JP2007048388A - Magnetic head and manufacturing method of magnetic head, and magnetic recording and reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic head, a manufacturing method of the magnetic head, and a magnetic recording and reproducing device with which reduction of an MR ratio can be suppressed and high sensitivity can be attained. <P>SOLUTION: The magnetic head 1 has layers including an anti-ferromagnetic member in layers laminated between electrodes and uses a GMR element A energizing the layers abutting on the electrodes vertically, the head is provided with a first electrode, a second electrode, and GMR films 13 (an anti-ferromagnetic layer, a first ferromagnetic layer, a non-magnetic intermediate layer, a second ferromagnetic layer, a base layer), the head is formed so that the area of the abutting plane on which the second electrode to the first ferromagnetic layer are abutted respectively is equal to a first area, the area of the abutting plane on which the anti-ferromagnetic layers and the base layer are abutted and the area of the abutting plane on which the substrate and the first electrode are abutted are equal to a second area, a third area being the area of the abutting plane on which the first ferromagnetic layer and the anti-ferromagnetic layer are abutted is larger than the first area, and is smaller than the second area or is equal to the second area. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a magnetic head, a magnetic head manufacturing method as a method of manufacturing the magnetic head, and a magnetic recording / reproducing apparatus using the magnetic head.

  In general, a magnetic head used in a hard disk device of a computer is known, and the increase in capacity of a hard disk device in recent years is a giant magnetoresistive element (GMR [Giant Magnet Resistance] element) used in this magnetic head. This is largely due to the development of

Incidentally, some conventional magnetic heads use a CPP (Current Perpendicular to Plane) spin valve sensor. Among these CPP spin valves, those using Co ₉₀ Fe ₁₀ and Co ₅₀ Fe ₅₀ are disclosed in Non-Patent Document 1, for example.

  Also, some conventional magnetic heads use a CPP spin valve, that is, a CPP-GMR (Giant Magnet Resistance) sensor. For example, Non-Patent Document 2 discloses the required characteristics of a magnetic head using this CPP-GMR sensor. Further, regarding the GMR characteristics (characteristics relating to the giant magnetoresistance effect) of the CPP-GMR sensor (CPP-GMR element), the MR (Magneto Resistance) ratio (magnetoresistance ratio) is essentially high. 3 is disclosed.

  The CPP-GMR element has a film having a plurality of layers stacked between electrodes. This CPP-GMR element is provided with a layer (magnetoresistance effect unit) having a high magnetoresistance effect among a plurality of layers. Further, some conventional magnetic heads use a CIP (Current-In-Plane) -GMR sensor (CIP-GMR element).

  The difference between the CPP-GMR element and the CIP-GMR element will be briefly described. In the CPP-GMR element, an IrMn antiferromagnetic material, an electrode material, and the like are in contact in series, and in this state, a current flows between the electrodes. In contrast to the vertical flow, the CIP-GMR element does not contact these materials in series, and in this state, there is a difference that current flows in parallel so as to spread in the plane.

Further, in the conventional CPP-GMR element, the MR ratio of the magnetoresistive effect unit (three layers of the ferromagnetic layer, the intermediate layer, and the ferromagnetic layer in the film in the element) is higher than that of the CIP-GMR element. The specific value of the MR ratio is about 15% to 50% (in the CIP-GMR element, about 20% is the limit).
H. Yuasa et al. “Output enhancement of spin-valve giant magneto-resistive in current-perpendicular-to-plane geometry”. Journal of applied physics 92. 2646, September 2002 M.M. Takagi et al., “The Clicability of CPP-GMR Heads” IEEE Transactions on Magnetics, 2002, Vol. 38, p. 2277 September 2002 Keiichi Nagasaka et al. “GMR characteristics of CPP elements using spin-valve films” Journal of Japan Society of Applied Magnetics 2001 25, P807-810 2001

  However, in the CPP-GMR element, (1) the resistance (electric resistance) of the magnetoresistive effect unit is small, (2) antiferromagnets such as IrMn do not directly contribute to the MR effect, and the resistance is high. (3) Since the magnetoresistive effect unit and the antiferromagnetic material and the electrode material are connected in series, the total MR ratio of the CPP-GMR element is greatly reduced. In other words, the MR ratio of the CPP-GMR element is lowered due to three complex factors (1) to (3).

  As a result, when the total MR ratio of the CPP-GMR element is greatly reduced, even if a magnetic head is manufactured using the CPP-GMR element, the hard disk device must have a high MR ratio. There is a problem that the sensitivity is not improved (not high sensitivity).

  SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a magnetic head, a magnetic head manufacturing method, and a magnetic recording / reproducing apparatus that can solve the above-described problems, can suppress a decrease in MR ratio, and have high sensitivity. .

In order to solve the above problem, a magnetic head according to claim 1 is provided.
In a magnetic head using a sensor having a layer containing an antiferromagnetic material in a layer laminated between electrodes and energized perpendicularly to a layer in contact with the electrode, the sensor includes a first electrode and a first electrode. Two electrodes, an underlayer, an antiferromagnetic layer, a first ferromagnetic layer, a nonmagnetic intermediate layer, a second ferromagnetic layer, and a capping layer, wherein the second electrode and the capping layer include The area of the abutting surface, the area of the abutting surface where the capping layer and the second ferromagnetic layer abut, and the abutting surface where the second ferromagnetic layer and the nonmagnetic intermediate layer abut. The area and the area of the abutting surface where the nonmagnetic intermediate layer and the first ferromagnetic layer abut are equal to each other as the first area, and the antiferromagnetic layer and the underlayer abut The area of the contact surface and the area of the contact surface where the underlayer and the first electrode contact each other are the second area. The third area, which is the area of the contact surface where the first ferromagnetic layer and the antiferromagnetic layer are in contact, is larger than the first area and the second area Smaller than or equal to the second area.

