JPH09274711A - Magnetoresistance effect magnetic head and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent discharge breakdown by an MR element by forming a base layer in such a manner that layer is Si-rich in the region near the slider and is C-rich in the region near a protective layer so as to increase the affinity near the adhesion region and forming an insulating hard carbon protective layer. SOLUTION: A base layer 2 and a protective layer 3 are formed on the floating face 1a of a slider 1. The base layer 2 contains C and Si in such a manner that the proportion (%) of C increases near the protective layer 3 while the proportion (%) of Si increases near the floating face 1a. Therefore, the affinity near the adhesion region can be increased and the base layer 2 adheres to the slider 1 as well as has high affinity with the protective layer 3. Moreover, the base layer has conductivity so that charges in the magnetoresistance effect MR element 6 and in the area near the element can be released through the slider 1 and a suspension 11 to the ground. The protective layer 3 consists of an insulating hard carbon and is formed into a diamond-like carbon or amorphous carbon film having 20 to 80Å thickness. Thereby, peeling of the protective layer from the slider and discharge breakdown by the MR element can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head used in a magnetic recording device such as a magnetic disk device, and more particularly to a magnetic head capable of preventing a magnetoresistive effect element provided in the magnetic head from being electrostatically destroyed. The present invention relates to a manufacturing method thereof.

[0002]

2. Description of the Related Art In recent years, the capacity of OSs and application software for personal computers has increased, and the recording density of hard disk devices has been increasing. Therefore, the conventional induction type head such as a thin film magnetic head is being changed to a magnetoresistive effect type magnetic head called an MR head. MR
A magnetoresistive effect element (MR element) used for a head has a resistance value that varies depending on a deviation angle between a magnetization direction of a film and a current direction, and a ferromagnetic material such as NiFe or NiCo is used. When reading information magnetically recorded on a magnetic disk using the MR element, the magnetization direction of the MR element changes due to the reversal of the magnetization direction of the magnetic disk medium. As a result, the electric resistance of the MR element changes. MR
By extracting the electric resistance change of the MR element as a voltage change between the terminals while applying a sense current to both terminals of the element,
You can read the recorded information.

With the progress of higher recording density, the recording bit becomes smaller and the recording magnetic field also becomes smaller. Therefore, the distance between the magnetic head and the magnetic disk is approaching several tens of nm. For this reason, the frequency of contact between the two has been increasing significantly. As described above, the MR element reads information while constantly passing a constant current, but a part of the sense current flows intermittently to the magnetic disk that is electrically grounded when both are in contact with each other, causing electrical noise. Could occur. As a result, the voltage change between the MR elements cannot be accurately read, which has a bad effect. Furthermore, a minute potential difference between the MR element and the magnetic disk causes a transient discharge current at the moment of momentary contact,
The MR element may cause damage called discharge breakdown. As a result, a part or the whole of the MR element is melted, and in the worst case, the MR element cannot operate. Furthermore, during manufacturing, electrostatic charges charged on the manufacturing equipment and workers flow to the MR element part,
Electrostatic breakdown (E) which causes breakdown by discharging exceeding the withstand voltage between the MR element and the shield layer arranged so as to sandwich the MR element.
There were two problems that SD occurred frequently.

First, the relationship between the structure of the MR head and the magnetic disk will be described with reference to FIG. As shown in the figure,
Slider 1 made of Al ₂ O ₃ -TiC which is a conductor
The MR element 6 is disposed on the outflow side end surface of the MR element 6 so as to be sandwiched between the shield layers 4 and 5. The end of the MR element 6 is exposed toward the medium surface of the magnetic disk 10. Further, a recording portion is formed next to the MR element 6 such that a magnetic core 7 sandwiching a coil is similarly exposed to the medium surface of the magnetic disk 10 with a predetermined gap width. And M
The R element 6, the shield layers 4 and 5, and the magnetic core 7 are electrically insulated and magnetically shielded from each other, and an insulating layer 8 made of an oxide such as Al ₂ O ₃ for holding and fixing them.
Are arranged on the slider 1 so as to cover them.

