JPH08167131A - Forming method of rail for floating thin film magnetic head, thin film magnetic head and magnetic disk device - Google Patents

Abstract

PURPOSE: To provide a rail for the floating face of a head to prevent redeposition by designing the angle of the side face of a mask to a specified range and ion milling a substrate while the substrate surface is tilted from the irradiation direction of ion beams by a specified range of angle and rotating the substrate. CONSTITUTION: A mask 41 having 37μm thickness is formed according to the desired rail shape by using a film-type photoresist on a substrate 8 comprising a ceramic material where the rail 2 for a floating face is to be formed. In this process, conditions of exposure, development, and the like are properly controlled so that the angle between the side face 70 of the mask 41 and the surface of the substrate 8 ranges from 50 deg. to 55 deg.. Then the substrate 8 is subjected to ion milling with ion beams 59 obtd. by generating plasma of inert gas such as Ar with microwaves to form a rail 2 for a floating face having desired depth, such as 6μm depth. During ion milling, the substrate 8 is rotated around the axis perpendicular to the surface to be processed while the rotation axis is tilted by a specified angle θ from the irradiation direction of the ion beams 59, for example, 45 deg..

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 having a so-called low flying non-linear air bearing surface rail having a small distance between a disk and a head, a magnetic disk device, and a non-linear air bearing surface rail in a thin film magnetic head. The present invention relates to a method for forming an air bearing surface rail of a thin film magnetic head for forming a magnetic field.

[0002]

2. Description of the Related Art As prior art, the contents described in Japanese Patent Publication No. 5-8488 and Japanese Patent Laid-Open No. 4-276367 are known. That is, in the former, a thin film magnetic head provided with a non-linear air bearing surface rail on which a protective film is formed, and a manufacturing method thereof are described. In the latter, a mask having a pattern corresponding to the shape of the negative pressure space is formed on the air bearing surface of the magnetic head rail substrate, the air bearing surface on which the mask is formed is irradiated with ions, and the negative pressure space is formed by ion milling. The method of forming the air bearing surface rail of the magnetic head for forming the magnetic head is described.

[0003]

In order to improve the recording density in the magnetic disk drive, it is necessary to reduce the flying height of the thin film magnetic head and stabilize it. In particular, formation of an air bearing surface rail that can reduce a change in flying height due to a difference in circumferential speed between the inner circumference and the outer circumference of a disk is an important issue for realizing high density recording.

However, in any of the above-mentioned prior arts, in order to realize high-density recording, it is possible to accurately form a defect-free non-linear air bearing surface rail in a thin film magnetic head by ion milling. Was not considered.

An object of the present invention is to solve the above problems.
In order to achieve high-density recording by reducing the flying height and stabilizing it, a non-linear air bearing surface rail with no defects can be formed with high precision by ion milling. It is to provide a method of forming.

Another object of the present invention is to provide a thin film magnetic head and a magnetic disk device which realizes high density recording by reducing the flying height and stabilizing the flying height.

[0007]

In order to achieve the above object, the present invention provides a mask having a pattern having a shape that corresponds to the shape of a non-linear air bearing surface rail, which is provided with an inclined flaring outward on the side surface. And a mask forming step of forming on the surface of the thin film magnetic head rail substrate on which the air bearing surface rail is formed, and the thin film magnetic head rail substrate on which the mask is formed in the mask forming step On the other hand, the surface on which the mask is formed is irradiated with the ions by being rotated at a predetermined angle with respect to a surface perpendicular to the surface, and ion milling is performed to a predetermined groove depth to form a non-linear air bearing surface rail. And a non-linear air bearing surface rail processing step for forming an air bearing surface rail of a thin film magnetic head.

Further, according to the present invention, a mask having a pattern having a shape corresponding to the shape of a non-linear air bearing surface rail, which is provided with an outwardly sloping side surface, is used as an air bearing surface rail of a thin film magnetic head rail substrate. A mask forming step of forming on the surface to be formed and a rail substrate for a thin film magnetic head on which a mask is formed in the mask forming step are tilted at a desired angle with respect to a plane perpendicular to the irradiation direction of the ions to be irradiated. And rotate the mask to irradiate the surface of the mask with the ions, and the sputtered particles are reattached to the side surface of the non-linear air bearing surface rail. The non-linear air bearing surface rail processing process is performed to increase the depth up to the depth and perform ion milling to form a non-linear air bearing surface rail with no reattachment layer on the side surface. A method of forming the air bearing surface rails of the thin-film magnetic head, characterized by.

Further, according to the present invention, a mask having a pattern that corresponds to the shape of a non-linear air bearing surface rail is provided, which is provided with an inclination that spreads outwards on the side surface, and the air bearing surface rail of a rail substrate for a thin film magnetic head is used. A mask forming step of forming on the surface to be formed and a rail substrate for a thin film magnetic head on which a mask is formed in the mask forming step are tilted at a desired angle with respect to a plane perpendicular to the irradiation direction of the ions to be irradiated. And rotate it to irradiate the surface of the mask with the ions, and sputter particles are reattached to the side surface of the non-linear air bearing surface rail. Non-linear air bearing surface rail machining process to increase the depth and perform ion milling to form a non-linear air bearing surface rail without reattachment layer on the side surface A method of forming the air bearing surface rails of the thin film magnetic head and having a.

Further, according to the present invention, a thin film magnetic head is provided with a mask having a pattern having a shape corresponding to the shape of a non-linear air bearing surface rail, which is inclined at a desired first inclination angle which spreads outward on the side surface. Forming step on the surface of the rail substrate for forming the air bearing surface rail, and a desired first inclination angle given to the side surface of the pattern in the mask forming step and the thin film magnetic head rail on which the mask is formed A rail substrate for a thin film magnetic head on which the mask is formed by setting or controlling a relationship between a desired second tilt angle with respect to a plane perpendicular to the irradiation direction of the irradiated ions applied to the substrate. Is rotated at an angle of the desired second tilt angle with respect to a plane perpendicular to the irradiation direction of the ions to be irradiated, and the ions are applied to the surface on which the mask is formed. The amount of sputtered particles is increased to a predetermined groove depth, and the amount of sputtered particles is reattached to the side surface of the non-linear air bearing surface rail by increasing the amount of processing to a predetermined groove depth. And a non-linear air bearing surface rail processing step of forming a non-linear air bearing surface rail having no layer.

Further, according to the present invention, a mask having a pattern that corresponds to the shape of a non-linear air bearing surface rail, which is provided with an inclination that spreads outward on the side surface, is used as the air bearing surface rail of a thin film magnetic head rail substrate. A mask forming step to be formed on the surface to be formed, and the thin film magnetic head rail substrate on which the mask is formed in the mask forming step are tilted at a predetermined angle with respect to a plane perpendicular to the irradiation direction of the ions to be irradiated. And a non-linear air bearing surface rail processing step of irradiating the ions on the surface on which the mask is formed by performing ion milling to a predetermined groove depth to form a non-linear air bearing surface rail. A mask removing step of removing a mask left on the non-linear air bearing surface rail formed in the linear air bearing surface rail processing step. A method of forming the air bearing surface rails of the thin-film magnetic head.

