JP2933916B1 - Manufacturing method of magnetoresistive head - Google Patents

Abstract

An object of the present invention is to provide a magnetoresistive head having good productivity, capable of narrowing a track, and having good reproduction waveform and output, and a method of manufacturing the same. A magnetoresistive film for converting a magnetic signal into an electric signal, a magnetic domain control film for applying a magnetic field to the film, an electrode for flowing a signal detection current, and an upper shield film for magnetically shielding the film And a magnetoresistive head having a lower shield film, the magnetoresistive effect film 3 is composed of a multilayer film, and Cr, Ru,
It has a layer made of Rh, Pd, Ir, Pt or an alloy containing at least one of them, and the electrode 5 is made of Ta,
A single-layer film made of W, Mo, Nb or an alloy containing at least one of them, or a layer of Ta, W, Mo, Nb or an alloy containing at least one of these on the lower shield film 1 side of the electrode 5. A magnetoresistive head in which a multilayer film is formed by reactive ion etching using SF ₆ gas and a method of manufacturing the same.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a magnetoresistive head for magnetically reproducing information from a storage medium, and more particularly to a magnetoresistive head utilizing a giant magnetoresistive effect.

[0002]

2. Description of the Related Art Along with miniaturization of a magnetic disk drive, a magnetoresistive head capable of obtaining a high reproduction output voltage without depending on a relative speed between a disk and a head has been used.

[0003] A magnetoresistive head is a magnetic sensor that utilizes the fact that the resistance is changed by the magnetic flux sensed, and can reproduce information from a magnetic medium, but cannot record information on the medium. Therefore, the recording head is usually used as a conventional magnetic induction type head, and the reproducing head is usually used as a recording / reproducing separation type magnetic head using a magnetoresistive head.

A magnetoresistive head employs an anisotropic magnetoresistive effect (AMR).
Although an AMR head utilizing ve) was used, a higher sensitivity than the AMR head was required in accordance with the increase in recording density. Therefore, a giant magnetoresistance effect as disclosed in JP-A-4-358310 was used. A spin valve head using the same has been proposed.

[0005] To increase the recording density, it is important to improve the track density as well as the sensitivity. The track density of a magnetoresistive head is determined by the reproduction track width, which is the electrode spacing.

As an example of the reproduction track forming method, there is a method called a hard bias as described in Japanese Patent Application Laid-Open No. Hei 3-125311. This method uses a lift-off pattern as a mask, cuts off both end portions of the magnetoresistive film by ion milling or the like, leaves the magnetoresistive film only on the magneto-sensitive portion, and arranges electrode films on both cut ends.

As another example, as described in JP-A-6-333215, a metal film is formed on a magnetoresistive film and the metal film is etched into an electrode shape using CF ₄ gas. Things.

[0008]

In the above prior art in which a hard bias method is used for a spin valve head, a lift-off process is used for forming an electrode.
In general, the pattern profile is generally an inverted trapezoid or an eave with an undercut formed in order to lift off well. As the recording density increases, the electrode interval becomes narrower, and the lift-off pattern requires further miniaturization.

However, an inverted trapezoid as described above, or
It is very difficult to form a fine eaves-like lift-off pattern. As a result, it becomes difficult to narrow the electrode interval with the increase in the recording density, so that it is impossible to cope with the increase in the recording density.

When the electrode is formed narrower than the width of the magnetoresistive film, the magnetoresistive film is as thin as several tens of nanometers. Damage is considerably increased, resulting in defective reproduction waveform and reduced output.

When the electrode is etched by using CF ₄ gas as in the conventional example, damage to the magnetoresistive film is considerably reduced as compared with ion milling. Even the slight etching damage can greatly affect the characteristics. In order to reduce such damage, it is effective to reduce the etching power or the like.
This leads to a drop in productivity.

An object of the present invention has good productivity, narrowing the electrode spacing, and, in the reproduction waveform and the output of the high precision to provide a process for the preparation of good magnetoresistive heads.

[0013]

The gist of the present invention to achieve the above object is as follows.

[0014]

[2] A magnetoresistive film for converting a magnetic signal into an electric signal using the magnetoresistive effect, a magnetic domain control film for applying a magnetic field to the magnetoresistive film, and a signal detection for the magnetoresistive film. In a method of manufacturing a magnetoresistive head having an electrode for flowing a current, and an upper shield film and a lower shield film for magnetically shielding the magnetoresistive film, the magnetoresistive film is formed of a multilayer film. Cr, Ru, Rh, Pd, I are provided on the upper shield film side of the multilayer film.
r or Pt, or a layer made of an alloy containing at least one of these, and the electrode is made of Ta, W, Mo.
Or a single-layer film made of Nb or an alloy containing at least one of these, or a layer made of Ta, W, Mo or Nb, or an alloy containing at least one of these, on the lower shield film side of the electrode. A method of manufacturing a magnetoresistive head is characterized in that a multilayer film is formed and these metals or alloys of the electrodes are formed by reactive ion etching (RIE) using SF ₆ gas.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic cross-sectional side view of the tip of a magnetoresistive head according to an embodiment of the present invention, as viewed from a direction in which a magnetic field is introduced from a medium. It comprises a lower shield film 1, a lower gap film 2, a magnetoresistive film 3, a magnetic domain control film 4, an electrode 5, an upper gap film 7, and an upper shield film 8.

