JPH05217746A - Ferromagnetic film - Google Patents

Abstract

PURPOSE:To provide a heat-resistant, good ferromagnetic film with high Bs and low Hc by using a Co-Fe alloy containing at least one element selected from specific transition metals. CONSTITUTION:A ferromagnetic film is composed of an alloy whose composition is expressed by CoxFeyTz, where T is selected from Al, Ta, Ti, Zr, Nb, Hf, Mo, and W. Assuming that x, y and z are given in at%, then 73<x<94, 5<y<=15, 1<z<12, and z+y+z=100. The addition of the selected element preferentially produces either (111)-oriented fcc crystal or (100)-oriented hcp crystal. Therefore, the magnetic anisotropy in the film is not significantly large, thus resulting in low Hc. If the T content is less than 1 at% high orientation is not realized. With the T content greater than 12 ate, on the other hand, low Hc is not achieved because of the intermetallic compound between T and Co, especially if the film is heat-treated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ferromagnetic film suitable for magnetic heads and the like.

[0002]

2. Description of the Related Art Generally, a magnetic film for a magnetic head has a high saturation magnetic flux density (high Bs) and a low holding power (low Bs) so that it can exhibit a sufficient recording ability for a high holding power (high Hc) recording medium. Hc) soft magnetic properties are required.

Fe, Co or FeCo based alloys have high Bs
However, since the crystal magnetic anisotropy is large, Hc becomes unnecessarily large, and it is difficult to obtain good soft magnetic characteristics suitable for a magnetic head or the like. Further, the FeAlSi alloy film and the NiFe alloy film whose crystal magnetic anisotropy is close to zero by adding an additive to these alloys show low Hc, but Bs is 1.1 [T] at the maximum. .. In addition, many Fe-based or Co-based alloy films have a low H content when made amorphous.
Although c is shown, its Bs is 1.0 [T] at maximum in consideration of heat resistance and the like.

However, theoretically, even a film having a large magnetocrystalline anisotropy can exhibit a low Hc by controlling the crystal orientation. Specifically, in the case of cubic (111) plane orientation, the influence of the magnetocrystalline anisotropy constant K1 can be neglected within the film plane, and low Hc is exhibited. For example, in the case of bcc phase Fe solid solution, (111) plane orientation is exhibited by selecting an appropriate underlayer, such as FeSi / ZnSn, and low Hc is exhibited (Hosono et al., J. Appl. Phys., 67). , 6990 (1990)).

In the case of Fe type, however, the bcc phase is stable, so that it usually exhibits (100) or (110) plane orientation. The surface energy of the (111) orientation is large and ZnS
It is difficult to grow stably except for the limited substrates such as e.

On the other hand, in the case of Co-based alloy, it can be confirmed from the phase diagram that a stable state of fcc single phase exists in an alloy (Bs about 1.9 [T]) having a composition near Co ₉₀ Fe ₁₀ . In the fcc phase, the (111) plane has a low surface energy and is a stable growth plane. In fact, such alloys are known to be oriented in the fcc phase (111) plane. However, in practice, it is difficult to form a good (111) plane orientation even with such an fcc phase alloy film.

A magnetic film in which a transition metal such as Zr or Ta and nitrogen are added to Fe or Co has a high Bs and is free from deterioration of soft magnetism due to heat, and is promising as a future magnetic recording head. Further, considering practicality in a high humidity environment containing chlorine, it is considered that the Co-based magnetic film is suitable because the Fe-based magnetic film has a problem in corrosion resistance.

As the Co-based nitrogen-added film, a nitrogen concentration modulation film having a multilayer structure (IEEE Trans. Magn., 23, 3707 (1987)),
Single layer CoNbZrN film (J. Appl. Phy., 68, 4760 (1990)
), CoFeAl, which the present inventors have intensively researched
N-film (Proceedings of the 14th Annual Meeting of the Japan Society for Applied Magnetics, 292 (1
990)) etc. are known. It is known that these magnetic films exhibit low Hc of 80 [A / m] or less, that is, comparable to conventional magnetic films, that is, exhibit good soft magnetism.

However, each of these magnetic films has the following drawbacks. For example, a nitrogen concentration modulation film has very good heat resistance with soft magnetism maintained up to about 700 [° C.], but its manufacturing process is complicated because of its multilayer structure. On the other hand, CoNbZrN film or CoFe
Since the AlN film is a single layer, it is easy to manufacture.
When heat treatment is performed at 0 [° C.] or higher, crystal growth gradually progresses, resulting in an increase in Hc and a decrease in resistivity. Especially 600
When applying these magnetic films to a laminate type head that employs a high temperature manufacturing process above [° C.],
An increase in Hc accompanying crystal growth becomes a serious problem. Also,
Since the eddy current increases when the resistivity decreases, the high frequency characteristics deteriorate. Further, the CoNbZrN film can obtain good characteristics by the ion beam sputtering method, but the normal R
It is known that in the F magnetron sputtering method, it is difficult to obtain good characteristics because perpendicular magnetic anisotropy is likely to occur, and the manufacturing margin is narrow. On the other hand, CoFeAl
The N film has insufficient corrosion resistance in water.

[0010]

As described above, a CoFe alloy having a large crystal magnetic anisotropy has a high saturation magnetic flux density of 1.9 [T] or more, but cannot achieve a good (111) orientation. Therefore, it is difficult to realize Hc that is low enough to be suitable for the magnetic film of the head magnetic pole.

Further, in a magnetic film in which a transition metal such as Zr or Ta and nitrogen are added to a ferromagnetic metal such as Co, heat treatment at a high temperature causes gradual crystal growth to result in an increase in Hc,
The problem of heat resistance that causes a decrease in resistivity and normal RF
The magnetron sputtering method has a problem that it is difficult to obtain good characteristics because perpendicular magnetic anisotropy is likely to occur.

It is an object of the present invention to provide a ferromagnetic film suitable for a magnetic head satisfying high Bs and low Hc, soft magnetic properties having good heat resistance, a wide manufacturing margin and high corrosion resistance.

[0013]

[Means for Solving the Problems] General formula Co _x Fe _y T _z
In the alloy represented by, T is Al, Ta, Ti, Z
At least one atom selected from the group consisting of r, Nb, Hf, Mo, and W, and x, y, and z, when the respective composition ratios are represented by at%, 73 <x <945 5 <y ≦ 15 1 <z <12 x + y + z = 100.

In the alloy represented by the general formula (M _a T _b ) _x N _y , M is Co or Co and Fe,
T is at least one atom selected from the group of transition metals consisting of Ta, Nb, Zr, Hf, Ti, Cr, Mo and W, and Al and N are nitrogen, and a, b, x and y are respectively When the composition ratio of is expressed as at%, 85 <a <96 4 <b <15 a + b = 100 80 <x <98 2 <y <20 x + y = 100 The Fe content in M is 0 ≦ Fe ≦ 15 at% The content ratio of Al in T is defined in the range of 4 <Al ≦ 50 at%).

In the alloy represented by the general formula (M _a T _b ) _x N _y , M is Co and Fe, T is at least one atom selected from Ta or Nb, and N is N.
Is nitrogen, and a, b, x, and y are the composition ratios of each.
When expressed by t%, it is specified in the range of 85 <a <95 5 <b <15 a + b = 100 82 <x <97.5 2.5 <y <18 x + y = 100), and the Fe content in M is Is specified within the range of 2.5 ≦ Fe ≦ 12.5 at%.

In the magnetic film of claim 3, the content of at least one atom selected from Pd and Re is 15 at%.
A ferromagnetic film characterized by being less than.

[0017]

The ferromagnetic film of the first invention is formed by various sputtering methods using argon gas (DC, RF, ion beam sputtering).
Alternatively, it can be manufactured by a vacuum deposition method. Further, the soft magnetic characteristics can be improved by performing the treatment after the film formation. In the film formation by sputtering, a small amount of oxygen or argon is inevitably contained in the film.

According to the present invention, Al, Ta, Ti, Z
By adding at least one element selected from the group consisting of T components of r, Nb, Hf, Mo and W, f
It is possible to preferentially orientate the cc phase (111) plane or the (100) plane of the hcp phase, and to achieve low Hc without causing large magnetocrystalline anisotropy in the film plane. You can

In the present invention, the amount of the T component added is set to 1 or more and 12 at% or less. When it is less than 1%, the above-mentioned high orientation cannot be realized, so that low Hc cannot be achieved, and when it is 12 at% or more. , Especially when subjected to heat treatment,
This is because low Hc cannot be achieved due to the formation of an intermetallic compound with Co. The appropriate composition range in which low Hc is obtained varies somewhat depending on the film forming method, film forming conditions, and heat treatment conditions.

In the ferromagnetic film of the present invention, by defining the addition amount of the T component within the above range, 1.3 to 1.9 is obtained.
It is possible to obtain a high Bs of [T] and a low Hc of 150 [A / m] or less. Therefore, by using this ferromagnetic film, a magnetic head extremely advantageous for high density recording can be stably supplied.

