JPH08315316A - Thin film magnetic head - Google Patents

Abstract

PURPOSE: To obtain excellent protecting characteristics for a head and wear resistance during use by forming a head structural layer between an upper protective layer and a lower protective layer and forming a diamond-like carbon film as at least one of the protective layers. CONSTITUTION: On a substrate 2, a lower protective layer 11, reproducing head structural layer 12, separating layer 13, recording head structure layer 14, and upper protective layer 15 are successively formed. At least one of the upper protective layer and the lower protective layer 11 is made of a diamond-like carbon film. Since a diamond-like carbon film is excellent in wear resistance compared to an Al2 O3 film which has been conventionally used, the obtd. head has excellent protecting characteristics for a head during mechanical processing such as cutting and grinding and has excellent wear resistance during use.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film magnetic head used in a magnetic disk drive or the like for relatively moving on a magnetic recording medium to write or read information.

[0002]

2. Description of the Related Art A thin film magnetic head has excellent frequency characteristics, and high density recording is possible by miniaturizing a track width and a bit length. Therefore, a magnetic head for recording / reproducing in a magnetic disk device or the like. Is used as. .

FIG. 2 is a perspective view showing a thin film magnetic head used in such a magnetic disk device. With reference to FIG. 2, the thin-film magnetic head 1 includes an AlTiC (Al ₂ O
A thin film forming a thin film magnetic head is laminated in a direction A shown in FIG. 2 on a substrate 2 made of ( _3- TiC) or the like to form a head portion 10. The thin film magnetic head 1 shown in FIG. 2 is arranged in a magnetic disk device or the like so that the slider surface 1a faces the magnetic recording medium.

FIG. 1 is an exploded perspective view for explaining the head portion 10 shown in FIG. 2 in more detail. In FIG. 1, the shape of each constituent layer of the head unit 10 is simplified and shown, and is different from the shape of the head unit 10 shown in FIG. Referring to FIG. 1, a lower protective layer 11, a reproducing head constituent layer 12, a separation layer 13, a recording head constituent layer 1 are provided on a substrate 2.
4 and the upper protective layer 15 are sequentially stacked.

The reproducing head constituent layer 12 is a layer in which a magnetic head composed of, for example, a magnetoresistive effect element (MR element) is constituted. The MR element is an element whose electric resistance changes according to a change in an applied magnetic field, and a change in the magnetic field can be detected by applying a current to the MR element and detecting the change in the electric resistance. The information recorded on the medium can be read.

A separating layer 1 is formed on the reproducing head constituting layer 12.
The recording head constituting layer 14 is laminated with the recording layer 3 sandwiched therebetween. The recording head constituent layer 14 is formed with, for example, an inductive magnetic head. As shown in FIG. 1, when the recording head constituent layer 14 is provided separately from the reproducing head constituent layer 12,
The inductive magnetic head is provided as a recording-only magnetic head. The inductive magnetic head has a lower reproduction sensitivity than the MR thin film head, but since it can perform not only recording but also reproduction, it may be provided as a head for both recording and reproduction. In such a case, the lower protective layer 11 is provided on the substrate 2, the inductive thin film magnetic head for both recording and reproduction is provided on the lower protective layer 11, and the upper protective layer 15 is provided on the inductive thin film magnetic head. Is provided.

Reproducing head constituent layer 12 and recording head constituent
Layer 14 is a thin film magnetic layer formed by laminating thin films.
It is a layer of a laminated structure that constitutes a head. Like above
The thin-film magnetic head is generally the above head on a mother substrate.
The mother of each constituent layer of the part 10 was formed by laminating
Cutting the thin film magnetic head mother into individual thin film magnetic heads
Then, mechanical processing such as polishing is performed. Lower protective layer 11, upper
The part protection layer 15 and the separation layer 13 are formed by such machining.
In this case, it has a role of protecting the head portion. Also intervening
Also has the role of providing electrical insulation between layers
There is. Conventionally, as the material of such protective layer and separation layer
Is generally Al₂O ₃Is used.