  According to such a configuration, the magnetic head includes, in the film laminated between the first electrode and the second electrode in the sensor, the area of the contact surface where the second electrode and the capping layer contact, the capping layer and the second electrode. The area of the abutting surface where the ferromagnetic layer abuts, the area of the abutting surface where the second ferromagnetic layer and the nonmagnetic intermediate layer abut, and the contact between the nonmagnetic intermediate layer and the first ferromagnetic layer The area of the contact surface is the same as the first area, the area of the contact surface where the antiferromagnetic layer and the underlayer abut, and the area of the contact surface where the underlayer and the first electrode abut Are equal to each other as the second area, and the third area, which is the area of the abutting surface where the first ferromagnetic layer and the antiferromagnetic layer abut, is greater than the first area, and the second area It is formed to be smaller than the area or equal to the second area. The area of the contact surface between the first ferromagnetic layer and the nonmagnetic intermediate layer may not be equal to the area of the contact surface between the nonmagnetic intermediate layer and the second ferromagnetic layer. It may be divergent toward one electrode. That is, in this case, compared to the area of the contact surface between the nonmagnetic intermediate layer and the second ferromagnetic layer, the area of the contact surface between the first ferromagnetic layer and the nonmagnetic intermediate layer is increased. It will be laminated.

  An embodiment in which manganese (Mn) is used as the antiferromagnetic material is assumed. In particular, PtMn and IrMn, which are compounds of manganese, have a large exchange coupling force and a high blocking temperature. Therefore, when used in the magnetic head, durability can be remarkably increased. That is, it is originally not preferable to obtain a high MR ratio (stacking a layer containing a manganese compound whose resistance is increased), but it is suitable for improving durability ( There is merit). Therefore, by etching so that the lamination positions on the lamination surface are almost equal, the result of suppressing the increase in resistance (the result of eliminating the disadvantages), the advantage that the compound of manganese improves the durability of the magnetic head Can only get.

  The magnetic head according to claim 2 is a magnetic head using a sensor having a layer containing an antiferromagnetic material in a layer laminated between electrodes, and being energized perpendicularly to the layer in contact with the electrode. The sensor includes a first electrode and a second electrode, an underlayer, an antiferromagnetic layer, a first ferromagnetic layer, a nonmagnetic intermediate layer, a second ferromagnetic layer, and a capping layer. The area of the abutting surface where the second electrode and the capping layer abut, the area of the abutting surface where the capping layer and the second ferromagnetic layer abut, the second ferromagnetic layer and the non-magnetic An area of the contact surface that contacts the intermediate layer and an area of the contact surface that contacts the nonmagnetic intermediate layer and the first ferromagnetic layer are equal to each other as the first area, and The area of the contact surface where the magnetic layer and the underlayer abut, and the underlayer and the first electrode abut The third area, which is the area of the contact surface where the first ferromagnetic layer and the antiferromagnetic layer contact, is formed so that the area of the contact surface is equal to the second area. The second area is formed to be equal to the area and larger than the first area.

  According to such a configuration, the magnetic head includes, in the film laminated between the first electrode and the second electrode in the sensor, the area of the contact surface where the second electrode and the capping layer contact, the capping layer and the second electrode. The area of the abutting surface where the ferromagnetic layer abuts, the area of the abutting surface where the second ferromagnetic layer and the nonmagnetic intermediate layer abut, and the contact between the nonmagnetic intermediate layer and the first ferromagnetic layer The area of the contact surface is the same as the first area, the area of the contact surface where the antiferromagnetic layer and the underlayer abut, and the area of the contact surface where the underlayer and the first electrode abut Are equal to each other as the second area, and the third area, which is the area of the abutting surface where the first ferromagnetic layer and the antiferromagnetic layer abut, is equal to the first area and the first area The second area is formed to be larger than the second area. That is, when formed in this way, the formation surface of the first ferromagnetic layer and the contact surface of the first ferromagnetic layer and the antiferromagnetic layer are formed substantially perpendicularly.

  The magnetic head according to claim 3 is a magnetic head using a sensor having a layer containing an antiferromagnetic material in a layer laminated between the electrodes and energizing the layer in contact with the electrode perpendicularly. The sensor includes a first electrode and a second electrode, an underlayer, an antiferromagnetic layer, a first ferromagnetic layer, a nonmagnetic intermediate layer, a second ferromagnetic layer, and a capping layer, The area of the abutting surface where the second electrode and the capping layer abut, the area of the abutting surface where the capping layer and the second ferromagnetic layer abut, the second ferromagnetic layer and the nonmagnetic intermediate The area of the abutting surface where the layer abuts, the area of the abutting surface where the nonmagnetic intermediate layer and the first ferromagnetic layer abut, the first ferromagnetic layer and the antiferromagnetic layer The area of the abutting contact surface is formed to be equal as the first area, the underlayer and the first electrode When the area of the contact surface that contacts is the second area, the third area that is the area of the contact surface that the antiferromagnetic layer and the underlayer contact is larger than the first area, and It is formed so as to be smaller than or equal to the second area.

  According to such a configuration, the magnetic head includes, in the film laminated between the first electrode and the second electrode in the sensor, the area of the contact surface where the second electrode and the capping layer contact, the capping layer and the second electrode. The area of the abutting surface where the ferromagnetic layer abuts, the area of the abutting surface where the second ferromagnetic layer and the nonmagnetic intermediate layer abut, and the contact between the nonmagnetic intermediate layer and the first ferromagnetic layer The contact surface area and the contact surface area where the first ferromagnetic layer and the antiferromagnetic layer are in contact with each other are formed to be equal to each other as the first area. When the area of the surface is the second area, the third area, which is the area of the abutting surface where the antiferromagnetic layer and the underlayer abut, is larger than the first area and smaller than the second area or It is formed to be equal to two areas.