The magnetic film of the second invention can be manufactured by a usual RF magnetron sputtering method in a mixed gas atmosphere of argon and nitrogen, and it is not always necessary to use a special method such as ion beam sputtering. Further, the soft magnetic characteristics can be improved by performing heat treatment after the film formation if necessary. Note that in film formation by sputtering, a trace amount of oxygen or argon is inevitably contained in the film.

The ferromagnetic film of the present invention can achieve the following effects by adding a transition metal and Al to the Co type nitride film. (1) A good soft magnetic property of about 30 [A / m] or less can be maintained even at a high temperature heat treatment of 600 [° C.] or more. (2) Since the resistivity increases, it is possible to prevent the deterioration of the high frequency characteristics due to the eddy current. (3) The manufacturing margin is wide even with the ordinary RF magnetron sputtering method. In the present invention, the concentration of each component in the film is defined as above for the following reasons.

When the concentration b of T component is less than 4 at% and the concentration y of N is less than 2 at%, low Hc cannot be obtained by heat treatment. On the other hand, the concentration b of the T component exceeds 15 at% and N
If the concentration y exceeds 20 at%, an excessive nitride is formed by the heat treatment, so that the soft magnetism deteriorates. When the concentration b of the T component is 4 at% or more and the concentration y of N is 2 at% or more, a microcrystalline structure having excellent heat resistance is obtained, and the heat resistance of the soft magnetic characteristics is improved.

The Fe content of the M component is 15a.
If it exceeds t%, the bcc phase becomes conspicuous even after the heat treatment, so that the magnetostriction increases (+ 1 × 10 ⁻⁵ or more), M
When the content of Fe in the component is in the range of 0 to 15 at%, the fcc phase becomes predominant after the heat treatment, so that low magnetostriction (+ 3 × 10
^-6 or less) can be realized. The content ratio of Fe in the M component is 10
It is more preferably at% or less.

When the content of Al in the T component (transition metal and Al) is 4 at% or less, there is no effect of addition, and crystal grains grow by high temperature heat treatment, so that it becomes difficult to reduce Hc. On the other hand, the Al content of the T component is 50
When it exceeds at%, adverse effects such as deterioration of corrosion resistance, decrease of resistivity, deterioration of heat resistance of soft magnetic characteristics, and the like occur. By defining the Al content in the T component within an appropriate range of 4 or more and 50 at% or less, the heat resistance is good, the resistivity is high, and the manufacturing margin is wide as compared with the conventional Co-based nitride film. A magnetic film is obtained. The content of Al in the T component is more preferably 25 or more and 50 at% or less. Within this range, low Hc is exhibited even before heat treatment.

Furthermore, even if Al is not contained, Ta
Similarly, by defining Nb and Nb as follows, a Co-based nitride film having excellent heat resistance can be similarly produced by a normal sputtering method.

That is, a part of Co in M is 2.5
By substituting Fe at a ratio of 12.5 at% or less, a magnetic anisotropy or rough (non-uniform) film growth that is likely to occur in the direction perpendicular to the film surface in the nitride film containing only Co can be achieved by the normal sputtering method. It can be reduced even by manufacturing, and as a result, 5 required for a metal in-gap head (hereinafter referred to as “MIG head”)
Soft magnetism (80 [A /
m] or less and a low Hc of + 3 × 10 ⁻⁶ or less). Furthermore, if the Fe concentration exceeds 5 at%,
If it is 2.5 at% or less, before heat treatment or 400
The bcc phase precipitates at a relatively low temperature of about [° C.], and then the fcc phase and a phase transformation into T nitride occur. At this time,
Even at a high temperature of 650 [° C.] or higher, crystal grain growth is suppressed and good soft magnetism is exhibited. As a result, it is possible to obtain a soft magnetic film having heat resistance of 650 to 700 [° C.], which is suitable not only for MIG heads but also for laminate type heads. On the other hand, in the Fe concentration film of 5 at% or less, the bcc phase does not appear and
Since phase separation occurs in the cc phase + Ta nitride, the crystal grains grow relatively quickly, and as a result, heat resistance of 650 [° C.] cannot be obtained. When the Fe concentration exceeds 12.5 at%, it becomes difficult to form the fcc phase required for low magnetostriction, and the bcc phase exhibiting high magnetostriction (+ 1 × 10 ⁻⁵ or more) becomes stable.

Further, in order to obtain the effect of substituting a part of Co with Fe, the concentration of the T component should be more than 5 at% and less than 15 at%, and preferably 7.2 at% or more and less than 15 at%. Must be set. The reason for this is as follows. First, when the T component concentration is 5 at% or less, amorphous microcrystals cannot be obtained immediately after film formation, and as a result, soft magnetism of Hc ≦ 80 [A / m] cannot be obtained. .. Also, 1
When the T component concentration is 5 at% or more, the nitrogen concentration also needs to increase in response to the increase in the T component as described later, so that (1) excessive nitride that inhibits low Hc is formed. There are adverse effects such as (2) vertical magnetic anisotropy is likely to occur, and (3) film peeling is likely to occur. Where T
If the component concentration is less than 7 at%, the heat resistance up to 550 [° C.] is the limit because the formation of nitrides is small. Considering application to laminate type heads, 7.2 at% or more 1
A T component concentration of less than 5 at% is desirable.

Further, in order to obtain the effects described so far, it is necessary to set the nitrogen concentration to more than 2.5 at% and less than 18 at%. The reason for this is as follows. First, when nitrogen is 2.5 at% or less with respect to the T component, it is difficult to obtain microcrystals or amorphization before heat treatment, and even if such a crystal state is obtained. Also, after the heat treatment of 550 [° C.] required for the MIG head is performed, crystal grains grow, and as a result, low Hc cannot be obtained. Considering application to a laminate type head, it is desirable to set the temperature at which crystal growth occurs and Hc increases to 650 [° C.] or higher, so the lower limit of the nitrogen concentration becomes stricter and 6 a
It is desirable to exceed t%. On the other hand, the nitrogen concentration is 18a
If it is t% or more, the same adverse effect as that of the excessive T component concentration appears.

Here, one more is added to the magnetic film having the above composition range.
Fe by adding less than 5 at% of Pd or Re
While maintaining the high Bs higher than that of AlSi and the soft magnetic property excellent in heat resistance, adjustment to zero magnetostriction desirable for application to a magnetic head becomes possible especially in a composition range with a high Fe concentration. Also,
The corrosion resistance is improved by adding Pd or Re.

As a result, a Co-based nitride film in which a part of Co is replaced by Fe and Ta or Nb is added has a high Bs of 1.3 [T] or more and a low Hc of 80 [A / m] or less, +3 x 10 ^-6
It exhibits the following low magnetostriction, and these magnetic properties are 55
Even after the heat treatment at 0 [° C.], 65 depending on the composition range
Since it does not deteriorate even by heat treatment at 0 [° C.] or higher, it can be applied to MIG heads and laminate type heads.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. [First Invention] (Example 1) A crystallized glass or Si single crystal subjected to organic alkali cleaning is used as a substrate and Co-11.5 at%
Fe-4at% Al alloy target or Co-10at
A magnetic film having a film thickness of about 1 μm was formed by bipolar magnetron sputtering in an Ar gas atmosphere using a composite target in which a chip of the additive T component was placed on the% Fe alloy target. The concentration of T component was adjusted to be about 5 at%. Sputtering was performed under the following conditions.

High frequency power density: 3.2 [W / cm ² ] Total sputtering gas pressure: 0.27 to 0.1 [Pa] Electrode distance: 90 [mm] Pre-evacuation: 1.3 × 10 ^-4 [ Pa] Various physical properties of the obtained magnetic film were measured as follows. The saturation magnetic flux density Bs and the coercive force Hc were measured by applying a maximum magnetic field of 400 [kA / m] in the hard axis direction of the magnetic film. The crystal structure of the film was examined by an X-ray analysis method using a θ-2θ scan (using CuKα ray). The concentrations of Co, Fe and T components in the film were examined by XFR (fluorescent X-ray) analysis.

With respect to the magnetic film formed under the above conditions, the diffraction intensity of the peak at 2θ to 44 ° (hereinafter referred to as “Imai
1) and the holding force Hc are shown in FIG. The values in FIG. 1 were measured in the as-made state (not heat-treated). The curve in FIG. 1 shows the relationship between Imain and the coercive force Hc regardless of the type of the additive element T. This peak is in the fcc phase (111) or the hcp phase (0
02) It is considered to be a peak.

From FIG. 1, it can be seen that the holding force Hc decreases monotonically as Imain increases. Where Ta,
When Ti, Al, Nb, Hf, W and Mo are added, Imain increases up to about 10 5 cps and the holding force Hc
Is also declining. On the other hand, when Si, Pd and Ru are added, Imain is less than 10 ⁴ cps and 10 ³ [A
/ M], which shows a high holding power.

