JPH04335202A - Production of vertical magnetic recording and reproducing thin-film head - Google Patents

Abstract

PURPOSE:To decrease the pole recession of a sliding surface and to improve head characteristics by controlling the Al/Ar atomic weight ratio of an Al2O3 film which is a head protective film on a main magnetic pole film to a specific range. CONSTITUTION:The characteristic hardness of the Al2O3 film which is the head protective film 9 to be formed on the main magnetic pole film 8 is adjusted by forming the Al2O3 film 9 having the Al/Ar atomic weight ratio = 2.8 to 2.9 under sputtering conditions under which 80 to 160V negative bias voltage impressed to a sputtering substrate side is impressed. Consequently, the Al2O3 film has the characteristic to allow easy polishing by mechanochemical polishing and its hardness is lowered. The polishing rates of the main magnetic pole film 8 and the Al2O3 film are substantially equal at the time of mechanochemically polishing the end faces of the laminated layers and, therefore, the recessed parts (pole recession) of the main magnetic pole part of the sliding surface facing a recording medium are drastically decreased and the recording and reproducing characteristics are greatly improved.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention relates to the improvement of perpendicular magnetic recording/reproducing thin film heads for computers, tapes, video recording, etc., and involves sputtering with a specific negative bias voltage when forming a protective film. An Al2O3 protective film with specific properties and hardness is formed, the magnetic substrate is cut into the required dimensions, and then mechanochemically polished to expose the main magnetic pole at a desired position on the end face of the laminated layer to reduce pole recession, thereby achieving recording in the thin film head. The present invention relates to a method of manufacturing a perpendicular magnetic recording/reproducing thin film head with improved characteristics.

0002

[Prior Art] Generally, perpendicular magnetic recording/reproducing thin film heads (
Thin-film heads (hereinafter referred to as thin-film heads) are suitable for high-density magnetic recording because their magnetic circuits are minute and they use magnetic thin films with high magnetic permeability and high saturation magnetic flux density, and their manufacturing process is based on semiconductor technology. Since this type of magnetic head is manufactured using a high-precision magnetic head, it is possible to manufacture a high-precision magnetic head at low cost, and it is thought that it will become the mainstream of perpendicular magnetic heads in the future.

[0003] A perpendicular magnetic recording/reproducing thin film head involves the following steps in order to form a large number of thin film head patterns on a magnetic substrate at once, and then to divide the magnetic substrate and process it into individual head chips. Manufactured by

That is, the manufacturing process of the perpendicular magnetic recording/reproducing thin film head according to the present invention will be explained based on FIG. 1. First, as shown in FIG. A plurality of main grooves 2 are arranged in a desired pattern at predetermined intervals on one main surface of a ferrite magnetic substrate 1, and each groove 2 is filled with glass, SiO2, A
Welding method of non-magnetic material 3 such as l2O3, barium titanate, etc.
After filling by sputtering or the like, the main surface of the magnetic substrate 1 on which the grooves 2 are provided is subjected to mechanochemical polishing.

As shown in FIG. 1B, <2> Au, Cu, Cr,
A thin film conductor coil 4 made of Al etc. is sputtered,
Formed by vacuum evaporation method. Note that the magnetic substrate is Mn-
In the case of Zn-based ferrite, an insulating layer is provided before forming the thin film conductor coil.

As shown in FIG. 1C, <3> For electrical insulation between the four thin film conductor coil layers and the thick main pole film 7 to be deposited later, SiO2, Al2O3
An interlayer insulating film 5 made of an inorganic oxide film such as or an organic film such as polyimide is formed.

As shown in FIG. 2A, <4> An interlayer insulation coating (
In order to remove the uneven surface of 5), precision polishing such as diamond polishing or an etch-back method is applied to flatten the surface to 500 Å or less.

As shown in FIG. 2B, <5> Thick film main pole film 7 and magnetic substrate 1 to be deposited in a subsequent process.
A return path portion 6 for connecting is formed in the interlayer insulating film 5 by a method such as ion etching or chemical etching.

