase fluctuates due to a subtle difference in the manufacturing conditions, and the magnetic characteristics also fluctuate with it, but in the present invention, the fcc single phase structure is 1 Oe. Since the following low coercive force can be obtained, the low coercive force soft magnetic thin film can be stably manufactured.

[0015]

Specific Structure The specific structure of the present invention will be described in detail below.

In the present invention, the soft magnetic thin film is formed by using the wet plating method. The soft magnetic thin film produced by the present invention contains Co, Fe and Cu as main components.

The content of Cu is preferably 4 to 30% by weight, more preferably 5 to 25% by weight. When the Cu content is less than the above range, sufficient magnetic properties and corrosion resistance cannot be obtained, and when it exceeds the above range, the saturation magnetic flux density is reduced.

The content of Fe is preferably 2 to 13% by weight, more preferably 8 to 12% by weight. When the Fe content is less than the above range, the saturation magnetic flux density is low, and when the Fe content exceeds the above range, the bcc phase appears, the magnetostriction increases to the positive side, and at the same time, the magnetic characteristics also deteriorate.

In the present invention, Co ions are used as the plating bath,
A plating bath containing Fe ions and Cu ions is used.
In the present invention, since it is preferable to use a plating bath that does not substantially contain Cl ions, the sources of Co, Fe, and Cu ions include chlorides such as sulfate, sulfamate, acetate, and nitrate. It is preferable to select a water-insoluble salt, and it is particularly preferable to use a sulfate because it is inexpensive. In addition, Co ions and Fe ions are
The metal can be supplied by immersing it in a plating bath to spontaneously dissolve it or by dissolving the anode by electrolysis.

It is most preferable that the plating bath contains no Cl ion at all, but if it does not substantially contain Cl ion, for example, the Cl ion concentration is preferably 0.01 mol / liter or less. The effect is obtained.

The concentration of Co ions in the plating bath is
It is preferably 0.05 to 5 mol / liter, more preferably 0.1 to 1 mol / liter. When the Co ion concentration is less than the above range, the deposition rate is remarkably reduced, and when it exceeds the above range, the viscosity of the plating bath is increased and the workability is deteriorated, and it is difficult to form a film in a fine resist pattern. Becomes

The Fe ion concentration in the plating bath is C
Since the ratio of the o ion concentration and the Fe ion concentration is a major factor in determining the film composition, it may be appropriately determined so as to obtain a desired film composition, but preferably 0.001 to 5 mol /
It is 1 liter, more preferably 0.01 to 1 mol / liter.

The concentration of Cu ions in the plating bath may be appropriately determined according to the intended composition, but is preferably 0.005 to 50 g / liter, more preferably 0.01 to 25 g / liter. .

In the plating bath, in addition to these ions,
An organic acid ion is contained as a stabilizer. The organic acid ion is preferably at least one selected from succinate ion, citrate ion, malonate ion, maleate ion, gluconate ion and tartrate ion,
Tartrate ion is particularly effective. The source of the tartrate ion may be appropriately selected and used from tartaric acid, sodium potassium tartrate (Rochelle salt), sodium tartrate and the like. The concentration of organic acid ions in the plating bath is
It is preferably 0.01 to 1.0 mol / liter. If the concentration of the organic acid ion is less than the above range, the effect of addition is insufficient, and if it exceeds the above range, the viscosity of the plating bath increases and the deposition rate decreases, and the cost of preparing the plating bath is high. turn into. The molar concentration of organic acid ions is preferably 0.1 to 2 times the molar concentration of metal ions in the plating bath.

The pH of the plating bath is preferably 2.0 to
It is 5.0, and more preferably 2.5 to 4.0. If the pH is less than the above range, hydrogen generation becomes dominant and the film forming rate becomes slow, and if it exceeds the above range, precipitation of trivalent iron is particularly likely to occur.

Although various additives which are usually used may be added to the plating bath, it is preferable that Cl ions are not contained in the present invention as described above. Therefore, it is generally used as a conductivity improver. It is preferable not to use chlorides such as sodium chloride.

