JP2002270920A - Magnetic sensor, magnetic head, and magnetic recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic sensor, a magnetic head, and a magnetic recorder using an antiferromagnetic domain control film without making it difficult to choose materials or to control a manufacturing process. SOLUTION: Either a part or all of a spin valve film is made to extend along each side of a magnetic sensing part, a bent part is provided to the extended part of the spin valve film, and antiferromagnetic layers 3 and 4 are arranged on the extended part extended from the bent parts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention is a magnetic sensor BACKGROUND OF THE INVENTION The magnetic head, and relates to a magnetic recording apparatus, in particular,
A magnetic sensor characterized by an arrangement structure of an antiferromagnetic film for controlling a magnetic domain of a free layer of a giant magnetoresistive film (GMR film) used for a reproducing head (read head) of a magnetic recording device such as a hard disk drive (HDD); The present invention relates to a magnetic head and a magnetic recording device.

[0002]

2. Description of the Related Art Conventionally, an induction type thin film magnetic head (inductive head) which senses a magnetic field by an induction current generated in a coil has been used as a magnetic head of a hard disk device or the like which is an external storage device of a computer. With the recent demand for higher density and higher speed of hard disk drives and the like, magnetic sensors for sensing the magnetic field itself have become the mainstream of magnetic heads for reproduction.

Conventionally, as such a magnetic sensor, a sensor utilizing a magnetoresistance (MR) effect has been adopted, but now a sensor utilizing a giant magnetoresistance (GMR) effect has been adopted. The reproducing principle of the MR head or the GMR head utilizes a phenomenon that, when a constant sense current flows from a lead electrode, the electric resistance of a magnetic thin film constituting a magnetoresistive element changes due to a magnetic field from a recording medium. is there.

[0004] With the high-density recording in recent years of the hard disk drive, together with the recording area of one bit decreases, the magnetic field generated is smaller, the recording density of a hard disk drive currently on the market 10Gbit
/ In ² (≒ 1.55 Gbit / cm ² ), but the increase in recording density is increasing at twice the annual rate. Therefore, with corresponding to even smaller magnetic field range, it is necessary to be able to sense changes in a small external magnetic field.

As described above, as a magnetic sensor utilizing the giant magnetoresistance effect, a magnetic sensor utilizing a spin valve element is widely used at present. This will be described with reference to FIG. FIG. 8A is a schematic plan view of a conventional magnetic sensor using a hard magnetic domain control film, and FIG. 8B connects AA ′ in FIG. 8A. FIG. 3 is a schematic cross-sectional view along a dashed line.

Referring to FIGS. 8 (a) and 8 (b), first, a lower magnetic shield layer made of a NiFe alloy or the like is formed on an Al ₂ O ₃ —TiC substrate serving as a slider base via an Al ₂ O ₃ film. (Not shown), and Al
_A NiFe layer 63, a CoFe free layer 64, a Ta underlayer 62 on a lower read gap layer 61 such as ₂ O ₃ .
Cu intermediate layer 65, CoFe pinned layer 66, and PdP
A spin valve film made of a tMn antiferromagnetic layer 67 is provided, and after covering with a Ta cap layer 68, patterned into a predetermined shape. Then, hard magnetic domain control layers 69 such as CoCrPt are provided at both ends of the spin valve film. .

Next, a conductive film made of Cr / Au or the like is deposited to form a pair of lead electrodes.
Upper magnetic shield layer made of NiFe alloy or the like via an upper read gap layer of ₂ O ₃ or the like (both not shown)
, M using a spin valve element
The basic configuration of the R head is completed.

[0008] Such a spin valve giant magnetoresistance effect is achieved by a CoFe pinned layer 66 whose magnetization direction is fixed in the direction indicated by an arrow in the figure by a PdPtMn antiferromagnetic layer 67 and the magnetization direction freely rotates in accordance with an external magnetic field. Co
The scattering depending on the spin of the conduction electrons changes due to the angle between the magnetization direction of the Fe-free layer and the electric resistance, and the change in the electric resistance changes. By detecting the change, the state of the external magnetic field, that is, the signal magnetic field from the magnetic recording medium is obtained.

In this spin-valve magnetoresistive sensor, if a magnetic domain exists in the CoFe free layer 64, Barkhausen noise is generated, so that it is necessary to control the magnetic domain. As described above, CoCrP is formed on both sides of the spin valve film.
A hard magnetic domain control layer 69 such as t, that is, a hard film is provided.

However, in a magnetic sensor having a spin valve structure using this hard film, a magnetization direction fixed layer having a width of about 0.05 μm is inevitably formed in a portion of the free layer in contact with the hard film. Since the fixed layer serves as a dead zone against an external magnetic field, there is a problem that characteristics are deteriorated.

On the other hand, as a method of controlling the magnetic domain of the free layer without generating such a dead zone, an attempt has been made to use an antiferromagnetic layer for the magnetic domain control film. A magnetic sensor using the antiferromagnetic domain control layer will be described. FIG. 9A is a schematic plan view of a magnetic sensor using a conventional antiferromagnetic domain control film, and FIG. 9B is a sectional view taken along line AA ′ in FIG. 9A. It is a schematic sectional drawing along the dashed-dotted line which connects.