Next, a cutaway view of the vicinity of the MR element 6 is shown in FIG. Electrode lead-out terminals 6a are arranged at both ends of the MR element 6, and each of the electrode lead-out terminals 6a is connected to a lead wire 9 to the outside of the magnetic head. As described above, the MR element 6, the shield layers 4 and 5, and the slider 1
Are electrically insulated by an insulator 8. The lead wire 9 connected to the MR element 6 via the terminal 6a is connected to the reproducing circuit 12, and is maintained at a potential close to the ground potential even during non-operation and operation. Similarly, the magnetic disk 10 is also grounded via a supporting portion (not shown), and both the slider 1 and the MR element 6 are always in a state close to the ground potential. With such a structure, the end portion of the MR element 6 exposed toward the medium surface of the magnetic disk 10 is the magnetic disk 1.
The recording information can be read by the resistance change of the MR element 6 caused by the recording information of the magnetic disk 10 and facing 0 at a minute interval.

Next, the phenomenon of discharge breakdown when the MR element 6 and the magnetic disk 10 contact each other will be described. Although the MR element 6 is connected to the reproducing circuit 12 and is maintained in a state close to the ground potential as described above, it does not always match the ground potential of the magnetic disk 10. Therefore, there is a slight potential difference between the MR element 6 and the magnetic disk 10. Further, the surface of the magnetic disk 10 facing the surface of the MR element 6 and rotating at a high speed is coated with an insulating material, and electrostatic charge due to friction may be charged only on the surface. Often have a potential difference between them. Therefore, when the protrusion on the surface of the magnetic disk 10 and the surface of the MR element 6 are momentarily contacted with each other, a discharge current corresponding to the potential difference is transiently generated, and a discharge phenomenon occurs between the MR element 6 and the magnetic disk 10. Occur. Due to this phenomenon, the MR element 6 causes damage called discharge breakdown. Due to this damage, part or almost all of the MR element 6 is melted and the MR element 6 does not operate normally.

Further, during manufacture of the MR head, electrostatic breakdown of the MR element 6 has occurred especially in the HGA (head gimbal assembly) process of connecting the lead wire 9 to the MR head and adhering the suspension 11. In the MR head after the lead wire 9 is connected, it is easy to easily pick up the static electricity charged in the manufacturing apparatus or the worker to the lead wire 9. The external charge charged on the MR element 6 through the lead wire 9 is MR.
Although accumulated in the element 6, the electrostatic capacity of the MR element 6 rises because the capacitance is at most several picofarads, and the withstand voltage of the insulator 8 between the shield layers 4 and 5 and the MR element 6 is exceeded. Therefore, discharge occurs between the MR element 6 and the shield layer 4 or the shield layer 5, and electrostatic breakdown occurs in both. MR by this destruction
The element 6 and the shield layers 4 and 5 may be electrically short-circuited, or in the worst case, the MR element 6 itself may be melted, and the operation may not be performed at all. At the manufacturing workplace, grounding of the manufacturing equipment and installation of an antistatic sheet are taken as countermeasures, but it is possible to sufficiently prevent the MR element 6 in which the capacitance of the element itself is minimized due to thinning. It wasn't something. Of course, similar problems occur in the drive assembly process.

The discharge breakdown and electrostatic breakdown of the MR element have been described above. As a magnetic head which prevents this discharge breakdown, there is one disclosed in Japanese Patent Laid-Open No. 7-6340. In this magnetic head, an intermediate layer of hard carbon, silicon, boron, titanium, aluminum and their carbides, nitrides, and oxides is provided on the sliding surface of the slider, and a hard amorphous carbon film is provided thereon. The MR element covers the portion of the slider that is exposed on the sliding surface. The intermediate layer and the hard amorphous carbon film prevent potential difference breakdown of the MR element, and further improve CSS characteristics relating to wear resistance and lubricity with respect to the magnetic disk, and further, the intermediate layer and the protective film. It is said that the adhesion of can be improved.

Further, Japanese Patent Laid-Open No. 6-243434 discloses that
A magnetic head in which the MR element is prevented from being electrostatically destroyed is disclosed. In this magnetic head, the slider sliding surface has 1
A film having an electric resistivity of 00 μΩcm to 10 ⁶ Ωcm is provided to prevent discharge from occurring between the MR element and the magnetic disk. Further, Japanese Patent Laid-Open No. 7-93720 also discloses a magnetic head in which the MR element is prevented from being electrostatically destroyed. In this magnetic head, a mixed film containing silicon carbide and carbon is formed on the slider sliding surface, and M
Discharge is less likely to occur between the R element and the magnetic disk, and CSS characteristics are further improved.