In the wet plating method using the above-mentioned plating bath, the film composition changes depending on the current density. That is, when the current density is low and less than the precipitation potential of Co and Fe, a pure Cu film is formed, and when the current density is high and the precipitation potential of Co and Fe is higher than the precipitation potential, a Co-Fe-Cu alloy is precipitated. And
As the current density increases, the deposition rate of Co and Fe increases, and the Cu content in the film decreases relatively. In order to keep the relative deposition ratio of Cu constant, the ions in the bath that decrease as the film formation proceeds are replenished. If the ion consumption is stable, replenishment becomes easy. In addition, by controlling the current density during film formation, that is, the potential, the Cu
The relative precipitation ratio of can be kept constant. In this case, the film formation rate changes, but the labor of bath management can be saved.

The Fe ions in the plating bath are preferably divalent ions, but the divalent ions are easily oxidized to trivalent ions and precipitate. As a method of reducing trivalent Fe ions, addition of a reducing agent such as ascorbic acid, hypophosphorous acid or a salt thereof, or a side reaction when the metals Co and Fe are immersed in a plating bath and naturally dissolved The method of use is generally known. However, if the amount of trivalent Fe ions is small, there is no problem and the leveling property may be effective. It is also preferable to add a chelating agent such as EDTA or gluconic acid to prevent precipitation. The above-mentioned organic acid ion also has such a precipitation preventing effect.

An organic brightener may be contained in the plating bath. Saccharin is preferred as the organic brightener. Although it is sufficient to add 0.5 g / liter or more, it is preferably 1 to 6 g / liter in consideration of consumption during use.

In addition to these, it is preferable that the plating bath appropriately contains a component such as a surfactant such as sodium lauryl sulfate added to a usual electroplating bath.

In order to obtain a soft magnetic thin film having excellent magnetic properties, it is preferable to remove fine particles and hydroxide in the plating bath by continuous filtering. In this case, when the capacity of the plating bath is V, the filtration flow rate is preferably V × 0.11 / minute or more. The filter mesh may be appropriately selected according to the application, but when forming a film in a fine resist pattern, it is preferably 0.2 μm or less.

From the viewpoint of removing fine particles, the anode is preferably insoluble TiPt or a ferrite electrode. However, since an oxidation reaction occurs at the anode, it is desirable to separate it from the cathode part by, for example, an ion exchange membrane.

The current density during film formation is, for example, 0.01 to 5
You can select it according to the purpose within the range of A / dm ² . In addition to direct current, it is also possible to use an alternating current combined type that performs pulse electrolysis and cathode dissolution. In particular, by applying a plurality of three or more voltages including zero voltage in pulse electrolysis, it is possible to produce a large difference in the co-deposition amount of Cu and form a multilayer film structure. In this case, a substitution reaction of Cu occurs at zero current and a non-magnetic Cu film is formed, so that a thin film having excellent high frequency characteristics can be obtained.

Further, by changing the current density continuously, it is possible to easily form a graded structure in which the Cu content changes in the film thickness direction. The saturation magnetic flux density of the film changes depending on the Cu content. When applied to a thin film magnetic head, it is also possible to arrange an isolated waveform at the time of reproduction by setting a high saturation magnetic flux density on the gap side and a low saturation magnetic flux density on the opposite side.

Further, instead of changing the voltage applied from the outside, a shield plate having a slit or a hole is placed near the cathode and the shield plate is moved to achieve the multi-layering. In this case, the region where the current density is locally concentrated due to the slit or the like and the other low current density regions have different compositions, and a multilayer film is obtained.

The film having a multi-layer structure is used as it is for the purpose of improving high frequency characteristics, but it can also be used as a film having a uniform composition by utilizing the diffusion effect by heat treatment or the like.

As a solvent for the plating bath, in addition to ordinary water, a non-aqueous solvent such as methyl alcohol, dimethylformamide, ethyl alcohol, propylene carbide,
Molten salt and the like can also be used.

The soft magnetic thin film of the present invention is made of Cr, S
n, Ru, Au, Pd, Ag, Mn, P, B, In, M
By containing 3% by weight or less of one or more kinds of elements selected from O, Pb, Re, W, Zn, Rh, Zr, Pt, etc., improvement of high frequency characteristics is expected. Further, even if a small amount of these elements is contained as an impurity, no particular problem is observed, so that the cost can be reduced by using an inexpensive reagent. However, if the content exceeds 3% by weight, care should be taken as it often adversely affects the magnetic properties or causes a decrease in the saturation magnetic flux density.

Care must be taken because C and S contained in a small amount in the film have a great influence on the magnetic characteristics. Specifically, it is desirable that both are 500 ppm or less.