[0012] FIG. 9 (a) and (b) see First, Al ₂ O ₃ -TiC substrate comprising a base of the slider, the lower magnetic shield layer made of NiFe alloy or the like through an Al ₂ O ₃ film (none (Not shown), and Al
_A NiFe layer 63, a CoFe free layer 64, a Ta underlayer 62 on a lower read gap layer 61 such as ₂ O ₃ .
Cu intermediate layer 65, CoFe pinned layer 66, and PdP
After providing a spin valve film made of a tMn antiferromagnetic layer 67 and covering it with a Ta cap layer 68, a CoF
It is patterned into a predetermined mesa shape until it reaches the e-free layer 64.

Next, an antiferromagnetic domain control film 71 made of PdPtMn is provided on the side surface of the mesa via a NiFe underlayer 70 by using a lift-off method, and then the antiferromagnetic domain deposited so as to be in contact with the mesa is provided. Control film 71 and NiFe
The underlayer 70 is selectively removed by ion milling,
Next, etching is performed again by ion milling until the semiconductor layer reaches the lower read gap layer 61 so that a predetermined element shape is obtained.

Then, a pair of lead electrodes is formed by depositing a conductive film made of Cr / Au or the like,
An upper magnetic shield layer made of NiFe alloy or the like through the upper lead gap layer, such as a ₂ O ₃ (both not shown)
, The basic configuration of the MR head using the spin valve element provided with the antiferromagnetic domain control film is completed. In such a magnetic sensor, it is possible to control the magnetic domain of the free layer without generating a dead zone.

[0015]

However, in such a spin-valve-structured magnetic sensor provided with an antiferromagnetic domain control film, the PdPtMn antiferromagnetic layer 67 constituting the spin-valve film has an antiferromagnetic layer in which the pin direction and the antiferromagnetic strength are reduced. Magnetic domain control film 7
As shown in FIG. 9 (a), it is necessary to make the pin directions perpendicular to each other as shown in FIG.

That is, when PdPtMn is used as the antiferromagnetic layer, when a magnetization direction is given to the antiferromagnetic layer, one of the directions perpendicular to the magnetic field applied at the time of film formation is applied in a vacuum.
While applying a DC magnetic field of at least 00 [Oe], for example, 2500 [Oe], heat treatment is performed in vacuum at 250 to 280 ° C, for example, 280 ° C for 0.5 to 5 hours, for example, 3 hours. Pd but constituting the spin valve film is performed under the same conditions when applying the magnetization direction in the magnetic domain control film
The PtMn antiferromagnetic layer 67 also rotates in the magnetization direction.

Therefore, it is necessary to select a material capable of providing magnetization at a temperature lower than that of PdPtMn as an antiferromagnetic material constituting the magnetic domain control film, and it is difficult to set temperature conditions when a magnetic field is applied.

Accordingly, an object of the present invention is to realize a magnetic sensor using an antiferromagnetic domain control film without making material selection and process control difficult.

[0019]

FIG. 1 is an explanatory view of the principle configuration of the present invention. Referring to FIG. 1, means for solving the problems in the present invention will be described. FIG.
FIG. 1A is a schematic plan view of a magnetic sensor, and FIG.
FIG. 2B is a schematic sectional view taken along a dashed line connecting AA ′ in FIG. See FIGS. 1A and 1B In order to achieve the above object, the present invention relates to a magnetic sensor in which at least a part or all of a spin valve film including at least a free layer 1 is provided on both sides of a magnetic sensing unit. In addition to the extension, the bent portion is provided in the extended portion, and the antiferromagnetic layers 3 and 4 are arranged on the extended portion from the bent portion.

As described above, by providing at least one of the spin valve film including the free layer 1 and the entirety thereof with the bent portions on both sides of the magnetic sensing portion,
The magnetization directions of the antiferromagnetic layers 3 and 4 forming the magnetic domain control layer and the antiferromagnetic layer 2 forming the spin valve film can be made the same, so that the same antiferromagnetic material can be used. When a magnetic field is applied to the antiferromagnetic layers 3 and 4 forming the magnetic domain control layer, the magnetization direction of the antiferromagnetic layer 2 forming the spin valve film is not affected. 4 and the antiferromagnetic layer 2 can be simultaneously magnetized in the same direction, and the process management is greatly simplified.
In addition, the number of steps can be reduced.

In the case of a spin-valve film having a normal stacked structure in which the free layer 1 is on the lower side, a part of the spin-valve film including the free layer 1 may be extended and bent. In the case of a spin-valve film having a reverse stacked structure in which the upper side of the spin-valve film including the free layer 1 is extended,
You only have to bend.

In this case, the bending directions may be opposite to each other on both sides of the magnetic sensing portion, or may be the same direction. When bending in the same direction, the bending direction is provided on one of the extensions from the bent portion. Between the ferromagnetic layer 3 and the free layer 1,
It is necessary to interpose either the laminated ferrifilm or the laminated antiferromagnetic coupling film 5.

