JP2003298144A - Magnetoresistive element and method of manufacturing the same, magnetic head and magnetic reproducing device - Google Patents

Abstract

(57) [Problem] In a perpendicular conduction type magnetoresistive element, a magnetoresistive film is formed flat even on a convex portion of a lower electrode, so that the magnetoresistive change is large and the characteristics are improved. An object of the present invention is to provide a stable magnetoresistive element and a method of manufacturing the same, and a magnetic head and a magnetic reproducing apparatus using the magnetoresistive element. SOLUTION: A lower electrode (2a) having a convex portion (P) protruding upward, an insulator layer (3a) provided so as to surround the periphery of the convex portion, and the convex portion and the same. A planarized conductive layer (5) having an upper surface formed to be substantially flat by embedding irregularities generated on the surface of the surrounding insulator layer, and the substantially flat upper surface (5B) of the planarized conductive layer. A magnetoresistive effect element comprising: a magnetoresistive effect film (6); and an upper electrode (2b) provided on the magnetoresistive effect film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetoresistive effect element, a method of manufacturing the same, a magnetic head and a magnetic reproducing device, and more specifically, a sense current is passed in a direction perpendicular to a film surface of a magnetoresistive effect film. The present invention relates to a magnetoresistive effect element having a structure, a method for manufacturing the same, a magnetic head and a magnetic reproducing apparatus using the same.

[0002]

2. Description of the Related Art In recent years, the magnetic recording density of HDDs (Hard Disk Drives) has dramatically improved, but further higher recording density is desired. Due to the miniaturization of the recording bit size accompanying the increase in recording density, the reproducing sensitivity of conventional thin film heads becomes insufficient, and nowadays magnetoresistive heads (MR heads) that utilize the magnetoresistive effect are the mainstream. Has become.
Among them, a spin-valve type giant magnetoresistive head (SVGMR head) has been attracting attention as one showing a particularly large magnetoresistive effect.

On the other hand, due to the increase in recording density, the flying height from the recording medium during traveling of the thin film magnetic head has decreased. This is to sense the small media bit field. From such a tendency, it is expected that it is inevitable to run the magnetic head while maintaining intermittent contact or steady contact with the recording medium. Further, from a viewpoint other than the high recording density, it is expected that the HDD will be mounted on AV equipment such as audio and video as the multimedia in the future advances. For mounting on an AV device, the reliability of the HDD, particularly the resistance to mechanical shock from the outside, is important. At that time, the magnetic head is considered to come into contact with the surface of the medium. Therefore, development of a magnetic head that is resistant to contact is desired.

However, the above-mentioned conventional SV head exhibits an abnormal resistance change due to the heat generated by the contact with the recording medium during reproduction (thermal asperity).
Is well known. Therefore, the conventional MR head and SVGMR head in which the magnetic sensitive portion is exposed on the medium facing surface are difficult to adapt to future high recording density.

Therefore, various yoke type magnetic heads have been devised. The yoke type magnetic head is resistant to the above-mentioned thermal asperity because the magnetically sensitive portion of the SV (spin valve) portion is not exposed on the medium facing surface. Among them, the "horizontal yoke type magnetic head", which can shorten the magnetic path and can easily reduce the weight of the head slider, is receiving attention.

From the viewpoint of MR elements, due to recent rapid miniaturization, a conventional CIP (Current In Plane) type electrode structure in which a sense current is passed in a direction parallel to a film surface is a manufacturing process. It is expected that microfabrication will be extremely difficult. Therefore, a CPP (Current Perpendicula) that conducts a sense current in a direction substantially perpendicular to the film surface
The r to Plane (vertical conduction) type MR element (CPP-MR element) is drawing attention. A typical example of the vertical conduction type element is a tunneling type MR element (Tunneling MagnetoResistive Effect: TMR element) which utilizes the tunneling effect of electrons, which has recently developed a huge magnetoresistive effect.
There is.

However, in such a perpendicular conduction type magnetoresistive effect magnetic head, it is necessary to increase the rate of change in resistance of the MR film in order to increase the reproduction output, and the conduction is increased. It is also necessary to solve the problem that the element is thermally destroyed by the heat generated by.

The improvement of the resistance change rate is being solved to some extent by material development, etc., but the current situation is that sufficient measures have not been taken against element destruction due to heat generation and stress.

On the other hand, the present inventor independently made a prototype
As a result of the examination, in the case of the perpendicular conduction type magnetoresistive effect element,
When the magnetoresistive effect film is formed on the pillar-shaped convex portion of the lower electrode, it is difficult to flatten the surface on which the magnetoresistive effect film is to be formed. As a result, there is a problem that the magnetoresistive effect film is curvedly formed according to the unevenness of the underlayer, the thickness of each layer of the magnetoresistive effect film is “uneven”, and the characteristics are easily deteriorated. It turned out to be.

FIG. 19 is a schematic cross-sectional view for explaining the "unevenness" of the film thickness of such a magnetoresistive effect film. That is, the figure shows the lower electrode 2a having the pillar-shaped protrusions P.
And the insulator layer 3a filling the periphery of the convex portion P and the magnetoresistive effect film 6 formed thereon.

Here, the lower electrode 2a has, for example, a film thickness of 1
Nickel iron (Ni ₈₀ F with a magnetic shield function of about 50 nanometers and a height of the convex portion P of about 50 nanometers)
e _{2 0} ) (composition is atomic percent). Then, the insulating layer 3a is formed around the convex portion P.
Then, the magnetoresistive effect film 6 having a film thickness of about 40 nanometers is formed thereon.

In this case, it is desirable that the surface on which the magnetoresistive effect film 6 is formed is flat. To do this, for example,
A method of flattening the surface by a method such as CMP (Chemical Mechanical Polishing) after forming the electrode 2a having the convex portion P and the insulator layer 3a can be considered.

However, since the materials of the electrode 2a and the insulating film 3a are significantly different, the etching methods are significantly different mechanically and chemically. Therefore, it has been found that it is difficult to make the surface sufficiently flat and smooth by the conventional flattening method including CMP. As an example thereof, for example, as shown in FIG. 19, the protrusion R may be formed near both ends of the electrode protrusion P. In addition to this, as will be described later in detail with respect to the embodiment of the present invention, the convex portion P of the electrode may be formed higher than the surrounding insulating layer 3a. On the contrary, the surrounding insulating layer 3a may be formed higher than the convex portion P. Furthermore, a groove-shaped concave portion may be formed between the convex portion P of the electrode and the insulating layer 3a.

According to the study by the present inventor, even when an attempt is made to optimize the polishing conditions and the slurry (polishing agent) by using the CMP method, these projections R, the projections P and the surrounding insulating layer are formed. It is difficult to completely eliminate the step with 3a or the groove-like recess, and the height is often about 10 nanometers or more.

Further, in addition to such a protrusion R, FIG.
As illustrated in FIG. 21, a groove-shaped “wrinkle” occurs around the convex portion P, or, as illustrated in FIG. 21, the height of the surface of the convex portion P is different from that of the insulating layer 3a. In some cases, there was a "step".

Therefore, the magnetoresistive film 6 having a film thickness of about 40 nanometers formed thereon has a "waviness" in the height direction so as to reflect the shapes of the protrusion R, the "rim" and the "step". Or "curved". As a result, the film thickness of the magnetic layer or the non-magnetic layer forming the magnetoresistive film 6 may be uneven, or magnetic coupling between the magnetic layers (magnetization pinned layer and magnetization free layer, etc.) may occur. Becomes uneven. And
Such "unevenness" and "non-uniformity" cause a decrease in the rate of change in magnetoresistance and a variation in characteristics.