[0008]

However, Al ₂
The hardness of O ₃ is about 1000 to 2000 kg / mm ² , and there is a problem that the head portion is damaged during polishing or the like. In order to protect the head, the film thickness is 3
It is necessary to have a thickness of about 0 μm to 40 μm, which causes a problem that it takes a long time to form the protective layer in the manufacturing process.

An object of the present invention is to provide a thin film magnetic head which is excellent in head protection characteristics and wear resistance and which can shorten the manufacturing process.

[0010]

A thin film magnetic head according to a first aspect of the present invention is a thin film magnetic head in which a head constituent layer is provided between an upper protective layer and a lower protective layer. At least one of the protective layers is formed of a diamond-like carbon coating. Such a thin film magnetic head is, for example, a thin film magnetic head in which an inductive magnetic head for recording and reproduction is provided in the head constituent layer.

A thin-film magnetic head according to a second aspect of the present invention is a recording head constituent layer in which a head constituent layer is provided between an upper protective layer and a lower protective layer, and the head constituent layer is laminated with a separation layer interposed therebetween. A thin-film magnetic head including a reproducing head constituent layer, characterized in that any one of an upper protective layer, a lower protective layer, and a separation layer is formed of a diamond-like carbon coating. As such a thin film magnetic head, for example, there is a merge type thin film magnetic head in which an inductive magnetic head is formed for recording in the recording head constituent layer and an MR head is formed in the reproducing head constituent layer for reproduction. Can be mentioned.

The diamond-like carbon coating in the present invention includes not only an amorphous diamond-like carbon coating but also a crystalline diamond coating. The hardness (Hv) of the diamond-like carbon coating is preferably 2000 kg / mm ² or more. The specific resistance is preferably 10 ⁷ Ω · cm or more.

When the diamond-like carbon coating in the present invention is amorphous and contains hydrogen, the hydrogen content is 5
% Or more, more preferably 15 to 15
20%. Here,% is atomic%.

In the present invention, when the upper protective layer or the lower protective layer is formed of a diamond-like carbon coating, the thickness thereof is preferably 20 μm or less, more preferably 5 μm or less.
μm to 20 μm. When the separation layer is formed of a diamond-like carbon coating in the present invention, the thickness thereof is preferably about 1 μm to 10 μm.

Further, in the present invention, in order to relax the internal stress of the diamond-like carbon coating and form a thin film with good adhesion, Si, Al and T are contained in the diamond-like carbon coating.
i, Zr, and at least one of these oxides and nitrides can be contained.

In the diamond-like carbon coating of the present invention, a stress relaxation layer made of at least one of Si, Al, Ti, Zr, and oxides and nitrides thereof may be provided. Such a stress relaxation layer is
The diamond-like carbon coating may be provided as an intermediate layer between the base layer and the diamond-like carbon coating, or may be provided so as to be interposed in the diamond-carbon coating. Further, a multilayer structure in which a plurality of such stress relaxation layers are interposed in the diamond-like carbon coating may be used. By providing such a stress relaxation layer in the diamond-like carbon coating, the stress at the time of forming the diamond-like carbon coating thin film can be relaxed, and the thin film can be formed with good adhesion.

[0017]

In the thin-film magnetic head of the present invention, the upper protective layer, the lower protective layer, or the separation layer is provided with a diamond-like carbon coating. The diamond-like carbon coating generally has a hardness higher than that of Al ₂ O ₃ used conventionally. Therefore, it is excellent in head protection characteristics in the polishing step and the like, and also in abrasion resistance.

Furthermore, since the film thickness can be made thinner than the conventional protective layer and separation layer using Al ₂ O ₃ , the protective layer or separation layer can be formed in a shorter time, and the manufacturing process Can be shortened. Furthermore, it is possible to improve yield and corrosion resistance in the manufacturing process.