As shown in FIG. 1B, between the antiferromagnetic layer 3 and the free layer 1 provided on one of the extended portions from the bent portion.
By providing the laminated ferrimagnetic film or the laminated antiferromagnetic coupling film 5, the magnetic film 8 is pinned by the antiferromagnetic layer 3 rightward in the figure. Since the magnetic film 8 and the magnetic film 6 are antiferromagnetically coupled, the magnetic film 6 is pinned in the direction opposite to the magnetic film 8, whereby the magnetization direction of the free layer 1 is The direction is the same as the direction. On the other hand, the magnetization direction of the free layer 1 immediately below the antiferromagnetic layer 4 is the same as the magnetization direction of the antiferromagnetic layer 4 because there is no reversal of the pin direction due to the antiferromagnetic coupling film. No magnetic circuit is formed, and the magnetic domain of the free layer 1 immediately below the antiferromagnetic layer 2 constituting the spin valve film is controlled. Note that CoFe provided via an intermediate layer 7 of Ru or the like is used.
If the thicknesses of the magnetic films 6 and 8 are the same, the laminated antiferromagnetic coupling film 5 is formed, and if the thicknesses are different, the laminated ferrimagnetic film is narrowly defined.

The extension of the free layer 1 is magnetically sensed (A
It is desirable to retreat from an air bearing surface (BS), thereby preventing crosstalk between adjacent tracks.

In addition, such a configuration has a CIP (Current in Current) in which a current flows in parallel to the film surface of the spin valve film.
CPP (Current perp) in which current flows perpendicularly to the plane of the the plane structure and the spin valve film
The present invention can be applied to any of the endless plane structures, and the CCP structure has no sense current dependency in the occurrence rate of Barkhausen noise.

Also, using such a magnetic sensor, MR
By constructing a composite thin-film magnetic head in which heads or inductive write heads are stacked, a magnetic head corresponding to high recording density can be constructed. Can be realized.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIGS.
The manufacturing process of the magnetic sensor according to the first embodiment of the present invention
Will be described. 2 (a) to 3 (d) show magnetic fields.
FIG. 3E is a schematic cross-sectional view of the sensor, and FIG.
FIG. 3E is a schematic plan view, and FIG.
Above, so that the PdPtMn antiferromagnetic layer 17 is exposed.
It is illustrated. FIGS. 2 (a) see First, Al as the base of the slider_TwoO_Three-TiC substrate
On top, Al_TwoO_ThreeUnder made of NiFe alloy or the like through the membrane
The magnetic shield layer (not shown)
C, Al_TwoO_ThreeAnd the like, and a lower read gap layer 11 is provided.
Next, the lower lead gap is formed using a sputtering method.
On the layer 11, a Ta underlayer 1 having a thickness of, for example, 5 nm
2. NiFe layer 13 having a thickness of, for example, 2 nm, thickness
However, for example, the CoFe free layer 14 having a thickness of 2 nm has a thickness of
For example, a 2.4 nm Cu intermediate layer 15 having a thickness
For example, a 2 nm CoFe pinned layer 16 and a thickness of
For example, a 13 nm PdPtMn antiferromagnetic layer 17 and
A Ta cap layer 18 having a thickness of, for example, 6 nm is sequentially formed.
Film. The composition ratio of the NiFe layer 13 in this case,
For example, Ni₈₁Fe₁₉, And the addition, CoFe free layer
14 and the composition of the CoFe pinned layer 16 are, for example, Co
₉₀Fe_TenAnd the PdPtMn antiferromagnetic layer 17
Is, for example, Pd₃₁Pt₁₇Mn₅₂It is.

Next, a resist pattern 19 having a width corresponding to the width of the spin valve film is provided, and ion milling is performed using the resist pattern 19 as a mask to obtain CoFe.
Etching is performed until the free layer 14 is exposed.

Subsequently, using the resist pattern 19 as it is as a lift-off pattern, a NiFe underlayer 20 having a thickness of, for example, 2 nm and a NiFe underlayer 20 having a thickness of, for example, 13 nm are formed by sputtering. PdPtMn antiferromagnetic layer 2
Sequentially deposited 1. In this case, the NiFe underlayer 2
0 is provided so as to improve the magnetic properties of the PdPtMn antiferromagnetic layer 21.
The composition ratio of the 0 and PdPtMn antiferromagnetic layers 21 is the same as the above composition ratio.

Next, after the resist pattern 19 is removed, 100 [Oe] or more, for example,
By applying a heat treatment at 250 to 280 ° C., for example, 280 ° C. for 0.5 to 5 hours, for example, 3 hours in vacuum while applying a DC magnetic field of 2500 [Oe], the PdPtMn reaction in the depth direction in the drawing is performed. By giving magnetization to the ferromagnetic layer 17 and the PdPtMn antiferromagnetic layer 21, PdPt
The pin direction of the CoFe pinned layer 16 under the Mn antiferromagnetic layer 17 and the pin direction of the CoFe free layer 14 under the PdPtMn antiferromagnetic layer 21 are determined.

Next, as shown in FIG. 3D, a resist pattern 22 having a predetermined opening is provided, and ion-milling is performed using the resist pattern as a mask, so that the exposed portion is formed of the CoFe free layer 1.
It is etched to reach 4, to remove an unnecessary portion of PdPtMn antiferromagnetic layer 21. Note that the shape of the removed portion is a region between the PdPtMn antiferromagnetic layer 21 and the PdPtMn antiferromagnetic layer 17 in FIG.

Next, by performing ion milling using the new resist pattern as a mask, the extending portion of the CoFe free layer 14 is formed in a mesa-shaped spin valve film portion, that is, a magnetic sensing portion. The PdPtMn is removed until it reaches the lower read gap layer 11 so as to bend in the opposite directions and to have an element shape in which the magnetic domain control layer 23 composed of the PdPtMn antiferromagnetic layer 21 exists on the extension from the bent portion. .