Here, a sample with Hc> 10 ³ [A / m], that is, Imain <10 ⁴ cps, and Hc ≦ 200 [A]
/ M], that is, a typical crystal structure of a sample having Imain> 10 ⁵ cps is shown in FIG. FIG. 2A shows CoFePd.
Film (composition: Co _BAL Fe ₉ Pd ₅ ), FIG.
3 is an X-ray diffraction image of a FeTa film (composition: Co _BAL Fe ₉ Ta ₄ ).

In the CoFePd film of FIG. 2A, 2θ =
A "shoulder" can be seen near 41 degrees. This corresponds to the hcp phase (100) plane reflection. The Hc of this sample is as large as 6 [kA / m]. This "shoulder" was confirmed in the X-ray diffraction curve in many other samples having a large Hc.
On the other hand, Imain> 10 ⁵ of the CoFeTa film or the like in FIG.
In the case of, this "shoulder" could not be confirmed. In addition, Ima
When the rocking curve of the main peak of the in> 10 5 film was measured, the full width at half maximum was 11 degrees or less.

From the above results, when the main peak of remarkably high intensity and no other peaks are observed, that is, fc
It can be seen that low Hc can be obtained when c (111) or hcp (002) high orientation is exhibited. Next, for the X-ray diffraction curve when the diffraction surface described so far is parallel to the film surface,
The X-ray diffraction curve was measured by shifting the diffraction surface of some films from the plane parallel to the film surface, and it was examined which phase the reflection of the main peak was attributed to. The result is shown in FIG.
FIG. 3A is a diffraction curve when the diffraction plane is shifted by 54.7 degrees (if the main peak is the fcc (111) peak, only the fcc (200) peak is confirmed). Further, FIG. 3B is a diffraction curve when the diffraction surface is shifted by 61.6 degrees (if the main peak is the hcp (002) peak, the hcp (101) peak is confirmed). Even if the X-ray incident direction was changed with respect to the in-plane direction of the film, the diffraction curve did not change significantly, and the film was not oriented in the film plane. In FIG. 3A, the Al-added film is fcc.
Only the (200) peak was confirmed, which is fcc (10
0) means orientation. Also, Ta and Nb
Neither peak was observed in the added film. On the other hand, in FIG. 3B, the hcp (101) peak is confirmed in the Ta-added film, which means that it is the hcp (001) oriented film. In the Ti-added film, neither reflection was observed, and it was not possible to discriminate between the hcp phase and the fcc phase.

FIG. 4 shows the relationship between the additive element concentration and the saturation magnetic flux density (Bs) of the magnetic film in the as-made state. The magnetic film without added element shows Bs of about 1.9 [T]. As the concentration of the additional element increases, Bs monotonically decreases.
When the additive element was Pd, this monotonous decrease tendency was slight, and conversely, when it was Ru or Cr, this monotonic decrease tendency was remarkable. Generally, when the concentration of the additional element is about 10 at%, Bs of about 1.4 [T] is shown. This value is higher than that of Sendust, Permalloy, or Co-based amorphous alloy.

Next, FIG. 5 shows the relationship between Ta concentration and Hc and Bs for the magnetic film containing Ta showing low Hc. Note that FIG. 5 shows the values before and after the heat treatment. The heat treatment conditions are shown below.

Heating temperature: 500 [° C.] Heating time: About 1 hour Heating atmosphere: In vacuum (2 to 3 × 10 ⁻³ [Pa]) Applied magnetic field: 20 [kA / m] Sample rotation speed: 100 [rpm] H at a Ta concentration of 2 at% regardless of the presence or absence of heat treatment.
It showed a high Hc of c> 500 [A / m]. In addition, the X-ray diffraction curve at this time could not obtain a highly oriented film in the case of the CoFe film to which Ta was not added. Ta concentration of 4
If it is increased to at% or more, it is 20 with or without heat treatment.
It exhibited a low Hc of 0 [A / m] or less. In particular, 6.5-9
At Ta concentration of at%, low Hc of 50 [A / m] or less was exhibited. The X-ray diffraction curve at this time exhibited a high hcp (001) orientation, similar to the curve shown in FIG. Also, Bs
Shows a high value of 1.3 [T] or more. When Ta concentration is increased to 12 at%, Hc before heat treatment is 30 [A / m].
Although the following low Hc was shown, Hc increased rapidly after the heat treatment.
In the X-ray diffraction curve at this time, an amorphous broad peak (2θ = 40 to 50 °) was confirmed before the heat treatment. After the heat treatment, a sharp peak of the CoTa intermetallic compound, which is peculiar to the amorphous crystallization, was detected. When the Ta concentration was increased to 12 at%, a highly oriented film could not be obtained, resulting in an amorphous film structure with insufficient heat resistance of Hc as previously reported.

Next, examples in which the Fe concentration was changed will be described. FIG. 6 shows Hc and F of the CoFeTa film when the Fe concentration was changed in the sample having a Ta concentration of about 8 at%.
It is a figure which shows the relationship of e density | concentration. In addition, in the Fe concentration of 0 to 15 at%, when the X-ray diffraction curve was examined, it was found that all h
cp (001) orientation was shown, and no clear difference in orientation degree was observed, but at a Fe concentration of 17.5 at% or higher, bcc
The phases were mixed and the degree of orientation deteriorated.

In a CoTa film containing no Fe, Hc is 9
A high Hc of about [kA / m] was exhibited. At this time, as shown in FIG. 7, the magnetization curve showed a shape peculiar to the perpendicular magnetic anisotropy. Since the c-axis is the easy axis of magnetization (Ku is positive), it is considered that perpendicular magnetic anisotropy occurred and high Hc was exhibited. When the Fe concentration increases, Hc decreases sharply,
Hc is 100 [A / m] when the concentration is 7.5 to 15 at%.
The following low values were exhibited, and the perpendicular magnetic anisotropy disappeared. It is considered that when Fe concentration was increased, Ku was decreased and became close to zero or became negative, that is, (001) plane became an easy magnetization plane, and thus Hc was lowered. However, when the Fe concentration exceeds 15 at%, the Hc increases corresponding to the deterioration of the orientation due to the inclusion of the bcc phase. (Example 2) FIG. 8 shows the relationship between Al concentration and Hc for a magnetic film containing Al as an additional element.

In the case of Al, Hc is greatly reduced even if it is added in a very small amount. That is, when the Al concentration is about 1 at%, H
c decreases to about 100 [A / m]. 3-10 at
%, Hc is about 10 [A / m], which is extremely low Hc.
Indicates. When it exceeds 10 at%, Hc starts to increase.

The Al concentration dependence of the crystal structure shows the same tendency as in the case of Ta. That is, the hcp (100) peak is slightly observed in the low Al concentration / high Hc region, and the degree of orientation is not good. In the proper Al concentration / low Hc region, the fcc phase (111) plane orientation is strong, and the hcp phase orientation is not included. In the high Al / high Hc region, an intermetallic compound of CoAl is generated and Al phase separation is also observed. (Example 3) Other elements (Ti, Nb, M) as additional elements
FIG. 9 shows the relationship between the additive element concentration and Hc for the magnetic film containing O, Zr, Hf, W). It can be seen that when these additive elements are used, low Hc is exhibited at a concentration of about 3 to 8 at%. The X-ray diffraction of the film shows a high-intensity peak of 2θ = 20 to 44 degrees in the proper concentration region. Even in the case of these additive elements, it is considered that the relationship between the composition and Hc changes depending on the film forming conditions and the like.

However, when Pd, Ru, Cr and Si are added, a good low Hc film cannot be obtained at any concentration. When the crystal structures of these films are evaluated, the hcp phase (100) peak is observed. As described above, CoF
In the e film, the fcc phase (111) or the hcp phase (00
1) It can be seen that there are additional elements that promote plane orientation and additional elements that suppress these orientations. [Second Invention] (Example 1) A mixed gas of argon and nitrogen is used, using a composite target composed of Co ₉₀ Fe ₁₀ or an alloy target in which Al content is changed and added to Co ₉₀ Fe ₁₀ and Ta pellets. A magnetic film having a thickness of 1 μm was formed on a crystallized glass substrate by an RF magnetron sputtering method in an atmosphere. The total concentration of Ta and Al in the magnetic film is 8 to
It was adjusted to be 10 at%. The sputtering was performed under the following conditions.

High frequency power density: 0.05 [W / mm ² ] Total sputter gas pressure: 0.3 [Pa] Nitrogen gas concentration: 25 at% Electrode distance: 60 [mm] Pre-evacuation: 2 × 10 ^-4 [ Pa] or less Substrate temperature: Approximately 100 [° C.] The heat treatment after film formation is 2 × 1 at a predetermined temperature for the magnetic film.
Under reduced pressure of 0-3 [Pa], 16 [kA / m], 100 [r
It was held for 1 hour in a rotating magnetic field of [pm].