Further, according to the present invention, a mask having a pattern which corresponds to the shape of a non-linear air bearing surface rail is provided with an inclined surface which spreads outward on the side surface of a rail substrate for a thin film magnetic head. A mask forming step to be formed on the surface to be formed, and the thin film magnetic head rail substrate on which the mask is formed in the mask forming step are tilted at a predetermined angle with respect to a plane perpendicular to the irradiation direction of the ions to be irradiated. The surface of the mask is rotated and rotated to irradiate the ions to control the depth of the groove to be ion-milled to a predetermined groove depth and have a non-linear air bearing surface having a desired width. A method of forming an air bearing surface rail of a thin film magnetic head, comprising: a non-linear air bearing surface rail processing step of forming a rail.

Further, according to the present invention, a mask having a side surface having an outwardly sloping slope and having a pattern corresponding to the shape of a non-linear air bearing surface rail is used as the air bearing surface rail of a thin film magnetic head rail substrate. A mask forming step to be formed on the surface to be formed, and the thin film magnetic head rail substrate on which the mask is formed in the mask forming step are tilted at a predetermined angle with respect to a plane perpendicular to the irradiation direction of the ions to be irradiated. The surface of the mask is rotated and rotated to irradiate the ions to control the depth of the groove to be ion-milled to a predetermined groove depth and have a non-linear air bearing surface having a desired width. It is left on the non-linear air bearing surface rail processing step for forming the rail and the non-linear air bearing surface rail formed in the non-linear air bearing surface rail processing step. A method of forming the air bearing surface rails of the thin film magnetic head and having a mask removing step of removing the disk.

Further, the present invention provides a mask having a pattern having a shape corresponding to the shape of a non-linear air bearing surface rail, which is provided with an inclination that spreads outward on the side surface, and is used for the air bearing surface rail of a thin film magnetic head rail substrate. A mask forming step to be formed on the surface to be formed, and the thin film magnetic head rail substrate on which the mask is formed in the mask forming step are tilted at a predetermined angle with respect to a plane perpendicular to the irradiation direction of the ions to be irradiated. And rotate the surface of the mask to irradiate the ions with the ions to control the depth of the groove in time to perform ion milling to a predetermined groove depth to form a non-linear shape having a desired width. And a non-linear air bearing surface rail processing step of forming the above-mentioned air bearing surface rail.

Further, according to the present invention, a mask having a side surface which is inclined outwardly and having a pattern having a shape corresponding to the shape of a non-linear air bearing surface rail is used as an air bearing surface rail of a thin film magnetic head rail substrate. A mask forming step of forming on the surface to be formed, and rotating the rail substrate for the thin film magnetic head on which the mask is formed in the mask forming step, irradiating the surface on which the mask is formed with the ions to a predetermined groove depth And a non-linear air bearing surface rail processing step of forming a non-linear air bearing surface rail by ion milling.

In order to achieve the above object, the present invention further comprises a non-linear air bearing surface rail having an outwardly extending inclined side surface without a redeposition layer, and between the non-linear air bearing surface rails. A thin film magnetic head having a groove depth of 4 μm to 8 μm and an inclined surface formed in the bottom surface of the groove near the non-linear air bearing surface rail.

According to the present invention, the rail width is 80 μm to 12 μm.
A non-linear air bearing surface rail having an inclined side surface which is 0 μm and does not have a redeposition layer and extends outward, and a groove depth formed between the non-linear air bearing surface rails is 4 μm to 8 μm.
The thin film magnetic head is characterized in that an inclined surface is formed near the non-linear air bearing surface rail on the bottom surface of the groove.

The present invention also comprises a non-linear air bearing surface rail having outwardly flaring sloped sides without redeposition layers,
A thin film magnetic head having a groove depth formed between the non-linear air-bearing surface rails of 4 μm to 8 μm and an inclined surface formed near the non-linear air-bearing surface rail on the bottom surface of the groove is used as a magnetic disk. On the other hand, the magnetic disk device is characterized in that it is made to fly low and information is recorded on the magnetic disk by the thin film magnetic head.

[0019]

With the above structure, the change in the flying height due to the difference in peripheral speed between the inner circumference and the outer circumference of the magnetic disk is reduced,
Moreover, a non-linear air bearing surface rail having a desired groove depth that can secure a flying height of 100 nm or less and increase recording density and has no defect due to a reattachment layer or the like is formed by ion milling with high accuracy. As a result, it is possible to realize a stable thin film magnetic head and a magnetic disk device having high recording density and high reliability. In particular, by providing a very gentle inclined surface near the air bearing surface rail on the bottom surface of the groove formed between the non-linear air bearing surface rails, the air flow is made smoother and the levitation characteristics are improved. be able to. Further, since the non-linear air bearing surface rail can be formed by ion milling without causing a defect due to a reattachment layer or the like, a magnetic disk device having high reliability that does not damage the magnetic disk is realized. be able to.

Further, with the above structure, a desired groove capable of reducing the change in the flying height due to the difference in peripheral speed between the inner circumference and the outer circumference of the magnetic disk and ensuring the flying height of 100 nm or less to increase the recording density. Non-linear air bearing surface rails having a depth can be manufactured efficiently by ion milling without causing defects such as redeposited layers and with less variation.

[0021]

Embodiments of the present invention will be specifically described with reference to the drawings.

FIG. 1 is a diagram showing a main part of a magnetic disk device using a thin film magnetic head according to the present invention.
Is a perspective view, (b) is a side view showing the flying state of the thin-film magnetic head, and an enlarged view of the writing / reading section. The thin-film magnetic head 1 is made of a material composed of a mixture of alumina titanium carbide, a rail substrate 8 having a non-linear air bearing surface rail 2 shown in FIG. 2 on the air bearing surface for the magnetic disk 9, and the rail substrate 8. And a device forming section 20 formed with a write core and a magnetic gap control film, a coil, and the like, on which a write inductive device and a read magnetoresistive device are formed. . The thin film magnetic head 1 includes a spring 3
The magnetic disk 9 is supported by and moves in the radial direction of the magnetic disk 9. The non-linear air bearing surface rail 2 of the thin-film magnetic head 1 is used for writing information on the magnetic disk 9 by the inductive element formed in the element forming portion 20 and by the magnetoresistive element formed in the element forming portion 20. When the information recorded on the magnetic disk 9 is read out, the air flows in from the air inflow end 21 and flows out from the air outflow end 22 due to the rotational movement of the magnetic disk 9, and the flying height f = 100 nm or less from the substrate surface of the magnetic disk 9. It is necessary to achieve high recording density by levitating in the minute gap.