[0033] Thereafter, those not shown, after removing the resist pattern, for example, by vapor deposition, thickness of, for example, the Cr adhesion layer and a thickness of 3nm example, 3
After deposition of Au electrode layer of 0 nm, again, by ion milling as a mask a new resist pattern to form a lead electrode made of a pair of Cr / Au film, then, for example, Al ₂ O ₃ The basic configuration of the magnetic sensor is completed by providing an upper magnetic shield layer made of a NiFe alloy or the like via the upper read gap layer.

In the first embodiment of the present invention, the PdPtMn antiferromagnetic layer 17 and the PdPtMn antiferromagnetic layer 21 are given a magnetization in a predetermined direction by applying a magnetic field under heating once, and the CoFe free layer 14 Can be controlled, and therefore, the magnetic domain control film can be made of the same antiferromagnetic material as the antiferromagnetic layer forming the spin valve film, and the configuration and steps are simplified.

In the first embodiment, the magnetic sensing surface (AB) facing the magnetic recording medium depends on the element shape.
(S plane) cannot be used, so it cannot be used for an MR head used for an HDD, but can be used as a general magnetic sensor such as a Gauss meter.

Next, a magnetic sensor according to a second embodiment of the present invention will be described with reference to FIG. 4. Since the basic manufacturing steps are the same as those of the above-described first embodiment, Illustration of the process is omitted. FIG. 4A is a schematic plan view of a magnetic sensor according to a second embodiment of the present invention, and FIG. 4B is a point connecting AA ′ in FIG. 4A. FIG. 4C is a schematic cross-sectional view taken along only a horizontal portion of a chain line, and FIG. 4C is a schematic cross-sectional view taken along a dashed-dotted line connecting BB ′ in FIG. In FIG. 4A, for convenience, the PdPtMn antiferromagnetic layer 17 is illustrated as being exposed.

Referring to FIGS. 4A and 4B, an Al ₂ O ₃ -TiC substrate serving as a slider base is placed on an Al ₂ O ₃ -TiC substrate just like the first embodiment.
_After a lower magnetic shield layer made of a NiFe alloy or the like (all not shown) is provided via the _three films, a lower read gap layer 11 of Al ₂ O ₃ or the like is provided, and then the lower read gap layer is formed by sputtering. On the layer 11, a Ta underlayer 12 having a thickness of, for example, 5 nm, a NiFe layer 13 having a thickness of, for example, 2 nm, and a thickness of, for example, 2 nm
CoFe free layer 14 having a thickness of, for example, 2.4 nm
Cu intermediate layer 15 having a thickness of, for example, 2 nm
Pinned layer 16, PdPtM having a thickness of, for example, 13 nm
n anti-ferromagnetic layer 17 and a T
The cap layer 18 is sequentially formed.

Next, a resist pattern is provided to cover the spin valve film portion and its right side portion in the figure, and ion etching is performed using this resist pattern as a mask to perform etching until the CoFe free layer 14 is exposed.

Subsequently, the NiFe underlayer 20 having a thickness of, for example, 2 nm and the PdPtMn antiferromagnetic layer 21 having a thickness of, for example, 13 nm are formed by sputtering using the resist pattern as it is as a lift-off pattern. Films are formed sequentially.

Next, after removing the resist pattern, a new resist pattern covering the spin valve film portion and the left portion thereof is provided in the figure, and ion milling is performed by using this resist pattern as a mask to perform Co milling.
The etching is performed until the Fe free layer 14 is exposed.

Subsequently, using this resist pattern as a lift-off pattern as it is, a NiFe underlayer 24 having a thickness of, for example, 2 nm, a CoFe layer 25 having a thickness of, for example, 2 nm, by a sputtering method.
A Ru layer 26 having a thickness of, for example, 0.8 nm, for example, 2
nm CoFe layer 27 and a thickness of, for example, 13n
Then, m PdPtMn antiferromagnetic layers 29 are sequentially formed. Note that the CoFe layer 25 / Ru layer 26 / CoFe layer 27 constitutes a laminated ferrilayer 28, more precisely, a laminated antiferromagnetic coupling film.

Next, after removing the resist pattern, while applying a strong DC magnetic field of 10,000 [Oe] or more, for example, 20,000 [Oe] in a vacuum, the resist is heated at 250 to 280 ° C., for example, 280 ° C. in a vacuum. 0.5-5 hours, for example, by performing a heat treatment for 3 hours, and the antiferromagnetic layer 17, PdPtMn antiferromagnetic layer 21, PdPtMn in the depth direction in FIG, PdP
The magnetization is given to the tMn antiferromagnetic layer 29, and the pin direction of the CoFe pinned layer 16 under the PdPtMn antiferromagnetic layer 17 is
The pin direction of the CoFe free layer 14 under the PdPtMn antiferromagnetic layer 21 and the PdPtMn antiferromagnetic layer 29 is determined.