[0019]

EXAMPLE According to the present invention, any one of the lower protective layer 11, the upper protective layer 15 and the separation layer 13 of the head portion 10 shown in FIG. 1 is formed by a diamond-like carbon coating. Further, when the head constituent layer is composed of an inductive magnetic head for recording / reproduction, etc., one of the lower protective layer 11 and the upper protective layer 15 is formed of a diamond-like carbon film. The method of forming such a diamond-like carbon coating is not particularly limited, but it can be formed using, for example, an ECR plasma CVD apparatus.

FIG. 3 is a schematic sectional view showing an ECR plasma CVD apparatus capable of forming a diamond-like carbon coating. Referring to FIG. 3, the vacuum chamber 28 includes
A plasma generation chamber 24 is provided. One end of the waveguide 22 is attached to the plasma generation chamber 24. The microwave supply means 21 is provided at the other end of the waveguide 22. The microwave generated by the microwave supply means 21 is guided to the plasma generation chamber 24 through the waveguide 22 and the microwave introduction window 23. The plasma generation chamber 24 is provided with a discharge gas introduction pipe 25 for introducing a discharge gas such as argon (Ar) gas into the plasma generation chamber 24. A plasma magnetic field generator 26 is provided around the plasma generating chamber 24. A high-density plasma is formed in the plasma generation chamber 24 by causing the high-frequency magnetic field generated by the microwave and the magnetic field from the plasma magnetic field generator 26 to act.

A cylindrical substrate holder 32 is provided in the vacuum chamber 28. The substrate holder 32 is rotatably provided around an axis (not shown) provided perpendicularly to the wall surface of the vacuum chamber 28. Board holder 3
Around the circumference of 2, a plurality of thin film magnetic head materials 33 to be substrates are mounted at equal intervals. The high frequency power supply 30 is connected to the substrate holder 32.

A metal cylindrical shield cover 34 is provided around the substrate holder 32 at a predetermined distance. The shield cover 34 is connected to the ground electrode. The shield cover 34 is provided in order to prevent electric discharge from being generated between the substrate holder 32 and the vacuum chamber 28 other than the film forming location by the RF voltage applied to the substrate holder 32 when the film is formed. There is.
The distance between the substrate holder 32 and the shield cover 34 is
It is arranged so that the distance is equal to or less than the mean free path of the gas molecules, and in this embodiment, 1 / m of the mean free path of the gas molecules.
The distance is about 5 mm, which is 10 or less.

An opening 35 is formed in the shield cover 34. Plasma drawn from the plasma generation chamber 24 is radiated to the thin film magnetic head material 33 mounted on the substrate holder 32 through the opening 35. A reaction gas introduction pipe 36 is provided in the vacuum chamber 28. The tip of the reaction gas introducing pipe 36 is located above the opening 35.

FIG. 4 is a plan view showing the vicinity of the tip of the reaction gas introducing pipe 36. Referring to FIG. 4, a reaction gas introducing pipe 36 is a gas introducing pipe 36a for introducing a raw material gas such as CH ₄ gas into the vacuum chamber from the outside, and a gas vertically connected to the gas introducing pipe 36a. Discharge part 36
b and. The gas discharge part 36b is arranged perpendicularly to the rotation direction A of the substrate holder 32, and is provided so as to be located on the upstream side in the rotation direction above the opening 35. The gas discharge part 36b has about 45 downwards.
A plurality of holes 41 are formed in the degree direction. In this embodiment, eight holes 41 are formed.

Using the ECR plasma CVD apparatus as described above, the plasma drawn from the plasma generating chamber 24 is radiated through the opening 35 onto the thin film magnetic head material 33 mounted on the substrate holder 32 to react. A diamond-like carbon film is formed on the thin film magnetic head material 33 by supplying a raw material gas such as CH ₄ from the gas introduction pipe 36.

Using a device as shown in FIG. 3, a diamond-like carbon film was formed on an AlTiC (Al ₂ O ₃ —TiC) substrate which is generally used as a substrate of a thin film magnetic head.