The present invention has been made based on the recognition of such problems. That is, the purpose is to provide a magnetoresistive effect element having a large magnetoresistive change and stable characteristics by forming the magnetoresistive effect film even on the convex portion of the lower electrode in the perpendicular conduction type magnetoresistive effect element. It is an object of the present invention to provide a resistance effect element and a manufacturing method thereof, and a magnetic head and a magnetic reproducing apparatus using the magnetoresistive effect element.

In order to achieve the above object, the first magnetoresistive effect element of the present invention surrounds the lower electrode having a convex portion protruding upward and the periphery of the convex portion. An insulating layer provided as described above, a flattening conductive layer whose top surface is formed to be substantially flat by embedding irregularities generated on the surface of the insulating layer around the convex portion and its surroundings, and the flattening conductive layer A magnetoresistive effect film laminated on the substantially flat upper surface, and an upper electrode provided on the magnetoresistive effect film are provided.

Here, the unevenness may be at least one of a step, a groove, and a protrusion formed on the surface of the insulating layer around the convex portion and the surrounding thereof.

Further, the second magnetoresistive effect element of the present invention comprises a lower electrode having a convex portion protruding upward, an insulator layer provided so as to surround the convex portion,
A flattening conductive layer provided on the convex portion and the insulating layer around the convex portion, a magnetoresistive effect film provided on the flattening conductive layer, and a magnetoresistive effect film provided on the magnetoresistive effect film. And the upper electrode contacting the magnetoresistive effect film is flatter than the lower surface contacting the protrusion and the insulating layer around the protrusion. It is characterized by

Further, the third magnetoresistive element of the present invention comprises a lower electrode having a convex portion protruding upward, an insulator layer provided so as to surround the convex portion,
A layer made of a conductive material is deposited on the above, and the surface thereof is subjected to a planarization treatment by etching or polishing to form a planarized conductive layer, and a magnetoresistive effect film is formed on the planarized conductive layer. It is characterized by having done.

Here, a pair of bias applying films provided adjacent to both sides of the magnetoresistive film are further provided, and the planarizing conductive layer extends below the pair of bias applying films. It can be provided.

Further, the insulator layer is formed in contact with the flattening conductive layer, is provided on the upper side of the first layer and is made of a first insulating material, and is provided under the first layer. And a second layer made of a second insulating material different from the first insulating material.

The magnetoresistive effect film has a magnetization pinned layer having a first magnetic film whose magnetization direction is substantially fixed in one direction, and a second magnetization direction whose magnetization direction changes in response to an external magnetic field. A magnetic free layer having a magnetic film, a nonmagnetic intermediate layer provided between the magnetic pinned layer and the magnetic free layer,
And a magnetoresistive effect film having.

On the other hand, the method of manufacturing a magnetoresistive effect element of the present invention comprises the steps of forming a lower electrode having a convex portion protruding upward and an insulating layer surrounding the convex portion,
A step of depositing a layer made of a conductive material on the convex portion and the insulating layer around the convex portion, and planarizing an upper surface of the layer made of the conductive material by etching or polishing to form a planarized conductive layer. And a step of forming a magnetoresistive effect film on the flattened conductive layer, while the magnetic head of the present invention comprises any of the magnetoresistive effect elements described above. It is characterized by that.

Further, the magnetic reproducing apparatus of the present invention is characterized in that it is provided with this magnetic head so that the information magnetically recorded on the magnetic recording medium can be read.

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic view illustrating a cross-sectional structure of a main part of a magnetoresistive effect element according to an embodiment of the present invention.

That is, the magnetoresistive element of the present invention is
A lower electrode 2a having a convex portion P formed so as to project upward, and a flattening conductive layer 5 provided thereon.
And a magnetoresistive effect film 6 provided thereon, and an upper electrode 2b provided by connecting a convex portion P in a pillar shape on the upper surface thereof.
And an insulator layer 3 provided so as to fill the periphery thereof.

That is, in the present invention, the lower electrode 2
The planarizing conductive layer 5 is provided between the a and the magnetoresistive effect film 6. This flattening conductive layer 5 is not flat when viewed from the lower surface 5A, and a step formed between the projection (not shown) on the surface of the projection P of the lower electrode 2a and the surrounding insulating layer 3 According to the non-planar. On the other hand, when the upper surface 5B of the flattening conductive layer 5 is viewed, it is formed substantially flat. That is, the film thickness of the flattening conductive layer 5 is not constant within the film surface, and has a function of filling the projection P of the lower electrode 2a or the projections, steps, grooves, etc. formed around the projection P to flatten it.

Further, depending on the design specifications of the magnetic head,
The planarized conductive layer 5 after planarization does not have to remain on the convex portion P of the lower electrode 2a, that is, the planarized conductive layer 5 remains around the convex portion P of the lower electrode 2a. May be.

The flattening conductive layer 5 is, as described in detail later,
It can be formed of various metals or compounds having conductivity. In addition, the film thickness of the flattening conductive layer 5 is appropriately determined according to the height of the unevenness around the convex portion P in order to absorb and flatten the unevenness around the convex portion P of the lower electrode 2a. Is desirable.

According to the present invention, first, by providing such a flattening conductive layer 5, the "unevenness" of the film thickness of the magnetoresistive effect film 6 and the "waviness" of the film as described above with reference to FIG. Alternatively, instability of magnetic coupling due to “curvature” can be eliminated. As a result, it is possible to stably provide a magnetoresistive element capable of suppressing a decrease in the magnetoresistive change rate and capable of highly sensitive magnetic detection.

Furthermore, according to the present invention, by providing the flattening conductive layer 5, it is possible to solve problems such as heat accumulation of the magnetoresistive effect film 6 and destruction due to film stress. That is, since the flattening conductive layer 5 acts as a heat dissipation path, heat dissipation from the magnetoresistive effect film 6 is improved. As a result, in a magnetic recording system having a recording density higher than that of the related art, even when the magnetic recording system is run close to a recording medium, deterioration of characteristics due to heat generation is suppressed, and stable reproduction is possible.

On the other hand, according to the present invention, the flattening conductive layer 5 can be made to act as a base layer of the bias film.

In FIG. 2, the planarizing conductive layer 5 is formed on the bias film 17.
It is a schematic cross section which illustrates the structure extended even below. That is, in the case of a magnetoresistive element such as a spin valve structure, the magnetic domain structure of the magnetization free layer (also referred to as “free layer”) is controlled so that Barkhausen noise (Ba
rkhausen noise) to suppress the magnetoresistive film 6
Bias films 17 are often provided on both ends of the. The bias film 17 is made of an antiferromagnetic material or a hard magnetic material.

According to the present invention, as shown in the figure, by extending the planarizing conductive layer 5 below these bias films 17, it is possible to act as a base layer for the bias films 17. That is, the flattening conductive layer 5 acts as a buffer or a seed to control the crystallinity and the orientation direction of the bias film 17 within a predetermined range and obtain a good bias magnetic field. it can.

An outline of a method of manufacturing such a flattened conductive layer 5 is as follows. That is, first
As a method of forming the lower electrode 2a having the convex portion P, an insulator is deposited on the lower electrode 2a and the surface is substantially flattened by a method such as etch back, and then the flattened conductive layer 5 is formed on the surface. Can be formed.