Next, a new resist pattern having a predetermined opening is provided, and ion milling is performed using this resist pattern as a mask, so that the exposed portion is made of Co.
PdP is etched until the Fe free layer 14 is reached.
Unnecessary portions of the tMn antiferromagnetic layers 21 and 29 are removed. Note that the shape of the removal portion is PdPt in FIG.
This is a region between the Mn antiferromagnetic layer 21, the PdPtMn antiferromagnetic layer 29, and the PdPtMn antiferromagnetic layer 17.

Next, ion milling is performed using the new resist pattern as a mask, so that the extending portion of the CoFe free layer 14 is bent in the same direction with respect to the mesa-shaped spin valve film portion, and the bent portion is formed. The PdPtMn antiferromagnetic layers 21 and 29 are removed until they reach the lower read gap layer 11 so that the magnetic domain control layer 23 has an element shape on the extension part.

After that, after removing the resist pattern (not shown), for example, using a vapor deposition method, the thickness of the Cr adhesion layer of, for example, 3 nm and the thickness of, for example,
After deposition of Au electrode layer of 30 nm, again, by ion milling as a mask a new resist pattern to form a lead electrode made of a pair of Cr / Au film, then, for example, Al ₂ O ₃ The basic configuration of the magnetic sensor according to the second embodiment of the present invention is completed by providing an upper magnetic shield layer made of a NiFe alloy or the like via an upper read gap layer.

Referring to FIG. 4 (c), in the magnetic sensor according to the second embodiment of the present invention, a broadly-defined lamination of a CoFe layer 25 / Ru layer 26 / CoFe layer 27 is provided on one free layer extension. ferri layer 28
Since the PdPtMn antiferromagnetic layer 29 is provided through the PdPtMn antiferromagnetic layer 29, the PdPtMn antiferromagnetic layer 29 and the PdPtMn antiferromagnetic layer 21 are simultaneously heat-treated to provide the laminated ferrilayer 28 even when the magnetization direction is the same. , CoFe
Layer 27 is pinned to the right by a PdPtMn antiferromagnetic layer 29 in the figure.

Since the CoFe layer 27 and the CoFe layer 25 and the NiFe layer 24 are antiferromagnetically coupled,
The CoFe layer 25 and the NiFe layer 24 are pinned in the opposite direction to the CoFe layer 27, so that the magnetization directions of the CoFe free layer 14 and the NiFe layer 13 are the same as the pin directions of the CoFe layer 25 and the NiFe layer 24.

On the other hand, the magnetization direction of the CoFe free layer 14 immediately below the PdPtMn antiferromagnetic layer 21 is the same as the magnetization direction of the PdPtMn antiferromagnetic layer 21 because the pin direction is not inverted by the antiferromagnetic coupling film. Free layer 1
4, an unclosed magnetic circuit is formed, and the magnetic domain of the CoFe free layer 14 immediately below the PdPtMn antiferromagnetic layer 17 constituting the spin valve film can be controlled well.

Next, a magnetic sensor according to a third embodiment of the present invention will be described with reference to FIG. 5. The magnetic sensor according to the third embodiment is similar to the magnetic sensor according to the second embodiment. When patterning into the element shape of the CoFe free layer 14 in the magnetic sensor of the above, the extended portion is recessed from the ABS surface, and the basic manufacturing process is exactly the same as in the second embodiment. description of such manufacturing process will be omitted. Incidentally, FIG. 5 (a) is a schematic plan view of a magnetic sensor of the third embodiment of the present invention, FIG. 5 (b), 5
FIG. 5A is a schematic cross-sectional view taken along only a horizontal portion of a dashed line connecting AA ′ in FIG. 5A, and in FIG. 5A, for convenience, the PdPtMn antiferromagnetic layer 17 is exposed. It is illustrated.

In the magnetic sensor according to the third embodiment, since the CoFe free layer 14 extending left and right from the spin valve film is recessed from the ABS, it is adjacent to the track to be read on the magnetic recording medium. The effect of adjacent tracks can be reduced, that is, crosstalk can be prevented, thereby enabling high-precision reading.

Next, a magnetic sensor according to a fourth embodiment of the present invention will be described with reference to FIG. 6. The magnetic sensor according to the fourth embodiment is similar to the magnetic sensor according to the second embodiment. The stacking order of the sensors is reversed, and there is no difference in basic manufacturing method and magnetic characteristics. FIG. 6A is a schematic plan view of a magnetic sensor according to a fourth embodiment of the present invention, and FIG. 6B is a point connecting AA ′ in FIG. 6A. FIG. 6A is a schematic cross-sectional view taken along only the horizontal portion of the chain line, and FIG. 6A shows the CoFe free layer 37 as exposed for convenience.

Referring to FIGS. 6A and 6B, first, a lower magnetic shield layer made of a NiFe alloy or the like (each of them) is formed on an Al ₂ O ₃ —TiC substrate serving as a base of the slider via an Al ₂ O ₃ film. (Not shown), and a lower read gap layer 31 of Al ₂ O ₃ or the like is provided.
Next, a Ta underlayer 3 having a thickness of, for example, 5 nm is formed on the lower read gap layer 31 by using a sputtering method.
2. a NiFe layer 33 having a thickness of, for example, 2 nm; a PdPtMn antiferromagnetic layer 34 having a thickness of, for example, 13 nm;
The thickness of the CoFe pinned layer 35 is, for example, 2 nm, the Cu intermediate layer 36 is, for example, 2.4 nm, the CoFe free layer 37 is, for example, 2 nm, and the thickness is,
For example, a 6 nm-thick Ta cap layer 38 is sequentially formed.