First, the inside of the vacuum chamber 28 is set to 10 ^-5 to 10 ^-7.
The gas is evacuated to Torr, the substrate holder 32 is rotated at a speed of about 10 rpm, and Ar gas is supplied from the discharge gas introducing pipe 25 to 5.
Supplied at 7 × 10 ⁴ Torr. Microwave supply means 2
From No. 1, a microwave of 2.45 GHz and 100 W was supplied to form Ar plasma in the plasma generation chamber 24. This Ar plasma was radiated to the surface of the AlTiC substrate through the opening 35. At the same time, the self-bias generated on the AlTiC substrate 33 is -10V, -20V,
An RF voltage of 13.56 MHz is applied to the substrate holder 32 from the high frequency power source 30 so that the voltage becomes −50 V and −150 V, and the CH ₄ gas is 1.3 × 10 ₃ from the reaction gas introducing pipe 36.
Supplied at ^-3 Torr.

As described above, the film thickness on the AlTiC substrate
A 1 μm diamond-like carbon coating was formed. As a comparison
On the AlTiC substrate by the ion plating method.
, Al₂O ₃A film was formed.

Regarding the coating film formed as described above,
The hardness (Vickers hardness) was measured. Table 1 shows the measurement results.

[0030]

[Table 1]

As is clear from Table 1, the diamond-like carbon film has a much higher hardness than the Al ₂ O ₃ film used conventionally. -20
A wear test was performed on a diamond-like carbon coating having a hardness of 3000 kg / mm ² formed by applying an RF voltage so as to have a self-bias voltage of V. A wear test was conducted by bringing a jig having abrasive grains attached thereto into contact with the diamond-like carbon film formed on the AlTiC substrate and reciprocating the jig. Wear resistance was evaluated by measuring the amount of wear. The amount of wear was calculated from the amount of wear in the depth direction.

For comparison, Al on the AlTiC substrate
_The wear resistance was similarly evaluated for the film having the ₂ O ₃ film formed thereon. As a result, the wear amount of the Al ₂ O ₃ film of Comparative Example was 1.5, while the wear amount of the diamond-like carbon coating film was 1. Therefore, it is understood that the diamond-like carbon coating has excellent wear resistance.

As is clear from the above results, the wear resistance in the case of using the diamond-like carbon coating is
_It can be seen that it is extremely superior to the ₂ O ₃ film. Therefore, it is understood that the head protection characteristic is excellent. Also,
Since the superior wear resistance, the conventional Al ₂ O ₃
In the case of a film, the upper protective layer and the lower protective layer are 30 μm
A film thickness of about 40 μm was required, but if the diamond-like carbon coating is used as the upper protective layer or the lower protective layer according to the present invention, the film thickness can be made smaller than before, for example, 10 μm or less. Can be

Further, the specific resistance of the diamond-like carbon coating shown in Table 1 is about 5 × 10 ⁸ Ω.
It was cm. Therefore, it can be seen that this diamond-like carbon coating has sufficient insulating properties required for the upper protective layer, the lower protective layer, and the separation layer. The hydrogen content in the diamond-like carbon coating formed with the self-bias voltage of −50 V was 13 atom%.

Next, in the thin film magnetic head having the laminated structure as shown in FIG. 1, a thin film magnetic head in which a diamond-like carbon coating was formed on the lower protective layer 11, the separation layer 13 and the upper protective layer 15 was produced. The diamond-like carbon coating is
It was formed using an apparatus as shown in FIG. Lower protective layer 1
The film thickness of 1 was 15 μm, the film thickness of the separation layer 13 was 3 μm, and the film thickness of the upper protective layer 15 was 15 μm. When the mother of the obtained thin film magnetic head was cut and subjected to polishing and the like, it was possible to manufacture it without damaging the head portion during such machining. Further, the obtained thin film magnetic head could be used without any problem in a normal recording / reproducing usage state.