  This magnetic head is formed so that the area of the contact surface between the underlayer and the antiferromagnetic layer is larger than the area of the contact surface of each layer forming the sensor. As a result, the resistance when a current is passed through becomes smaller, so that a high MR ratio can be obtained. This is because the current path spreads in the high resistance portion, so that the parasitic resistance is reduced and the MR ratio is increased. However, the MR ratio is lowered even if this current path is excessively widened. This is because the effect of spin accumulation, which is a phenomenon peculiar to a sensor (especially CPP-GMR) energized perpendicularly to the layer (film surface) is reduced, and the current component perpendicular to the film surface is reduced. It means that the MR ratio is lowered even if it is too much. In this magnetic head, the MR ratio is increased by reducing both the parasitic resistance and the effect of spin accumulation.

  The magnetic head according to claim 4 is a magnetic head using a sensor having a layer containing an antiferromagnetic material in a layer laminated between electrodes, and energizing perpendicularly to the layer in contact with the electrode. The sensor includes a first electrode and a second electrode, an underlayer, an antiferromagnetic layer, a first ferromagnetic layer, a nonmagnetic intermediate layer, a second ferromagnetic layer, and a capping layer, The area of the abutting surface where the second electrode and the capping layer abut, the area of the abutting surface where the capping layer and the second ferromagnetic layer abut, the second ferromagnetic layer and the nonmagnetic intermediate The area of the abutting surface where the layer abuts, the area of the abutting surface where the nonmagnetic intermediate layer and the first ferromagnetic layer abut, the first ferromagnetic layer and the antiferromagnetic layer The area of the abutting contact surface is formed to be equal as the first area, the underlayer and the first electrode When the area of the abutting contact surface is the second area, the third area, which is the area of the abutting surface where the antiferromagnetic layer and the underlayer abut, is equal to the first area, and the first area The second area is formed to be larger than one area.

  According to such a configuration, the magnetic head includes, in the film laminated between the first electrode and the second electrode in the sensor, the area of the contact surface where the second electrode and the capping layer contact, the capping layer and the second electrode. The area of the abutting surface where the ferromagnetic layer abuts, the area of the abutting surface where the second ferromagnetic layer and the nonmagnetic intermediate layer abut, and the contact between the nonmagnetic intermediate layer and the first ferromagnetic layer The contact surface area and the contact surface area where the first ferromagnetic layer and the antiferromagnetic layer are in contact with each other are formed to be equal to each other as the first area. When the area of the surface is the second area, the third area, which is the area of the contact surface where the antiferromagnetic layer and the underlayer contact, is equal to the first area, and the second area is more than the first area. It is formed to be large.

  In this magnetic head, the area of the contact surface of each layer (from the capping layer to the antiferromagnetic layer) forming the sensor is made equal to each other. As a result, a high MR ratio can be obtained. This is because the current path spreads in the high resistance portion, so that the parasitic resistance is reduced and the MR ratio is increased. However, the MR ratio is lowered even if this current path is excessively widened. This is because the effect of spin accumulation, which is a phenomenon peculiar to a sensor (especially CPP-GMR) energized perpendicularly to the layer (film surface) is reduced, and the current component perpendicular to the film surface is reduced. It means that the MR ratio is lowered even if it is too much. In this magnetic head, the MR ratio is increased by reducing both the parasitic resistance and the effect of spin accumulation.

  According to a fifth aspect of the present invention, there is provided a magnetic head manufacturing method comprising: a layer including an antiferromagnetic material in a layer laminated between electrodes; and a magnetic head using a sensor that is energized to the layer in contact with the electrode. In the magnetic head manufacturing method to be manufactured, the procedure includes an etching step, a detection step, and an end step.

  According to such a procedure, in the etching step, the magnetic head manufacturing method etches the uncovered region of the ferromagnetic layer containing the ferromagnetic material stacked on the layer containing the antiferromagnetic material to a predetermined depth. In the magnetic head manufacturing method, the detection step detects whether or not the ferromagnetic material is detected in the etching step, and the etching is terminated when the ferromagnetic material is not detected in the end step. To do. That is, the etching depth is optimized by terminating the etching when no ferromagnetic material is detected. The detection of the ferromagnetic material in the detection step is performed by monitoring using SIMS (Secondary Ion Mass Spectrometry) or the like during etching.

  The magnetic head manufacturing method according to claim 6, wherein a magnetic head using a sensor having a layer containing an antiferromagnetic material in a layer laminated between electrodes and energizing a layer in contact with the electrode is provided. In the magnetic head manufacturing method to be manufactured, the procedure includes an etching step, a detection step, and an end step.

  According to such a procedure, the magnetic head manufacturing method etches the uncovered region of the layer containing the antiferromagnetic material to a predetermined depth in the etching step. Here, the etching is performed by sputtering, for example, an ion beam in a region other than the region where the resist (coating) is provided. In the magnetic head manufacturing method, in the detection step, it is detected whether or not the antiferromagnetic material is detected in the etching step, and in the end step, the etching is terminated when the antiferromagnetic material is used up. To do. That is, the etching depth is optimized by terminating the etching when no antiferromagnetic material is detected. The detection of the antiferromagnetic material in the detection step is performed by monitoring using SIMS or the like during etching.

  A magnetic recording / reproducing apparatus according to a seventh aspect includes the magnetic head according to any one of the first to fourth aspects.

  According to such a configuration, the magnetic recording / reproducing apparatus uses a magnetic head having a low resistance and a high MR ratio (a reduction in the MR ratio is suppressed), so that a magnetic recording medium such as a hard disk provided in the apparatus is used. Even if the recording areas are formed with high density, data can be recorded / reproduced in the high-density recording areas.

According to the present invention, since the current flowing straight from the first ferromagnetic layer to the antiferromagnetic layer flows straight and diffuses, the resistance of the entire film in this case is reduced, resulting in a high MR ratio. Can be obtained.
Further, according to the present invention, the recording density on the magnetic recording medium can be improved by using a highly sensitive magnetic head.

Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
<Configuration of magnetic head>
FIG. 1 is a diagram showing an outline of a magnetic head. As shown in FIG. 1A, the magnetic head 1 is integrated with the tip of a suspension 3 of a hard disk device (not shown) incorporated in a computer (not shown) or the like. It is attached to the slider 5. FIG. 1A illustrates the magnetic head 1 from a surface (floating surface floating from the magnetic recording medium) facing a magnetic recording medium (not shown, hard disk).

  As shown in FIG. 1A, the magnetic head 1 includes a write unit 7 that writes data to a magnetic recording medium and a read unit 9 that reads data written on the magnetic medium. This magnetic head 1 uses a CPP spin valve sensor A for a lead portion 9.

  FIG. 1B is an enlarged view of the surface of the lead portion 9 of the magnetic head 1 attached to the slider 5 that faces the magnetic recording medium. In this embodiment, as shown in FIG. 1B, the GMR element A, which is a CPP spin valve sensor, has a thickness of 0.1 on the lower shield (also lower electrode) 11 having a NiFe thickness of 1.5 μm. A GMR film 13 which is a spin valve film processed to 15 μm is provided, and an upper shield (also serving as an upper electrode) 15 having a NiFe thickness of 1.5 μm is provided thereon.

In addition, the GMR element A includes a hard film 17 made of CoCrPt that stably operates the GMR element A on both sides of the GMR film 13, and an insulator made of SiO ₂ that insulates the lower shield 11 and the upper shield 15 from each other. 19.

  Further, the GMR element A has a structure in which a current flows perpendicularly (perpendicular) to the GMR film 13 by energizing the lower shield 11 to the upper shield 15 or the upper shield 15 to the lower shield 11. It has become.

Next, each film laminated on the GMR film 13 will be described with reference to FIG.
The GMR film 13 is formed by forming a lower shield 11 (see FIG. 1B) with a NiFe thickness of 1.5 μm on a substrate made of Al ₂ O ₃ TiC (see FIG. 3), and then forming Ta / Cu ( An antiferromagnetic underlayer a) is formed, and IrMn (antiferromagnetic layer b) is formed on the Ta / Cu (antiferromagnetic underlayer a). Further, Co _x Fe _(1-x) (pinned layer c) is formed on the IrMn (antiferromagnetic layer b), and Cu (non-coated) is formed on the Co _x Fe _(1-x) (pinned layer c). A magnetic intermediate layer d) is formed, and Co _x Fe _(1-x) (free layer e) is formed. Further, Cu / Ta (capping layer f) is formed on Co _x Fe _(1-x) (free layer e).

Here, these layers are formed by DC magnetron sputtering. Further, in Co _x Fe _(1-x) (pinned layer c) and Co _x Fe _(1-x) (free layer e), x is an arbitrary decimal number satisfying 0 <x <1.

The antiferromagnetic layer b may use PtMn, NiMn, PdPtMn, NiO, Fe ₂ O ₃ or the like instead of IrMn which is an antiferromagnetic material. In particular, IrMn and PtMn, which are antiferromagnetic materials containing Mn, have a large exchange coupling force and a high blocking temperature. Therefore, when used in a magnetic head, the durability of the head is remarkably improved. Become.

Further, in the underlayer a made of antiferromagnetic material, NiCr alloy, Ta, NiFeCr or the like may be used instead of Ta / Cu. The underlayer made of these materials is mainly for controlling the orientation and crystal grain size of the antiferromagnetic material.
Further, the Co _x Fe _(1-x) (pinned layer c) may have a synthetic-ferri structure such as CoFe / Ru / CoFe.

  Here, a method for manufacturing the GMR element A will be further described with reference to FIGS. FIG. 3 is a view showing a process from the GMR film 13 shown in FIG. FIG. 4 is a flowchart for explaining a method of manufacturing the magnetic head. FIG. 3 shows a process in which a heat treatment is performed for 2 hours in a magnetic field maintained at a temperature of 260 ° C. after the GMR film 13 is formed.

First, FIG. 3A shows a result of forming a lower shield pattern (lower electrode 11) with a resist on a substrate made of Al ₂ O ₃ TiC (alumina titanium carbide) and performing etching by Ar ion milling. Yes. In FIG. 3A, a laminated film (GMR film 13) is laminated on the lower electrode 11. In the flowchart of the magnetic head manufacturing method shown in FIG. 4, a lower electrode pattern (lower electrode 11) is formed on a substrate (step S1), and a GMR film 13 is laminated (step S2).

  FIG. 3B shows a result of forming a resist pattern (simply resist) of 0.15 μm × 1 μm on the lower electrode 11 by electron beam lithography.

FIG. 3C shows the result of forming an insulating layer by etching to a desired depth by Ar ion milling. When this etching is performed, the etching material (the material to be scraped off including the antiferromagnetic material) is detected by the mass spectrometer SIMS. Further, SiO ₂ (or Al ₂ O ₃ ) (20 nm) is formed as the insulating layer, and CoCrPt (20 nm) is formed as the hard film 17 for the magnetization stable bias of the free layer e.

  In the flowchart of the magnetic head manufacturing method shown in FIG. 4, Ar etching is performed (step S3), SIMS determines whether an antiferromagnetic material is detected (step S4), and if it is detected (Yes in step S4). ), Ar etching is continued, and if not detected (No in step S4), an insulator (insulating layer) is formed (step S5).

  FIG. 3D shows the result of lift-off and forming a hole for the upper shield (upper electrode 15). FIG. 3E shows the result of forming the thickness of NiFe as the upper shield (upper electrode 15) to 1.5 μm.

  The flow chart of the magnetic head manufacturing method shown in FIG. 4 corresponds to lift-off (step S6) and formation of the upper electrode 15 (step S7). In this way, the manufacturing process of the GMR element A (CPP-GMR element) is completed.