[0010]

In the magnetic head using the MR element described in the above-mentioned prior art, in order to prevent the MR element from being electrostatically destroyed, the sliding surface of the slider is made of carbon, silicon or boron. There is one in which an electrostatic breakdown of the MR element is prevented by providing an intermediate layer made of, for example, and a hard carbon film thereon. However, when it is attempted to control the hardness and toughness of the hard layer in consideration of the compatibility of slidability with the magnetic disk, the stress due to the compressive stress of the hard layer itself causes peeling from the lower part of the hard layer, and In some cases, the adhesion of the hard layer was not sufficient. Further, since the MR element only covers the portion of the slider exposed on the air bearing surface with the insulator,
Although it is possible to prevent discharge breakdown due to the potential difference between the element and the magnetic disk, it is not possible to release the charge accumulated in the MR element from the outside such as an operator or a manufacturing apparatus during the manufacturing process or the drive assembly. However, electrostatic breakdown of the MR element cannot be sufficiently prevented. Further, in a magnetic head in which a film having an electric resistivity of 100 μΩcm to 10 ⁶ Ωcm is provided on the slider sliding surface, or a mixed film containing silicon carbide and carbon is formed, discharge breakdown and electrostatic breakdown of the MR element are caused. However, there is a problem in durability such as CSS characteristics of the film provided on the slider air bearing surface. Also, since the entire mixed film formed is conductive, it is possible to prevent the problem that a part of the sense current intermittently flows to the magnetic disk side when the MR element and the magnetic disk are in contact with each other, thereby causing electrical noise. This leads to a reproduction error when operating the MR element. Thus, C in the magnetic disk device
For an effective MR head that achieves SS characteristics, adhesion between the slider and the protective film, and reliability during reproduction, and at the same time not only during normal operation of the MR head, but also during the manufacturing process, to prevent destruction of the MR element. For the protective film of
It is not mentioned in any of the above-mentioned prior art.

Therefore, according to the present invention, in a magnetic head provided with an MR element, the discharge breakdown of the MR element is prevented, and the C
An underlayer is provided which has an effect of improving the SS characteristics and which can be attached to the air bearing surface of the slider with a large adhesive force, which is a protective layer having electrical insulation from the magnetic disk. It is another object of the present invention to provide the underlayer with a certain degree of conductivity so that electric charges in the vicinity of the MR element can easily escape to the slider ground side, and discharge breakdown and electrostatic breakdown of the MR element can be sufficiently prevented.

[0012]

According to the present invention, a magnetoresistive element is provided at a predetermined position of a slider, and
The above object is achieved in a magnetic head in which an air bearing surface is formed on a surface of a slider facing a magnetic recording medium. An underlayer and a protective layer are laminated on the air bearing surface of the slider of the magnetic head. In this underlayer, the slider side is Si-rich, the protective layer side is C-rich, and the protective layer is made of hard carbon. Characterize. In the above description, the underlayer has a concentration gradient in which the Si concentration decreases and the C concentration increases from the slider side toward the protective layer side. The base layer may be formed by alternately stacking a plurality of Si and C. Further, the underlayer may be formed of a mixed film of Si and C. Note that Si
Alternatively, a plurality of SiC and C are alternately laminated, and the amount of each lamination is appropriately adjusted to form a base layer. Then, by performing the film formation time of each layer for several tens of seconds to several minutes, each layer has no clear boundary and the underlayer becomes a mixed film. The protective layer is
It is an insulating film and can be formed of diamond-like carbon or amorphous carbon.