Various characteristics of the obtained magnetic film were measured as follows. The coercive force was measured by applying a maximum magnetic field of 250 [Oe] in the hard axis direction of the magnetic film. Bs is
A magnetic field of 10 kOe was applied to the magnetic film, and measurement was performed using a vibration type magnetometer. The crystal structure of the film was examined by an X-ray diffraction method using a θ-2θ scan (using CuKα ray). The nitrogen concentration in the film was investigated by using steam distillation / Nessler absorption spectrophotometry and Auger photoelectron spectroscopy in combination. Co, Fe, Ta in the film
The concentrations of Al and Al were examined by fluorescent X-ray analysis.

FIG. 10 shows the heat treatment temperature dependency of Hc for each magnetic film produced under the above conditions, with the content ratio of Al in the T component (hereinafter, referred to as "Al substitution amount for Ta") as a parameter. ..

First, a magnetic film that has not been heat treated will be examined. The film without Al added is 800
A high Hc of [A / m] or more is shown. This film also exhibits a magnetization curve that suggests weak perpendicular magnetic anisotropy. This result is
This agrees with the results of Co-based nitride films that have been reported so far. When the Al substitution amount is 25 to 50 at%, Hc decreases to 10 [A / m] or less. However, when the Al substitution amount increases to 75 at% or more, Hc slightly increases to 40 [A / m] or less. From these results, it is understood that the harmful perpendicular magnetic anisotropy can be suppressed by adding Al, and low Hc can be realized without performing heat treatment.

Next, the influence of the heat treatment at 350 to 550 [° C.] will be examined. High H without heat treatment
In the film in which Al showing c is not added, Hc is lowered to about 10 [A / m] by the heat treatment at this temperature. Al
In the film having a substitution amount of 10 at% or more, there is almost no change in Hc due to the heat treatment in this temperature range.

Further, the effect of heat treatment at 550 [° C.] or higher will be examined. Al-free film and Al
Hc rapidly increases in a film having a substitution amount of 75 at% or more. On the other hand, when the Al substitution amount is 10 at%, it is 600
Hc sharply decreases by heat treatment at [° C]. And A
A film having a substitution amount of 10 to 50 at% exhibits a low Hc of 10 [A / m] or less by heat treatment up to about 650 [° C].

From these results, the substitution amount of Al is 75a.
When it is less than t%, heat resistance of 600 [° C.] or more, which can withstand the manufacturing process of the laminated head, can be realized.

Here, there is a concern that the characteristics of high Bs may be impaired by substituting part of Ta with Al. Therefore, regarding the magnetic film heat-treated at 600 [° C.],
FIG. 11 shows the relationship between the substitution amount and Bs. Even if the Al substitution amount changes, Bs changes only slightly, and
It can be seen that a high Bs of 1.5 [T] can be obtained.

It is considered that the addition of Al improves the heat resistance of soft magnetism because the crystal structure of the film changes. Then, the result of examining the Al substitution amount dependency of the X-ray diffraction curve is shown in FIG.

First, a magnetic film that has not been heat treated will be examined. For a film to which Al is not added, 2θ =
At about 45 degrees, a so-called broad peak characteristic of the Co-based amorphous alloy film, which is remarkably widened, is recognized. In the film in which the Al substitution amount is 50 at%, the wide-angle side of this broad peak swells. Furthermore, in the film in which the Al substitution amount is 75 at%,
A clear peak appears at 2θ = about 50 degrees. It is presumed that these changes are due to a change from an amorphous phase to a structure containing fine crystals due to the addition of Al.

Next, the influence of heat treatment at 450 [° C.] will be examined. 2 if the Al substitution amount is 50 at% or less
At θ = about 35 degrees, a remarkably broad peak that is considered to be TaN _x is observed. At the same time, the width of the peak at 2θ = about 45 degrees becomes narrow. It is presumed that this is because crystallization corresponding to the phase separation between the nitrided phase and the non-nitrided phase is progressing. A
No clear peak corresponding to the nitride appears in the film having the l substitution amount of 75 at% or more, and the peak becomes clear at 2θ = about 45 degrees and about 50 degrees. Also in this case, it is considered that crystal growth is progressing.

Further, the effect of heat treatment at 600 degrees will be examined. In the film to which Al is not added and the film in which the amount of Al substitution is 75 at% or more, the main peak (2θ = approximately 45
The full width at half maximum (.degree.) Decreases, and the crystal grain growth is clear. Al
In the film with the substitution amount of 50 at%, the crystal grain growth is relatively small.

In order to further clarify the effect of suppressing the growth of crystal grains by the addition of Al, the heat treatment temperature and 2θ = 44 to 40 ° C. for the film not added with Al and the film with the Al substitution amount of 50 at%. Full width at half maximum (F of 45 degrees)
FIG. 13 shows the relationship with WHM). From FIG. 13, it is clear that the addition of Al can suppress the decrease in the half-value width due to the heat treatment, that is, the growth of crystal grains.

From the results of FIG. 12 and FIG. 13, when a part of Ta is replaced with Al up to 50 at%, crystallization including a nitride occurs at a relatively low temperature (400 [° C.]). It turns out that growth can be suppressed. As a result, it is considered that the heat resistance of Hc is improved.

Although the effect of improving the heat resistance of Hc by adding Al has been described above, the effect of increasing the resistivity can also be obtained by adding Al.

FIG. 14 shows the Al substitution amount dependency of the resistivity of the film heat-treated at 600 [° C.]. The resistivity is 0.55 [μΩm] for the film without Al substitution, and the Al substitution amount is 50 at.
% Is 0.7 [μΩm]. However, when the Al substitution amount increases to 75 at% or more, the resistivity drops sharply. It is considered that the increase in the resistivity in the film in which the Al substitution amount is 50 at% is due to the suppression of crystal grain growth. Since the eddy current can be suppressed by increasing the resistivity in this way, good high frequency magnetic permeability can be expected.

Here, if the substitution amount of Al for Ta is increased, the corrosion resistance is adversely affected. The results are shown in Table 1. The corrosion resistance was evaluated by leaving the magnetic film in water having a pH of 6.0 at room temperature for 100 hours and then observing the surface condition with an optical microscope. Al substitution amount is 50 at
%, No change was observed on the surface of the film. However, when the Al substitution amount is further increased, a remarkable surface change due to rust is observed. From this result, it can be seen that when a large amount of Al is added, there is a problem that the corrosion resistance of the magnetic film is deteriorated.

[0064]

[Table 1] Example 2 A magnetic film was formed under the conditions of Example 1 except that the nitrogen gas concentration was changed within the range of 0 to 50 at%.
The Al substitution amount with respect to Ta is 10 at%.

FIG. 15 shows the relationship between the nitrogen gas concentration and Hc of the magnetic film heat-treated at 600 [° C.]. Nitrogen gas concentration is 5 at% or less (nitrogen concentration in the film is 2 at% or less), or 50 at% or more (nitrogen concentration in the film is 20 at%
% Or more), the high Hc of 400 [A / m] or more. On the other hand, the film produced with a nitrogen gas concentration of 5 to 50 at% exhibits a low Hc of 30 [A / m] or less. From this, it is understood that the low Hc film excellent in heat resistance can be obtained by setting the nitrogen concentration in the film to 2 to 20 at%. (Example 3) The Al content in the alloy target and the number of Ta chips were adjusted so that the substitution amount of Al with Ta was almost constant (about 50 at%), and the concentration b of the T component (Ta and Al) was changed. A magnetic film was formed under the conditions of Example 1.

In FIG. 16, H of the film heat-treated at 550 [° C.]
The dependence of c on concentration b is shown. A film having a concentration b of 4 at% exhibits a relatively high Hc of about 300 [A / m]. Concentration b is 5
A film of ˜13 at% exhibits a low Hc of 30 [A / m] or less. A film having a concentration b of 15 at% or more shows a low Hc of 30 [A / m] or less. Within the range of 4 <b <15, 30 [A /
It can be seen that a low Hc of m] or less can be obtained.

FIG. 17 shows the relationship between the concentration b and Bs. Bs gradually decreases due to an increase in the concentration b, but b = 15
Even at at%, a high Bs of Bs = 1.25 [T], which is higher than that of a conventional NiFe alloy or FeAlSi alloy, can be obtained. (Embodiment 4) In the above embodiment, the case where Ta and Al are contained as the T component has been described. However, Zr, Nb, Hf, Ti, or Tr instead of Ta is used as the transition metal in the T component.
Similar results are obtained when Cr, Mo or W is used. An example of the result is shown in Table 2. Table 2 shows the values of Hc and Bs after each magnetic film was heat-treated at 600 [° C.]. Any of the magnetic films exhibits good magnetic properties such that Hc is 30 [A / m] or less and Bs is 1.2 [T] or more.

[0068]

[Table 2] Next, an example of a magnetic head to which the magnetic film according to the present invention is applied will be described with reference to FIGS.

FIG. 18 is a sectional view of a thin film magnetic head corresponding to a longitudinal recording hard disk. The first insulating layer 4 is laminated on the substrate 1 so as to form the ferromagnetic film 2 and the predetermined gap 3 on the head tip side, the coil 5 is wound on the first insulating layer 4, and the coil 5 is further attached. The second insulating layer 6 is laminated so as to cover it. The ferromagnetic film 7 is formed on the surface of the insulating layer.
A part of it is formed so as to contact the ferromagnetic film 2, and a gap 3 is formed between the ferromagnetic film 2 and the ferromagnetic film 7 on the head tip side.
Is formed. A protective film 8 is formed on the ferromagnetic film 7.