As shown in FIG. 2C, <6> A thick main pole film made of an Fe-based alloy such as Permalloy or Sendust, or amorphous material is formed on the five surfaces of the interlayer insulating film and the one surface of the magnetic substrate of the return path section 6. 7 is deposited and patterned by a sputtering method, vapor deposition method, plating method, etc.

As shown in FIG. 3A, <7> Then, a main pole film 8 is deposited on the thick main pole film 7 by sputtering, vapor deposition, plating, etc.
Make a pattern.

<8> A head protective film 9 is laminated and deposited (see B in FIG. 3). The head protective film was sputtered using an Al2O3 target with a purity of 99.9%, an Ar flow rate of 100SCCM, an RF input of 3kW, and an Ar pressure of 20mTo.
A laminated film is formed on the main pole film under the conditions of rr and substrate side negative bias voltage of 0. The resulting Al2O3 protective film is Al/Ar
The atomic weight ratio is 1.5 to 2.5.

As shown in FIG. 3C, <9> Thereafter, in order to prevent the protective film 9 made of oxide from peeling off when cutting into the required size and shape, only the protective film 9 portion is coated. For example, the preliminary groove portion 10 is formed using a #2000 diamond blade.

As shown in FIG. 4A, <10> A groove smaller than the width of the preliminary groove 10, for example #20.
The magnetic substrate 1 on which the films are laminated is cut with a diamond blade having a grain size of 0.

<11> The main magnetic pole film 8 formed and laminated on the magnetic substrate 1 is separated by 10 μm from the tip of the thick main magnetic pole film 7 toward the sliding surface.
Perform diamond polishing to position m (see B in Figure 4)
.

As shown in FIG. 4C, <12> The magnetic substrate 1 is cut and removed to a thickness of 800 μm from the pattern portion where the films are laminated.

As shown in FIG. 5A, <13> The sliding surface side of the magnetic substrate 1 facing the magnetic recording medium is processed to have dimensions of 300 μm×300 μm.

As shown in FIG. 5B, <14> In order to further reduce the sliding noise, an angled diamond blade is used to cut the sliding surface side by 100 μm×5.
Shape processed to 0 μm size.

As shown in FIG. 5C, <15> Next, the head chip is cut into pieces having the required size and shape.

[0019]

[Problem to be solved by the invention] Step <8 in the above steps
>, Al2O3 obtained under conventional sputtering conditions
The hardness of the protective film 9 made of oxide is Hv800, and C
The hardness of the main pole film 8 made of o-Zr system is Hv450, N
The hardness of the magnetic substrate 1 made of i-Zn ferrite is Hv.
750, the lower hardness of the main pole film 8 is 200 Å to 200 Å lower than the opposing sliding surface of the recording medium, depending on the hardness difference and the properties of the Al2O3 protective film, that is, the Al/Ar atomic weight ratio.
It was found that a recess (pole recession) of 300 Å was formed.

Generally, the output recording density of a thin film magnetic head is greatly influenced by the spacing between the magnetic head and the recording medium. Therefore, recently, the amount of spacing between the magnetic head and the recording medium is becoming less than 0.1 μm.
If the recess is between 0 Å and 300 Å, the spacing loss increases by the amount of the recess, causing problems such as deterioration of head characteristics such as output and recording/reproduction.

[0021] Therefore, the inventor first developed a return path magnetic material in which a thin film conductor coil, an interlayer insulating film, a main pole film, and a head protection film were formed and laminated, and the magnetic substrate and the main pole film were connected at the return path part. After cutting the substrate to the required dimensions and polishing, an Al2O3 film is formed on the laminated end face of the sliding surface facing the recording medium, and the oxide is filled into the recessed part of the main pole part due to cutting and polishing. , the Al2O3 coating on the laminated end face and the Al2O3 filled in the recess of the main pole part are removed by precision machining or dry etching, and one layer is removed from the laminated end face.
Proposed a method of exposing the main magnetic pole at a position of 00 Å or less (Japanese Patent Application No. 2-185891, Patent Application No. 2-220578)
However, there is a problem in that it requires a large number of steps and man-hours, leading to an increase in product cost.