That is, when the thin film magnetic head 1 is levitated, as shown in FIG.
A spring-pressing type air bearing slider mechanism as shown in FIG. The air bearing slider mechanism is an air layer formed between the magnetic disk 9 and the non-linear air bearing surface rail 2 (specifically shown in FIG. 2) formed on the upper surface of the thin film magnetic head 1, that is, the air bearing surface. Bearing mechanism,
The flying height of the head 4 due to the spring pressing force of the spring 3 applied to the thin film magnetic head 1 from the outside and the rail floating force generated by the interface air between the thin film magnetic head 1 and the magnetic disk 9.
Is being adjusted. Here, the thin-film magnetic head 1 is in physical contact with the disk when the magnetic disk 9 stops rotating, whereas the thin-film magnetic head 1 is in contact with the disk when the magnetic disk 9 is rotating by the air flowing in from the air inflow end 21. An air bearing is formed to generate a levitation force, and the magnetic disk 9 and the thin-film magnetic head 1 are separated from each other and maintained at a predetermined distance (flying amount f). The inflowing air flows out from the air outflow end 22 of the element forming portion 20. The flying height f depends on the number of revolutions of the magnetic disk 9, the shape of the non-linear air bearing surface rail 2 of the thin film magnetic head 1, the spring force, etc., but is kept as low as possible in order to increase the recording density of the magnetic disk device. It is necessary to set the amount f to 100 nm or less. Therefore, the dimension of the non-linear air bearing surface rail 2 formed on the air bearing surface of the thin film magnetic head 1 in order to secure a constant flying height f is required to have high precision and high reliability without defects.

Here, the relationship between the flying height and the rail width W has the tendency shown in FIG. The relationship between the flying height and the rail groove depth tends to be as shown in FIG. FIG. 3 shows the relationship between the rail width and the flying height in the case where the rail groove depth is constant. The rail width W (as shown in FIG. 2 is thin at the center of the non-linear air bearing surface rail 2). It shows the part that became.)
The smaller is, the smaller the flying height is, and the higher recording density can be realized. FIG. 4 shows the relationship between the rail groove depth H ₀ and the flying height when the rail width is constant.
_{When 0} takes a certain value, the flying height f becomes a minimum of about 70 nm, and the flying height increases before and after that. As shown in FIG. 2, when the air bearing surface rail 2 has a non-linear shape, the flying height is minimized when the rail groove depth W is 5 μm to 6 μm. In such a case, the design value of the rail groove depth is 5 μm to 6 μm (the desirable range is 4 μm to 8 μ at which the flying height is about 90 nm or less).
m). From the relationship of FIG. 3, the rail width W is set to 80 in order to set the flying height f to about 100 nm or less.
It is necessary to set in the range of μm to 120 μm.

On the other hand, the geometrical shape of the rail surface is used to obtain a predetermined flying height in the air bearing, or to minimize the influence on rail manufacturing error and rail groove depth machining error, and further In order to reduce the change in flying height due to the difference in peripheral speed between the inner circumference and the outer circumference, a curved shape is used as shown in a non-linear air bearing surface rail (non-linear air bearing surface rail) 2 as shown in FIG.

Next, a method of manufacturing the thin film magnetic head 1 will be described with reference to FIG. In FIG. 5A, a magnetic core, a magnetic gap regulating film, a coil, etc. are formed on a ceramic substrate 31 made of a material composed of a mixture of alumina titanium carbide using a thin film manufacturing process similar to that of an LSI. An element forming process for forming an element 32 including an inductive element for writing and a magnetoresistive element for reading is shown. FIG. 5B shows a cutting process in which the element formed in the element forming process is cut into a predetermined size to produce the head block 33 shown in FIG. 5C. Then, both surfaces of the head block 33 are polished to manufacture the head block 33 having a desired thickness. The head block 33 whose both surfaces are polished in this way
FIG. 5D shows a head block setting process for setting the head block fixing jig 34 on the head block fixing jig 34. Then, as will be described later, a mask 41 having a pattern having an inclined side surface that expands upward is formed on the head block 33 set on the head block fixing jig 34 by photolithography, and thereafter, a non-linear shape is formed by ion milling. The air bearing surface rail 2 is formed, and thereafter, it is cut into each element, whereby the thin film magnetic head 1 shown in FIGS. 1 and 2 is manufactured.

That is, as described above, the non-linear air bearing surface rail 2 has a complicated shape, and due to the necessity of highly accurate processing, it is formed by the dry processing technique, particularly the ion milling technique. . This dry processing technology uses photolithography to form a mask pattern that matches the rail shape, uses this pattern as a mask to irradiate the ion beam, and then etches the rail substrate (ion milling processing). This is a method of removing the mask 2 and forming the non-linear air bearing surface rail 2.

First, a method of forming the mask 41 will be described. A film-shaped photoresist is used as the mask material, and the compounding ratio of the sensitizer, photosensitizer, photopolymerization initiator, dye, etc. of the photoresist is changed, and the exposure conditions (for example, negative and positive are different but tilted). Change the exposure conditions according to the angle.) ・ Change the development conditions,
The initial mask section inclination angle β ₀ that spreads upward (the mask section inclination angle β is the angle formed by the straight line drawn on the side surface 70 of the mask 41 and the surface of the rail substrate 8 as shown in FIG. 8A). 8B, when the developed mask pattern has a hem, the angle between the longest straight line portion of the side surface 70 of the mask 41 and the surface of the rail substrate 8 is 40. Predetermined angle within the range of ° to 70 ° 50 ° to 55
Has a side surface of 20 ° and an initial mask film thickness T ₀ of 20 μm to 10 μm.
The rail substrate 8 for forming the air bearing surface rail 2 of the head block 33 is the ion milling mask 41 having a non-linear pattern formed with a predetermined 37 μm within the range of 0 μm.
Formed on the surface of.

Next, a method of forming the non-linear air bearing surface rail 2 by ion milling will be described.
That is, the ion milling apparatus has (1) a thermoelectron generating filament, toroidal motion is applied to the thermoelectrons generated from this filament by an external magnetic field, and plasma is generated by efficient ionization of the active gas, An ion milling system that draws active ions (ion beams) from the plasma through the electrodes
(2) Electron cyclotron resonance (Electron Resonance) with microwave and external magnetic field
Cyclotron Resonance) to generate plasma by efficient ionization of active gas, and extract active ions from the plasma from the electrode,
There is an ion milling apparatus (apparatus shown in FIG. 6) having an ECR ion source of a processing type.

The ion milling apparatus shown in FIG. 6 includes a microwave oscillator 51 for generating a microwave and a waveguide 52 for guiding the microwave oscillated by the microwave oscillator 51 to the plasma generation chamber 53. , The waveguide 52
Introduction window 54 for introducing the microwave guided by the plasma generation chamber 53, and an active gas (Ar gas or Ar gas and fluorohydrocarbon gas (C ₂ H ₂ F ₄ gas) ionized in the plasma generation chamber 53. ) Mixed gas, or SF ₆
Gas, a mixed gas of SF ₆ gas and Ar gas, or a mixed gas of SF ₆ gas and fluorohydrocarbon gas (C ₂ H ₂ F ₄ gas), and a plasma generation chamber A solenoid coil 56 which is an external magnetic field generating means for ionizing the active gas supplied by the gas supply means 55 in 53 with the microwave introduced from the introduction window 54 by electron cyclotron resonance to generate plasma. The permanent magnet 57 that forms a magnetic field along the wall that prevents the plasma generated in the plasma generation chamber 53 from striking the wall and disappearing, and the plasmatized ion beam 59 generated in the plasma generation chamber 53 are sampled. Ion beam extraction electrode 58 for irradiating the chamber 60
It has and.