Next, at least C in FIG.
A resist pattern covering reactive ion etching corresponding to the exposed portion of the oFe free layer 37 and the PdPtMn antiferromagnetic layer 46 is provided, and RIE (reactive ion etching) is performed using the resist pattern as a mask to form the Ta cap layer 38. The exposed portion is removed to expose the CoFe free layer 37.

Subsequently, using the resist pattern as it is as a pattern for lift-off, a NiFe underlayer 39 having a thickness of, for example, 2 nm and a PdPtMn antiferromagnetic layer 40 having a thickness of, for example, 13 nm are formed by sputtering. Films are formed sequentially.

[0055] Next, after removing the resist pattern, at least CoFe free layer 3 in FIGS. 6 (a)
7 and a resist pattern covering reactive ion etching corresponding to the PdPtMn antiferromagnetic layer 40 is provided, and RIE is performed using the resist pattern as a mask, thereby removing the exposed portion of the Ta cap layer 38, and
The oFe free layer 37 is exposed.

Subsequently, by using the resist pattern as it is as a pattern for lift-off, a NiFe underlayer 41 having a thickness of, for example, 2 nm, a CoFe layer 42 having a thickness of, for example, 2 nm, by a sputtering method.
Thickness of, for example, Ru layer 43 of 0.8 nm, for example, 2
nm CoFe layer 44 and a thickness of, for example, 13n
Sequentially depositing a m of PdPtMn antiferromagnetic layer 46. In this case also, the CoFe layer 42 / Ru layer 43 / CoF
The laminated ferrilayer 45 is formed by the e-layer 44.

Next, after removing the resist pattern, while applying a strong DC magnetic field of 10,000 [Oe] or more, for example, 20,000 [Oe] in a vacuum, the vacuum is applied at 250 to 280 ° C., for example, 280 ° C. in a vacuum. By performing the heat treatment for 0.5 to 5 hours, for example, 3 hours, the PdPtMn antiferromagnetic layer 34, the PdPtMn antiferromagnetic layer 40, and the PdPtMn antiferromagnetic layer 40 extend in the depth direction in the drawing.
magnetization is imparted to the tMn antiferromagnetic layer 46, and the pin direction of the CoFe pinned layer 35 under the PdPtMn antiferromagnetic layer 34;
The pin direction of the CoFe free layer 37 under the PdPtMn antiferromagnetic layer 40 and the PdPtMn antiferromagnetic layer 46 is determined.

Next, ion milling is performed using the new resist pattern as a mask, so that the extending portion of the CoFe free layer 37 is bent in the same direction with respect to the mesa-shaped spin valve film portion, and the bent portion is formed. The PdPtMn antiferromagnetic layers 40 and 46 are removed until they reach the lower read gap layer 31 so that the element has a magnetic domain control layer on the extended portion.

After that, after removing the resist pattern (not shown), for example, a 3 nm-thickness Cr adhesion layer and a thickness of, for example, 3 nm are formed using, for example, an evaporation method.
After deposition of Au electrode layer of 30 nm, again, by ion milling as a mask a new resist pattern to form a lead electrode made of a pair of Cr / Au film, then, for example, Al ₂ O ₃ By providing an upper magnetic shield layer made of a NiFe alloy or the like via an upper read gap layer, the basic configuration of the magnetic sensor according to the fourth embodiment is completed.

In the fourth embodiment, the step of forming the mesa structure of the spin valve film is not required because the inversely laminated structure is employed. Therefore, the manufacturing process is simplified, and the process damage is reduced. Thus, characteristic deterioration can be reduced.

Next, a magnetic sensor having a CPP structure according to a fifth embodiment of the present invention will be described with reference to FIG. 7. The basic manufacturing steps are the same as those of the third embodiment. Therefore, illustration of the manufacturing process is omitted. FIG. 7A is a schematic plan view of a magnetic sensor according to a fifth embodiment of the present invention, and FIG.
FIG. 7A is a schematic cross-sectional view taken along only a horizontal portion of a dashed line connecting A ′, and in FIG.
The tMn antiferromagnetic layer 17 is shown as being exposed, and the illustration of the SiO ₂ film and the upper electrode is omitted.

[0062] FIGS. 7 (a) and (b) see First, Al ₂ O ₃ -TiC substrate comprising a base of the slider, the lower magnetic shield layer made of NiFe alloy or the like through an Al ₂ O ₃ film (none (Not shown), and a lower read gap layer 11 such as Al ₂ O ₃ is provided.
Next, a Cr adhesion layer 51 having a thickness of, for example, 10 nm and an Au lower electrode 52 having a thickness of, for example, 30 nm are deposited using an evaporation method.

Next, a Ta underlayer 12 having a thickness of, for example, 5 nm, a NiFe layer 13 having a thickness of, for example, 2 nm, and a thickness of, for example, 2 nm, are formed on the Au lower electrode layer 52 by sputtering. CoFe free layer 14, a Cu intermediate layer 15 having a thickness of, for example, 2.4 nm, a CoFe pinned layer 16 having a thickness of, for example, 2 nm, a PdPtMn antiferromagnetic layer 17 having a thickness of, for example, 13 nm, and A Ta cap layer 18 having a thickness of, for example, 6 nm is sequentially formed. After that, until the process of patterning into the element shape,
This is performed substantially in the same manner as in the third embodiment.