Since the ferromagnetic film of the present invention has a higher Bs than the conventional NiFe film, Co-based amorphous film, etc., sufficient recording is possible even on a high coercive force medium. In addition, since the resistivity is higher than that of a conventional Co-based nitride film to which Al is not added, recording / reproduction with excellent high frequency characteristics becomes possible. Furthermore, since it shows low Hc even without heat treatment,
Even an organic material having poor heat resistance can be used as an insulating layer, and a low-cost magnetic field head can be manufactured.

FIG. 19 is a sectional view of a thin film magnetic head compatible with perpendicular recording. A main pole 12 made of a ferromagnetic film according to the present invention and a first insulating layer 13 are sequentially stacked on a substrate 11,
The coil 14 is wound around the first insulating layer 13, and the second insulating layer 15 is further laminated so as to cover the coil 14.
A return path magnetic body 16 is formed on the surface of the insulating layer so that a part of the return path magnetic body 16 contacts the main magnetic pole 12. A protective film 17 is formed on the return path magnetic body 16.

The ferromagnetic film of the present invention used for the main magnetic pole 12 can further reduce the thickness of the saturated magnetic pole as compared with the conventional Co-based amorphous film, and as a result, it has a high linear recording density and a high density perpendicular magnetic recording layer. Magnetic recording becomes possible.

FIG. 20 is a perspective view of the MIG head. 1
Ferromagnetic films 24 and 24 according to the present invention are formed on the opposing surfaces of the pair of ferrite cores 21 and 22 via intermediate layers 23 and 23, respectively. The intermediate layer 23 is used for strengthening the adhesive force and for preventing mutual diffusion between the ferrite core and the ferromagnetic film, and is made of Cr, Si.
O ₂ , NiFe, etc. are suitable. These ferrite cores 21 and 22 are fused by glass 26 so that a gap 25 is formed between the ferromagnetic films 24 and 24.
A coil 27 is wound around the ferrite core 21.

When manufacturing such a head, about 5
Although the glass welding step is performed at a high temperature of 5 [° C.], the ferromagnetic film of the present invention has a heat resistance of 600 [° C.] and can be applied to this head. Further, since the resistivity after the heat treatment is higher than that of the Co-based nitride film to which Al is not added, the high frequency characteristic is also good. Since the metal-in-gap type head has a large film thickness, a magnetic film having a high resistivity is particularly required.

FIG. 21 is a perspective view of a laminate type head. The ferromagnetic film 3 according to the present invention is formed on the pair of non-magnetic substrates 31 and 31 with the intermediate layers 32 and 32 for enhancing the adhesive force interposed therebetween.
A laminate layer is formed by alternately laminating 3, 33 and insulating layers 34, 34. Substrates 36, 36 are formed on this via the first welding glass 35, 35.
A pair of blocks 37, 38 having the above configuration
Are bonded by the second glass 39 for welding on the substrate cross section to form a predetermined gap. One, block 3
A coil 40 is wound around 7.

When manufacturing such a laminated head, the first glass 3 is melted during the welding of the second glass 39.
5 is required to be stable. Therefore, it is desirable that the welding temperature of the first glass 35 is higher than the welding temperature of the second glass 39, that is, a high temperature of 600 ° C. or higher. Since the ferromagnetic film of the present invention can sufficiently withstand such a high temperature process, it can be applied to a laminated head. (Embodiment 5) In this embodiment, a composite type target made of a Co ₉₀ Fe ₁₀ alloy and Ta pellets is used to form a crystallized glass substrate by RF magnetron sputtering.
A Cr film having a thickness of about 10 [nm] was interposed between the substrate and the magnetic film according to the present invention in order to maintain the adhesive force with the substrate. Sputtering was performed under the following conditions.

High frequency power density: 0.05 [W / mm ² ] Total sputtering gas pressure: 0.3 [Pa] Nitrogen gas concentration: 25 at% Electrode distance: 60 [mm] Pre-evacuation: 1 × 10 ^-4 [ Pa] or less Film thickness: 3 [μm] Substrate temperature: 100 [° C.] Coercive force was measured with a vibrating magnetometer by applying a magnetic field with a maximum of 20 [kA / m] in the difficult axis direction. The effective magnetic permeability was obtained by the 8-shaped coil method. The frequency at this time is 1 [M
Hz]. Bs was measured with a vibrating magnetometer by applying a magnetic field of 10 [kOe]. The anisotropic magnetic field Hk due to the in-plane uniaxial magnetic anisotropy is a linear minor in the hard axis direction.
It was obtained by the method of extending the magnetization curve to the saturation point. Saturation magnetostriction λs is Hk when unidirectional stress is applied to the film.
Obtained from the change. The Young's modulus and Poisson's ratio of the film are C
The value of o was substituted. The crystal structure is θ using CuKα ray.
It was examined by the X-ray diffractometry method of -2 theta scan. The nitrogen concentration in the film was examined by a combination of steam distillation / Nesla-absorption photometry and Auger photoelectron spectroscopy.
It was 12 at% before the heat treatment and decreased to about 10 at% after the heat treatment at 700 [° C.] for 1 hour. When the concentrations of Co, Fe and Ta in the film were examined by X-ray fluorescence analysis, C
It was o ₈₃ Fe ₉ Ta ₈ .

FIG. 22 is a diagram showing the heat treatment temperature (Tan) dependence of the effective magnetic permeability μ and Hc in the magnetic film produced under the above conditions. The heat treatment is performed in a rotating magnetic field (16 [kA /
m], 100 [rpm]) at each temperature for 1 hour. Some anisotropy (anisotropic magnetic field Hk = 100-300 in the film)
[A / m]), the magnetic permeability changed according to the in-plane magnetic field application direction, but the maximum magnetic permeability value was shown in FIG. 22, and the difference in Hc was hardly seen. In addition, the error represents the variation in a plurality of samples. Before the heat treatment, the high Hc of about 200 [A / m] and the low magnetic permeability of about 180 were shown, but when the heat treatment temperature was increased, the Hc was decreased and the magnetic permeability was increased. It can be seen that a low Hc of about 30 [A / m] and a high magnetic permeability of 1000 or more can be obtained in the heat treatment range of 550 [° C.] to 700 [° C.].

FIG. 23 is a diagram showing the heat treatment temperature dependence of Bs and λs. When the heat treatment temperature was increased, Bs was 1.
It increased from 4 [T] to 1.7 [T]. On the other hand, λs
Was not measurable before the heat treatment because the soft magnetism was not good, but +1 when the heat treatment temperature increased above 450 [° C].
It decreased from × 10 ^-5 to + 2 × 10 ^-6 . About 700 [℃]
It can be seen that a high Bs of 1.7 [T] and a low magnetostriction of + 2 × 10 ⁻⁶ can be obtained by the heat treatment of (1). The above is the result when the uniaxial magnetic anisotropy is small because it is subjected to heat treatment in a rotating magnetic field. However, depending on the head structure, the magnetic property with an appropriate uniaxial magnetic anisotropy is added to stabilize the magnetic domains. Membranes may be preferred.

Therefore, an example of a method for controlling the uniaxial magnetic anisotropy will be described next. First, heat treatment is performed at a predetermined temperature in a fixed magnetic field to apply a predetermined Hk to the film. Figure 24 shows
It is a figure which shows the relationship between Hk at this time, magnetic permeability, and heat processing temperature. Hc showed a low value similar to that when heat treatment was performed in a rotating magnetic field. Hk is 28 in heat treatment at 450 [° C]
Although a large value of 00 [A / m] was shown, the heat treatment temperature was 7
When it increased to 00 [° C], it decreased to 1350 [A / m]. Corresponding to this decrease in Hk, the magnetic permeability is 350 to 7
Increased to 50. The broken line in FIG. 24 shows the magnetic permeability in the ideal magnetization rotation expected from Hk, and it can be seen that it coincides with the actually measured magnetic permeability. next,
Temperature lower than this heat treatment (400-600 [° C])
Then, a predetermined Hk can be imparted by applying a fixed magnetic field in a direction orthogonal to the previous heat treatment magnetic field direction and performing heat treatment for a predetermined time.

An example thereof is shown below. FIG. 25 shows 700
The relationship between the heat treatment time and Hk when the heat treatment is performed at a temperature of 525 [° C.] by applying a fixed magnetic field in a direction orthogonal to the magnetic field direction after preliminary heat treatment in a fixed magnetic field for 1 hour at [° C.] or 550 [° C.] FIG. In FIG. 25, positive Hk means that the direction of applying a magnetic field in the preliminary heat treatment has an easy axis, and negative Hk means that the method orthogonal to it has an easy axis. By controlling the heat treatment time, 0-960 [A /
m] in the range of 550 [° C.] preheated film, 0 to 1
It can be seen that Hk can be controlled in the range of 420 [A / m]. Here, in the preheat-treated film at 700 [° C.], Hk hardly changed even after the heat treatment for a longer time than this, but this Hk was 4 times that of Hk immediately after the preheat treatment.
The value was as small as about 00 [A / m]. The Hk can be controlled by controlling the temperature instead of the time of the second heat treatment. Furthermore, first, heat treatment may be performed in a rotating magnetic field, and then heat treatment may be performed in a fixed magnetic field, and the conditions (temperature, time, etc.) of the heat treatment in the fixed magnetic field may be used as variables.