A head block fixing jig 34 is mounted in the sample chamber 60, and a line perpendicular to the surface of the rail substrate 8 forming the air bearing surface rail 2 of the head block 33 with respect to the irradiation direction of the ion beam 59 ( Rotation axis) tilt angle θ = about 4
Substrate tilt rotary table mechanism 6 that tilts and rotates at 5 °
1 is provided. The substrate tilt angle θ is an angle formed by the irradiation direction of the ion beam 59 and a vertical line (rotation axis) on the surface of the rail substrate 8. Then, the substrate tilt rotary table mechanism 6
1 is configured to be driven and controlled so as to rotate about the rotation axis, and the substrate inclination angle θ can be further changed. Further, the substrate tilt rotation table mechanism 61 may be configured to automatically drive and control the substrate tilt angle θ. Further, the substrate tilt rotary table mechanism 61 is provided with a substrate cooling mechanism 62 for cooling the mounted head block fixing jig 34.

An exhaust means 63 is connected to the sample chamber 60. Further, the replacement of the head block fixing jig 34 on the substrate tilt rotary table mechanism 61 in the sample chamber 60 is performed by opening and closing the load lock mechanism 64. Ion milling is performed by plasma ion source (plasma generation chamber) 5
The cations 59 of Ar are extracted from the sample 3 using the ion extraction electrode 58, and this is irradiated to the rail substrate 8 on which the mask 41 is formed. Ar as gas
, Acceleration voltage 800V, ion current density 0.5mA
/ Cm ² , and the degree of vacuum in the sample chamber 60 is 2 × 10 ⁴ (torr). The control of the machining groove depth H is performed by, for example, the control device 65.
In the above, the ion beam 59 is controlled from the time when the irradiation of the ion beam 59 is started by controlling the ion extraction electrode 58 and the like.
The time it takes to stop the irradiation is monitored. In this way, even if the processing groove depth H is controlled during the irradiation time of the ion beam 59, it is possible to secure the variation of the groove depth H within ± 0.2 μm. Further, a sample for processing depth monitor (for example, a film made of the same material as the rail substrate 8 and having a thickness corresponding to a desired groove depth H ₀ is formed on the surface of the metal on the head block fixing jig 34. It is possible to detect a desired groove depth H ₀ by detecting a secondary ion, a secondary electron, etc. obtained from the above). Even in this case, the groove depth can be detected with the same accuracy (variation).

FIG. 7 shows a modeled process of the air bearing surface rail 2 by ion milling when a mask 41 such as a photoresist is used. At the same time that the mask 41 is etched by the ion beam 59, the rail substrate 8 is also etched to form the air bearing surface rail 2. Here, the etching rates of the mask 41 and the rail substrate 8 are generally determined by the incident angle dependence of the ion milling speed shown in FIG. That is, in FIG. 9, the upper surface of the mask 41 is processed by changing the ion beam incident angle to 4
The ion milling speed is 5 degrees (substrate tilt angle θ = about 45 °), and the side surface 70 of the mask 41 is approximately the mask section tilt angle β (initial mask section tilt angle β ₀ = 55 °) to the tilt angle of the substrate. Processing is performed at an ion milling speed (see FIG. 9) corresponding to an incident angle of 10 ° obtained by subtracting θ (about 45 °). Similarly, the bottom surface 73 of the groove between the air bearing surface rails 2 is processed by ion beam incidence angle of 45 degrees (substrate inclination angle θ =
The ion milling speed is about 45 °, and the side surface 72 of the air bearing surface rail 2 is commensurate with the incident angle obtained by subtracting the tilt angle θ (about 45 °) of the substrate from the tilt angle α of the rail cross section of the air bearing surface. Processed at ion milling speed. However, when the ion milling is actually carried out, the processing speed is complicated not only by the dependence of the ion milling speed on the incident angle. In addition to the above-mentioned milling action, the particles 7 sputtered by the ion beam 59 are
1 is again the side surface 72 of the air bearing surface rail 2 or the bottom surface 7 of the groove.
This is because the phenomenon of adhesion to No. 3, that is, the re-adhesion phenomenon occurs.

FIG. 10 is a diagram showing a change over time in the cross-sectional shape of the air bearing surface rail 2 including the mask 41 when the rail substrate 8 is not tilted (the substrate tilt angle θ is 0 °) and ion milling is performed. is there. From this figure, the cross-sectional shape of the mask 41, particularly the mask cross-sectional inclination angle β and the rail cross-sectional inclination angle α
However, it can be seen that it changes with time.

In FIG. 11, the film thickness T _{0 of the} mask 41 is 37.
μm, and the inclination angle θ (substrate inclination angle θ) of the rail substrate 8 in the substrate inclination rotary table mechanism 61 is set to 45 °.
The rotation speed of the rail substrate 8 in the substrate tilt rotary table mechanism 61 is set to 10 rpm, and the initial mask sectional tilt angle β _0.
When the air bearing surface rail 2 is formed by performing the ion milling process on the rail substrate 8 whose 40 ° to 90 ° are changed in steps of 10 °, the mask 41 after the ion milling process is performed.
And the cross-sectional shape of the air bearing surface rail 2. As is clear from this figure, the smaller the initial mask sectional inclination angle β ₀ , the smaller the sectional inclination angle of the air bearing surface rail 2 and the smaller the rail width. Further, the inclined slope 110 is formed on the bottom of the groove between the air bearing surface rails 2 because the rail substrate 8 is rotated with the inclination angle θ of the rail substrate 8 (substrate inclination angle θ) set to 45 °. Mask 41 and air bearing surface rail 2
Is generated because the ion beam 59 is not irradiated to the bottom when is located above. This phenomenon is because when the initial mask cross-sectional tilt angle β ₀ approaches 90 °, the mask 41 blocks more of the ion beam 59 and does not irradiate the bottom, so that a more tilted slope 110 is formed. become.

In FIG. 12, the film thickness T _{0 of the} mask 41 is 37.
μm, and the inclination angle θ (substrate inclination angle θ) of the rail substrate 8 in the substrate inclination rotary table mechanism 61 is set to 45 °.
The air bearing surface rail 2 was formed by ion milling the rail substrate 8 in the substrate tilt rotary table mechanism 61 at a rotation speed of 10 to 20 rpm so that the groove depth H ₀ was 6 μm. FIG. 6 is a diagram showing the relationship between the initial mask cross-sectional inclination angle β ₀ and rail width accuracy (μm / μm). The rail width accuracy (μm / μm) is the rail width W when the groove depth H varies ± 1 μm.
The ratio (in μm) of the variation of (the minimum width of the center of the non-linear air bearing surface rail shown in FIG. 2) is shown.
When the groove depth H is ion milled with a variation of ± 0.2 μm or less, the variation of the rail width W is rail width accuracy × ± 0.2 μm. As is clear from this figure, the initial mask taper angle (initial mask section inclination angle) β
_{When 0} is about 90 °, the side surface 70 of the mask 41 and the side surface 72 of the air bearing surface rail 2 move when the mask 41 and the air bearing surface rail 2 are located above due to the rotation of the rail substrate 8. It can be seen that the ion beam 59 is blocked by the surface rail 2 and the amount of the redeposited layer formed by the sputtered particles 71 is slightly larger than the amount of the ion milling process, and therefore it is almost independent of the groove depth. That is,
It depends on the accuracy of the mask. On the other hand, as the initial mask taper angle (initial mask cross-sectional inclination angle) β ₀ becomes smaller than 90 °, the side surface 70 of the mask 41 is ion-milled more than the redeposition amount, and the accuracy of the groove depth is improved. On the other hand, when the initial mask taper angle (initial mask sectional inclination angle) β ₀ is 60 °, the rail width accuracy is 1
μm / μm, the initial mask taper angle (initial mask section inclination angle) β ₀ is 40, and the rail width accuracy is 3.7.
μm / μm. This phenomenon can also be seen from the final cross-sectional shape of the air bearing surface rail 2 shown in FIG. As described above, since the variation of the groove depth H ₀ can be set to ± 0.2 μm or less, the variation of the mask width W is suppressed to ± 2 μm, and the stable flying characteristic of the thin film magnetic head 1 is secured. To set the rail width accuracy target value to 1
It may be set to 0 μm / μm or less. As described above, when the inclination angle θ of the rail substrate 8 (substrate inclination angle θ) is 45 °, if the initial mask sectional inclination angle β _{0 is} 40 ° or more, the rail width accuracy target value of 10 μm / μm Can be satisfied with a sufficient margin. However, if the initial mask sectional inclination angle β ₀ is less than 40 °, as described above, when the mask 41 is formed on the rail substrate 8 by photolithography in the mask forming step, variations in exposure and development may occur. It becomes large, and it becomes difficult to obtain a mask with high dimensional accuracy, and the width and shape accuracy of the air bearing surface rail 2 obtained after ion milling also deteriorate. Therefore, it is desirable that the initial mask sectional inclination angle β ₀ is 40 ° or more.