As a second method, the lower electrode 2a having the convex portion P is formed, then an insulator is formed on this electrode, and then the substrate surface is directly polished by CMP, or After applying a low-viscosity organic resist,
RIE (reactive ion etching) and ion milling (io
n milling) or the like is used to substantially flatten the unevenness of the surface to, for example, 30 nanometers to 100 nanometers.

In this flattening step, in order to obtain a better surface property, the slurry used in CMP is optimized, or the height of the convex portion P of the lower electrode 2a is lowered to reduce the initial step difference. Although measures such as reducing the size can be considered, in any case, it is not easy to apply to a magnetoresistive effect type magnetic head of perpendicular conduction to the film surface.

Therefore, by forming the flattening conductive layer 5 on the film surface in which the unevenness of the surface is approximately flattened from about 30 nanometers to about 100 nanometers in this way, the electrode generated during the substantially flattening is formed. It is possible to cover irregularities such as “protrusions”, “steps” and “grooves” generated at the boundary between different materials of the convex portion P and the insulator 3a.

The surface of the flattened conductive layer 5 can be surely and easily polished flat and smooth by CMP using a general slurry. That is, since a single material is polished, there are few scratches after polishing.
A smoothness well below nanometers can be easily obtained.

As the material of the flattening conductive layer 5, titanium (Ti) or zirconium (Z) of group IVa in the periodic table is used.
r), hafnium (Hf), Va group vanadium (V), niobium (Nb), tantalum (Ta), VIa group chromium (Cr), molybdenum (Mo), tungsten (W), precious metal copper (Cu). , Silver (Ag), gold (A
u), platinum (Pt), palladium (Pd), rhodium (Rh), osmium (Os), aluminum (Al), silicon (Si), and the like can be used. And, more preferably, titanium (Ti), zirconium (Zr), hafnium (Hf), niobium (N
b), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), aluminum (A
l), alloys containing at least one of silicon (Si), and oxides thereof (eg, TiOx, ZrOx, H
fOx, TaOx, CrOx, etc.) and nitrides (eg, T
iNx, ZrNx, HfNx, TaNx, CrNx, M
oNx, WNx, AlNx, SiNx, etc.) and oxynitride compounds thereof having conductivity.

The electric resistance (ρ) of the flattening conductive layer 5 is ρ ≦
It is preferably 1000 μΩcm. When the electric resistance (ρ) of the flattening conductive layer 5 is 1000 μΩcm or more,
It becomes difficult for a current to flow between the convex portion P of the lower electrode 2a and the magnetoresistive effect film 6, and when a large current is applied to obtain an output, the resistance due to the disturbance of the magnetic domain of the magnetoresistive effect film 6 due to the current magnetic field. This is because problems such as a decrease in change and breakage of the magnetoresistive effect film 6 may occur.

On the other hand, the film thickness (t) of the flattening conductive layer 5 is such that the surface in the vicinity of the projection P of the lower electrode 2a after the substantially flattening step before depositing the flattening conductive layer 5 has a concave shape. In this case, it is preferable that the thickness is thicker than the depth (d0) of this recess and that d0 <t <(d0 + 100) (nanometer). Film thickness t is d0
If the thickness is less than the above, the recess cannot be sufficiently filled even if CMP is applied, and if the film thickness t is (d0 + 100) nanometers or more, the amount of polishing in CMP is large and the controllability of the amount of polishing tends to be poor. Because you can see.

On the other hand, in the case where the surface of the lower electrode near the convex portion P after the substantially flattening before the deposition of the flattening conductive layer 5 has a convex shape, if the height of this convex is d'0, The film thickness t is 0 <t
It is desirable to be in the range of <(d'0 + 50) (nanometer), and it is more desirable to be in the range of 0 <t <d'0.

On the other hand, the material of the lower electrode 2a and the shape of the convex portion P may be in accordance with the design specifications of the CPP-MR element, and are not particularly limited. The material of the insulator layer 3 used at this time is not particularly limited, but, for example, oxides or nitrides of silicon (Si) or aluminum (Al) and their composites can be used, and electrical insulation can be achieved. In order to sufficiently secure the above, a multilayer film in which these are laminated may be used. However, the film thickness of the insulator layer 3 needs to be slightly thicker than minus 20% with respect to the height of the convex portion P, and the thickness of the convex portion P must be +200 (nanometer) or less. Is desirable. As described above, by setting the height of the convex portion P in the range of minus 20% to plus 200 (nanometer), it becomes easier to control the "wrinkle" and the surface unevenness in the substantially flattening.

In the present invention, the convex portion P of the lower electrode is
As a forming method, in addition to the above-described method, an insulating layer having an opening may be formed on a flat electrode and the opening may be filled with an electrode material. That is, by embedding the electrode material in the opening of the insulator layer, the protrusion P
May be formed, and the entire surface may be substantially flattened by a method such as CMP, ion milling or etch back, and a flattening conductive layer may be provided on the flattened conductive layer to perform final polishing (for example, CMP). Also in this case, by providing the flattening conductive layer 5, it is possible to absorb the "wrinkle" generated on the surface of the convex portion P and obtain a sufficiently flat and smooth surface.

Further, in this case, by providing the flattening stopper layer on the outermost surface of the insulating layer, it becomes easy to monitor at the time of substantially flattening, and the flattening degree is improved. Further, by using a non-magnetic high resistance material, preferably an insulating material, as the flattening stopper layer, the insulation probability between the upper and lower electrodes is significantly improved. The electric resistance (ρ) of this flattening stopper layer is preferably 1000 μΩcm or more. Further, an insulator adhesion layer may be provided between the concave insulator and the electrode.

The embodiments of the present invention will be described in more detail below with reference to examples.

(First Embodiment) First, as a first embodiment of the present invention, a trial manufacture example of a magnetoresistive effect element having the structure shown in FIG. 1 will be described.

3 to 5 are process cross-sectional views showing a main part manufacturing process of the magnetoresistive effect element of this embodiment.

In this embodiment, first, as shown in FIG. 3A, an electrode 2a having a convex portion P and an electrode terminal portion (not shown) for measurement are formed. In this example, the main purpose was to confirm the magnetic characteristics of the magnetoresistive effect element, and therefore, the magnetic shield, the magnetization fixed film, and the recording portion required to function as the magnetic head were not manufactured.

First, on a silicon substrate 1 having a thickness of about 0.6 mm and a diameter of 3 inches, a tantalum (T:
a), 400 nm thick copper (Cu), and 10 nm thick tantalum (Ta) were laminated.

Then, a resist pattern (V9 having a diameter of about 1 μm and a height of about 1.2 μm) is formed.
0: manufactured by Tokyo Ohka Co., Ltd.) using a g-line stepper (step type projection exposure apparatus), and further using an ion milling apparatus, acceleration voltage is 500 [eV] until the height of the convex portion P reaches 500 nanometers. After irradiation with argon (Ar) ions having a beam current of 200 [mA] at
The resist is removed by a normal semiconductor process, and the result is shown in FIG.
The convex portion P as shown in FIG.

Next, as shown in FIG. 3B, the electrode 2
An insulator 3a having a thickness of 700 nanometers was formed on a. Here, as the insulator 3a, silicon oxide (Si
Ox) was used. As a specific method of forming the insulator 3a, the reactivity obtained by introducing a mixed gas of argon (Ar) gas and oxygen (O ₂ ) gas targeting silicon (Si) having a diameter of 5 inches and a thickness of 8 nanometers is used. Sputtering was performed and the film thickness was formed to be thicker than the height of the convex portion P. Further, in order to adjust the taper angle of the convex shape of the surface of the insulator 3a which reflects the convex portion P, a high frequency bias was applied during the sputtering. A cross section of the structure of FIG. 3B produced under such conditions is SEM (scanning electron microscope:
When observed with a Scanning Electron Microscope), the taper angle of the insulator 3a is about 42 degrees, and the “deviation” of the position of the electrode 2a with respect to the convex portion P is 50 nanometers or less.
It was also confirmed that the alignment accuracy was very good.