Next, the diamond-like carbon film is coated with SiO.
An example containing ₂ will be described. As a device for forming a diamond-like carbon film, an EC as shown in FIG.
An R plasma CVD apparatus was used. The apparatus shown in FIG. 5 is an apparatus obtained by adding an ion sputtering apparatus to the ECR plasma CVD apparatus shown in FIG. Parts corresponding to those of the device shown in FIG. 3 are designated by the same reference numerals. Figure 5
In the device shown in FIG. 2, the second opening 43 is provided below the shield cover 34. A target 46 is provided near the second opening 43. Further, in the vacuum chamber 28, an ion gun 47 for emitting ions to the target 46 is provided. In this embodiment, a target made of Si is used as the target 46.

Using the apparatus shown in FIG. 5, a thin film containing SiO ₂ was formed on the diamond-like carbon film. First,
The inside of the vacuum chamber 28 is evacuated to 10 ⁻⁵ to 10 ⁷ Torr, and the substrate holder 32 is rotated at a speed of about 10 rpm. Next, oxygen is introduced into the vacuum chamber 28, Ar gas is supplied to the ion gun 47 to take out Ar ions, and the Ar ions are emitted to the surface of the target 46 made of Si. At this time, the acceleration voltage of Ar ions was set to 900 eV and the ion current density was set to 0.4 mA / cm ² . The oxygen partial pressure was 1 × 10 ⁻⁴ Torr.

Next, while supplying Ar gas at 2.0 × 10 ⁻⁴ Torr from the discharge gas introducing pipe 25 of the ECR plasma CVD apparatus, the microwave supplying means 21 to 2.4.
By supplying microwave of 5 GHz and 100 W, Ar plasma is formed in the plasma generation chamber 24, and the formed Ar is formed.
Plasma is radiated to the surface of the thin film magnetic head material 33 through the first opening 35. At the same time, an RF voltage of 13.56 MHz is applied to the substrate holder 32 from the high frequency power source 30 so that the self-bias generated in the thin film magnetic head material 33 becomes −20 V, and CH ₄ gas is supplied from the reaction gas introducing pipe 36. Supply at 3.0 × 10 ⁻⁴ Torr.

By performing the above steps for about 100 minutes, a diamond-like carbon coating film having a uniform thickness of 20 μm of SiO ₂ was formed on the AlTiC substrate as the material for the thin film magnetic head.

As described above, 20% by weight of SiO ₂ is used.
Fifty samples were prepared by forming the contained diamond-like carbon film on an AlTiC substrate and evaluated the adhesion.
For comparison, a sample in which a diamond-like carbon coating containing no SiO ₂ was formed on the AlTiC substrate was used.
Individual pieces were produced (self-bias voltage of −10 V) and the adhesion was evaluated. The adhesion was evaluated by an indentation test with a constant load (load = 1 kg) using a Vickers indenter. The number of peeled carbon coatings formed directly on the AlTiC substrate was counted to evaluate the adhesion.

[0041] In this result diamond-like carbon film not containing SiO _2, the release occurs number whereas was 10, flaking number is a diamond-like carbon film containing SiO ₂ was 0 .

Next, an example in which a diamond-like carbon coating film containing Si is formed will be described. The formation method is
Similar to SiO ₂ , it was formed by using an apparatus as shown in FIG. 5 without supplying oxygen into the vacuum chamber 28. Others were formed under the same conditions as in the case of SiO ₂ .

In the same manner as in the above example, 50 samples were prepared by forming a diamond-like carbon coating containing Si in an amount of 10% by weight on an AlTiC substrate, and the adhesion was evaluated. As a result, the number of peeling occurrences was 0.

Next, SiO₂Die stress relief layer consisting of
An example formed in a yamond-like carbon coating will be described.
It As the forming device, a device as shown in FIG. 5 is used,
Place the substrate on the substrate holder 32 below the first opening 35.
And a predetermined position below the second opening 43.
By fixing the position for a time
Formed. FIG. 6 is a cross-sectional view showing a laminated structure of thin films.
It As shown in FIG. 6, stress is applied on the AlTiC substrate 50.
SiO as a relaxation layer₂Layer (film thickness 1 μm) 51, diamond
Mond carbon coating 52 (film thickness 9 μm) 52, stress relaxation layer
As SiO ₂Layer (film thickness 1 μm) 53 and diamond
Bonded carbon coatings (film thickness 9 μm) 54 were sequentially formed. form
Except for the above-mentioned fixed position of the substrate holder,
Note SiO ₂Was carried out in substantially the same manner as in the examples containing.