The soft magnetic thin film of the present invention is preferably provided with uniaxial anisotropy in a desired direction. As a method for imparting uniaxial anisotropy, film formation in a magnetic field or magnetic field annealing after film formation can be used. As the film formation in a magnetic field, a method of forming a film in a constant DC magnetic field is generally used. However, in the soft magnetic thin film of the present invention, the anisotropic magnetic field Hk is often too large, and it is often necessary to optimize Hk in order to obtain high magnetic permeability. As a method of optimizing Hk, it is effective to perform film formation in a perpendicular magnetic field, annealing in a rotating magnetic field, or to make the magnetic field directions at the time of film formation in a DC magnetic field and the annealing in a DC magnetic field in-plane orthogonal. Film formation in an orthogonal magnetic field can be performed by generating a magnetic field with a coil and alternately applying a current. When a permanent magnet is used, it is possible to rotate the cathode by 90 °. Since the saturation magnetostriction value often increases in the positive direction during annealing, it is preferable to form the film so that the saturation magnetostriction value after annealing becomes a desired value. In order to reduce the Barkhausen noise of the thin film magnetic head, it is said that it is necessary to keep the saturation magnetostriction value of the soft magnetic thin film at a small negative value. For this purpose,
The film is designed to have a slightly large negative magnetostriction during film formation and a small negative value after annealing.

The thickness of the soft magnetic thin film of the present invention may be appropriately determined according to the purpose and is not particularly limited, but it is usually about 0.5 to 10 μm in order to obtain a low coercive force. Preferably, the thickness is about 0.5 to 4.5 μm when applied to a thin film magnetic head, and about 3 to 7 μm when applied to a thin film transformer.

[0042]

EXAMPLES The present invention will be described in more detail below by showing specific examples of the present invention.

Example 1 A substrate having a thickness of 10 mm × 10 mm × 0.7 mm, Corning 7059 glass, titanium of 50 A and permalloy of 500 A formed by sputtering was used. 1N-hydrochloric acid (normal temperature) as a pretreatment for plating
After immersing in, for 30 seconds and washing with water, a soft magnetic thin film sample was formed under the following plating conditions. As a sample for measuring the saturation magnetostriction value, a glass plate having a thickness of 0.1 mm was subjected to the same treatment as the above-mentioned substrate.

An auxiliary cathode was provided by a copper plate around the substrate in the plating bath. The whole cathode had a disk shape of 3 inches, and a TiPt plate having a diameter of 4 inches was used for the anode. A paddle having a triangular cross section was used for stirring, and paddle stirring was performed at a position 2 mm from the cathode at a cycle of 60 times / minute. The plating solution had the following composition, and the total amount was about 7 liters.

Plating bath composition (in 1 liter) Cobalt sulfate 0.2 mol Iron (II) sulfate 0 to 0.02 mol Copper sulfate 0 to 3 g Ammonium sulfate 15 g Boric acid 25 g Saccharin sodium 1 g Sodium potassium tartrate 0.1 mol

The plating bath temperature was 40 ° C., the pH of the plating bath was 3.7, the current density was 1.5 A / dm ² , the plating time was 5 minutes, and electroplating was performed while applying a DC magnetic field of 600 Oe. A soft magnetic thin film sample having a thickness of 1.2 μm was obtained.

After the film formation, for the purpose of controlling the induced magnetic anisotropy, vacuum annealing was performed at 300 ° C. for 1 hour while applying a DC magnetic field of 2 kOe in the direction of the hard axis during film formation.

The following measurements were performed on each of the obtained samples.

(Composition) The composition was measured using a fluorescent X-ray analyzer and ICP.

(Coercive force Hc) Measured at 60 Hz with an AC BH tracer.

(Saturation magnetic flux density Bs) Measured by VSM.

(Natural Electrode Potential) Using a silver / silver chloride electrode as a reference electrode, measurement was carried out in a 0.1N HCl solution at room temperature.

(Saturation magnetostriction value) 3 Hz, 10 by optical lever method
It was measured in a magnetic field of 0 Oe.

(Permeability) 5 MHz by the figure-eight coil method,
It was measured at 3 mOe.

(X-ray diffraction) Cu-kα ray (30 kV, 40
It was evaluated by (mA). Regarding the crystal lattice, a lattice spacing of 2.05A was identified as an fcc (111) plane and 1.98A was identified as a bcc (110) plane.

(C, S analysis) Quantitative analysis was carried out using a CS meter.