  In the magnetic head manufacturing method shown in FIG. 4, SIMS determines whether or not an antiferromagnetic material is detected in step S4, but is laminated on an antiferromagnetic layer containing the antiferromagnetic material. The ferromagnetic material contained in the first ferromagnetic layer may be detected. That is, the first ferromagnetic layer is etched by Ar etching (corresponding to the type B GMR film in FIG. 5B described later).

  Next, the Ar etching (Ar ion milling process) shown in FIG. 3C will be described with reference to FIG. FIG. 5 shows the GMR film when the etching depth is changed to three types.

  In the type A GMR film shown in FIG. 5A, only the capping (capping layer e) is etched. In the type B GMR film shown in FIG. 5B, the CoFe / Cu / CoFe (free layer) is used. e, the nonmagnetic intermediate layer d, and the pinned layer c) are etched to the IrMn (antiferromagnetic layer b) in the type C GMR film shown in FIG. 5C. .

  In the type B GMR film, CoFe / Cu / CoFe (free layer e, nonmagnetic intermediate layer d, pinning layer c) is etched, capping (capping layer f), and CoFe / Cu / CoFe (free layer). e, the area (first area) of the contact surface for each layer with the nonmagnetic intermediate layer d and the pinning layer c) becomes equal, and CoFe / Cu / CoFe (free layer e, nonmagnetic intermediate layer d, pin) The area (third area) of the contact surface between the lowermost layer (pinned layer c: first ferromagnetic layer) and IrMn (antiferromagnetic layer b) of the stopping layer c) is CoFe / Cu / CoFe (free layer). e, etching is performed so as to be larger than the area (first area) of the contact surface with the nonmagnetic intermediate layer d and the pinning layer c).

  That is, the type B GMR film has a contact surface area where the upper electrode 15 and the capping (capping layer f) contact each other, and the capping (capping layer f) and CoFe / Cu / CoFe (free layer e, nonmagnetic intermediate layer). Layer d, pinned layer c) and the uppermost layer (free layer e: second ferromagnetic layer), the area of the abutting surface, and the uppermost layer and CoFe / Cu / CoFe (free layer e, nonmagnetic intermediate) The area of the abutting surface where the intermediate layer (nonmagnetic intermediate layer d) of the layer d and the pinned layer c) abuts is equal to the area of the abutting surface where the intermediate layer and the lowermost layer abut (first layer). 1 area), the area of the contact surface where the IrMn (antiferromagnetic layer b) and the antiferromagnetic underlayer (underlayer a) abut, and the antiferromagnetic underlayer (underlayer a) and the lower electrode 11 abut. The area of the contact surface becomes equal (second area), and CoFe / Cu / C The third area, which is the area of the contact surface where the lowermost layer (pinned layer c) of Fe (free layer e, nonmagnetic intermediate layer d, pinned layer c) and IrMn (antiferromagnetic layer b) contact, is , Larger than the first area and smaller than or equal to the second area.

  In addition, the area of the contact surface for each layer, the lowermost layer (pinned layer c: first ferromagnetic layer) of CoFe / Cu / CoFe (free layer e, nonmagnetic intermediate layer d, pinned layer c) and IrMn The area of the contact surface with the (antiferromagnetic layer b) becomes equal, the area of the contact surface of the capping layer e that contacts the upper electrode 15, and the CoFe / Cu / CoFe (free layer e, nonmagnetic intermediate layer) d, etching may be performed so that the contact area of each pinning layer c) is equal.

  That is, the type B GMR film has a contact surface area where the upper electrode 15 and the capping (capping layer f) contact each other, and the capping (capping layer f) and CoFe / Cu / CoFe (free layer e, nonmagnetic intermediate layer). Layer d, pinned layer c) and the uppermost layer (free layer e: second ferromagnetic layer), the area of the abutting surface, and the uppermost layer and CoFe / Cu / CoFe (free layer e, nonmagnetic intermediate) The area of the abutting surface where the intermediate layer (nonmagnetic intermediate layer d) of the layer d and the pinned layer c) abuts is equal to the area of the abutting surface where the intermediate layer and the lowermost layer abut (first layer). 1 area), the area of the contact surface where the IrMn (antiferromagnetic layer b) and the antiferromagnetic underlayer (underlayer a) abut, and the antiferromagnetic underlayer (underlayer a) and the lower electrode 11 abut. The area of the contact surface becomes equal (second area), and CoFe / Cu / C The third area, which is the area of the contact surface where the lowermost layer (pinned layer c) of Fe (free layer e, nonmagnetic intermediate layer d, pinned layer c) and IrMn (antiferromagnetic layer b) contact, is The second area may be larger than the first area and equal to the first area.

  In the type C GMR film, etching is performed up to IrMn (antiferromagnetic layer b) so that the contact surface area of each layer is equal. Etching is performed so that the area of the contact surface between IrMn (antiferromagnetic layer b) and the antiferromagnetic underlayer (underlayer a) is larger than the area of the laminated surface for each layer.

  That is, the type C GMR film has a contact surface area where the upper electrode 15 and the capping (capping layer f) abut, a capping (capping layer f), and a CoFe / Cu / CoFe (free layer e, nonmagnetic intermediate layer). Layer d, pinned layer c) and the uppermost layer (free layer e: second ferromagnetic layer), the area of the abutting surface, and the uppermost layer and CoFe / Cu / CoFe (free layer e, nonmagnetic intermediate) Layer d, pinned layer c) and the contact layer with which the intermediate layer (nonmagnetic intermediate layer d) contacts, the area of the contact surface with which the intermediate layer and the lowermost layer contact, and the lowermost layer The area of the contact surface with which IrMn (antiferromagnetic layer b) abuts is equal (first area), and the area of the contact surface with which the antiferromagnetic layer base (underlayer a) contacts the lower electrode 11 Is the second area, IrMn (antiferromagnetic layer b) and antiferromagnetic underlayer (underlayer) Third area a) and is the area of the abutting abutment surface is larger than the first area, and are formed to be equal to the smaller or secondary area than the second area.