By the way, since it has been found that the above-mentioned dependence of the magnetic characteristics on the heat treatment has a strong correlation with the crystal structure, the results are shown below. FIG. 26 is a diagram showing the heat treatment temperature dependence of the X-ray diffraction curve, and FIG. 27 is a half-width FWHM of the main peak and the heat treatment temperature of the surface spacing d at 2θ = 44 to 45 degrees in the X-ray diffraction curve. It is a figure which shows a dependency. Immediately after the film formation, only the peak (2θ to 44 °) that was blown, similar to the Co-based amorphous film, was detected. When subjected to heat treatment at 400 ° C, this peak is bc
An increase in peak intensity and a decrease in full width at half maximum were observed, shifting to a position approximately coincident with the position of the c-phase (110) peak. In addition, (20) of bcc phase
0) and (211) peaks were detected. It can be seen that the 400 [° C.] heat-treated film exhibits bcc microcrystals. 550
When the heat treatment temperature is increased from [° C] to 700 [° C], b
The cc phase (110) peak is shifted to the position of the fcc phase (111) peak of 2θ = about 44 degrees, and further, the (200) peak, (220) peak, (311) of the fcc phase. ) A peak was recognized. A peak of TaN was also recognized. Therefore, when the heat treatment is advanced to 700 [° C.], bc
It can be seen that the phase is transformed from the c phase to the fcc phase + TaN two phases. It is assumed that the peak half-width was reduced and the crystal grain size was increased by this phase transformation. However, when the crystalline state was observed by transmission electron microscopy, it was found to be 550
In the heat treatment film at [° C.], the average crystal grain size is about 5 nm,
The average grain size is about 10n even after heat treatment at 700 ° C.
It kept fine particles of m. As a result, it is considered that the soft magnetism was good even at a high temperature of 700 [° C.].

Considering the relationship between this phase transformation and the magnetic characteristics, the bcc phase has a high λs phase and the fcc phase has a low λs phase.
It turns out that it corresponds to the phase of. In the amorphous CoFeTa film known so far, λs has a large value (about +1).
It was difficult to apply it to the magnetic head because it was × 10 ⁻⁵ ), but it can be seen that low λs can be obtained by stabilizing the fcc phase in which Ta or N is less solid-dissolved.

The above characteristics were the same even when Ta was replaced with Nb. (Embodiment 6) Next, an embodiment will be described in which the Fe concentration is changed by adjusting the Fe concentration of the CoFe alloy target. The Ta concentration was similar to that of the film of Example 1.

FIG. 28 shows the Fe concentration dependence of Hc after the heat treatment (in a rotating magnetic field) at 550 [° C.] for 1 hour as PN.
It is a figure shown about the case of ₂ = 15at% and 25at%. The Fe concentration is the substitution amount of Co (Fe / (Co +
Fe)). When PN ₂ = 15at%,
A film without Fe added has a high Hc of 80 [A / m] or more.
However, by setting the Fe concentration to 2.5 at% or more, a low Hc of 80 [A / m] or less was obtained. On the other hand, P
The N ₂ = 25 at% film showed a high Hc of 80 [A / m] or more when the Fe concentration was 5 at% or less, but it was 7.5 at%.
As described above, low Hc of 80 [A / m] or less was exhibited. It can be seen that Hc tends to increase due to the decrease in Fe concentration and the increase in PN ₂ . However, when the PN ₂ = 15 at% film was heat-treated at a higher temperature, Hc increased in all Fe concentration films. FIG. 29 is a diagram showing the Fe concentration dependence of Hc after heat treatment at 650 ° C. for 1 hour (in a rotating magnetic field). With a PN ₂ = 15 at% film, high H which is difficult to apply to a magnetic head of 240 [A / m] or more at all Fe concentrations.
c was shown. On the other hand, with a PN ₂ = 25 at% film, 7.5
By setting the Fe concentration to ˜12.5 at%, a low Hc of 80 [A / m] or lower was still exhibited, and this low Hc was stable even at a heat treatment of 700 [° C.]. Therefore, it can be seen that low Hc having excellent heat resistance can be obtained by increasing the Fe concentration. However, if the Fe concentration is increased too much, λs
Has the adverse effect of increasing.

FIG. 30 is a diagram showing the dependence of λs on the Fe concentration in a film heat-treated at 550 [° C.] and 700 [° C.] when manufactured with PN ₂ = 12.5 at%. 1
In the Fe concentration film of 2.5 at% or less, the absolute value of λs showed a low value of 3 × 10 ⁻⁶ or less after the heat treatment at 700 [° C.], but in comparison with the 15 at% Fe film, λs was 700.
Even after the heat treatment at [° C.], it showed a large value of 1 × 10 ⁻⁵ or more.

From the above results, when applied to the MIG head which requires heat treatment at about 550 [° C.], the Fe concentration is regulated within the range of 2.5 to 12.5 at%.
It can be seen that low Hc of 0 [A / m] or less and low λs of 3 × 10 ⁻⁶ or less are exhibited. Further, when applied to a laminate type head in which a glass welding temperature of about 650 [° C.] is desirable, it is necessary to set the Fe concentration to 7.5 at% or more and 12.5 at% or less.

Now, let us consider the reason why Hc increases as the Fe concentration decreases. It has been reported that, in a Co-based nitride film containing no Fe, columnar film growth occurs, so that perpendicular magnetic anisotropy easily occurs, and as a result, low Hc is not exhibited. Therefore, the shape of the magnetization curve and the film growth behavior were investigated. FIG. 31 shows a typical high Hc film (PN ₂ = 25 at).
%, Fe is not added), and a magnetization curve suggesting perpendicular magnetic anisotropy is obtained.

Therefore, FIG. 32 shows the relationship between the saturation magnetic field Hs and the Fe concentration, which are indexes of the perpendicular magnetic anisotropy. 2.5
When the Fe concentration decreased to at% or less, Hs increased and the perpendicular magnetic anisotropy became remarkable. Although it is not clear in the 5 at% Fe film, it can be seen that there is a correlation between the perpendicular magnetic anisotropy and the increase of Hc. Further, the result of examining the structure of the film cross section by FESEM is schematically shown in FIG. The 10at% Fe film has a smooth structure, but the Fe concentration film of 5at% or less has a clear spherical structure. The Fe concentration film of 5 at% or less has a rough structure, so it is expected that the magnetic interaction is blocked and the Hc is increased. It can be said that this is one of the causes of the high Hc in the 5 at% Fe film. Therefore,
By mixing Fe, the film growth becomes uniform, and as a result,
It can be seen that low Hc is obtained.

Furthermore, there is a strong correlation between the phase transformation behavior and the heat resistance of Hc, that is, the crystal grain size. This will be described in detail below. FIG. 34 is a diagram showing the relationship between the X-ray diffraction curve and the Fe concentration at each heat treatment temperature in the PN ₂ = 25 at% film. Further, FIG. 35 shows the diffraction peak strength (fcc) of the PN ₂ = 25 at% film in the heat treatment of 650 [° C.].
Phase (111) or bcc phase (110)) and half width Fe
It is a figure which shows a density dependence. Before any heat treatment, any Fe concentration film showed a markedly broad amorphous diffraction curve. When heat treatment is performed at 550 [° C.], 0 to 5 at%
In the Fe film, fcc phase crystallites are formed, and when Fe falls,
An increase in the strength of the black wire and a decrease in the full width at half maximum were observed. Also, Ta
The nitride was clear. On the other hand, 5 at 10 at% Fe film
The bcc phase was observed and the fcc phase was not observed in the heat treatment at 50 [° C.]. It can be seen that the diffraction peak is blown more, that is, the crystal grains are finer than the Fe concentration film of 5 at% or less. Further, when heat treatment is performed at 700 [° C.], even the 10 at% Fe film undergoes phase transformation into the fcc phase and Ta nitride, but it is clear that crystal growth is less likely to occur as compared with the Fe film at 5 at% or less. That is, it is understood that when the fcc phase and the Ta nitride are phase-separated through the bcc phase during the heat treatment, the heat resistance of the crystal grains is good, and as a result, soft magnetism excellent in heat resistance can be realized.
The reason why the heat resistance of the PN ₂ = 15 at% film is poor will be described later.

Although it has already been described that λs is related to the crystal structure, when the Fe concentration increases, even if the heat treatment is performed at 700 [° C.], the crystal structure mainly composed of bcc remains and the fcc phase remains. The appearance of was small. That is, when the Fe concentration is increased, the bcc phase is stabilized, so that a low λs cannot be obtained.