[0022] In the manufacturing process of the above-mentioned perpendicular magnetic recording/reproducing thin film head, the present invention eliminates concave portions (poles) that occur in the main pole film having low hardness when the magnetic substrate is divided and processed into individual head chips. The purpose of the present invention is to provide a method for manufacturing a thin film head that can reduce recession (recession) and improve head characteristics such as output and recording/reproduction.

[0023]

[Means for Solving the Problems] The present invention has a main groove on one main surface of a return path magnetic member parallel to a sliding surface facing a magnetic recording medium, and fills the groove with a nonmagnetic material. After forming and laminating at least a thin film conductor coil, an interlayer insulating film, and a main pole film on the main surface of the nonmagnetic material, Al/
After forming an Al2O3 protective film having an Ar atomic weight ratio of 2.8 to 9.2 and cutting the return path magnetic substrate, which is connected to the magnetic substrate and the main magnetic pole film at the return path portion, into required dimensions, the recording medium is processed. This method of manufacturing a perpendicular magnetic recording/reproducing thin film head is characterized in that the end face of the laminated layer facing the sliding surface is mechanochemically polished to expose the main pole at a position of 100 Å or less from the end face of the laminated layer.

[0024]

[Operation] This invention aims to improve head characteristics such as output and recording/reproduction of a thin film magnetic head, and when manufacturing a magnetic head chip from a magnetic substrate laminated with films, the thin film magnetic head is exposed to the opposing sliding surface of the recording medium. In order to reduce the number of recesses formed in the main pole part as much as possible, we have conducted various studies and found that depending on the sputtering conditions, the Al2O3 film of the head protection film formed on the main pole film is
It has been found that the properties and hardness of the Al2O3 film change. As a result of further investigation, we found that by controlling the Ar atomic weight contained in the Al2O3 film to a specific composition ratio range with respect to the Al atomic weight using sputtering conditions in which the negative bias voltage applied to the substrate side is within a specific range, the Al2O3 film can be formed. The property becomes easy to polish by mechanochemical polishing and the hardness decreases, and when the end face of the stack is mechanochemically polished, the polishing speed of the main pole film and the Al2O3 film is almost the same, so that the sliding surface facing the recording medium It has been found that the concave portion of the main magnetic pole portion on the surface is significantly reduced, and the recording and reproducing characteristics are greatly improved.

Disclosure Based on the Drawings FIGS. 1 to 5 are explanatory diagrams showing the manufacturing process of a perpendicular magnetic recording/reproducing thin film head according to the present invention. Figure 1 A to Figure 3
The process shown in A is the conventional process <1> to <7> described above.
, and the steps shown in C in FIG. 3 and A in FIG. 4<9
><10>, and further steps shown from C in FIG. 4 to C in FIG. 5<
12> to <15> are the same, and the process <8> shown in B of FIG. 3 and the step <1 shown in B of FIG. 4, which are the characteristics of this invention.
1> will be explained.

As shown in FIG. 3B, Al2O3 is applied as a head protective film on the main pole film 8 obtained in step <8><7>.
The sputtering conditions for forming the film were Al with a purity of 99.9%.
Using 2O3 target, Ar flow rate 200SCCM,
Apply RF input of 3 kW, Ar pressure of 20 mTorr, and substrate side negative bias voltage of 80 to 160 V, and deposit an Al2O3 protective film having an Al/Ar atomic weight ratio of 2.8 to 9.2 on the main pole film. .

In this invention, if the negative bias voltage on the substrate side of the sputtering conditions is less than 80V, the resulting Al2O3
The negative bias voltage on the substrate side is set to 80 to 160 V because the internal stress of the protective film is large and the hardness is undesirable, and if it exceeds 160V, the hardness becomes too low and the protective film no longer functions.