After patterning into the device shape shown in FIG. 7A, a SiO ₂ film 53 having a thickness of, for example, 70 nm is deposited on the entire surface, and then a contact hole for the Ta cap layer 18 is formed. For example, after depositing a Cr adhesion layer 54 having a thickness of, for example, 3 nm and an upper Au electrode layer 55 having a thickness of, for example, 30 nm using an evaporation method, ions using a new resist pattern as a mask are again formed. A fifth embodiment of the present invention is achieved by forming an upper electrode by milling and finally providing an upper magnetic shield layer made of a NiFe alloy or the like via an upper lead gap layer of Al ₂ O ₃ or the like. The basic configuration of the magnetic sensor having the CPP structure described above is completed.

In the fifth embodiment, the CPP
Since the structure, that is, the sense current flows perpendicularly to the film surface of the spin valve film, the magnetic field generated by the sense current does not adversely affect the pin direction of the free layer, and the characteristics change according to the magnitude of the sense current. Nothing.

Next, the magnetic sensor according to the sixth embodiment having the CPP structure corresponding to the magnetic sensor according to the first embodiment and the C sensor corresponding to the magnetic sensor according to the second embodiment described above.
The magnetic sensor according to the seventh embodiment having the PP structure and the magnetic sensor according to the eighth embodiment having the CPP structure corresponding to the magnetic sensor according to the fourth embodiment are configured. In any case, the magnetic sensor having the CIP structure is provided with the lower electrode and the upper electrode via the SiO ₂ film, just like the fifth embodiment. since differences not in manufacturing steps and structure, description will be omitted.

With respect to the magnetic sensors of the first to eighth embodiments, an applied magnetic field of ± 500 [O
e), the MR curve was measured, and the occurrence of Barkhausen noise was investigated. In this case, the number of samples is 100 per each embodiment, what 1/100 jump of the total resistance change Barkhausen noise is the sample that occurred.

[0068]

[Table 1]

Table 1 shows that the magnetic sensor of each of the embodiments described above shows the occurrence rate of Barkhausen noise and the sensor current of 1 m.
A, 2 mA, 3 mA, 4 mA, and 5 mA are shown for the five conditions, and C of the first to fourth embodiments is shown.
In the magnetic sensor having the IP structure, the occurrence rate of Barkhausen noise increases as the sense current increases.
0% or less.

On the other hand, the CPP of the fifth to eighth embodiments
In the magnetic sensor having the structure, the occurrence rate of Barkhausen noise did not depend on the sense current, and the occurrence rate was 5% or less. This is because, in the magnetic sensor having the CIP structure, the magnetic field generated by the sense current flowing along the free layer disturbs the magnetization direction for controlling the magnetic domain, whereas the magnetic field generated by the sense current changes the magnetic field generated by the magnetic domain control. It is considered that the characteristics do not change depending on the magnitude of the sense current without affecting the magnetization direction.

The resistance change rate is as-deposited.
t of the membrane, ie, is within a drop of less than 20% relative to a solid film, this decrease is believed to be the process damage by the steps leading up to formation into element shape.

Although the embodiments of the present invention have been described above, the present invention is not limited to the configurations described in the embodiments, and various modifications are possible. For example, in the description of each of the above embodiments, the lead electrode is patterned by a normal photolithography process, but may be formed by a lift-off method using a resist pattern.

Further, the second to fifth embodiments described above,
In the seventh embodiment and the eighth embodiment, the laminated ferrilayer, that is, the laminated ferrilayer in a broad sense, is constituted by a laminated antiferromagnetic coupling film in which a pair of magnetic films have the same thickness. However, the present invention is not limited to the laminated antiferromagnetic coupling film, but may be formed of a narrowly-defined laminated ferrimagnetic layer in which a pair of magnetic films have different thicknesses.

[0074] Also, in the description of the fifth to the eighth embodiment of the present invention, is used an SiO ₂ film as an insulating film for forming contact holes, it is not limited to the SiO ₂ film, Al ₂ An O ₃ film may be used. When an Al ₂ O ₃ film is used, a Cl-based gas may be used as a reactive gas in the RIE process.

The materials of the magnetic layer, the antiferromagnetic layer, and the conductive layer described in each of the above embodiments are merely examples, and various known magnetic materials, antiferromagnetic materials, and conductive materials may be used. It goes without saying that a combination of materials may be used.

Although the embodiments of the present invention have been described as a single magnetic sensor for a Gauss meter or an MR head, the present invention is not limited to a single magnetic sensor, but is an inductive type. It is needless to say that the present invention is also applied as a magnetic sensor for an MR head constituting a composite type thin film magnetic head laminated with the above thin film magnetic head.