In FIG. 13, the film thickness T _{0 of the} mask 41 is 37.
μm, and the inclination angle θ (substrate inclination angle θ) of the rail substrate 8 in the substrate inclination rotary table mechanism 61 is set to 45 °.
When the rotation speed of the rail substrate 8 in the substrate tilt rotary table mechanism 61 is set to 10 rpm and the air bearing surface rail 2 is formed by performing ion milling processing on the rail substrate 8 so that the groove depth H ₀ becomes 6 μm. It is a figure showing the relation between the initial mask cross-sectional inclination angle β ₀ and the redeposition thickness (μm). As is clear from this figure, when the initial mask taper angle (initial mask cross-sectional inclination angle) β ₀ is 90 °, when the mask 41 and the air bearing surface rail 2 are located above due to the rotation of the rail substrate 8, the mask 41 and the air bearing surface rail 2 block the ion beam 59, and the side surface 72 of the air bearing surface rail 2 is formed by the ion milled sputtered particles 71 from the groove bottom 73 rather than the ion milling amount.
The amount of the redeposited layer deposited on the substrate is slightly increased, and the accumulated redeposited layer cannot be removed, and the redeposited layer 10 having a thickness of 1 μm remains. On the other hand, the initial mask taper angle (initial mask sectional inclination angle) β ₀
Is smaller than 90 °, the side surface 7 of the mask 41
0 is also ion-milled, and the side surface 72 of the air bearing surface rail 2 is also ion milled, so that the sputtered particles attached to the side surface 72 of the air bearing surface rail 2 are also processed and removed, and the thickness of the redeposited layer 10 is increased. Is decreasing. Then, the initial mask taper angle (initial mask sectional inclination angle) β
_{When 0} becomes 60 ° or less, the ion milling speed becomes higher than the redeposition speed attached to the side surface 72 of the air bearing surface rail 2, that is, the ion milling processing amount is larger than the redeposition amount in total. Therefore, the redeposition thickness from the side surface 72 of the air bearing surface rail 2 can be zero, that is, the redeposition layer 10 can be eliminated.

After the ion milling process, as shown in FIG. 14, in the mask removing step, the air bearing surface rail 2 is made of an organic solvent.
Remove the mask left over. However, if the redeposition layer 10 is present on the side surface 72 of the air bearing surface rail 2, the redeposition layer 10 is the rail substrate material sputtered and adhered. Therefore, in the mask removing step, the redeposition layer 10 is removed with an organic solvent. It is not possible. Further, the attached redeposited layer 10 cannot be removed by oxygen plasma ashing. Thus, after the ion milling process is completed, the reattachment layer 10 that remains attached to the side surface 72 of the air bearing surface rail 2 remains.
It is difficult to reliably remove the air bearing surface rail 2 without damaging it. On the other hand, if the thin film magnetic head 1 is mounted and operated while the redeposition layer 10 is not completely removed, the magnetic disk 9 is damaged and the recorded information is also lost, resulting in a failure. Therefore, it must be removed at the end of the ion milling process.

On the other hand, FIG. 15 shows the inclination angle θ of the rail substrate 8.
(Substrate tilt angle θ) and substrate ion milling speed (μm /
The relationship with h) is shown. As is clear from this figure, when the substrate tilt angle θ is 45 °, the substrate ion milling speed (μ
m / h) is maximized, and the air bearing surface rail 2 can be ion-milled most efficiently. The substrate ion milling speed (μm / h) is preferably 1 μm / h or more, and thus the substrate inclination angle θ is in the range of 23 ° to 60 °.

As described above, when the substrate tilt angle θ, which has the highest ion milling efficiency, is set to 45 ° by setting or controlling the substrate tilt rotary table mechanism 61, the redeposition layer 10 is removed and the surface is floated. In order to satisfy the width accuracy of the surface rail, in the mask forming step described above, the exposure condition and the developing condition are set or controlled so that the initial mask section inclination angle β ₀ is 40 ° to 60 °. is necessary.

Next, the substrate tilt angle (substrate holder tilt angle) θ
A case other than 45 ° will be described. That is, FIG.
With respect to the rail substrate 8 in which the film thickness of the mask 41 is 37 μm, the initial mask sectional inclination angle β ₀ is 75 °, the substrate rotation speed is 10 to 20 rpm, and the substrate inclination angle θ is changed in the range of 0 to 90 °. , Substrate tilt angle θ and rail width accuracy (μm when the air bearing surface rail 2 is formed by performing ion milling
/ Μm). In FIG. 17, the film thickness of the mask 41 is 37 μm, the initial mask sectional inclination angle β ₀ is 75 °, the substrate rotation speed is 10 to 20 rpm, and the substrate inclination angle θ is 0 to 90 °.
The relationship between the substrate inclination angle θ and the redeposition thickness (μm) when the air bearing surface rail 2 is formed by performing the ion milling process on the rail substrate 8 changed in the above range. FIG.
16 shows changes in cross-sectional shape due to ion milling when the substrate inclination angle θ was changed to 15 °, 45 °, and 75 ° under the same conditions as shown in FIGS. 16 and 17. .

If the substrate tilt angle θ is too small, the result shown in FIG.
As shown in (a), the initial mask sectional inclination angle β ₀ = 75.
According to the angle, the side surface of the mask 41 is also subjected to large ion milling processing, and the rail substrate 8 is also subjected to ion milling processing according to the ion milling processing of the side surface of the mask 41 to increase the amount of receding of the rail width. As shown in FIG. Although the target value of accuracy is 10 μm / μm or less, the rail width accuracy deteriorates to 4 to 6 μm / μm, while the ion milling processing speed is higher than the redeposition speed at which the sputtered particles 71 are attached to the side surface of the air bearing surface rail 2. Is large, and the total amount of ion milling is larger than the reattachment amount,
As shown in FIG. 17, there is almost no redeposition thickness at the end of the ion milling process. Furthermore, the substrate tilt angle θ
Is too small, the substrate ion milling speed becomes slow as shown in FIG. 15, resulting in inefficiency.