The above characteristics were the same even if Ta was replaced with Nb. (Embodiment 7) Next, an embodiment in which the Ta concentration (controlled by the number of Ta chips on the Co ₉₀ Fe ₁₀ alloy target) is changed will be described. The concentration of Fe in Co was 10 at% as in the target. PN ₂ was set to 25 at%.

FIG. 36 shows that the heat treatment temperatures are 550 [° C.] and 6
It is a figure which shows Ta concentration dependence of Hc in 50 [degreeC]. When the heat treatment temperature was 550 [° C.], the 5 at% Ta film showed a high Hc of 80 [A / m] or more, but when the Ta concentration became 5.7 at%, a low Hc of 80 [A / m] or less was obtained. Indicated. However, when the Ta concentration increased to 15 at%, Hc increased to 80 [A / m] or more, showing a magnetization curve suggesting perpendicular magnetic anisotropy similar to FIG. on the other hand,
When the heat treatment temperature is 650 [° C.], the range of Ta concentration at which low Hc can be obtained becomes narrower, and high Hc is shown at Ta concentrations of 7.2 at% or more and less than 15 at%, and 80 [A / m ] The following low Hc was shown. 550 [℃]
When the magnetic film of the present invention is applied to the MIG head which is required to have the above heat resistance, the Ta concentration exceeds 5 at% and is 1
When the magnetic film of the present invention is applied to a laminar type head which is required to have a heat resistance of 650 [° C.] or more, the Ta concentration is 7.2 at% or more and 15 at% or more.
It must be less than at%.

Next, the reason why Hc and its heat resistance change depending on Ta will be described. FIG. 37 shows a typical T
It is a figure which shows the heat processing temperature dependence of the X-ray-diffraction curve in a concentration film. For a 4 at% Ta film, Ta ≧ 5.7 at%
Unlike the amorphous or microcrystalline structure close to that in the film, the (200) peak and the (111) peak of the fcc phase were already clear before the heat treatment. Furthermore, the peak intensity was remarkably increased after the heat treatment, and no detectable peak of TaN was observed. Ta concentration is 4a
It can be seen that when t% or less, low Hc cannot be obtained because fine crystals cannot be obtained. On the other hand, in the case of Ta ≧ 5.7 at% film,
It exhibits an amorphous crystal structure before heat treatment and is 550
Even after the heat treatment at [° C.], no significant increase in the diffraction peak or no significant decrease in the half width was observed as compared with the 4 at% Ta concentration film. However, when the heat treatment was performed at 650 [° C.] or higher, the growth of batch peaks was clear in the 5.7 at% Ta concentration film, and the full width at half maximum was also reduced. That is, crystal growth was remarkable. As a result, it is considered that Hc increased in the heat treatment at 650 [° C.] or higher. Contrary to this, Ta
In the> 5.7 at% film, the increase in the diffraction peak and the decrease in the half value width were slight as compared with the 5.7 at% Ta film (FIG. 26).
reference). In addition, if the Ta concentration is increased to 15 at%,
(110) of the mother phase (bcc phase) mainly composed of Co and Fe
Diffraction peak intensity is weak, but clear Ta nitride and Co
A peak of Ta compound was observed. That is, the growth of non-magnetic inclusions is obvious, and this is considered to be one of the causes of the increase in Hc. PN ₂ = 2 for high concentration Ta film
Since the nitrogen concentration is too low under the film forming conditions of 5 at%, f
bcc phase and Ta nitride or C without phase transformation to cc
It may have undergone phase transformation into a mixed phase of the oTa compound. Therefore, a film having a Ta concentration of 15 at% was formed by increasing PN ₂ to 35 at%.
A magnetization curve showing a perpendicular magnetic anisotropy at a high Hc of 200 [A / m] was obtained. It can be seen that in the high-concentration Ta film, perpendicular magnetic anisotropy occurs when PN ₂ is increased even if the Fe concentration is increased. Further, the high PN ₂ film also had insufficient adhesion.

The above characteristics were the same even when Ta was replaced with Nb. (Embodiment 8) Next, an embodiment of the magnetic film in which the nitrogen concentration in the film is changed will be described. As the target, a composite target in which a Ta chip was added to a Co ₉₀ Fe ₁₀ alloy target so that the Ta concentration was about 8 at% was used. Nitrogen concentration in the film is PN ₂
It was adjusted by.

First, FIG. 38 is a diagram showing the relationship between PN ₂ and the nitrogen concentration in the film. It can be seen that the nitrogen concentration in the film increases approximately linearly as PN ₂ increases. FIG. 39 shows 5
PN of Hc after heat treatment at 50 [℃] and 650 [℃]
It is a figure which shows ₂ dependence. When the heat treatment temperature is 550 [° C.], PN ₂ = 7.5 at% (nitrogen concentration in the film: 2 at)
%) Shows a high Hc of 80 [A / m] or more, but PN ₂
= 12.5 to 35 at% (nitrogen concentration in the film: 4.8 to 14)
At%), low Hc of 80 [A / m] or less was exhibited. However, when PN ₂ was increased to 40 at% (nitrogen concentration in the film: 18 at%), film peeling occurred and Hc was 80 [A / A].
m] or more. On the other hand, the heat treatment temperature is 650 [° C]
In the case of, PN ₂ ≦ 15 at% (film nitrogen concentration 4.5a
t%) showed a high Hc of 80 [A / m] or more, but P
N ₂ = 17.5 to 30 at% (Nitrogen concentration in the film: 7 to 13)
In the range of at%), low Hc of 80 [A / m] or less was shown. However, PN ₂ was 35 at% (nitrogen concentration in the film: 14
When it was increased to at% or more), a high Hc of 80 [A / m] or more was exhibited, and film peeling occurred. From the above results, 550
In order to apply the magnetic film of the present invention to a MIG head which requires heat resistance of [° C.] or higher, PN ₂ is more than 7.5 at% and 40
Less than at% (Nitrogen concentration in the film exceeds 2 at% and 18 at
% Or less), and in order to apply the magnetic film of the present invention to a laminar type head that requires heat resistance of 650 [° C.] or higher, PN ₂ exceeds 15 at% and less than 35 at% ( It can be seen that it is necessary to set the nitrogen concentration in the film to more than 4.5 at% and less than 13 at%).

Next, the reason why Hc is increased in the low PN ₂ film and the high PN ₂ film will be described. FIG. 40 shows 80 [A / m]
More low PN2 film exhibited high Hc, i.e., a diagram illustrating a typical example of the heat treatment temperature dependence of the X-ray diffraction curve in the film nitrogen concentration is less film and a high PN ₂ film. The low PN ₂ film (PN ₂ = 15 at%) has the same bcc phase as the optimum nitrogen concentration film showing low Hc by heat treatment at 350 ° C. However, the heat treatment temperature increased to 550 [° C.] and Hc
As a result, the precipitation of Ta nitride and CoTa intermetallic compound became clear in addition to the mother phase mainly composed of Co and Fe in the bcc phase. Part of this precipitate peak has a narrow half-width and crystal growth is apparent. That is, it is understood that the reason why the heat resistance of Hc in a film having a low nitrogen concentration is not good is that nitrides and the like are easily precipitated from the bcc phase without phase transformation into fcc. On the other hand, even with a high PN ₂ film (PN ₂ = 40 at%), the heat treatment temperature is 350
At [° C], the same bcc as the optimum nitrogen concentration film showing low Hc
When the heat treatment temperature was increased to 550 [° C.], the phase transformation to the fcc phase was completed, and a considerable amount of Ta nitride peak was clearly observed. That is, it is understood that the reason why the heat resistance of Hc is not good in the film having a high nitrogen concentration is that the phase transformation from the bcc phase to the fcc phase is likely to occur, and as a result, the crystal grain growth is likely to occur. It can be seen that the nitrogen concentration in the film close to the Ta concentration is necessary for realizing high heat resistance.

The above characteristics were the same even when Ta was replaced with Nb. (Example 9) In the film shown above, when the Fe concentration is increased, λ
In some cases, s exceeded + 1 × 10 ^-6 . Considering the application to a magnetic head, it is desirable that λs be as small as possible. Therefore, when various kinds of additional elements were added to the film of Example 5 and experiments were carried out, when Pd or Re was added, FeA
Maintaining high Bs (1.1 [T] or more) exceeding 1Si,
Moreover, it has been found that λs = 0 can be almost realized without deteriorating the soft magnetism. As an example, FIG. 41 shows 550.
It is a figure which shows the Pd density | concentration dependence of Bs, Hc, and (lambda) s after [degreeC] heat processing. However, only PN ₂ was set to a value suitable for each Pd concentration, unlike the case of Example 5. This optimum P
N ₂ is 25 when the Pd concentration increases from 0 to 15 at%.
It fell from at% to 10 at%. From FIG. 41, P
As d concentration increases, λs shifts in the negative direction without increasing Hc, and λs = about 10 at% at Pd concentration.
It can be seen that 0 can be almost achieved. The Pd concentration at which λs became almost zero increased as the Fe concentration increased, and decreased when the heat treatment temperature increased to 550 ° C or higher. Further, Bs decreased to a value (1.1 [T]) similar to that of the FeAlSi film when the Pd concentration increased to 15 at%, but FeAlSi decreased at a Pd concentration of less than 15 at%.
It showed high Bs across the membrane.