Here, the detailed features of the present invention will be described with reference to FIG. 1 again. 1 (a) and 1 (b) (Appendix 1) At least one or all of the spin valve film including at least the free layer 1 is extended to both sides of the magnetic sensing portion, and a bent portion is provided in the extended portion. A magnetic sensor, wherein antiferromagnetic layers 3 and 4 are disposed on an extension from the bent portion. (Supplementary Note 2) The magnetic sensor according to Supplementary Note 1, wherein the bending directions are opposite to each other on both sides of the magnetic sensing unit. (Supplementary Note 3) The bending direction is a same direction on both sides of the magnetic sensing section, and, between the antiferromagnetic layer 3 and the free layer 1 provided on one of the extension portion from the bent portion, the laminated ferri 2. The magnetic sensor according to claim 1, wherein one of the film and the laminated antiferromagnetic coupling film 5 is interposed. (Supplementary note 4) The magnetic sensor according to supplementary note 3, wherein an extension of the free layer 1 is retracted from the magnetic sensing surface. (Supplementary note 5) The magnetic sensor according to any one of Supplementary notes 1 to 4, wherein a direction in which the sense current flows is perpendicular to a film surface of the spin valve film. (Supplementary Note 6) A magnetic read head using the magnetic sensor according to any one of Supplementary Notes 3 to 5. (Supplementary Note 7) A composite thin-film magnetic head, wherein the magnetic read head according to Supplementary Note 6 and an inductive magnetic write head are stacked. (Supplementary Note 8) A magnetic recording apparatus equipped with any one of the magnetic read head described in Supplementary Note 6 and the composite thin-film magnetic head described in Supplementary Note 7.

[0078]

According to the present invention, when the magnetic domain control film is formed of an antiferromagnetic layer, an extension having a bent portion is provided in the free layer, and the arrangement of the antiferromagnetic layer is devised. Therefore, in a single magnetic field application step, a predetermined magnetization direction can be imparted to the antiferromagnetic layer constituting the spin valve film and the magnetic domain control film constituting the magnetic domain control film,
Since the material selection becomes easy and the manufacturing process is simplified, it greatly contributes to the popularization and low price of HDD devices with high recording density.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a basic configuration of the present invention.

FIG. 2 is an explanatory diagram of a manufacturing process partway through the first embodiment of the present invention.

FIG. 3 is an explanatory view of a manufacturing process of the first embodiment of the present invention after FIG. 2;

FIG. 4 is an explanatory diagram of a magnetic sensor according to a second embodiment of the present invention.

FIG. 5 is an explanatory diagram of a magnetic sensor according to a third embodiment of the present invention.

FIG. 6 is an explanatory diagram of a magnetic sensor according to a fourth embodiment of the present invention.

FIG. 7 is an explanatory diagram of a magnetic sensor according to a fifth embodiment of the present invention.

FIG. 8 is an explanatory diagram of a magnetic sensor using a conventional hard magnetic domain control film.

FIG. 9 is an explanatory view of a magnetic sensor using a conventional antiferromagnetic domain control film.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 free layer 2 antiferromagnetic layer 3 antiferromagnetic layer 4 antiferromagnetic layer 5 stacked antiferromagnetic coupling film 6 magnetic film 7 intermediate layer 8 magnetic film 11 lower read gap layer 12 Ta underlayer 13 NiFe layer 14 CoFe free layer Reference Signs List 15 Cu intermediate layer 16 CoFe pinned layer 17 PdPtMn antiferromagnetic layer 18 Ta cap layer 19 Resist pattern 20 NiFe underlayer 21 PdPtMn antiferromagnetic layer 22 Resist pattern 23 Magnetic domain control layer 24 NiFe underlayer 25 CoFe layer 26 Ru layer 27 CoFe Layer 28 Stacked ferrilayer 29 PdPtMn antiferromagnetic layer 31 Lower read gap layer 32 Ta underlayer 33 NiFe layer 34 PdPtMn antiferromagnetic layer 35 CoFe pinned layer 36 Cu intermediate layer 37 CoFe free layer 38 Ta cap layer 39 NiFe underlayer 40 PdPtM n antiferromagnetic layer 41 NiFe underlayer 42 CoFe layer 43 Ru layer 44 CoFe layer 45 laminated ferrilayer 46 PdPtMn antiferromagnetic layer 51 Cr adhesion layer 52 Au lower electrode 53 SiO ₂ film 54 Cr adhesion layer 55 Au upper electrode 61 lower Read gap layer 62 Ta underlayer 63 NiFe layer 64 CoFe free layer 65 Cu intermediate layer 66 CoFe pinned layer 67 PdPtMn antiferromagnetic layer 68 Ta cap layer 69 Hard magnetic domain control film 70 NiFe underlayer 71 Antiferromagnetic domain control film

Continued on front page F-term (reference) 2G017 AD55 AD59 AD63 AD65 5D034 BA03 BA04 BA05 CA08 5E049 AC05 BA12 BA16 DB12

Claims (5)

[Claims] 1. A with extended part or one of all the sides of the magnetic sensing part of the spin-valve film including at least the free layer, a bent portion is provided in the extended portion, on the extension portion from the bent portion A magnetic sensor comprising an antiferromagnetic layer. 2. The device according to claim 1, wherein the bending directions are opposite to each other on both sides of the magnetic sensing unit.
A magnetic sensor as described. 3. A laminated ferri-film between an antiferromagnetic layer and a free layer provided on one side of an extension from the bent portion, wherein the bending direction is the same on both sides of the magnetic sensing portion. 2. The magnetic sensor according to claim 1, wherein one of the laminated antiferromagnetic coupling films is interposed. 4. A magnetic head using the magnetic sensor according to claim 3 as a read head. 5. A magnetic recording apparatus comprising the magnetic head according to claim 4.