Fifty samples were prepared by forming a diamond-like carbon coating having the above-mentioned laminated structure on an AlTiC substrate,
When the adhesion was evaluated in the same manner as in the above example, the number of peeled occurrences was 0.

As is clear from the above, SiO ₂
It is understood that the stress is relaxed and the adhesion is enhanced by providing the stress relaxation layer of the film. In the above-mentioned embodiments, the stress relaxation component or the stress relaxation layer is made of SiO ₂ and Si as an example. However, Al, Ti, Zr and their oxides and nitrides also improve the adhesion. It has been confirmed to be effective.

[0047]

In the thin film magnetic head of the present invention, the upper protective layer, the lower protective layer, or the separation layer is formed of a diamond-like carbon coating. The diamond-like carbon film is superior in wear resistance to the Al ₂ O ₃ film used conventionally. Therefore, it is excellent in head protection characteristics in machining such as cutting and polishing, and is also excellent in wear resistance during use.

Further, by using the diamond-like carbon film according to the present invention, the film thickness can be made thinner than before. Therefore, the process for forming a thin film becomes shorter than in the conventional case, and the manufacturing process can be shortened.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a thin film magnetic head composed of a recording head constituent layer and a reproducing head constituent layer in which head constituent layers are laminated with a separation layer interposed therebetween.

FIG. 2 is a perspective view showing an external shape of a thin film magnetic head.

FIG. 3 ECR used in an embodiment according to the present invention
The schematic sectional drawing which shows an example of a plasma CVD apparatus.

FIG. 4 is a plan view showing the vicinity of the opening of the device shown in FIG.

FIG. 5: ECR used in an embodiment according to the present invention
The schematic sectional drawing which shows the other example of a plasma CVD apparatus.

FIG. 6 is a sectional view showing a laminated structure of a diamond-like carbon coating in another example according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Thin film magnetic head 1a ... Slider surface of a thin film magnetic head 2 ... Substrate 10 ... Head part 11 ... Lower protective layer 12 ... Reproducing head constituent layer 13 ... Separation layer 14 ... Recording head constituent layer 15 ... Upper protective layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Seiichi Kiyama 2-5-5 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Co., Ltd.

Claims (8)

[Claims] 1. A thin film magnetic head having a head constituent layer provided between an upper protective layer and a lower protective layer, wherein at least one of the upper protective layer and the lower protective layer is formed of a diamond-like carbon coating. A thin film magnetic head characterized in that 2. A thin film magnetic comprising a head constituent layer provided between an upper protective layer and a lower protective layer, and the head constituent layer is composed of a recording head constituent layer and a reproducing head constituent layer laminated with a separation layer interposed therebetween. In the head, any one of the upper protective layer, the lower protective layer, and the separation layer is formed of a diamond-like carbon coating film. 3. The hardness of the diamond-like carbon coating is 2
The thin film magnetic head according to claim 1 or 2, which has a weight of 000 kg / mm ² or more. 4. The thin film magnetic head according to claim 1, wherein the diamond-like carbon film has a specific resistance of 10 ⁷ Ω · cm or more. 5. The thin film magnetic head according to claim 1, wherein the diamond-like carbon film has a hydrogen content of 5% or more. 6. The diamond-like carbon coating contains S
i, Al, Ti, Zr, and at least one of these oxides and nitrides are contained.
6. The thin film magnetic head according to any one of 5 above. 7. The diamond-like carbon coating contains S
7. The thin film magnetic head according to claim 1, further comprising a stress relaxation layer made of at least one of i, Al, Ti, Zr, and oxides and nitrides thereof. 8. The diamond-like carbon coating contains S
The thin film according to any one of claims 1 to 6, wherein a plurality of stress relaxation layers made of i, Al, Ti, Zr, and at least one of oxides and nitrides thereof are provided in between. Magnetic head.