The relationship between the Cu content and the coercive force is shown in FIG.
2 shows the relationship between the e content and the coercive force, FIG. 3 shows the relationship between the Fe content and the saturation magnetostriction value, and FIG. 4 shows the relationship between the Cu content and the spontaneous potential.

As shown in FIG. 1, a particularly low coercive force is obtained in the Cu content range of 5 to 25% by weight. Although there are samples with high coercive force even when the Cu content is in the range of 5 to 25% by weight, these are samples with a large saturation magnetostriction value because the Fe content is too large.

Further, as shown in FIGS. 2 and 3,
Particularly low coercive force is obtained in the range of Fe content of 2 to 13% by weight, and the saturation magnetostriction value is zero or less in this range. Although there are samples with high coercive force even when the Fe content is in the range of 2 to 13% by weight in FIG. 2, these are samples in which the Cu content is out of the preferred range.

Further, as shown in FIG. 4, it can be seen that the inclusion of Cu brings the spontaneous potential close to zero and significantly improves the corrosion resistance.

Co-10% by weight Fe-10% by weight
Cu film has C content of 410ppm, S content of 330ppm
The other samples also showed almost the same value.

The results of the X-ray diffraction were roughly classified into two according to the positive / negative of the saturation magnetostriction value. That is, in the sample having a saturation magnetostriction value of zero or less, as shown in the upper part of FIG.
10) Almost no peaks on the surface are detected, whereas
In the sample having a positive saturation magnetostriction value, the bcc (110) plane was clearly observed as shown in the lower part of FIG. That is, a film having a negative saturation magnetostriction value preferable as a thin film magnetic head is
It was found to be substantially a single phase of fcc (111).

Further, Co-10% by weight Fe-10% by weight
The Cu sample was annealed in a magnetic field at 300 ° C. for 1 hour in vacuum to control the induced magnetic anisotropy, and Hk = 8 Oe
In the sample, the magnetic permeability of 2000 (5 MHz) was obtained. Note that this sample is f before and after annealing.
It was a single phase of cc (111). Further, the saturation magnetostriction value was −3.2 × 10 ⁻⁶ before annealing, but −− after annealing.
It was 0.9 × 10 ⁻⁶ , which was a preferable range.

Example 2 A soft magnetic thin film sample was prepared using the following plating bath.

Plating bath composition (in 1 liter) Cobalt sulfamate 0.1 mol Iron sulfamate 0.008 mol Copper sulfamate 2 g Ammonium sulfamate 15 g Boric acid 30 g Saccharin sodium 1 g Potassium tartrate 0.2 mol

The pH of the plating bath was initially set to 3.0,
After that, film formation was continuously performed on the substrate.

Plating bath temperature is 45 ° C., current density is 1 A / dm
^{2. The} plating time was 10 minutes, and a DC magnetic field of 200 Oe was applied to form a soft magnetic thin film sample having a thickness of 1.6 μm. The plating bath during film formation was transparent.

<Comparative Example 1> A sample was prepared under the same conditions as in Example 2 except that potassium tartrate was not added to the plating bath. The plating bath became cloudy during film formation, and when the plating solution was discharged from the plating bath after the film formation was completed, a colloidal substance adhered to the wall and bottom of the bath.

The coercive force of each sample of Example 2 and Comparative Example 1 was measured. Results are shown in FIG. As shown in FIG. 6, when a plating bath containing tartrate ions is used, the magnetic properties of the soft magnetic thin film do not change even when a large number of films are continuously formed for a long time, whereas plating containing no tartrate ions is used. It was found that in the bath, the magnetic properties of the soft magnetic thin film deteriorate rapidly as the number of films formed increases.

Example 3 In the plating bath of Example 1, iron sulfate was fixed at 0.02 mol and copper sulfide was fixed at 2.5 g, while the pH of the plating bath was varied within the range of 2 to 4.6.
Film formation was performed once each time.

The plating bath temperature is 45 ° C. and the current density is 1.5.
A / dm ² , plating time was 20 minutes, and a DC magnetic field of 600 Oe was applied. It was found that the film thickness of the obtained sample became thinner as the pH was lower, and the deposition efficiency was lowered. At a pH of 3.5 or higher, an almost constant thickness (about 5 μm) was obtained.