The air bearing surface of the MR head is formed by a grinding and lapping method. However, when comparing the MR element and the insulator holding and fixing the MR element with the slider material, there is a difference in hardness. Steps are created by processing. Also, a step difference of about 20 to 100 angstrom may be seen between the MR element and the insulator. Therefore, the base layer and the protective layer are formed as follows. That is, the underlayer is formed with a thickness of 10 to 60 Å. If the thickness is less than 10 angstroms, it becomes difficult to form the underlayer as a layer, and an island-shaped discontinuous film tends to be formed, and the conductivity between the MR element and the slider cannot be secured. Further, the protective layer does not serve as an adhesive layer. From the viewpoint of increasing the distance between the magnetic head and the magnetic disk, it is preferably about 60 angstroms or less. 2 protective layers
It is formed with a thickness of 0 to 80 angstroms. If it is thinner than 20 angstroms, it is easily corroded due to its material properties.
Corrosion of the R element is observed, and a thicker one is desirable from the viewpoint of long-term reliability and protection of the MR element. Therefore, the thickness of the protective layer is determined within the allowable range of the distance between the magnetic head and the magnetic disk. A material in which any one of SiC, Ge, and Ba is substituted instead of Si which is the component thereof can be applied to the above-mentioned underlayer. The resistivity of the underlying layer is 1Ω
cm to 10 ⁶ Ωcm. This is the MR of the slider
This is because electric charges charged in the vicinity of the element can be released to the holding member side of the slider to prevent electrostatic breakdown. As the slider material, a non-magnetic material containing carbide can be applied. Also, the main composition of the slider material is Al ₂ O ₃ --Ti
It can be C system or ZrO ₂ -Al ₂ O ₃ -TiC based.

The invention of a method of manufacturing a magnetoresistive effect magnetic head is characterized in that Si is used as an underlayer in the above magnetic head,
When a mixed film of C or SiC is obtained, the power supply power is applied to the Si target and the C target, and the balance of the film forming rates of the Si target and the C target are mutually changed,
It is characterized by forming a mixed film in which the content ratio of both is changed in the thickness direction. Further, while applying power source power to the Si target and the C target, instead of mutually changing the balance of the film forming rates, the Si target and the C target are alternately sputtered and the respective sputtering times are changed. You may do it. Further, instead of Si, any one of SiC, Ge or Ba may be used as a target. In the above magnetic head, the air bearing surface of the slider is provided with the underlayer which is Si-rich on the slider side and C-rich on the surface side. Therefore, the underlayer firmly adheres to the slider and the protective layer also serves as the underlayer. The layers adhere firmly to each other, and each layer provided on the air bearing surface of the slider is hard to peel off. Further, since the protective layer is formed of hard carbon, the CSS characteristics of the magnetic head are improved and the durability is increased. In addition, since the portion of the MR element provided on the slider that is exposed on the air bearing surface is covered with the underlayer and the protective layer, discharge is unlikely to occur between the MR element and the magnetic disk, and the MR element is electrostatically destroyed. Can be prevented. Furthermore, since the C-rich portion of the underlayer has a certain degree of conductivity, it is possible to dissipate the charges charged in the vicinity of the MR element of the slider to the ground side via the holding member of the slider, resulting in discharge breakdown and static electricity of the MR element. Electrostatic breakdown can be sufficiently prevented.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION In the magnetic head of the present invention, since the slider is made of a non-magnetic material and the air bearing surface is provided with an underlayer which is Si-rich on the slider side and C-rich on the protective layer side. The Si-rich portion, which is one of the materials that easily adapts to the slider material, enhances the affinity with the slider. Similarly, the affinity between the C-rich portion on the surface of the underlayer, which is easily adapted to carbon as a protective layer, and the protective layer is increased, and each layer provided on the air bearing surface of the slider is less likely to peel off. Further, the protective layer is formed of hard carbon. Therefore, the CSS characteristics of the magnetic head are improved and the durability is increased. Also,
Since the portion of the MR element provided on the slider that appears on the air bearing surface is finally covered with the protective layer of the insulating film, a part of the sense current is intermittently applied to the magnetic disk side when the MR element and the magnetic disk are in contact with each other. Since it does not flow into the electric field, electrical noise can be prevented. Furthermore, discharge is unlikely to occur between the MR element and the magnetic disk, and it is possible to prevent the MR element from being destroyed by discharge. Since the underlayer is composed of Si and C and has a certain degree of conductivity, the charge charged near the MR element of the slider has a larger electrostatic capacitance than that of the MR element, and the ground side via the slider body. You can escape to. As a result, the MR element can be sufficiently prevented from electrostatic breakdown even during head manufacturing and drive assembly.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an embodiment of a magnetic head provided with the MR element of the present invention. In the embodiment of the present invention, the same reference numerals are given to the same components as those described in FIG. 3 of the above-mentioned conventional example. Air bearing surface 1 of slider 1
In contrast to a, the underlayer 2 and the protective layer 3 according to the present invention are provided, and the underlayer 2 is formed so that the slider 1 side is Si-rich and the surface side is C-rich. Further, the underlayer 2 has a specific resistance of 1 Ωcm to 10 ⁶ Ωcm and is slightly conductive, and the MR element 6 provided at the magnetic medium outflow end of the slider 1 and a slider which is a conductor for electric charges in the vicinity thereof. 1 and further to the ground side via the suspension 11 supporting the slider 1. This specific resistance does not affect the reproducing operation of the MR element 6 and does not hinder the transfer of charges. The magnetic head of the present embodiment has the same structure as that of the conventional example shown in FIG. 3 except for the underlayer 2 and the protective layer 3 provided on the air bearing surface of the slider 1, and records and reproduces information on and from the magnetic disk 10. do.