Next, as shown in FIG. 3C, a flattening resist 4 having a thickness of 1.2 micrometers was applied and baked. As the flattening resist 4, a low viscosity OFR (manufactured by Tokyo Ohka) resist was used. The surface roughness of the sample thus coated / baked was measured by α step (a stylus-type surface step meter).
It was confirmed to be very flat below nanometer.

Next, the flattening resist 4 and the insulator 3a were etched back to make the surfaces relatively flat to obtain the state shown in FIG. 4 (a). As a concrete method of etching back in the present embodiment, a sample is set in a parallel plate type RIE (Reactive Ion Etching) apparatus, and then carbon tetrafluoride (CF) is used as an etching gas.
₄ ) was introduced until the pressure reached 5 Pascal (Pa), and then a high frequency of 100 watt (w) was applied to carry out etching. At this time, the etching rate of the flattening resist 4 was 97 nanometer per minute (nm / min.).
x insulator 3a is 110 nanometers per minute (nm / mi
n. ) And the etching rate of both are almost equal.

As a method of etching back, RI is used.
Instead of E, ion milling and RI are used so that the etching rates of the flattening resist 4 and the insulator 3a are substantially equal.
BE (Reactive Ion Beam Etching) and ICP (Inducti)
It is also possible to use another etching method such as vely coupled plasma or another method such as a method of directly performing CMP without applying a planarizing resist.

The surface roughness of the sample, which was substantially flattened by the etch-back method using RIE, was measured by the α step.
It was 30 nanometers.

Next, as shown in FIG. 4B, a flattening conductive layer 5 was formed. In this embodiment, the planarizing conductive layer 5
As the material of, tantalum (Ta), which is the same material as the outermost surface of the convex portion P of the electrode 2a, was selected. The film thickness was 50 nanometers, which was slightly larger than the roughness after etching back. The film formation of the flattening conductive layer 5 was performed by a normal RF magnetron sputtering method, and then the surface irregularities were measured, and it was confirmed that it was 50 nanometers or less.

Next, as shown in FIG. 4C, the flattening conductive layer 5 was subjected to a flattening polishing treatment by CMP to flatten the surface. At this time, as the slurry for CMP, CHS700 (manufactured by Shibaura Mechatronics Co., Ltd.)
Was used. As a result, the surface irregularities after CMP became very small, and when the surface irregularities were measured with an AFM (Atomic Force Microscope), it was 5 nanometers or less around the convex portion P of the electrode 2a, which was very flat and smooth. It was confirmed that a surface having excellent properties was obtained.

In addition, the vicinity of the convex portion P of the electrode 2a is FIB
(Focused Ion Beam) was used for cross-section observation, and the remaining amount of the flattened conductive layer 5 and the embedded state of the “rim” were observed with a high resolution SEM (Scanning Electron Microscope). It was confirmed that the amount was about 10 nanometers, and the flattening conductive layer was finely embedded in the "rimming" portion on the boundary between the convex portion P of the electrode 2a and the insulating layer 3a.

Next, a magnetoresistive effect film 6 is formed on the flattening conductive layer 5 having good surface properties as described above, and a device resist pattern is formed and etching and the resist are removed. ) Was formed.

Here, the magnetoresistive film 6 is composed of a tantalum (Ta) underlayer having a film thickness of 5 nanometers and a nickel iron (NiFe) film having a film thickness of 2 nanometers in this order from the flattening conductive layer 5 side. Cobalt iron with a thickness of 3 nanometers (CoF
e), a magnetization free layer (free layer), a copper (Cu) nonmagnetic intermediate layer (spacer layer) having a thickness of 2 nanometers, and a cobalt iron (CoFe) magnetization pinned layer (pin layer) having a thickness of 4 nanometers. With a thickness of 10 nanometer platinum manganese (Pt
(Mn) antiferromagnetic layer.

The magnetoresistive film 6 was formed by the usual sputtering method. Then, in a state where a magnetic field of 8 × 10 ⁵ amps / meter (A / m) is applied, it is 270 ° C. in vacuum.
In the above, heat treatment was performed for about 4 hours to impart uniaxial magnetic anisotropy to the magnetization fixed layer of the magnetoresistive effect film 6.

Then, a V90 (manufactured by Tokyo Ohka) resist having a thickness of 400 nanometers is applied on the magnetoresistive film 6, exposed by a stepper, and then developed to have an element size of 3.2 × 3.2 μm. Form the remaining pattern of the meter. Next, the magnetoresistive effect film 6 was etched by ion milling, and a normal resist removing process was performed.

Next, as shown in FIG. 5A, the insulating layer 3b was formed. That is, by using the same sputtering method as the formation of the insulator layer 3a, an S
The iOx insulator layer 3b was formed. At this time, the insulator layer 3a
A convex shape reflecting the convex portion P of the electrode 2a is formed on the surface of the. The height of this convex shape was about 20 nanometers.

Next, as shown in FIG. 5B, a V90 resist pattern 7 having an opening diameter of about 0.8 micrometers and a thickness of 400 nanometers was formed.

After that, the insulator layer 3b is etched at a power of 150 watts (w) for about 7 minutes by an RIE apparatus in which CHF ₃ gas is introduced until the pressure reaches 1 Pascal (Pa), and the electrode 2b is connected. Therefore, a contact hole and a contact hole (not shown) for the measuring electrode portion of the electrode 2a were formed.

Next, as shown in FIG. 5C, the upper electrode 2b was formed. That is, the electrode 2 is formed by embedding the electrode material in the contact hole formed by RIE.
b was formed. The film structure of the electrode 2b is the magnetoresistive film 6
In order from the above, a tantalum (Ta) adhesion layer having a film thickness of 5 nanometers, copper (Cu) having a film thickness of 400 nanometers, and a film thickness of 200
It has a laminated structure of nanometer gold (Au). Also,
A normal sputtering method was used for the film formation, but copper (C
Only during the film formation of u), a high frequency bias of 100 watts (w) was applied for the purpose of improving the embedded state in the contact hole. After that, a measurement electrode resist pattern (not shown) for the lower electrode 2a and the upper electrode 2b was formed, and etching by ion milling or the like was performed to form a magnetoresistive effect element.

FIG. 6 is a graph showing the relationship between the magnetic field and the resistance (MR characteristic) of the CPP type magnetoresistive effect element thus obtained.

In the case of the element according to the present invention (represented by the solid line), the resistance increases with the application of the magnetic field in the positive direction,
A flat characteristic that a high resistance value was maintained in a wide magnetic field range was obtained.

On the other hand, in the case of the magnetoresistive effect element of the comparative example (represented by the broken line) in which the magnetoresistive effect film 6 is formed directly on the lower electrode 2a without providing the flattening conductive layer 5. , The change of resistance value with the increase of magnetic field is peaked,
The range of the magnetic field where high resistance is obtained is extremely narrow. this is,
As described above with reference to FIG. 19, the projection P of the lower electrode 2a is formed.
It is considered that this is because "unevenness" or "non-uniformity" occurs in the film thickness of each layer constituting the magnetoresistive effect film 6 due to a step or a protrusion around the. That is, in the element of the comparative example, the antiferromagnetic coupling between the upper and lower ferromagnetic layers (pin layer and free layer) via the non-magnetic intermediate layer (spacer layer) becomes very weak, and therefore the magnetization from a comparatively small magnetic field occurs. It is considered that the resistance decreases due to the inversion.