Further, if the substrate tilt angle θ is too large, FIG.
As shown in (c), the side surface of the mask 41 and the side surface 72 of the air bearing surface rail 2 are ion-milled more to increase the receding amount of the rail width, and as shown in FIG. 16, the substrate inclination angle θ is 70 °. When the above is the case, the rail width accuracy becomes poor, and on the other hand, the ion milling rate is significantly higher than the reattachment rate at which the sputtered particles 71 are attached to the side surface of the air bearing surface rail 2, and the ion milling rate is greater than the reattachment rate in total. As shown in FIG. 17, there is almost no redeposition thickness at the end of the ion milling process. Further, if the substrate tilt angle θ is too large, the substrate ion milling speed will be drastically reduced as shown in FIG. 15, resulting in a very inefficient operation.

As shown in FIG. 17, when the initial mask sectional inclination angle β ₀ is 75 °, the substrate inclination angle θ is 10 ° to
Redeposition is observed in the range of 60 °. Therefore, it is necessary to reduce the initial mask cross-sectional inclination angle β ₀ so that redeposition does not occur.

Further, as shown in FIG. 19, the substrate holder inclination angle θ is 45 ° and the initial mask sectional inclination angle β ₀ is 75 °.
Although the redeposition layer 10 remains, the initial film thickness T ₀ of the mask 41 is 20 to 100 μm (30 in FIG. 9).
Shown from μm. Even if it fluctuates within the range of), the rail width accuracy shows about 0.6 μm / μm, and it can be confirmed that there is no fluctuation. However, the initial film thickness T _{0 of the} mask 41 is 100.
If it exceeds .mu.m, the resolution of the resist after exposure and development is deteriorated, and there is a high possibility that a rail having a high rail width accuracy cannot be formed. Due to the rotation of the rail substrate 8, the mask 41 causes the ion beam to rotate. Irradiation of 59 is blocked and redeposition on the side surface of the mask 41 remains without being removed. From this, the initial film thickness T ₀ of the mask 41 is preferably 20 to 100 μm. Note that when the initial film thickness T ₀ of the mask 41 is smaller than 20 μm, FIG.
Since the residual film of the mask 41 becomes small during the ion milling due to the ion milling speed characteristic of the mask shown in (1), the rail width accuracy may be rapidly deteriorated, or the rail groove with a predetermined depth may not be formed. Will be more likely.

FIG. 20 shows a summary of the above. In FIG. 20, A-B-C-D-E-F-G-H
The region surrounded by -I-J-K-L-M-N-O-P-Q-R-A has a desired depth H ₀ by the ion milling process.
= 6 μm, when the groove is processed, there is no redeposition layer 10 on the side surface of the air bearing surface rail 2 and the rail width accuracy is 10 μm.
The relational condition between the initial mask cross-sectional tilt angle β ₀ and the substrate holder tilt angle (substrate tilt angle) θ that is equal to or less than / μm is shown. Especially rail width accuracy (variation) is 8μm / μm or less, and 6
When the accuracy is required to be more and less than μm / μm, there is almost no range where the initial mask cross-sectional tilt angle β ₀ can be set or controlled when the substrate holder tilt angle (substrate tilt angle) θ is 25 ° or less. .

As described above, considering the ion milling speed, the substrate tilt angle θ is set in the range of 23 ° to 60 °, and the initial mask cross-section tilt angle β ₀ is set in the range of 40 ° to 70 °. In order to prevent the adhesion layer 10 from remaining on the side surface of the air bearing surface rail, the initial mask cross-section tilt angle β ₀ is set or controlled in the mask forming step, and the substrate tilt rotation table mechanism 61 in the ion milling device sets the substrate tilt angle θ. Control. Since the side surface of the mask 41 retreats by ion milling as shown in FIG. 11 according to the initial mask cross-sectional tilt angle β ₀ and the substrate tilt angle θ, the substrate tilt angle θ is set or controlled to 45 °, for example. When the initial mask cross-section inclination angle β ₀ is set or controlled to 55 ° and the irradiation time of the ion beam 59 is set so that the groove depth H ₀ becomes 6 μm, the width W of the air bearing surface rail 2 is one side, As shown in FIG. 12, 1.3 × 6
.mu.m, the pattern of the non-linear air bearing surface rail 2 to be finally formed when the mask pattern is formed on the rail substrate 8 in the mask forming step (the non-linear pattern shown in FIG. 2). Among them, the minimum width W of the central pattern needs to be determined in consideration of the retreat amount with respect to 90 μm to 120 μm).

Most preferably, the substrate tilting rotary table mechanism 61 in the ion milling apparatus sets or controls the substrate tilting angle θ within the range of 30 ° to 50 °, and the initial mask section tilting angle β in the mask forming step.
It is preferable to set or control ₀ within the range of 45 ° to 55 °.

Further, the above description is based on the premise that the substrate inclination angle θ is not changed during the ion milling process. Therefore, in the mask forming step, the initial mask sectional inclination angle β ₀ is set to, for example, 75 ° or When the substrate tilt angle θ is controlled or set to about 45 °,
As can be seen from FIG. 7 and FIG. 20, the redeposited layer 10 to which the sputtered particles are attached remains on the side surface of the air bearing surface rail 2. However, during the ion milling process, if the substrate tilt rotation table mechanism 61 is controlled to change the substrate tilt angle θ in accordance with the groove depth H calculated from the controller 65, the boundary AB shown in FIG. C-D-E-F
The redeposition layer can also be eliminated in the area above -GHIJK. That is, in the mask forming step, the initial mask cross-sectional inclination angle β _{0 is set} to, for example, 80 ° to 88 °.
Set or control the substrate tilt angle θ to be about 45 ° to 62 °.
Ion milling processing by setting or controlling at
For example, the groove depth H is about 4 by monitoring the time from the control device 65.
When it is calculated that the substrate tilting angle reaches ˜5 μm, as is apparent from FIG. 16, if the substrate tilting rotary table mechanism 61 is controlled so as to change the substrate tilting angle θ having a large ion milling amount to about 75 °. The reattachment layer 10 that was present when the groove depth H was about 5 μm was ion milled,
When the groove depth H ₀ finally becomes 6 μm, the redeposition layer 10 can be removed. Further, at this time, the rail width accuracy increases from about 0.6 μm / μm, but does not reach about 7.5 μm / μm as shown in FIG. 16, and can be kept within 3 to 4 μm / μm. If the substrate tilt rotation table mechanism 61 is controlled to change the substrate tilt angle θ during the ion milling process as described above, FIG.
Also in the region other than the region shown, the substrate ion milling rate in total to obtain a final groove depth H ₀ even at very high speeds, by increasing the ion milling amount than redeposition amount as a total to obtain the final groove depth H ₀ The redeposition layer can be eliminated, and furthermore, the non-linear air bearing surface rail 2 that satisfies the target value (specification) as the rail width accuracy can be processed.