As described above, in order to form each rich portion in the underlayer 2, a plurality of Si or SiC and C are alternately formed in sequence, and each deposition amount is appropriately adjusted and formed. The thickness of the underlayer 2 is such that the film does not become island-like and can be formed as a layer, and the gap between the MR element 6 and the magnetic disk 10 is made small, so that 1
It is formed in the range of 0 to 60 angstrom.

When the underlayer 2 was formed as described above, the film was formed by sputtering in this embodiment. For film formation, targets of Si and C are used as targets.
It was performed by a high frequency sputtering device. The conditions are Ar gas atmosphere, no substrate heating, and sputtering pressure is 1.3 Pa.
And RF power is 20 for 8 inch diameter target
The film formation was performed by bias sputtering with 0 to 300 W and a bias of about 100V.

The film forming procedure will be described below. Plasma cleaning is performed with the intention of cleaning the slider air bearing surface 1a and improving the adhesion. After that step, the steps of Si film formation and C film formation are alternately performed to form the underlayer 2. At this time, the sputter time is shortened from the initial set time for Si, and conversely is increased from the initial set time for C, to form the underlayer 2. The amount of film formation is C: S for each initial setting time.
Determine i to be 1: 9 or 2: 8. As another method of forming the underlayer 2, the Si target and the C target are simultaneously applied with the power supply of the sputtering, and the film formation rates are changed while the film formation rates are mutually changed. That is, on the slider air bearing surface 1a, the power source power is determined so that the film formation amount of Si is 1: 9 or 2: 8 with C: Si, Si is decreased and C is increased in reverse. While varying the amount, the air bearing surface 1a is made to be Si-rich and the surface of the underlayer 2 is made to be C-rich.

The protective layer 3 is made of insulating hard carbon, and is formed of either diamond-like carbon or amorphous carbon. The protective layer has a thickness of 20 to 80 Å. 20
Although a protective layer having a thickness of about angstrom can improve the CSS characteristics, a thicker layer is more preferable from the viewpoint of increasing the number of protective layers in consideration of long-term reliability and protection of MR elements that are easily corroded due to material properties. Further, it is necessary to determine whether the protective layer 3 is amorphous or diamond-shaped depending on the compatibility with the magnetic disk 10 serving as a magnetic recording medium, and the sputtering power and bias voltage and the gas pressure are controlled to obtain the optimum film quality and film thickness. However, good results described later were obtained. As another means, CH is used as a reactive gas.
There is a CVD method using a mixed gas of ₄ , H ₂ , and Ar. It is well known that information can be written at a high density by reducing the gap between the head and the disk which is the magnetic recording medium. However, if the gap becomes smaller, a thinner and more stable protective layer 3 is required, and even with CVD, the thickness is about 25 angstroms. It was confirmed that a stable protective layer could be formed.