On the other hand, in the device of this embodiment, high resistance is maintained in a wide magnetic field range, very clean MR characteristics with less noise are obtained, and the flattening conductive layer 5 is used.
I was able to confirm the effectiveness of.

(Second Embodiment) Next, a second embodiment of the present invention will be described.

FIG. 7 and FIG. 8 are process cross-sectional views showing the main part manufacturing process of the magnetoresistive effect element of this embodiment. Also in this embodiment, as in the first embodiment, the steps for the magnetic shield and the magnetic recording portion are omitted.

First, as shown in FIG. 7A, the insulating layer 3a for forming the convex portion P is formed on the flatly formed electrode 2a, and the opening H is formed by patterning. . Specifically, first, an electrode 2a made of an alloy of Cu and Ag (Cu ₉₅ Ag ₅ : composition is atomic percent) having a film thickness of about 300 nanometers is first formed on a thermally oxidized silicon substrate (not shown). MR is formed by a normal sputtering method.
An electrode pattern (not shown) for characteristic measurement was formed by a normal semiconductor process. And aluminum oxide (Al
₂ O ₃ ) target is used to obtain a film thickness of 2
A 00 nanometer Al ₂ O ₃ insulator layer 3a was deposited.
Further, a remaining resist pattern having a thickness of 300 nanometers and a diameter of about 400 nanometers was formed thereon by an I-line stepper. Next, after etching the insulator layer 3a by ion milling, the resist was removed to form an opening H for forming a protrusion P having a diameter of about 400 nanometers and a depth of about 200 nanometers.

Next, as shown in FIG. 7B, an electrode layer 2a 'for forming the convex portion P was formed on the insulator layer 3a. Here, the electrode layer 2a ′ has a film thickness of 15
Copper (Cu) having a thickness of 0 nanometer was formed by IBD (Ion Beam Deposition) in which the directivity of sputtered particles is high. When a part of the formed sample was cross-section processed by FIB (Focused Ion Beam) and observed by SEM, the electrode layer 2a '
It was confirmed that was completely embedded in the opening H of the insulating layer 3a.

Next, the entire surface of the substrate was substantially flattened by CMP, and as shown in FIG. 7C, the electrode layer 2a 'other than the convex portion P was removed. A slurry for copper (Cu) was used for CMP, and the electrode layer 2a ′ was polished by about 150 nanometers. Here, as shown in FIG. 7C, the insulator layer 3a
A level difference of about 50 nanometers (the height of the projections P is lower than that of the insulating layer 3a) and a "wrinkle" or groove having a depth of about 20 nanometers were confirmed between the and the projections P.

When the magnetoresistive effect film 6 is directly formed on the substrate having the unevenness of the order of several tens of nanometers as described above, it is formed into a "waviness" or a "curvature" as illustrated in FIG. The film thickness also has "unevenness" and "unevenness". As a result, the magnetic coupling between the layers becomes unstable, and as shown by the broken line in FIG.

On the other hand, in this embodiment, as shown in FIG.
As shown in (d), the flattening conductive layer 5 is formed and the surface thereof is flattened. In this embodiment, the flattening conductive layer 5 is formed by sputtering titanium (Ti), which is a conductive metal, to a film thickness of 50 nanometers. However, as the material of the planarizing conductive layer 5 in this case, other than titanium (Ti), for example, aluminum (Al), tantalum (Ta), tungsten (W), molybdenum (M
o) or their alloys, or tantalum nitride (TaN),
A nitride such as titanium nitride (TiN), aluminum nitride / titanium ((Al, Ti) N), or tungsten nitride (WN) may be used.

Next, in order to form a CPP type magnetoresistive effect element having good MR characteristics, C for flattening / smoothing is formed.
MP was performed to obtain a cross-sectional shape as shown in FIG. At this time, the surface was flat and smooth by adjusting the polishing amount of CMP to about 50 nanometers. When the surface property was measured with an AFM, the surface roughness was about 4 nanometers, and the “step” that the surface of the insulator layer 3a and the surface of the protrusion P had.
It was confirmed that and "rimming" were largely eliminated and a flat surface was obtained.

Next, as shown in FIGS. 8A to 8D, the magnetoresistive effect film 6 is formed, the magnetoresistive effect film 6 is patterned, and the insulator layer 3b is formed and patterned.
A CPP type magnetoresistive effect element was completed by forming the upper electrode 2b.

The plane size of the magnetoresistive element of this embodiment is 1.5 μm × 1.5 μm, and the diameter of the contact hole in which the electrode 2b is embedded is 400.
It is a nanometer, and the upper electrode 2b has a film thickness of 30.
0 nanometer copper (Cu) was deposited.

When the relationship between the magnetic field and the resistance (MR characteristic) of the CPP type magnetoresistive effect element thus obtained was examined, it was found that the flattening conductive layer 5 was not provided as in the result shown in FIG. Very clean MR with less noise than
The characteristics were obtained, and the effectiveness of the present invention was similarly confirmed in this example using the planarizing conductive layer 5.

(Third Embodiment) Next, a third embodiment of the present invention will be described.

FIG. 9 is a sectional view showing the structure of the main part of the magnetoresistive effect element of this embodiment. In this figure, elements similar to those described above with reference to FIGS. 1 to 8 are marked with the same reference numerals and not described in detail.

That is, in this embodiment, the insulator adhesion layer 8 is provided on the lower electrode 2a. The insulator adhesion layer 8 has a role of improving the adhesion strength between the lower electrode 2a and the insulator layer 3a, and can be formed of tantalum (Ta) having a film thickness of about 10 nanometers.

The structure of the magnetoresistive effect element of this embodiment will be described below in accordance with its manufacturing procedure. The main part of the manufacturing process of the magnetoresistive effect element according to the present embodiment can be the same as that described above with reference to FIGS. 3 to 5, and will be described below with reference to these drawings.

First, as in the case of the first embodiment, as the lower electrode 2a, tantalum (Ta) having a film thickness of 5 nanometers, copper (Cu) having a film thickness of 300 nanometers, in this order from the substrate side,
After forming tantalum (Ta) with a film thickness of 10 nanometers,
A protrusion P having a height of 100 nanometers and a diameter of 100 nanometers is formed by ion milling to form the structure shown in FIG.

Next, after tantalum (Ta) having a film thickness of 10 nanometers is formed as the insulator adhesion layer 8 for the purpose of improving the adhesion between the lower electrode 2a and the insulation layer 3a, the film thickness is reduced to 1
An insulator layer 3a made of SiOx having a thickness of 50 nanometers was formed by reactive bias sputtering (FIG. 3B). After that, an OFR planarizing resist having a thickness of 400 nanometers is applied (FIG. 3C), and the SiOx insulator layer 3 is formed by RIE.
It was flattened until a became a film thickness of about 100 nanometers (FIG. 4A).

Next, as the flattening conductive layer 5, the film thickness is 20.
Nanometer aluminum nitride / titanium ((Al, T
i) N) is formed by MBE (Molecular Beam Epitaxy) (FIG. 4B), and then the surface is flattened (FIG. 4B).
(B)) It did.