FIG. 2 is a schematic cross-sectional view showing a manufacturing process of the magneto-resistance effect type magnetic head shown in FIG.

Step (a): NiF as lower shield film 1
e, an insulating film of alumina or the like as the lower gap film 2, and NiFe / Cu / NiF as the magnetoresistive film 3 here.
A multilayer film composed of e / FeMn / Cr and CoCrPt as the magnetic domain control film 4 are formed.

Step (b): A Ta film is formed as the electrode 5, and then a resist pattern 6 is formed by photolithography.

Step (c): Using the resist pattern 6 as a mask, the electrode 5 is etched into a desired shape by reactive ion etching (RIE) using SF ₆ gas. Note that a helicon type plasma etching apparatus was used as the RIE apparatus.

When Ta is etched as the electrode 5, the uppermost Cr layer of the magnetoresistive film 3 functions as an etching stopper.
It does not damage the u / NiFe / FeMn layer. Further, since RIE is dry etching, processing with higher precision than wet etching can be performed.

Step (d): After removing the resist pattern 6,
Forming an insulating film such as alumina as the upper gap film 7;
NiFe is formed as the upper shield film 8.

In the magnetoresistive film 3 composed of a plurality of multilayer films, the layer on the upper shield film 8 side of the multilayer film is Cr, but other than Cr, Ru, Rh, Pd, Ir,
A simple substance selected from Pt or an alloy containing at least one of them is used.

The FeMn antiferromagnetic layer includes:
An alloy containing at least one of Cr, Ru, Rh, Pd, Ir, and Pt may be used.

The electrode 5 is a single-layer Ta film, but may be a single-layer film or a multi-layer film. In the case of a multilayer film, at least the lower shield film 1 side of the electrode is Ta, W, M
At least one of o and Nb or an alloy containing the same is formed.

As the RIE device, a helicon type plasma etching device is used, but an ECR type plasma etching device, an ICP type plasma etching device, a parallel plate type etching device or the like can be used.

When etching the electrode 5 at least by etching the electrode layer on the lower shield film 1 side by RIE, the electrode 5 can be formed by using RIE and ion milling in combination. For example, from the lower shield film 1 side, Ta
It is also possible to form a multilayer film of / Au / Ta, etch Au / Ta by ion milling, and etch Ta on the lower shield film 1 side, that is, Ta on the side in contact with the magnetoresistive film 3 by RIE. is there.

FIG. 3 is a graph showing the relationship between the etching rate and the selectivity when using a helicon type plasma etching apparatus, the gas used, and the helicon RF power.

Here, an example using Cr and Ta as an etching material will be described. Further, the gas used in the CHF ₃ gas and SF ₆ gas, the cathode fall voltage indicating gas pressure 1.2 mTorr, a substrate bias -100 V, helicon RF power is 100～700W. FIG. 3A shows the case of the CHF ₃ gas, and FIG. 3B shows the case of the SF ₆ gas. The selectivity (Ta etching rate / Cr etching rate) of both gases decreases as the helicon RF power is increased, but the SF ₆ gas has a high selectivity. Further, Ta etching rate (nm / min) is about 2 to 10 times greater than when SF ₆ gas using a CHF ₃ gas. That is, Ta is used as an etching material, Cr is used as an etching stopper film, and RI is formed using SF ₆ gas.
By performing E, high-speed etching and a high selectivity can be obtained.

The Ta etching in the step (c) of FIG. 2 was performed at a SF ₆ gas pressure of 1.2 mTorr, a cathode drop voltage of −100 V, and a helicon RF power of 100 W.
At this time, the Ta film thickness was 100 nm, the overetching was performed 50%, and the etching time was completed in a short time of about 3 minutes. The amount of etching damage of Cr acting as a stopper film is about 2 nm, and such an amount of etching damage does not affect the characteristics of the magnetoresistive film 3.

In this embodiment, a single-layer Ta film is used for the electrode 5, but a multi-layer film may be used.
As described above, a, W, Mo or Nb, or an alloy containing the same may be used.

The layer on the upper shield film 8 side of the magnetoresistive effect film is made of Cr, but Cr, Ru, Rh, Pd,
As described above, a layer made of Ir or Pt or an alloy containing the same may be used.

Using the above metals, SF ₆ gas is used for R
By performing IE, high-speed etching and a high selectivity can be obtained.