In the MR head manufactured as described above, Auger electron spectroscopy analysis was performed from the surface of the protective layer 3 in the thickness direction of the air bearing surface 1a of the slider to obtain a distribution curve as shown in FIG. . In the Auger electron spectroscopy, the irradiation area was narrowed down as much as possible, but some elements that could be part of the slider body were also detected on the protective layer surface. For this reason,
In the figure, only Si and C are plotted for convenience, but the count of these total atoms is not necessarily 100%. FIG.
As can be seen from the above, C is present at the bonding portion between the protective layer 3 and the base layer 2.
Is about 50% (C rich) and Si is about 3%.
As the surface of the slider is approached, C decreases and Si increases little by little.
In the vicinity of the bonding area of C, C is about 18% and Si is about 30% (S
i rich). In this region, the Si sputtered particles also enter the slider material and form a kind of mixed layer. This is due to the effect of bias sputtering. C is 0
This does not occur because C of the slider material has been detected. As described above, the underlayer 2 has a concentration gradient that C% increases as it approaches the protective layer 3, and has a concentration gradient that Si% increases as it approaches the air bearing surface 1a of the slider and has affinity in the vicinity of each adhesion region. Can be raised.

The film breaking load of the magnetic head in which the hard magnetic layer was formed on the underlayer and the underlayer formed of only the Si film and having the above-described structure was evaluated by a scratch tester. The scratch tester gradually increased the load while vibrating a diamond needle having a radius of curvature of 5 μm in a width of 80 μm, and the load at the time when film peeling occurred was taken as the film breaking load.
When the underlayer was only the Si film, the load was broken at 22 mN, whereas in the magnetic head of this embodiment, it was 46 m.
The strength was almost double that of N.

Further, in the present invention, the density of the base film can be easily and arbitrarily set by changing the RF power, the bias voltage and the gas pressure. Table 1 shows the results of evaluation by changing the film thickness. In addition, the evaluation of the adhesive force was performed by using the scratch tester described above, and the needle load 1
Film peeling occurred at 0 mN or less was defined as film peeling.

[Table 1] As a result of assembling the magnetic heads of Examples 1 to 3 in the HGA process, the defect rate of the magnetic head due to electrostatic breakdown of the MR element was about 50% in the past, but no occurrence occurred. Further, no MR element destruction due to the discharge phenomenon was observed in the drive assembly either. As is clear from this, it was confirmed that the conductive underlayer according to the present invention sufficiently suppressed electrostatic breakdown and discharge breakdown. When preparing the samples of Examples 1 to 3 and Comparative Examples 1 and 2 in Table 1, a dummy substrate having an area such that the specific resistance of each underlayer can be measured was prepared at the same time, and their specific resistances were measured. As a result of measurement, those of Examples 1 to 3 were 1
It was -10 ⁶ Ωcm, but 10 in Comparative Examples 1 and 2.
It was ⁷ Ωcm or more.

Further, the magnetic resistance of the magnetic head in which the underlayer 2 is formed by alternately depositing a plurality of layers of C and Si to a thickness of 30 Å and the protective layer 3 is formed by changing the thickness of diamond carbon is used. , CSS characteristics were evaluated. The results are shown in Table 2. Note that the corrosion resistance was evaluated by observing the air bearing surface element portion after holding 100 sliders at a temperature of 70 ° C. and a humidity of 100% for 24 hours, and the ratio of the sliders in which corrosion occurred. Also, the CSS characteristics are 2.
The static friction coefficient (μ) was measured under the conditions of 5 inches, 5400 rpm and a spring load of 3.5 gf, and the case where the degree of increase in μ was small was defined as a pass.

[Table 2] As a result, the MR head according to the present invention has good corrosion resistance, no damage is observed in the protective layer even after 50,000 CSS cycles, and the insulation between the MR element and the magnetic disk can be ensured. The occurrence was suppressed and the reliability during playback was improved. The comparative example had problems in corrosion resistance and CSS characteristics. In the above examples, the Si target was used, but it was confirmed that the same effect can be obtained by using any one of SiC, Ge and Ba as the target instead of Si.

[0025]

As described above, in the magnetic head of the present invention, since the underlayer having the Si side on the slider side and the C side on the surface side is provided on the air bearing surface of the slider, the underlayer is the slider. And the protective layer also adhere to the underlayer with good affinity, the air bearing surface of the slider and the protective layer are difficult to separate, and CSS characteristics can be further improved. Also, M provided on the slider
Since the portion of the R element exposed on the air bearing surface is covered with the underlayer and the insulating protective layer of the present invention, discharge is unlikely to occur between the MR element and the magnetic disk, and the MR element is prevented from being destroyed by discharge. It can be prevented. Moreover, since a part of the sense current does not intermittently flow to the magnetic disk side when the MR element and the magnetic disk are in contact with each other, electrical noise can be prevented. Furthermore, since the underlayer is composed of Si and C and has a certain degree of conductivity, the charge charged near the MR element of the slider is
The element can be released to the ground side through the slider body having a larger capacitance than the element and the slider body.
As a result, the MR element can be sufficiently prevented from electrostatic breakdown even during the manufacture of the magnetic head and during the drive assembly.