  The area of the contact surface of the capping layer e that contacts the upper electrode 15, the area of the contact surface of each layer, and the IrMn (antiferromagnetic layer b) and the antiferromagnetic underlayer (underlayer a) Etching may be performed so that the area with the contact surface becomes equal.

  That is, the type C GMR film has a contact surface area where the upper electrode 15 and the capping (capping layer f) abut, a capping (capping layer f), and a CoFe / Cu / CoFe (free layer e, nonmagnetic intermediate layer). Layer d, pinned layer c) and the uppermost layer (free layer e: second ferromagnetic layer), the area of the abutting surface, and the uppermost layer and CoFe / Cu / CoFe (free layer e, nonmagnetic intermediate) Layer d, pinned layer c) and the contact layer with which the intermediate layer (nonmagnetic intermediate layer d) contacts, the area of the contact surface with which the intermediate layer and the lowermost layer contact, and the lowermost layer The area of the contact surface with which IrMn (antiferromagnetic layer b) abuts is equal (first area), and the area of the contact surface with which the antiferromagnetic layer base (underlayer a) contacts the lower electrode 11 Is the second area, IrMn (antiferromagnetic layer b) and the base of the antiferromagnetic layer (under Third area layer a) and is the area of the abutting abutment surface is equal to the first area, and may be formed so than the first area is the second area increases.

  The MR characteristics of type A, type B and type C are shown in FIG. In FIG. 6, the horizontal axis represents the etching depth, the left vertical axis represents MR ratio (MR ratio), and the right vertical axis represents the RA product. Note that ΔR indicates a difference between the resistance value R obtained by subtracting the minimum value from the maximum value of the resistance value R, and the RA product is obtained by multiplying the resistance value R by the area of the laminated surface.

  As shown in FIG. 6, as the etching depth is increased (type C> type B> type A), the MR ratio increases, that is, the MR ratio is 1.88 for type A and 2. 88 or 2.93 and 3.31 for Type C. In the MR characteristics shown here, the MR ratio of the type C GMR element etched up to IrMn (antiferromagnetic layer b) was the largest. Since the MR ratio is proportional to the reproduction output of the magnetic head, the reproduction output of the magnetic head using the type C GMR element is the largest among the magnetic heads using the type A to type C GMR elements. Become.

<Configuration of magnetic recording / reproducing apparatus>
Next, a magnetic recording / reproducing apparatus using the magnetic head 1 shown in FIG. 1 will be described with reference to FIG. FIG. 7 is a diagram showing the appearance of the magnetic recording / reproducing apparatus and the configuration incorporated in the apparatus.

  As shown in FIG. 7, the magnetic recording / reproducing apparatus 21 includes the magnetic head 1, the suspension 3, and the slider 5 shown in FIG. 1, a disk-shaped magnetic medium 23 on which data is read and written by the magnetic head 1, A spindle 25 that rotatably fixes the recording medium 23, a motor 27 that rotates the spindle 25, and an arm 29 that is integrally connected to the suspension 3 are provided. The magnetic recording / reproducing apparatus 21 controls the voice coil motor 31 by seeking the arm 29 (moving on the magnetic recording medium 23) and changing the position of the magnetic head 1 and the voice coil motor 31. A head position control circuit 33 and a data input / output circuit 35 for inputting / outputting data to be read / written from / to the magnetic recording medium 23 are provided.

  As described above, in the magnetic recording / reproducing apparatus 21 provided with the magnetic head 1, the magnetic head 1 is highly sensitive. Therefore, even if the recording density of the magnetic recording medium 23 is improved, the recorded data can be read accurately. Can write data.

  Next, in the case where a CPP-GMR element is used as the sensor A of the magnetic head 1, the MR characteristics obtained by experiment after manufacturing this CPP-GMR element and the dependency of the MR curve on the etching depth An image taken with a transmission electron microscope will be described with reference to FIGS.

Prior to these explanations, materials, devices, etc. used in the production of CPP-GMR elements, production processes, and devices used in experiments will be described.
The CPP-GMR element has a structure in which current flows perpendicularly to the film surface of the laminated film from the lower (upper) electrode to the upper (lower) electrode. As CoFe contained in this film (spin valve film [GMR film]), a highly spin-polarized material having a composition of Co ₇₅ Fe ₂₅ and a conventionally used material having a composition of Co ₉₀ Fe ₁₀ are used. .

  This spin-valve film is formed on a thermally oxidized Si substrate by an ion beam sputtering apparatus manufactured by Iontech under the conditions of a beam voltage of 850 v and a beam current of 100 mA. After the spin valve film was formed, heat treatment was performed in a magnetic field in which the ambient temperature of the film was maintained at 260 ° C. to impart anisotropy. Then, a lower electrode pattern was formed by optical photolithography and Ar ion etching.

Thereafter, a resist pattern of 0.2 to 0.4 μmφ is formed on the lower electrode by using an electron beam photolithography technique, etched with Ar ions, and the SiO ₂ insulating layer is contacted by lift-off as seen in the film formation. Was made. In order to accurately estimate the completion of Ar etching, monitoring was performed by SIMS (Secondary Ion Mass Spectrometry) during etching. Subsequently, the upper electrode (Cu) was formed by optical photolithography and lift-off.

An apparatus used for the experiment for measuring the MR characteristics of the CPP-GMR element using Co ₇₅ Fe ₂₅ and Co ₉₀ Fe ₁₀ shown in FIG. 8 is an MRW 200 manufactured by KLA Tencor. In the measurement experiment in this case, ± 1200 Oe is applied to 50 CPP-GMR elements having a size of 0.04 to 0.15 μm ² manufactured on the same wafer.

Furthermore, the apparatus used for the experiment for measuring the dependency of the MR curve etching depth shown in FIG. 9 is the MLA 200 manufactured by KLA Tencor, similar to FIG. Even in the measurement experiment in this case, ± 1200 Oe is applied to 50 CPP-GMR elements having a size of 0.04 to 0.15 μm ² fabricated on the same wafer.