In this invention, sputtered Al2
If the Al/Ar atomic weight ratio of the O3 protective film is less than 2.8, the difference in hardness between the main pole film and the Al2O3 protective film becomes large, resulting in large pole recession, and if the ratio exceeds 9.2, the hardness of the protective film increases. is too low, which is undesirable,
The Al/Ar atomic weight ratio is set to 2.8 to 9.2.

As shown in FIG. 4B, <11> Magnetic substrate 1
The main pole film 8 laminated thereon is subjected to diamond polishing from the tip of the thick main pole film 7 to a position of 10 μm on the sliding surface side, and then mechanochemical polishing is performed.

[0030] In this invention, the mechanochemical polishing method (MCP polishing method) uses MgO, S with a particle size of 0.1 μm or less
Processing materials are placed in a container containing a solution in which fine powders of iO2, Al2O3, and ZrO2, either alone or mixed, are suspended in pure water at a concentration of 3 to 10 wt% at a pH of 9 to 12 using a polisher made of hard cloth, Sn, etc. 5μ than the polisher
It is preferable to use a method in which the surface is floated to a height of 5 m or less or brought into contact with the surface and polished for 5 to 60 minutes.

[0031] MgO, SiO2, and abrasive grains during MCP polishing
If the particle size of the Al2O3, ZrO2 fine powder exceeds 0.1 μm, or if the concentration of the fine powder in the suspension is less than 3 wt%, the polishing speed is slow and the polishing efficiency is poor;
If it exceeds this, scratches, scratches, etc. will be formed on the processed surface.
Unfavorable because the surface condition is poor. If the pH of the suspension is less than 9, the etching effect will decrease and scratches and scratches will increase on the workpiece, and if it exceeds 12, the corrosion rate will increase and the ferrite surface of the workpiece will deteriorate. Undesirable.

If the polishing time exceeds 60 minutes, the difference in level between the auxiliary magnetic pole made of ferrite and the Al2O3 film becomes so large that a magnetic circuit cannot be formed, and if the polishing time exceeds 5 minutes, the concave portion of the main magnetic pole does not decrease, which is not preferable.

As the polisher, Sn is preferable because it causes less waviness on the processed surface. Furthermore, if the flying height of the workpiece from the polisher during MCP polishing exceeds 5 μm, the polishing speed will decrease and the surface will be undulated, which is not preferable.

[0034]

EXAMPLE A plurality of grooves each having a width of 0.15 mm x a depth of 0.025 mm x a length of 50 mm are formed by machining on a Ni--Zn ferrite substrate whose surface has been precisely finished. After filling the obtained groove with Al2O3 in a state where the number of bubbles of 5 μm or more is 1 bubble/mm3 or less, the main surface is subjected to mechanochemical polishing, and a Cu film for a thin film conductor coil is sputtered on the polished surface. and pattern it into a predetermined shape.

As an interlayer insulation coating for electrical insulation,
After coating with polyimide resin, the surface was flattened using an etch-back method. Thereafter, a thick main magnetic pole film made of Co-based amorphous was formed into an adhesion pattern by sputtering, and a thin main magnetic pole film made of Co-based amorphous was formed into an adhesion pattern by sputtering.

Furthermore, using an Al2O3 target with a purity of 99.9%, an Ar flow rate of 200SCCM, and an RF input of 3
kW, an Ar pressure of 20 mTorr, and a negative bias voltage on the substrate side of 120 V were applied to form an Al2O3 protective film on the main pole film. The obtained Al2O3 protective film has a hardness of H
v=700, and Al/Ar atomic weight ratio=4.9.

[0037] After that, #2000 was applied to the Al2O3 protective film.
Depth 20μm x width 300mm with diamond blade
After forming a preliminary groove of μm, # is smaller than the preliminary groove width.
After cutting the magnetic substrate on which the films were laminated using a diamond blade having a grain size of 200, diamond polishing was applied to the main pole part from the tip of the thick film part to a position of 10 μm on the sliding surface side, and further MCP polishing was performed. In MCP polishing, MgO powder with a particle size of 0.1 μm or less is suspended at 4 wt% in ultrapure water, and Sn
The pH was adjusted to 10.5 using a disc-shaped polisher made of
It was floated and polished for 15 minutes.