[Brief description of drawings]

FIG. 1 is a schematic view of a magnetic head provided with an MR element of the present invention.

FIG. 2 is a composition explanatory diagram showing atomic% in a thickness direction of an underlayer and a protective layer of a magnetic head of the present invention.

FIG. 3 is an explanatory diagram of a flying state of a conventional magnetic head.

FIG. 4 is a cutaway view of a medium outflow side of a conventional magnetic head.

[Explanation of symbols]

 1 slider 1a air bearing surface 2 underlayer 3 protective layer 6 MR element

Claims (16)

[Claims] 1. A magnetic head in which a magnetoresistive effect element is provided at a predetermined position of a slider, and an air bearing surface is formed on a surface of the slider facing a magnetic recording medium. A magnetic resistance type magnetic head in which a protective layer is laminated, and the underlayer is Si-rich on the slider side and C-rich on the protective layer side, and the protective layer is made of hard carbon. 2. The magnetoresistive effect magnetic head according to claim 1, wherein the underlayer has a concentration gradient in which the Si concentration decreases and the C concentration increases from the slider side toward the protective layer side. 3. The magnetoresistive effect magnetic head according to claim 1, wherein the underlayer has a plurality of Si and C alternately stacked. 4. The magnetoresistive head according to claim 1, wherein the underlayer is a mixed film of Si and C. 5. The magnetoresistive effect magnetic head according to claim 1, wherein the protective layer is formed of diamond-like carbon. 6. The magnetoresistive effect magnetic head according to claim 1, wherein the protective layer is formed of amorphous carbon. 7. The magnetoresistive effect magnetic head according to claim 5, wherein the protective layer is an insulating film. 8. The magnetoresistive effect magnetic head according to claim 1, wherein the underlayer has a thickness of 10 to 60 angstroms. 9. The magnetoresistive effect magnetic head according to claim 1, wherein the protective layer has a thickness of 20 to 80 angstroms. 10. Instead of Si, which is a component of the underlayer,
10. The magnetoresistive head according to claim 1, wherein any one of SiC, Ge and Ba is substituted. 11. The specific resistance of the underlayer is 1 Ωcm to 10 ⁶ Ω.
The magnetoresistive effect magnetic head according to claim 1, wherein the magnetoresistive effect magnetic head is cm. 12. The magnetoresistive effect magnetic head according to claim 1, wherein the slider material is made of a non-magnetic material containing carbide. 13. The main composition of the slider material is Al ₂ O ₃
-TiC system or ZrO ₂ -Al ₂ O ₃ magnetoresistive head according to any one of claims 1 to 12, characterized in that a -TiC system. 14. A slider is provided with a magnetoresistive effect element at a predetermined position, and an air bearing surface is formed on a surface of the slider facing the magnetic recording medium. The air bearing surface of the slider is a slider material and an underlying layer thereon. And a protective layer. The underlayer is a method of manufacturing a magnetic head in which the slider side is Si-rich and the protective layer side is C-rich, and the protective layer is made of hard carbon. In doing so, by applying power source power to the sputtering by the Si target and the C target, the balance of the respective film forming rates is mutually changed,
A method of manufacturing a magnetoresistive effect magnetic head, comprising forming a mixed film in which the content ratio of both is changed in the thickness direction. 15. The Si target and the C target are replaced with each other while the power supply power is applied to the Si target and the C target so as to mutually change the balance of the film forming rates.
15. The method of manufacturing a magnetoresistive effect type magnetic head according to claim 14, wherein the sputtering with the target is alternately performed and the respective sputtering times are changed. 16. SiC, Ge or B instead of Si
16. The method of manufacturing a magnetoresistive effect magnetic head according to claim 14, wherein any one of a is used as a target.