Although FeMn is used as the antiferromagnetic film, an alloy containing Cr, Ru, Rh, Pd, Ir or Pt can be used, and the formation of the etching stopper film on the antiferromagnetic film is omitted. It is possible.

[Embodiment 2] Since a magnetoresistive head is exclusively for reproduction, it is used as a composite magnetic head integrated with an inductive magnetic head for recording. FIG. 4 shows an example of the configuration of the composite magnetic head.

The inductive magnetic head 51 includes a conductor coil 42 for passing an electric signal and an insulating film 43 for obtaining electric insulation.
An upper magnetic core 44 for converging a magnetic flux induced by an electric signal applied to the conductor coil 42, and
A lower magnetic core 40 also serves as an upper shield film, and a recording gap film 41 as a magnetic gap for leaking the focused magnetic flux to the outside.

The magnetoresistive head manufactured according to the present invention has a lower shield film 1, a magnetoresistive film 3,
It has a magnetic domain control film 4 and electrodes 5, and a lower magnetic core 40 also serving as an upper shield film.

Even in this case, since the characteristics of the magnetoresistive head of the present invention are utilized, it is possible to provide a composite magnetic head capable of obtaining a good reproduction output.

Further, the composite magnetic head of this embodiment can be used for a magnetic recording / reproducing apparatus. FIG. 5 schematically shows a magnetic recording / reproducing apparatus.

The magnetic recording / reproducing apparatus includes a magnetic recording medium 60 for magnetically recording information, a spindle 61 for rotating the magnetic recording medium 60, and a composite head for recording and reproducing signals on and from the magnetic recording medium 60. 100, a suspension 63 for supporting the same, an actuator 64 for controlling the position of the composite head 62, a circuit 65 for processing a recording / reproducing signal, and a lead wire 66 for connecting the same to the composite head 100. Have.

By using a composite magnetic head capable of obtaining a good reproduction output even with a narrow track width, it is possible to provide a magnetic recording / reproducing apparatus capable of achieving a higher recording density than before.

[0043]

According to the present invention, it is possible to provide a magnetoresistive head having good reproduction waveform and output because the productivity is good, the electrode interval can be narrowed, and the precision can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a configuration of a magnetoresistive head according to a first embodiment of the invention.

FIG. 2 is a schematic cross-sectional view showing an example of a manufacturing process of the magnetoresistive head of FIG.

FIG. 3 is a graph showing an example of a relationship between an etching rate and a selectivity when a CHF ₃ gas and an SF ₆ gas are used.

FIG. 4 is a perspective view showing a configuration of a composite magnetic head according to a second embodiment of the present invention.

FIG. 5 is a schematic side sectional view of a magnetic recording / reproducing apparatus.

[Description of Signs] 1 ... Lower shield film, 2 ... Lower gap film, 3 ... Magnetoresistance effect film, 4 ... Magnetic domain control film, 5 ... Electrode, 6 ... Resist pattern, 7 ... Upper gap film, 8 ... Upper shield film , 4
0: lower magnetic core also serving as upper shield film, 41: recording gap film, 42: conductor coil, 43: insulating film, 44: upper magnetic core, 50: magnetoresistive head (reproducing head), 51: induction magnetic head (Recording head), 60 ...
Magnetic recording medium, 61 spindle, 63 suspension, 64 actuator, 65 signal processing circuit, 66
... lead wire, 100 ... composite type head, A ... NiFe layer,
B: Cu layer, C: NiFe layer, D: FeMn layer, E: C
r layer.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hiroshi Fukui 1-280 Higashi Koigabo, Kokubunji-shi, Tokyo Central Research Laboratory, Hitachi, Ltd. (56) References JP-A-10-124823 (JP, A) (58) Survey Field (Int.Cl. ⁶ , DB name) G11B 5/39

Claims (1)

(57) [Claims] 1. A magnetoresistance effect film for converting a magnetic signal into an electrical signal using a magneto-resistance effect, a magnetic domain control film for applying a magnetic field to said magnetoresistive <br/> film, said magnetoresistive In a method of manufacturing a magnetoresistive head having an electrode for flowing a signal detection current through the film and an upper shield film and a lower shield film for magnetically shielding the magnetoresistive film, the magnetoresistive film is a multilayer film. A layer made of Cr, Ru, Rh, Pd, Ir or Pt, or an alloy containing at least one of them, is formed on the upper shield film side of the multilayer film, and the electrode is made of Ta, W, Mo or Nb, or a single layer film made of an alloy containing at least one of these, or Ta, W, Mo or Nb, or at least one of these, on the lower shield film side of the electrode. Forming a multilayer film having a layer made of non-alloy, method of magnetoresistive head, characterized by forming by reactive ion etching (RIE) of these metals or alloys by SF ₆ gas in the electrode.