  Furthermore, the transmission electron microscope used for photographing the image shown in FIG. 10 is a general one, and the analysis method is also a general method. Imaging in this case is performed with the CPP-GMR element completed.

FIG. 8 is a diagram showing the MR characteristics of the CPP-GMR element. FIG. 8A shows the case where the pinned layer c and the free layer e (see FIG. 2) are Co ₇₅ Fe _25. ) Shows the case where the pinned layer and the free layer are Co ₉₀ Fe ₁₀ . The etching depth of the GMR element is the same as that of type B in FIG. In FIG. 8, when the resistance value of the magnetization of the pinned layer c and the free layer e (see FIG. 2) is R _P and the anti-parallel resistance value is R _AP , R≡R _P , ΔR≡ R _AP -R _P , resistance value R is [Ω] on the left vertical axis, ΔR is [mΩ] on the right vertical axis, and l / A is [μm ⁻² ] on the horizontal axis. It is a thing. Incidentally, the CPP-GMR element has a size of 0.04 to 0.15 μm ² .

As shown in FIG. 8, the pinned layer c and the free layer e, that is, the ferromagnetic layers (first ferromagnetic layer and second ferromagnetic layer) are made of Co ₇₅ Fe ₂₅ , so that the MR ratio becomes 2. It was confirmed that the MR ratio can be increased to about 1.5 times compared to the MR ratio of Co ₉₀ Fe ₁₀ used in the past was 1.98%. This can be presumed to be an effect of Co ₇₅ Fe ₂₅ which is a material having a high spin polarization.

FIG. 9 shows the MR curves for each type shown in FIG. 5, where (a) shows the MR curve of type A shown in FIG. 5 (a) and (b) shows FIG. 5 (b). The MR curve of type B shown is shown, and (c) shows the MR curve of type C shown in FIG. 5 (c). This MR curve is
About 0.04 to 0.15 μm ² size CPP-GMR elements, about 50 CPP-GMR elements were measured by applying ± 1200 Oe (Oe; magnitude of magnetic field), and the vertical axis represents resistance R in (Ω) The field (magnetic field) applied to the horizontal axis is taken as [Oe].

As shown in FIG. 9, the MR ratios are 1.9%, 2.9%, and 3.3%, respectively. The types B and C shown in (b) and (c) have a larger H _c (magnetic shift amount) of the free layer e (see FIG. 2) than the type A shown in (a). Further, the center of the minor loop is greatly shifted (H _s ). Also, H _c is also larger (Hs: shift amount of the center of the minor loop, when the Hs> 0, the free layer e · pinned layer c stable parallel position, when the Hs <0, the free layer e・ Pinning layer c is stable in antiparallel position).

FIG. 10 shows a photograph (image) of the type B GMR element shown in FIG. 5B taken with a transmission electron microscope.
As shown in FIG. 10, IrMn (antiferromagnetic layer b: see FIG. 2) stacked on the lower electrode 11 (see FIG. 1) (strictly, there is an underlayer) is an ion milling process (etching process). It turns out that it is not completely cut. That is, it is shown that IrMn is accurately detected by SIMS during ion milling (during etching).

1A and 1B are diagrams for explaining a magnetic head according to an embodiment of the present invention, FIG. 1A is a schematic diagram of a magnetic head, and FIG. 2B is a diagram showing a schematic structure of a GMR element. It is the figure shown about the GMR film | membrane shown in FIG.1 (b). It is a figure showing a manufacturing method of a GMR element. 3 is a flowchart showing a method for manufacturing a GMR element. It is the figure shown about the etching depth of the GMR element. It is the figure shown about the MR characteristic of each type of GMR element shown in FIG. It is the figure which showed the outline of the magnetic recording / reproducing apparatus. It is the figure shown about the MR characteristic of a CPP-GMR element. It is the figure which showed the MR curve according to the type shown in FIG. It is the figure which showed the photograph (image) which imaged the type B GMR element shown in FIG.5 (b) with the transmission electron microscope.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Magnetic head 3 Suspension 5 Slider 7 Write part 9 Lead part 11 Lower shield (lower electrode, 1st electrode)
13 GMR film 15 Upper shield (upper electrode, second electrode)
DESCRIPTION OF SYMBOLS 17 Hard film 19 Insulator 21 Magnetic recording / reproducing apparatus 23 Magnetic recording medium 25 Spindle 27 Motor 29 Arm 31 Voice coil motor 33 Head position control circuit 35 Data input / output circuit A GMR element (CPP spin valve sensor, sensor)
a antiferromagnetic underlayer b antiferromagnetic layer c pinned layer (first ferromagnetic layer)
d Nonmagnetic intermediate layer e Free layer (second ferromagnetic layer)
f Capping layer

Claims (7)

In a magnetic head using a sensor having a layer containing an antiferromagnetic material in a layer laminated between electrodes and energized perpendicularly to the layer in contact with the electrode,
The sensor is
A first electrode and a second electrode;
An underlayer provided in contact with the first electrode;
An antiferromagnetic layer laminated on the underlayer and containing the antiferromagnetic material;
A first ferromagnetic layer comprising a ferromagnetic material, laminated on the antiferromagnetic layer;
A nonmagnetic intermediate layer laminated on the ferromagnetic layer and containing a nonmagnetic material;
A second ferromagnetic layer laminated on the nonmagnetic intermediate layer and containing the ferromagnetic material;
A capping layer laminated on the second ferromagnetic layer and provided in contact with the second electrode;
The area of the abutting surface where the second electrode and the capping layer abut, the area of the abutting surface where the capping layer and the second ferromagnetic layer abut, the second ferromagnetic layer and the non-magnetic The area of the contact surface with which the intermediate layer contacts and the area of the contact surface with which the nonmagnetic intermediate layer and the first ferromagnetic layer contact are made equal to each other as a first area,
The area of the contact surface where the antiferromagnetic layer and the underlayer abut and the area of the contact surface where the underlayer and the first electrode abut are equal to each other as a second area,
The third area, which is the area of the abutting surface where the first ferromagnetic layer and the antiferromagnetic layer abut, is greater than the first area and smaller than the second area or the second area The magnetic head is formed so as to be equal to In a magnetic head using a sensor having a layer containing an antiferromagnetic material in a layer laminated between electrodes and energized perpendicularly to the layer in contact with the electrode,
The sensor is
A first electrode and a second electrode;
An underlayer provided in contact with the first electrode;
An antiferromagnetic layer laminated on the underlayer and containing the antiferromagnetic material;
A first ferromagnetic layer comprising a ferromagnetic material, laminated on the antiferromagnetic layer;
A nonmagnetic intermediate layer laminated on the ferromagnetic layer and containing a nonmagnetic material;
A second ferromagnetic layer laminated on the nonmagnetic intermediate layer and containing the ferromagnetic material;
A capping layer laminated on the second ferromagnetic layer and provided in contact with the second electrode;
The area of the abutting surface where the second electrode and the capping layer abut, the area of the abutting surface where the capping layer and the second ferromagnetic layer abut, the second ferromagnetic layer and the non-magnetic The area of the contact surface with which the intermediate layer contacts and the area of the contact surface with which the nonmagnetic intermediate layer and the first ferromagnetic layer contact are made equal to each other as a first area,
The area of the contact surface where the antiferromagnetic layer and the underlayer abut and the area of the contact surface where the underlayer and the first electrode abut are equal to each other as a second area,
The third area, which is the area of the contact surface where the first ferromagnetic layer and the antiferromagnetic layer abut, is equal to the first area, and the second area is larger than the first area. The magnetic head is formed as described above. In a magnetic head using a sensor having a layer containing an antiferromagnetic material in a layer laminated between electrodes and energized perpendicularly to the layer in contact with the electrode,
The sensor is
A first electrode and a second electrode;
An underlayer provided in contact with the first electrode;
An antiferromagnetic layer laminated on the underlayer and containing the antiferromagnetic material;
A first ferromagnetic layer comprising a ferromagnetic material, laminated on the antiferromagnetic layer;
A nonmagnetic intermediate layer laminated on the ferromagnetic layer and containing a nonmagnetic material;
A second ferromagnetic layer containing the ferromagnetic material and laminated on the nonmagnetic intermediate layer; and a capping layer laminated on the second ferromagnetic layer and provided in contact with the second electrode,
The area of the abutting surface where the second electrode and the capping layer abut, the area of the abutting surface where the capping layer and the second ferromagnetic layer abut, the second ferromagnetic layer and the non-magnetic The area of the contact surface with which the intermediate layer contacts, the area of the contact surface with which the nonmagnetic intermediate layer and the first ferromagnetic layer contact, and the first ferromagnetic layer and the antiferromagnetic layer It is formed so that the area of the contact surface to contact is equal as the first area,
When the area of the contact surface where the underlayer and the first electrode are in contact is the second area, the third area, which is the area of the contact surface where the antiferromagnetic layer and the underlayer are in contact, is A magnetic head, wherein the magnetic head is formed so as to be larger than the first area and smaller than or equal to the second area. In a magnetic head using a sensor having a layer containing an antiferromagnetic material in a layer laminated between electrodes and energized perpendicularly to the layer in contact with the electrode,
The sensor is
A first electrode and a second electrode;
An underlayer provided in contact with the first electrode;
An antiferromagnetic layer laminated on the underlayer and containing the antiferromagnetic material;
A first ferromagnetic layer comprising a ferromagnetic material, laminated on the antiferromagnetic layer;
A nonmagnetic intermediate layer laminated on the ferromagnetic layer and containing a nonmagnetic material;
A second ferromagnetic layer laminated on the nonmagnetic intermediate layer and containing the ferromagnetic material;
A capping layer laminated on the second ferromagnetic layer and provided in contact with the second electrode;
The area of the abutting surface where the second electrode and the capping layer abut, the area of the abutting surface where the capping layer and the second ferromagnetic layer abut, the second ferromagnetic layer and the non-magnetic The area of the contact surface with which the intermediate layer contacts, the area of the contact surface with which the nonmagnetic intermediate layer and the first ferromagnetic layer contact, and the first ferromagnetic layer and the antiferromagnetic layer It is formed so that the area of the contact surface to contact is equal as the first area,
When the area of the contact surface where the underlayer and the first electrode are in contact is the second area, the third area, which is the area of the contact surface where the antiferromagnetic layer and the underlayer are in contact, is A magnetic head, wherein the magnetic head is formed so as to be equal to the first area and to have the second area larger than the first area. In a magnetic head manufacturing method for creating a magnetic head using a sensor having an antiferromagnetic material layer in a layer laminated between electrodes and being energized perpendicularly to a layer in contact with the electrode,
An etching step of etching an uncovered region of a ferromagnetic layer including a ferromagnetic material stacked on the layer including the antiferromagnetic material to a predetermined depth;
In this etching step, a detection step of detecting the ferromagnetic material;
In this detection step, an ending step for ending etching when the ferromagnetic material is no longer detected,
A method of manufacturing a magnetic head, comprising: In a magnetic head manufacturing method for creating a magnetic head using a sensor having an antiferromagnetic material layer in a layer laminated between electrodes and being energized perpendicularly to a layer in contact with the electrode,
An etching step of etching an uncovered region of the layer comprising the antiferromagnetic material to a predetermined depth;
In this etching step, a detection step of detecting the antiferromagnetic material,
In this detection step, an ending step for ending etching when the antiferromagnetic material is no longer detected, and
A method of manufacturing a magnetic head, comprising: A magnetic recording / reproducing apparatus comprising the magnetic head according to claim 1.

Images