Comparative Example 2 A plating bath was prepared in the same manner as in Example 3 except that the same amount of ammonium chloride was used instead of ammonium sulfate, and the pH was changed in the same manner as in Example 3 to form a film. I did.

The coercive force of each of the samples obtained in Example 3 and Comparative Example 2 was measured. FIG. 7 shows the relationship between the pH of the plating bath and the coercive force of the soft magnetic thin film. Figure 7
As shown in, it is clear that in Comparative Example 2 using the plating bath containing Cl ions, the pH range in which a low coercive force is obtained is narrow. Further, the sample having a film thickness of 2 μm or more obtained from the plating bath containing Cl ions had poor adhesion to the substrate and partial peeling was observed. This is probably because the internal stress is high. No such development was observed when a plating bath containing no Cl ions was used.

From the above results, the effect of the present invention is clear.

[Brief description of drawings]

FIG. 1 is a graph showing a relationship between Cu content and coercive force of a soft magnetic thin film.

FIG. 2 is a graph showing the relationship between the Fe content of a soft magnetic thin film and the coercive force.

FIG. 3 is a graph showing the relationship between the Fe content of a soft magnetic thin film and the saturation magnetostriction value.

FIG. 4 is a graph showing the relationship between the Cu content of a soft magnetic thin film and the natural potential.

FIG. 5 is an X-ray diffraction chart of a soft magnetic thin film.

FIG. 6 is a graph showing changes in coercive force due to an increase in the number of soft magnetic thin films formed.

FIG. 7 is a graph showing the relationship between the pH of the plating bath and the coercive force of the soft magnetic thin film.

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] May 7, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

By the way, Cu on the CoFe alloy plating film
The effect of the addition of Al is to reduce the coercive force.
PROC of ctrochemical Society
EEDINGS OF THE SYMPOSIUM
ON MAGNETIC MATERIALS, PRO
CESSES AND DEVICES, 91-2, p
579. In this report, a coercive force of 0.60e and a saturation magnetic flux density twice as high as that of permalloy are obtained when the Fe content is 10.5% by weight. The CoFeCu alloy plated film in this report has a structure in which the fcc phase and the bcc phase are mixed. Further, the composition range of low coercive force is mainly controlled by the Fe content, and the coercive force is 10e or less only in the narrow range of the Fe content of 10 to 12% by weight. On the other hand, regarding Cu, the coercive force becomes low when it is contained in an amount of 2% by weight or more, and it is disclosed that the addition amount is determined for controlling Hk.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0055

[Correction method] Change

[Correction content]

(X-ray diffraction) Cu-kG line (30 kV, 4
It was evaluated at 0 mA). The crystal structure is (111) plane, (2
It was identified as fcc from the (00) plane and bcc from the (110) plane.

Claims (10)

[Claims] 1. A method for producing a soft magnetic thin film containing Co, Fe and Cu as main components by a wet plating method, which comprises adding Co ions, Fe ions and Cu ions,
A method for producing a soft magnetic thin film, which comprises using a plating bath containing organic acid ions. 2. The production of a soft magnetic thin film according to claim 1, wherein the organic acid ion is at least one selected from succinate ion, citrate ion, malonate ion, maleate ion, gluconate ion and tartrate ion. Method. 3. The method for producing a soft magnetic thin film according to claim 2, wherein tartrate ions are used as the organic acid ions. 4. The method for producing a soft magnetic thin film according to claim 1, wherein the concentration of the organic acid ions in the plating bath is 0.01 to 1.0 mol / liter. 5. A method for producing a soft magnetic thin film containing Co, Fe and Cu as main components by a wet plating method, characterized by using a plating bath containing substantially no Cl ions. Method for manufacturing magnetic thin film. 6. A sulfate is used as a source of Co ions, Fe ions and Cu ions in the plating bath.
Method for manufacturing soft magnetic thin film of. 7. The method for producing a soft magnetic thin film according to claim 5, wherein the plating bath according to any one of claims 1 to 4 is used as the plating bath. 8. The method for manufacturing a soft magnetic thin film according to claim 1, wherein annealing is performed in a magnetic field after the soft magnetic thin film is formed. 9. The method according to claim 1, wherein the Cu content is 4 to 30% by weight, the Fe content is 2 to 13% by weight, and the balance is substantially Co. A soft magnetic thin film characterized by the above. 10. A soft magnetic thin film containing Co, Fe and Cu as main components, which is composed of an fcc phase and has a coercive force of 1 Oe or less.