Although Ar is excellent as the ion milling gas, if a fluorocarbon gas such as SF6 or tetrafuromethane is used instead of Ar, or if a gas in which Ar and the above fluorocarbons are mixed is used, the mask 41 will be removed. Film thickness is 2
Even if the thickness is 0 μm or less, the predetermined air bearing surface rail 2 can be formed. However, regarding the upper limit of the film thickness, about 100 μm
If it exceeds this, the irradiation of the ion beam 59 is blocked by the mask 41 due to the rotation of the rail substrate 8, and reattachment to the side surface of the mask 41 remains without being removed.

As the ion milling gas, He, N
A rare gas such as e or Xe may be used alone or in combination. The amounts may be mixed so that an appropriate vacuum degree (1 to 5 × 10 to ⁴ Torr) is obtained when performing ion milling. The mixing of these rare gases has little effect on the ion milling speed, rail width accuracy and reattachment.

[0052]

According to the present invention, the change in the flying height due to the difference in the peripheral speed between the inner circumference and the outer circumference of the disk is reduced, and the flying height is secured to 100 nm or less to increase the recording density and To realize a thin-film magnetic head and a magnetic disk device that can form a non-linear air bearing surface rail without defects due to an adhesion layer or the like with high precision by ion milling, and as a result, increase reliability and recording density. There is an effect that can.

Further, according to the present invention, the change in the flying height due to the difference in peripheral speed between the inner circumference and the outer circumference of the disk is reduced,
In addition, the flying height is 100 nm or less, the recording density is increased, and the non-linear air bearing surface rail having no defect due to the reattachment layer or the like can be efficiently formed by ion milling with less variation. Play.

[Brief description of drawings]

FIG. 1 is a diagram showing a main part of a magnetic disk device using a thin film magnetic head according to the present invention, where (a) is a perspective view showing the flying state of the thin film magnetic head, and (b) is a side view thereof. It is the figure which expanded and showed the writing / reading part.

FIG. 2 is a perspective view showing a thin film magnetic head having a non-linear air bearing surface rail according to the present invention.

FIG. 3 is a diagram showing the relationship between the rail width and the flying height of a non-linear air bearing surface rail in the thin film magnetic head according to the present invention.

FIG. 4 is a diagram showing a relationship between a rail groove depth and a flying height of a non-linear air bearing surface rail in a thin film magnetic head according to the present invention.

FIG. 5 is a diagram showing a manufacturing process up to forming an air bearing surface rail in the thin film magnetic head according to the present invention.

FIG. 6 is a schematic configuration diagram showing an embodiment of an ion milling device according to the present invention.

FIG. 7 is a view showing a state in which an air bearing surface rail is formed by performing ion milling on a rail substrate on which a mask according to the present invention is formed.

FIG. 8 is a diagram showing a sectional inclination angle β of a mask formed on a rail substrate.

FIG. 9 is a diagram showing the dependence of the ion milling speed on the incident angle for each of the mask and the rail substrate.

FIG. 10 is a diagram showing changes over time in the shape of the air bearing surface rail by ion milling with the substrate inclination angle θ set to 0 °.

FIG. 11 is a diagram showing cross-sectional shapes of the mask and the rail substrate after ion milling according to the initial mask cross-sectional tilt angle β ₀ by rotating the rail substrate with the substrate tilt angle θ of 45 °.

FIG. 12 shows an initial mask taper angle (initial mask cross-sectional inclination angle) β ₀ and rail width accuracy (μ when ion milling is performed by rotating a rail substrate with a substrate inclination angle θ of 45 °.
(m / μm).

FIG. 13 shows an initial mask taper angle (initial mask cross-sectional inclination angle) β ₀ and a re-deposition thickness (μ when ion milling is performed by rotating a rail substrate with a substrate inclination angle θ of 45 °.
It is the figure which showed the relationship with m).

FIG. 14 is a diagram showing a state where the mask remaining on the air bearing surface rail is removed and the redeposited layer attached to the side surface of the air bearing surface rail cannot be removed.

FIG. 15 is a diagram showing a relationship between a substrate tilt angle θ and a substrate ion milling speed (μm / h) when subjected to ion milling.

FIG. 16 is a diagram showing the relationship between the substrate inclination angle θ and the rail width accuracy (μm / μm) when the rail substrate is rotated with the initial mask cross-sectional inclination angle β ₀ of 75 ° and ion milling is performed. is there.

FIG. 17 is a diagram showing the relationship between the substrate inclination angle θ and the re-deposition thickness (μm) when ion milling is performed by rotating the rail substrate with the initial mask cross-sectional inclination angle β ₀ of 75 °. .

18 (a), (b) and (c) respectively show a substrate tilt angle θ of 15 when ion milling is performed by rotating the rail substrate with the initial mask cross-sectional tilt angle β ₀ of 75 °.
It is a figure which shows the time-dependent change of the shape of an air bearing surface rail including the mask in the case of (degrees), 45 degrees, and 75 degrees.

FIG. 19 is a diagram showing the relationship between the initial film thickness T ₀ of the mask and the rail width accuracy (μm / μm) when ion milling is performed.

FIG. 20 is a diagram showing rail width accuracy and presence / absence of reattachment when the air bearing surface rail according to the present invention is subjected to ion milling, by changing the substrate holder inclination angle θ and the initial mask section inclination angle β ₀ . is there.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Thin film magnetic head, 2 ... Non-linear air bearing surface rail, 3 ... Spring 5 ... Tapered part, 8 ... Rail substrate, 9 ... Magnetic disk, 10 ... Redeposition layer 20 ... Element formation part, 31 ... Ceramic substrate, 32 ...
Element 33 ... Head block, 34 ... Head block fixing jig 53 ... Plasma generation chamber, 55 ... Gas supply means, 58
... Ion extraction electrode 59 ... Ion beam, 60 ... Sample chamber, 61 ... Substrate tilt rotation table mechanism 62 ... Substrate cooling mechanism, 63 ... Exhaust means, 65 ... Control device 70 ... Mask side surface, 71 ... Sputtered particles, 72 ...
Air bearing surface Side of rail 73 ... Bottom of groove

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hirotaka Imayama 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Stock Engineering Institute, Hitachi, Ltd.