Further, a magnetoresistive film 6 was formed and processed into a pattern having an element size of 1 micrometer × 1 micrometer (FIG. 4 (d)). This processing was performed by patterning with a stepper, etching by ion milling, and resist removal.

Next, Al ₂ O ₃ having a film thickness of 150 nanometers is formed as the insulator layer 3b by the sputtering method (see FIG. 5).
After (a)), a blank pattern having a diameter of 100 nanometers was formed by an EB exposure device (FIG. 5 (b)).

Then, after forming a contact hole for the electrode 2b by etching, the film thickness is reduced to 30 by IBD.
The electrode 2b made of 0 nanometer copper (Cu) was deposited. Thereafter, measurement electrode resist patterns of the electrodes 2a and 2b, etching by ion milling, and the like were performed.

When the relationship between the magnetic field and the resistance (MR characteristic) of the CPP type magnetoresistive effect element thus obtained was examined, the flattening conductive layer 5 was not used as in the case described above with reference to FIG. As compared with the case, a very clean MR characteristic with less noise was obtained. Further, in this example, the film peeling from the electrode 2a of the insulator layer 3a during the CMP polishing in the step shown in FIG.
It was significantly improved from about 10% (ratio of the film peeling area) of the example to 0%, and the effectiveness of the insulator adhesion layer 8 of the present example was also confirmed.

(Fourth Example) Next, a fourth embodiment of the present invention will be described.

FIG. 10 is a schematic view showing the cross-sectional structure of the magnetoresistive effect element of this embodiment. Also in this figure, elements similar to those described above with reference to FIGS. 1 to 9 are marked with the same reference numerals and not described in detail.

That is, in this embodiment, the flattening stopper layer 9 is provided between the insulator layer 3a and the flattening conductive layer 5. The flattening stopper layer 9 has a role of alleviating a "step" between the convex portion P of the lower electrode 2a and the surrounding insulator layer 3a.

The basic manufacturing process of the element of this embodiment can be the same as that of the second embodiment described above. Therefore, hereinafter, with reference to FIG. 7 and FIG. 8, the description will be focused on the points different from those described above.

The present embodiment is characterized in that, in addition to the second embodiment, the planarization stopper layer 9 is formed on the insulator layer 3. Here, in this embodiment, SiOx is formed as the insulator layer 3a, and the flattening stopper layer 9 is formed.
As the aluminum oxynitride, aluminum oxynitride (Al (O, N)) having a film thickness of 5 nm was formed by MBE. After that, an opening H for forming the convex portion P of the lower electrode 2a is formed, and after filling the opening H with an electrode material, etching back is performed by on-milling until the planarization stopper layer 9 is exposed (FIG. 7). (C)).

As a result, the "wrinkle" at the boundary between the convex portion P of the lower electrode 2a and the insulator layer 3a (flattening stopper layer 9).
Although it is about 20 nanometers, the “step” between the convex portion P and the surface of the flattening stopper layer 9 is about 10 nanometers, and it was confirmed that the “step” can be reduced.

Next, the flattening conductive layer 5, the magnetoresistive effect film 6, the insulator layer 3b, and the electrode 2b were sequentially formed to manufacture a head for MR characteristic evaluation.

When the relation between the magnetic field and the resistance (MR characteristic) of the CPP type magnetoresistive effect element thus obtained was examined, again, the noise was extremely small compared to the case where the flattening conductive layer 5 was not used. A clear MR characteristic was obtained, and the effectiveness of the present invention was similarly confirmed in the fourth embodiment using the planarizing conductive layer 5.

(Fifth Embodiment) Next, a fifth embodiment of the present invention will be described with reference to FIGS. 11 and 12. The main part of the manufacturing process of the magnetoresistive effect element of the present embodiment is
Since it can be similar to the element of the first embodiment, different points will be mainly described below.

First, similarly to the first embodiment, the lower electrode 2a is formed.
In order from the substrate side, tantalum (Ta) having a film thickness of 5 nanometers and nickel iron (Ni) having a film thickness of 200 nanometers are sequentially formed.
₈₀ Fe ₂₀ : atomic percent).
As shown in (a), an inverse taper resist pattern 20 having a width of 200 nanometers and a height of 200 nanometers was formed by an excimer stepper.

Next, ion milling was performed at an incident angle of 20 degrees (deg), and as shown in FIG. 11 (b),
A convex portion P having a height of 50 nanometers was formed on the electrode 2a.

Next, IBS having a high directivity of sputtered particles
By forming Al2O3 with a film thickness approximately the same as the height of the protrusion P by (Ion Beam Sputtering) or the like, as shown in FIG.
As shown in (c), the insulator layer 3a was formed. Next, the resist 20 was removed to obtain a form as shown in FIG. When the surface roughness (Rmax) was measured, a surface property of about 20 nanometer was obtained.

Next, as shown in FIG. 12 (b), tantalum (Ta) having a film thickness of 30 nanometers is formed as the flattening conductive layer 5 by ordinary sputtering to obtain a surface roughness Rmax.
Of 15 nm was obtained.

Next, as shown in FIG. 12C, the flattening conductive layer 5 is polished by CMP to a film thickness of tantalum (Ta) of about 25 nanometers to obtain a surface roughness R.
When the max was 3 nanometers or less, a surface having excellent flatness and smoothness was obtained.

Thereafter, the CPP is processed by the same method as in the first embodiment.
After forming the magnetoresistive effect type film 6, a pattern having an element size of 300 nanometers × 300 nanometers was formed by patterning with an EB stepper and etching by ion milling, and the resist was removed.

Next, as the insulator layer 3b, the film thickness is 150.
After forming a film of nanometer aluminum oxide (Al ₂ O ₃ ) by a sputtering method, a blank pattern having a diameter of 100 nanometer is formed by an EB exposure device, and the electrode 2 is etched.
A contact hole for b was formed. After that, nickel iron (Ni ₈₀ Fe) having a film thickness of 200 nanometer was measured by IBD.
_The electrode 2b composed of ₂₀ : atomic percent was formed.

Thereafter, the electrode resist pattern for measurement of the electrodes 2a and 2b was formed, and etching by ion milling was performed.

When the relation between the magnetic field and the resistance (MR characteristic) of the CPPG MR element thus obtained was examined, it was found that the MR characteristic was very clean with less noise compared to the case where the flattening conductive layer 5 was not used. Obtained and planarized conductive layer 5
Was confirmed to be effective.

(Sixth Embodiment) Next, as a sixth embodiment of the present invention, a magnetic reproducing apparatus equipped with the magnetoresistive effect element of the present invention will be described. That is, FIGS.
The magnetoresistive effect element or the magnetic head of the present invention described in relation to the above can be incorporated in, for example, a recording / reproducing integrated magnetic head assembly and mounted in a magnetic recording / reproducing apparatus.

FIG. 13 is a main part perspective view illustrating the schematic structure of such a magnetic recording / reproducing apparatus. That is, the magnetic recording / reproducing apparatus 150 of the present invention is an apparatus of the type using a rotary actuator. In the figure, a recording medium disc 200 is mounted on a spindle 152,
The motor is rotated in the direction of arrow A by a motor (not shown) in response to a control signal from a drive device controller (not shown). The magnetic recording / reproducing apparatus 150 of the present invention is provided with a plurality of medium disks 20.
It may have 0.

A head slider 153 for recording / reproducing information stored in the medium disk 200 is attached to the tip of a thin film suspension 154. Here, the head slider 153 has, for example, the magnetoresistive effect element or the magnetic head according to any of the above-described embodiments mounted near the tip thereof.

When the medium disk 200 rotates, the medium facing surface (ABS) of the head slider 153 is held with a predetermined flying height above the surface of the medium disk 200. Alternatively, the slider may be a so-called “contact traveling type” in which the slider contacts the medium disk 200.

The suspension 154 is connected to one end of an actuator arm 155 having a bobbin portion for holding a drive coil (not shown). A voice coil motor 156, which is a kind of linear motor, is provided at the other end of the actuator arm 155. The voice coil motor 156 includes a drive coil (not shown) wound around the bobbin of the actuator arm 155, and a magnetic circuit including a permanent magnet and a facing yoke that are arranged to face each other so as to sandwich the coil.

The actuator arm 155 is held by ball bearings (not shown) provided at the upper and lower portions of the spindle 157, and the voice coil motor 156.
With this, it is possible to freely rotate and slide.

FIG. 14 is an enlarged perspective view of the magnetic head assembly ahead of the actuator arm 155 as seen from the disk side. That is, the magnetic head assembly 1
The reference numeral 60 has an actuator arm 155 having, for example, a bobbin portion that holds a drive coil, and a suspension 154 is connected to one end of the actuator arm 155. A head slider 153 equipped with any of the magnetoresistive effect elements or magnetic heads described above with reference to FIGS. 1 to 12 is attached to the tip of the suspension 154. The suspension 154 has a lead wire 164 for writing and reading signals, and the lead wire 164 and each electrode of the magnetic head incorporated in the head slider 153 are electrically connected. In the figure, 165 is an electrode pad of the magnetic head assembly 160.

According to the present invention, by providing the magnetoresistive effect element or the magnetic head of the present invention as described above with reference to FIGS. 1 to 12, magnetic recording is performed on the medium disk 200 at a higher recording density than before. It is possible to reliably read the information provided.

(Seventh Embodiment) Next, as a seventh embodiment of the present invention, a magnetic memory equipped with the magnetoresistive effect element of the present invention will be described. That is, using the magnetoresistive effect element of the present invention described with reference to FIGS. 1 to 12, for example, a random access magnetic memory in which memory cells are arranged in a matrix form.
Magnetic memory such as.

FIG. 15 is a conceptual diagram illustrating the matrix configuration of the magnetic memory of this embodiment.

That is, the figure shows the circuit configuration of the embodiment when the memory cells are arranged in an array. A column decoder 350 and a row decoder 351 are provided to select one bit in the array, and the switching transistor 330 is turned on by the bit line 334 and the word line 332 to be uniquely selected and detected by the sense amplifier 352. As a result, the bit information recorded in the magnetic recording layer of the magnetoresistive effect element 321 can be read.

Bit information is written by a magnetic field generated by passing a write current through a specific write word line 323 and bit line 322.

FIG. 16 is a conceptual diagram showing another specific example of the matrix configuration of the magnetic memory of this embodiment. That is, in this specific example, the bit lines 322 and the word lines 334 arranged in a matrix are selected by the decoders 360 and 361, respectively, and a specific memory cell in the array is selected. Each memory cell has a structure in which a magnetoresistive effect element 321 and a diode D are connected in series. Here, the diode D has a role of preventing the sense current from bypassing in the memory cells other than the selected magnetoresistive effect element 321.

Writing is performed by a magnetic field generated by applying a write current to each of the specific bit line 322 and write word line 323.

FIG. 17 is a conceptual diagram showing a sectional structure of a main part of the magnetic memory according to the embodiment of the present invention. 18 is a sectional view taken along the line AA ′ of FIG.

That is, the structure shown in these figures corresponds to one memory cell included in the magnetic memory illustrated in FIG. That is, it is a memory cell of a 1-bit portion of a magnetic memory that operates as a random access memory. This memory cell has a storage element portion 311 and an address selection transistor portion 312.

The storage element portion 311 includes a magnetoresistive effect element 321 and a pair of wirings 322 and 324 connected to the magnetoresistive effect element 321.
Have and. The magnetoresistive effect element 321 is shown in FIGS.
The magnetoresistive effect element of the present invention as described above with respect to the present invention, which is an element having the GMR effect, the TMR effect, and the like and provided with the planarizing conductive layer 5.

In the case of having the GMR effect, a sense current may be passed through the magnetoresistive effect element 321 at the time of reading bit information to detect the resistance change.

In particular, magnetic layer / nonmagnetic tunnel layer /
When a ferromagnetic double tunnel junction having a structure of magnetic layer / non-magnetic tunnel layer / magnetic layer is included, a magnetoresistive effect can be obtained by a resistance change due to the tunnel magnetoresistive (TMR) effect.

In these structures, one of the magnetic layers can act as a magnetic pinned layer and any of the other magnetic layers can act as a magnetic recording layer.

On the other hand, the selection transistor portion 312 is provided with a transistor 330 connected via a via 326 and a buried wiring 328. The transistor 330 performs a switching operation according to the voltage applied to the gate 332, and controls the opening / closing of the current path between the magnetoresistive effect element 321 and the wiring 334. In addition, below the magnetoresistive effect element 321, write wiring 323 is provided.
Are provided in a direction substantially orthogonal to the wiring 322. The write wirings 322 and 323 can be formed of, for example, aluminum (Al), copper (Cu), tungsten (W), tantalum (Ta), or an alloy containing any of these.

In the memory cell having such a structure, when the bit information is written in the magnetoresistive effect element 321,
A write pulse current is passed through the wirings 322 and 323, and a synthetic magnetic field induced by those currents is applied to appropriately reverse the magnetization of the recording layer of the magnetoresistive effect element.

When reading the bit information, the magnetoresistive effect element 321 including the wiring 322 and the magnetic recording layer.
And a lower electrode 324, and a sense current is caused to flow therethrough, and the resistance value of the magnetoresistive effect element 321 or a change in the resistance value is measured.

In the magnetic memory of this example, a stable magnetoresistance change rate can be obtained by using the magnetoresistance effect element as described above with reference to FIGS. As a result, even if the cell size is miniaturized, the magnetic domain of the recording layer can be surely controlled to ensure the reliable writing and the reliable reading.

The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. For example, regarding the specific structure of the magnetoresistive film, and other shapes and materials such as electrodes, bias applying films, and insulating films, the present invention can be similarly carried out by appropriately selecting from a range known to those skilled in the art. , A similar effect can be obtained.

For example, when the magnetoresistive effect element is applied to a reproducing magnetic head, the magnetic shields may be provided above and below the element to define the detection resolution of the magnetic head.

Further, the present invention can be similarly applied to a magnetic head or a magnetic reproducing apparatus of not only the longitudinal magnetic recording system but also the perpendicular magnetic recording system to obtain the same effect.

Further, the magnetic reproducing apparatus of the present invention may be a so-called fixed type in which a specific recording medium is constantly provided, or a so-called “removable” type in which the recording medium is replaceable.

In addition, based on the magnetic head and the magnetic storage / reproducing apparatus described above as the embodiments of the present invention, all magnetoresistive effect elements, magnetic heads, and magnetic storage / reproduction that can be appropriately modified and implemented by those skilled in the art. Devices and magnetic memories are likewise within the scope of the invention.

[0142]

As described above in detail, according to the present invention, a flattening conductive layer is formed on a surface which is substantially flattened by etching back or the like, and the surface is flattened by processing such as CMP. The flatness and smoothness are remarkably excellent as compared with the conventional flattening technique, and the deterioration of the MR characteristics of the magnetoresistive effect film formed on the flattening technique can be significantly suppressed.

As a result, a highly sensitive magnetic detection can be stably obtained, a magnetic head having a high output and a high S / N even at a high recording density, a magnetic reproducing apparatus equipped with the magnetic head, and a highly integrated magnetic memory. It is possible to provide such as, and industrial merit is enormous.

[Brief description of drawings]

FIG. 1 is a schematic diagram illustrating a cross-sectional structure of a main part of a magnetoresistive effect element according to an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view illustrating a structure in which a planarizing conductive layer 5 is extended below a bias film 17.

FIG. 3 is a process cross-sectional view illustrating a main part manufacturing process of the magnetoresistive effect element according to the first embodiment of the present invention.

FIG. 4 is a process cross-sectional view illustrating a main part manufacturing process of the magnetoresistive effect element according to the first embodiment of the present invention.

FIG. 5 is a process cross-sectional view illustrating a main part manufacturing process of the magnetoresistive effect element according to the first embodiment of the present invention.

FIG. 6 is a graph showing the relationship between the magnetic field and the resistance (MR characteristics) of the CPP type magnetoresistive effect element obtained by the present invention.

FIG. 7 is a process cross-sectional view showing a main part manufacturing process of a magnetoresistive effect element according to a second embodiment of the present invention.

FIG. 8 is a process cross-sectional diagram illustrating a main part manufacturing process of a magnetoresistive effect element according to a second embodiment of the present invention.

FIG. 9 is a cross-sectional view showing the structure of a main part of a magnetoresistive effect element according to a third embodiment of the present invention.

FIG. 10 is a schematic diagram showing a cross-sectional structure of a magnetoresistive effect element according to a fourth example of the present invention.

FIG. 11 is a process sectional view showing a process of manufacturing a magnetoresistive effect element according to a fifth embodiment of the present invention.

FIG. 12 is a process sectional view showing a process of manufacturing a magnetoresistive effect element according to a fifth embodiment of the present invention.

FIG. 13 is a perspective view of a main part illustrating a schematic configuration of a magnetic recording / reproducing apparatus of the present invention.

FIG. 14 is an enlarged perspective view of the magnetic head assembly from the actuator arm 155 as viewed from the disk side.

FIG. 15 is a conceptual diagram illustrating the matrix configuration of the magnetic memory of the present invention.

FIG. 16 is a conceptual diagram showing another specific example of the matrix configuration of the magnetic memory of the present invention.

FIG. 17 is a conceptual diagram showing a cross-sectional structure of a main part of a magnetic memory according to an embodiment of the present invention.

18 is a cross-sectional view taken along the line A-A ′ of FIG.

FIG. 19 is a schematic cross-sectional view for explaining “unevenness” of the film thickness of the magnetoresistive effect film.

FIG. 20 is a schematic view illustrating a state in which a groove-shaped “wrinkle” is formed around the convex portion P.

FIG. 21 is a schematic diagram showing a state in which the heights of the convex portion P and the surface of the insulating layer 3a are different and a “step” is generated.

[Explanation of symbols]

1 Silicon substrate 2a Lower electrode 2b Upper electrode 3, 3a, 3b Insulator layer 4 Flattening resist 5 Flattening conductive layer 6 Magnetoresistive film 7 Resist pattern 8 Insulator adhesion layer 9 Flattening stopper layer 17 Bias film 12 Insulating film 20 resist 20 Reverse taper resist pattern 150 Magnetic recording / reproducing device 152 spindle 153 head slider 154 suspension 155 actuator arm 156 voice coil motor 157 spindle 160 Magnetic head assembly 164 Lead wire 200 magnetic recording media disk 311 Memory element part 312 Transistor for address selection 312 Transistor part for selection 321 Magnetoresistive effect element 322 bit line 322 wiring 323 word line 323 wiring 324 Lower electrode 326 via 328 wiring 330 switching transistor 332 gate 332 word line 334 bit line 334 word lines 350 column decoder 351 row decoder 352 sense amplifier 360 decoder H opening P convex part R protrusion

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takeo Sakubo             1st Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa             Inside the Toshiba Research and Development Center (72) Inventor Masashi Sahashi             1st Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa             Inside the Toshiba Research and Development Center F term (reference) 5D034 AA02 BA03 BA08 BA15 DA07                 5F083 FZ10 GA11 JA36 JA37 JA38                       JA39 JA40 LA04 LA05 MA06                       MA16 MA19 PR04 PR40

Claims (10)

[Claims] 1. A lower electrode having a protrusion protruding upward, an insulator layer provided so as to surround the periphery of the protrusion, and a surface of the insulator and the insulator layer around the protrusion. And a magnetoresistive effect film laminated on the substantially flat upper surface of the flattened conductive layer, and a magnetoresistive effect film formed on the magnetoresistive effect film. A magnetoresistive effect element comprising: an upper electrode provided on the. 2. The magnetoresistive effect element according to claim 1, wherein the unevenness is at least one of a step, a groove, and a projection formed on the surface of the insulating layer around the convex portion and the periphery thereof. . 3. A lower electrode having a protrusion protruding upward, an insulator layer provided so as to surround the periphery of the protrusion, and the insulator and the insulator layer around the protrusion. A flattening conductive layer, a magnetoresistive effect film provided on the flattening conductive layer, and an upper electrode provided on the magnetoresistive effect film, the flattening conductive layer The magnetoresistive effect element is characterized in that an upper surface thereof in contact with the magnetoresistive film is formed flatter than a lower surface thereof in contact with the convex portion and the insulating layer around the convex portion. 4. A layer made of a conductive material is deposited on a lower electrode having a protrusion protruding upward and an insulating layer provided so as to surround the periphery of the protrusion. A magnetoresistive effect element characterized in that a flattening conductive layer is formed by further flattening the surface by etching or polishing, and a magnetoresistive effect film is formed on the flattening conductive layer. 5. A pair of bias applying films provided adjacent to both sides of the magnetoresistive film, wherein the flattening conductive layer extends below the pair of bias applying films. The magnetoresistive effect element according to claim 1, wherein the magnetoresistive effect element is provided. 6. The insulating layer comprises a first layer made of a first insulating material provided on the upper side in contact with the planarizing conductive layer, and the first layer provided under the first layer. The 2nd layer which consists of a 2nd insulating material different from the 1st insulating material is included, The magnetoresistive effect element in any one of Claims 1-5 characterized by the above-mentioned. 7. The magnetoresistive film comprises a magnetic pinned layer having a first magnetic film whose magnetization direction is pinned substantially in one direction, and a second magnetic pinned layer whose magnetization direction changes in response to an external magnetic field. 7. A magnetoresistive effect film having a magnetization free layer having the magnetic film of claim 1 and a nonmagnetic intermediate layer provided between the magnetization pinned layer and the magnetization free layer. 7. The magnetoresistive effect element according to any one of 1 to 6. 8. A step of forming a lower electrode having a protrusion protruding upward and an insulator layer surrounding the periphery of the protrusion, and the protrusion and the insulator layer around the protrusion, A step of depositing a layer made of a conductive material; a step of flattening an upper surface of the layer made of a conductive material by etching or polishing to form a flattened conductive layer; and a magnetoresistive effect on the flattened conductive layer. A method of manufacturing a magnetoresistive effect element, comprising: a step of forming a film. 9. A magnetic head comprising the magnetoresistive effect element according to claim 1. Description: 10. A magnetic reproducing apparatus comprising the magnetic head according to claim 9 and capable of reading information magnetically recorded on a magnetic recording medium.