As a result of measuring the pole recession of the main pole film on the opposing sliding surface of the recording medium that has undergone MCP polishing using a non-contact surface profile measuring machine manufactured by WYKO, the pole recession of the thin film magnetic head according to the present invention was found. is 100Å
It was below. By the way, the pole recession of thin film magnetic heads obtained by conventional manufacturing methods is 200 Å to 3
It was 00 Å.

FIG. 6 shows the results of measuring the magnetic recording characteristics of the thin film heads obtained by the method of this invention and the conventional method. The test conditions under which the recording characteristics in FIG. 6 were measured are as follows. Test conditions for measuring recording characteristics Relative speed: 7.5 m/sec Recording current: 20 mAp-p Medium: Co-Cr/Ni-Fe dual layer medium Recording frequency: 0.5 to 20 MHz, rotation speed: 1800 rpm

[0040]

[Effects of the Invention] When manufacturing a perpendicular magnetic recording/reproducing thin film head, the properties and hardness of the Al2O3 film, which is the head protective film formed on the main pole film, can be controlled by applying a negative bias voltage to the sputter substrate side. The Al/Ar atomic weight ratio in the Al2O3 film is controlled within a specific range by sputtering conditions set in a specific range, so that the Al2O3 film has properties and hardness that are easy to polish by mechanochemical polishing, and the main surface of the sliding surface facing the recording medium is The concave portion (pole recession) in the magnetic pole portion can be significantly reduced, and as shown in the embodiments, particularly in FIG. 2, the recording and reproducing characteristics are greatly improved.

[Brief explanation of drawings]

FIGS. 1A, 1B, and 1C are explanatory diagrams showing the manufacturing process of a perpendicular magnetic recording/reproducing thin film head according to the present invention.

FIGS. 2A, 2B, and 2C are explanatory diagrams showing the manufacturing process of the perpendicular magnetic recording/reproducing thin film head according to the present invention.

FIGS. 3A, 3B, and 3C are explanatory diagrams showing the manufacturing process of the perpendicular magnetic recording/reproducing thin film head according to the present invention.

FIGS. 4A, 4B, and 4C are explanatory diagrams showing the manufacturing process of the perpendicular magnetic recording/reproducing thin film head according to the present invention.

FIGS. 5A, 5B, and 5C are explanatory diagrams showing the manufacturing process of the perpendicular magnetic recording/reproducing thin film head according to the present invention.

FIG. 6 is a graph showing the relationship between recording frequency and reproduction output of a thin film magnetic head.

[Explanation of symbols]

1 Magnetic substrate 2 Groove 3 Non-magnetic material 4 Thin film conductor coil 5 Interlayer insulation coating 6 Return path section 7 Thick film main pole film 8 Main pole film 9 Head protective film 10 Preliminary groove part

Claims (1)

[Claims] [Claim 1] On one main surface of the return path magnetic member,
It has a main groove section parallel to the sliding surface facing the magnetic recording medium,
After filling the groove with a nonmagnetic material and depositing at least a thin film conductor coil, an interlayer insulating film, and a main pole film on the main surface of the nonmagnetic material, sputtering is performed by applying a negative bias voltage of 80 to 160 V to the substrate side. Under the conditions, Al/Ar atomic weight ratio = 2.8 ~ 9
．． After forming an Al2O3 protective film having 2 and cutting the return path magnetic substrate connected to the magnetic substrate and the main pole film at the return path portion into required dimensions, the laminated end surface of the sliding surface facing the recording medium is A method for manufacturing a perpendicular magnetic recording/reproducing thin film head, characterized in that the main magnetic pole is exposed at a position of 100 Å or less from the end face of the laminated layer by mechanochemical polishing.