[0099]

As described in detail above, the ferromagnetic film of the first aspect of the present invention maintains a high Bs of more than 1.3 [T] while maintaining a high Bs of 80%.
A low Hc of [A / m] or less can be realized. Therefore, by using the ferromagnetic film of the present invention, a magnetic head having excellent recording ability can be manufactured.

The ferromagnetic film of the second invention is 600
It exhibits soft magnetism with good heat resistance above [° C], and it can be expected to have good high-frequency characteristics due to its high resistivity, has good corrosion resistance, and can be manufactured with a wide manufacturing margin by ordinary RF magnetron sputtering. .. As a result, by using the ferromagnetic film of the present invention, a magnetic head having excellent recording ability can be manufactured. In particular, the ferromagnetic film of the present invention has 6
Since it has a heat resistance of not less than 00 [° C.], it can be applied to a wide range of magnetic heads including a MIG head and a laminated head that require a glass welding process.

[Brief description of drawings]

FIG. 1 shows a coercive force Hc of a ferromagnetic film according to the present invention.
The figure which shows the main diffraction peak intensity dependence of.

FIG. 2A is a diagram showing an X-ray diffraction curve in the vicinity of 2θ = 45 degrees for a CoFePd film and FIG. 2B for a CoFeTa film.

FIG. 3 shows the as-ma of the ferromagnetic film according to the present invention.
The figure which shows the additive element concentration dependence of the saturation magnetic flux density Bs in a de state.

FIG. 4 is a diagram showing an X-ray diffraction curve when the diffraction surface is tilted by a predetermined angle from a state parallel to the film surface.

FIG. 5 shows Hc and B for the ferromagnetic film according to the present invention.
The figure which shows Ta concentration dependence of s.

FIG. 6 shows Hc of Fe in the ferromagnetic film according to the present invention.
The figure which shows a density dependence.

FIG. 7 is a diagram showing an example of a magnetization curve of a film containing no Fe.

FIG. 8 is a schematic diagram of a ferromagnetic film according to the present invention.
The figure which shows a density dependence.

FIG. 9 is a diagram showing the concentration dependence of other additive elements of Hc in the ferromagnetic film according to the present invention.

FIG. 10 is a diagram showing the heat treatment temperature dependency of Hc for the magnetic film according to the present invention, using the amount of Al substitution for Ta as a parameter.

FIG. 11 is a diagram showing a relationship between Al substitution amount and Bs for a magnetic film according to the present invention which is heat-treated at 600 ° C.

FIG. 12 is a diagram showing the Al substitution amount dependency of the X-ray diffraction curve for the magnetic film according to the present invention, using the heat treatment temperature as a parameter.

FIG. 13 is a diagram showing a relationship between a heat treatment temperature and a full width at half maximum (FWHM) of a main peak of a film to which Al is not added and a magnetic film having an Al substitution amount of 50%.

FIG. 14 is a diagram showing the Al substitution amount dependency of the resistivity of the magnetic film according to the present invention which is heat-treated at 600 ° C.

FIG. 15 is a diagram showing the relationship between the nitrogen gas concentration and Hc of the magnetic film according to the present invention which is heat-treated at 600 ° C.

FIG. 16 is a diagram showing the dependency of Hc on the concentration b of the magnetic film according to the present invention which was heat-treated at 600 ° C.

FIG. 17 shows concentrations b and B of the magnetic film according to the present invention.
The figure which shows the relationship with s.

FIG. 18 is a sectional view of a thin film magnetic head corresponding to a longitudinal recording hard disk.

FIG. 19 is a cross-sectional view of a thin film magnetic head compatible with perpendicular recording.

FIG. 20 is a sectional view of a metal in-gap head.

FIG. 21 is a perspective view of a laminated head.

FIG. 22: PN ₂ = 25 at% deposited Co ₈₃ Fe ₉ film
Shows a thermal treatment temperature dependence of the magnetic permeability and Hc in ta ₈ film.

FIG. 23: PN ₂ = 25 at% deposited Co ₈₃ Fe ₉ film
Shows a thermal treatment temperature dependence of Bs and λs in a rotating magnetic field heat treatment in ta ₈ film.

FIG. 24: PN ₂ = 25 at% deposited Co ₈₃ Fe ₉ film
Shows a thermal treatment temperature dependence of Hk and permeability in a fixed magnetic field heat treatment in ta ₈ film.

FIG. 25: PN ₂ = 25 at% deposited Co ₈₃ Fe ₉ film
Shows a heat treatment time dependence of Hk and permeability at ta ₈ film.

FIG. 26: PN ₂ = 25 at% deposited Co ₈₃ Fe ₉ film
Shows a thermal treatment temperature dependence of the X-ray diffraction curve at ta ₈ film.

FIG. 27: PN ₂ = 25 at% deposited Co ₈₃ Fe ₉ film
Shows a thermal treatment temperature dependence of the half width and spacing of the X-ray diffraction main peak in ta ₈ film.

FIG. 28 is a diagram showing Hc concentration dependence of a film heat-treated at 550 ° C.

FIG. 29 is a diagram showing the Fe concentration dependence of Hc in an 8 at% Ta film after heat treatment at 650 ° C.

FIG. 30 is a diagram showing the Fe concentration dependence of magnetostriction.

FIG. 31 is a diagram showing an example of a magnetization curve showing a high Hc film in a CoTaN film.

FIG. 32 is a diagram showing the Fe concentration dependence of a saturation magnetic field.

FIG. 33 is a diagram showing a result of measurement of a film fracture surface by FESEM.

FIG. 34 is a graph showing the full width at half maximum of the X-ray diffraction main peak and the Fe spacing.
The figure which shows a density dependence.

FIG. 35 is a diagram showing the Fe concentration dependence of an X-ray diffraction curve.

FIG. 36 is a diagram showing Ta concentration dependence of Hc.

FIG. 37 is a diagram showing Ta concentration dependence of an X-ray diffraction curve.

FIG. 38 is a diagram showing PN ₂ dependence of nitrogen concentration.

FIG. 39 is a diagram showing PN ₂ dependence of Hc.

FIG. 40 is a diagram showing PN ₂ dependence of an X-ray diffraction curve.

FIG. 41 is a diagram showing Pd concentration dependence of Bs, Hc, and λs.

[Explanation of symbols]

 1 Substrate 2 Ferromagnetic film 3 Gap 4 First insulating layer 5 Coil 6 Second insulating layer 7 Ferromagnetic film 8 Protective film Substrate 11 Main pole 12 First insulating layer 13 Coil 14 Second insulating layer 15 Return path magnetic substance 16 Protection Film 17 Ferrite core 21, 22 Intermediate layer 23, 23 Ferromagnetic film 24, 24 Gap 25 Glass 26 Coil 27 Non-magnetic substrate 31, 31 Intermediate layer 32, 32 Ferromagnetic film 33, 33 Insulating layer 34, 34 Welding glass 35 , 35 substrate 36, 36 block 37, 38 glass for welding 39 coil 40

Claims (4)

[Claims] 1. A general formula Co _x Fe _y T _z (where T is Al, Ta, Ti, Zr, Nb, Hf,
It is at least one atom selected from the group consisting of Mo and W, and x, y, and z each represent a composition ratio in at%, and 73 <x <945 5 <y ≦ 151 <z <12 x + y + z = 100) A ferromagnetic film comprising an alloy represented by the above. 2. The general formula (M _a T _b ) _x N _y (where M is Co or Co and Fe, and T is T
at least one atom selected from the group of transition metals consisting of a, Nb, Zr, Hf, Ti, Cr, Mo and W and Al and N are nitrogen, and a, b, x and y are composition ratios, respectively. Is expressed as at% and 85 <a <96 4 <b <15 a + b = 100 80 <x <98 2 <y <20 x + y = 100 The content of Fe in M is 0 ≦ Fe ≦ 15 at% Al in T The ferromagnetic film is characterized by comprising an alloy represented by a content ratio of 4 <Al ≦ 50 at%). 3. A compound represented by the general formula (M _a T _b ) _x N _y (wherein M is Co and Fe, T is at least one atom selected from Ta or Nb, and N is nitrogen, Each of a, b, x, and y represents a composition ratio in at% and is expressed by 85 <a <95 5 <b <15 a + b = 100 82 <x <97.5 2.5 <y <18 x + y = 100). In the magnetic film made of the alloy described above, the content ratio of Fe in M is 2.5 ≦ Fe ≦ 12.5 at%. 4. The magnetic film according to claim 3, wherein the content of at least one atom selected from Pd and Re is 15 at.
%, The ferromagnetic film.