Claims (12)

[Claims] 1. A surface for forming an air bearing surface rail of a rail substrate for a thin film magnetic head, which is provided with a mask having a pattern that corresponds to the shape of a non-linear air bearing surface rail and is provided with an inclination that spreads outward on the side surface. And the mask forming step for forming the thin film magnetic head rail substrate on which the mask is formed in the mask forming step is rotated at a predetermined angle with respect to a plane perpendicular to the irradiation direction of the ions to be irradiated. And a non-linear air bearing surface rail processing step of forming a non-linear air bearing surface rail by irradiating the surface of the mask formed with the ions with ions to a predetermined groove depth. And method for forming air bearing surface rail of thin film magnetic head. 2. A surface for forming an air bearing surface rail of a thin film magnetic head rail substrate, which is provided with a mask having a pattern having a shape that corresponds to the shape of a non-linear air bearing surface rail, which is provided with an inclination that spreads outward on the side surface. And the mask forming step of forming the mask and the rail substrate for a thin film magnetic head on which the mask is formed in the mask forming step are rotated at a desired angle with respect to a plane perpendicular to the irradiation direction of the ions to be irradiated. The surface on which the mask is formed is irradiated with the ions so that the amount of sputtered particles is greater than the amount of redeposition of the sputtered particles reattaching to the side surface of the non-linear air bearing surface rail within a predetermined groove depth. It is characterized by having a non-linear air bearing surface rail processing step of enlarging and performing ion milling to form a non-linear air bearing surface rail without a redeposition layer on the side surface. The method of forming the air bearing surface rails of the thin-film magnetic head according to. 3. A surface for forming an air bearing surface rail of a rail substrate for a thin film magnetic head, which is provided with a mask having a pattern having a shape that corresponds to the shape of a non-linear air bearing surface rail, which is provided with an inclination that spreads outward on the side surface. And the mask forming step of forming the mask and the rail substrate for a thin film magnetic head on which the mask is formed in the mask forming step are rotated at a desired angle with respect to a plane perpendicular to the irradiation direction of the ions to be irradiated. The surface on which the mask is formed is irradiated with the ions, and the sputtered particles are sputtered at a processing speed up to a predetermined groove depth, which is faster than the re-deposition rate at which the sputtered particles reattach to the side surface of the non-linear air bearing surface rail. And a non-linear air bearing surface rail processing step of forming a non-linear air bearing surface rail without increasing the size of the re-deposited layer by ion milling. The method of forming the air bearing surface rails of the thin-film magnetic head is characterized. 4. A rail substrate for a thin film magnetic head, comprising a mask having a pattern having a shape corresponding to the shape of a non-linear air bearing surface rail, which is inclined at a desired first inclination angle which spreads outward on the side surface. A step of forming a mask on the surface forming the air bearing surface rail, and a desired first tilt angle given to the side surface of the pattern in the mask forming step and the rail substrate for a thin film magnetic head on which the mask is formed. A rail substrate for a thin film magnetic head on which the mask is formed by setting or controlling a relationship between a desired second tilt angle with respect to a plane perpendicular to the irradiation direction of the irradiated ions to be irradiated. The surface on which the mask is formed is irradiated with the ions by inclining at a desired second inclination angle with respect to a surface perpendicular to the irradiation direction of the ions to be irradiated, and The amount of spattering is larger than the amount of redeposition that the particles reattach to the side surface of the non-linear air bearing surface rail up to the specified groove depth, and ion milling is used to remove the redeposition layer on the side surface. And a non-linear air bearing surface rail processing step for forming a linear air bearing surface rail. 5. A surface for forming an air bearing surface rail of a rail substrate for a thin-film magnetic head, which is provided with a mask having a pattern having a shape corresponding to the shape of a non-linear air bearing surface rail, which is provided with an inclination that spreads outward on the side surface. And the mask forming step for forming the thin film magnetic head rail substrate on which the mask is formed in the mask forming step is rotated at a predetermined angle with respect to a plane perpendicular to the irradiation direction of the ions to be irradiated. A non-linear air bearing surface rail processing step of forming a non-linear air bearing surface rail by irradiating the surface of the mask with the ions to ion-mill it to a predetermined groove depth, and And a mask removing step for removing a mask left on the non-linear air bearing surface rail formed in the air bearing surface rail processing step. The method of forming the air bearing surface rails. 6. A surface for forming an air bearing surface rail of a rail substrate for a thin film magnetic head, which is provided with a mask having a pattern that corresponds to the shape of a non-linear air bearing surface rail and is provided with an inclination that spreads outward on the side surface. And the mask forming step for forming the thin film magnetic head rail substrate on which the mask is formed in the mask forming step is rotated at a predetermined angle with respect to a plane perpendicular to the irradiation direction of the ions to be irradiated. By controlling the groove depth formed by irradiating the surface with the mask with the ions, a non-linear air bearing surface rail having a desired width is formed by ion milling to a predetermined groove depth. And a non-linear air bearing surface rail processing step for forming the air bearing surface rail of the thin film magnetic head. 7. A surface for forming an air bearing surface rail of a rail substrate for a thin film magnetic head, which is provided with a mask having a pattern having a shape corresponding to the shape of a non-linear air bearing surface rail, which is provided with an inclination that spreads outward on the side surface. And the mask forming step for forming the thin film magnetic head rail substrate on which the mask is formed in the mask forming step is rotated at a predetermined angle with respect to a plane perpendicular to the irradiation direction of the ions to be irradiated. By controlling the groove depth formed by irradiating the surface with the mask with the ions, a non-linear air bearing surface rail having a desired width is formed by ion milling to a predetermined groove depth. The non-linear air bearing surface rail processing step and the mask left on the non-linear air bearing surface rail processing step formed in the non-linear air bearing surface rail processing step are removed. The method of forming the air bearing surface rails of the thin film magnetic head and having a mask removing step. 8. A surface for forming an air bearing surface rail of a rail substrate for a thin film magnetic head, which is provided with a mask having a pattern having a shape that corresponds to the shape of a non-linear air bearing surface rail, which is provided with an inclination that spreads outward on the side surface. And the mask forming step for forming the thin film magnetic head rail substrate on which the mask is formed in the mask forming step is rotated at a predetermined angle with respect to a plane perpendicular to the irradiation direction of the ions to be irradiated. The non-linear air bearing surface having a desired width by ion milling to a predetermined groove depth by temporally controlling the groove depth formed by irradiating the surface on which the mask is formed with the ions. And a non-linear air bearing surface rail processing step of forming a rail, the method of forming an air bearing surface rail of a thin film magnetic head. 9. A surface for forming an air bearing surface rail of a rail substrate for a thin film magnetic head, wherein a mask having a pattern having a shape corresponding to the shape of a non-linear air bearing surface rail, which is provided with an outwardly sloping side surface, is formed. And a step of forming a mask in the mask forming step, and rotating the rail substrate for the thin film magnetic head on which the mask is formed in the mask forming step to irradiate the ions on the surface on which the mask is formed to perform ion milling to a predetermined groove depth. And a non-linear air bearing surface rail processing step for forming a non-linear air bearing surface rail. 10. A non-linear air bearing surface rail having an outwardly extending inclined side surface without a redeposition layer, wherein a groove depth formed between the non-linear air bearing surface rails is 4 μm to 8 μm.
m, a thin film magnetic head characterized in that an inclined surface is formed near the non-linear air bearing surface rail on the bottom surface of the groove. 11. A non-linear air bearing surface rail having a rail width of 80 μm to 120 μm and having an inclined side surface extending outward without a redeposition layer, and is formed between the non-linear air bearing surface rails. A thin film magnetic head having a groove depth of 4 μm to 8 μm and having an inclined surface formed in the bottom surface of the groove in the vicinity of the non-linear air bearing surface rail. 12. A non-linear air bearing surface rail having an inclined side surface that extends outward without a redeposition layer, and a groove depth formed between the non-linear air bearing surface rails is 4 μm to 8 μm.
At m, a thin film magnetic head having an inclined surface formed near the non-linear air bearing surface rail on the bottom surface of the groove is floated low on the magnetic disk, and information is recorded on the magnetic disk by the thin film magnetic head. A magnetic disk device characterized by being configured to: