JP2013047998A - High-frequency magnetic field assist perpendicular magnetic recording head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the controllability of oscillation properties of a high-frequency oscillatory element in a high-frequency magnetic field assist magnetic recording head.SOLUTION: The width of a high-frequency oscillatory element 110 in a cross track direction is made narrower as it goes away from a medium-opposing surface. When the medium-opposing surface is polished, the electric resistance of the high-frequency oscillatory element is measured, and if it reaches a target electric resistance value, the polishing is finished.

Description

  The present invention relates to a magnetic recording head having a function of inducing magnetization reversal by applying a high frequency magnetic field to a magnetic recording medium.

2. Description of the Related Art Magnetic recording / reproducing devices represented by HDD (Hard Disk Drive) are widely used as an infrastructure for information infrastructure. Along with the development of the information society with the spread of the Internet, the amount of digital data generated has continued to explode, and the information storage required for its storage includes reliability, cost, environmental impact, and energy consumption. There is a need to improve performance from a different perspective. Of these, cost is one of the most important performance requirements for current information storage devices. On the other hand, in the HDD, technological development for reducing the bit cost by improving the surface recording density has been advanced. The increase in recording density reaches about 40% per year, and the surface recording density is expected to reach 1 Tbits / inch ² around 2012.

  The surface recording density has been improved by miniaturizing the magnetic recording head and the reproducing head and by miniaturizing the particle diameter of the magnetic recording medium. However, the problem of insufficient recording capability is becoming apparent due to a decrease in the recording magnetic field strength accompanying the miniaturization of the magnetic recording head. On the other hand, when the particle size of the magnetic recording medium becomes finer, the problem of thermal fluctuation becomes obvious. Therefore, it is necessary to increase the coercive force and anisotropic energy of the medium at the same time as making the particle diameter finer. It becomes difficult. Therefore, as a technique for overcoming the above conflict, assist recording has been proposed in which the coercive force of a magnetic recording medium is temporarily reduced only during recording by application of heat or a high-frequency magnetic field. An assist recording method by applying “heat” is described in Patent Document 1, for example.

  On the other hand, a method using a high frequency magnetic field has recently attracted attention together with the name “microwave assisted recording (MAMR)”. In MAMR, a high-frequency magnetic field of a strong microwave band is applied to a nanometer unit region to locally excite a recording medium, and a magnetization reversal magnetic field is reduced to record information. Since magnetic resonance is used, it is necessary to use a high-frequency magnetic field having a high frequency proportional to the anisotropic magnetic field of the recording medium in order to obtain a reduction effect of a large magnetization reversal magnetic field. Patent Document 2 discloses a high-frequency oscillation element having a structure in which a laminated film having a structure similar to a GMR element (giant magnetoresistive element) for generating a high-frequency assist magnetic field is sandwiched between electrodes. The high-frequency oscillation element can generate a local high-frequency oscillating magnetic field by injecting conduction electrons having a spin fluctuation generated in the GMR structure into the magnetic material via the non-magnetic material. Similarly, Non-Patent Document 1 reports microwave oscillation by spin torque. In Non-Patent Document 2, a high-frequency magnetic field generating layer that rotates at high speed by spin torque is arranged adjacent to the main pole of a perpendicular magnetic head to generate a microwave (high-frequency magnetic field), and magnetic recording with a large magnetic anisotropy. A technique for recording information on a medium is disclosed. Further, in Non-Patent Document 3, an oscillating element is disposed between the main magnetic pole of a magnetic recording head and a trailing shield behind the main magnetic pole, and the rotation direction of the high-frequency magnetic field is changed in accordance with the recording magnetic field polarity, thereby magnetic recording. A technique for efficiently assisting magnetization reversal of a medium is disclosed.

JP-A-7-244801 JP 2005-025831 A JP 2001-101634 A Japanese Patent Laid-Open No. 2006-344381

Nature 425, 380 (2003) “Microwave Assisted Magnetic Recording” J-G. Zhu et. Al., IEEE trans. Magn., Vol.44, NO.1, 125 (2008) “Medium damping constant and performance characteristics in microwave assisted magnetic recording with circular ac filed” Y. Wang, et al., Journal of Applied Physics, Vol.105, p.07B902 (2009)

  When an oscillating element having a structure similar to that of a GMR element is formed by a method similar to that of a conventional reproducing head, the length in the cross-track direction is determined by photolithography, and the slider is polished (wrapped) like the conventional reproducing element. ) In the process, the length of the oscillation element in the flying height direction is determined. At this time, the characteristics (frequency and magnetic field strength) of the oscillation element strongly depend on the outer shape as the element becomes finer. This is because the influence of the demagnetizing field on the outer peripheral portion of the element becomes significant. Therefore, suppressing shape and position variations in the wafer manufacturing process and controlling the lapping amount with high accuracy are important issues in producing a head with good performance with high yield. In particular, it is effective in controlling the final dimensional variation to detect the amount of processing in the polishing step, which is a subsequent step, in a non-destructive and simple manner and to determine the amount of processing.

  As a technique for improving the accuracy of the polishing process, an electric resistance detection element is used in which the volume decreases with the progress of polishing and the electric resistance increases with the volume. For example, Patent Document 3 discloses a method in which a dummy resistance detection film is embedded in a polished surface, and a polishing amount is adjusted while monitoring a resistance value that changes as it is polished. Further, in Patent Document 4, polishing processing is performed in the form of a slider, the resistance value of the resistance detection element formed in the slider is detected during the processing, and the detected resistance value or the floating value of the reproducing element converted from the resistance value is detected. A method is disclosed in which polishing is stopped when the length in the height direction reaches a predetermined value.

  In the recording head including the high-frequency oscillation element targeted by the present invention, it is possible to control the length of the oscillation element in the flying height direction with a certain accuracy by using the same electric resistance detection element. However, a general electric resistance detection element is manufactured separately from the high-frequency oscillation element, and the relative positional relationship between the two elements varies depending on the fine processing accuracy. Therefore, the shape variation of the high-frequency oscillation element is highly accurate. It cannot be suppressed.

  The present invention suppresses variations in oscillation characteristics due to variations in wafer processing and slider polishing processes in a magnetic recording head including a high-frequency oscillation element.

  An electric circuit capable of measuring the electric resistance of the high-frequency oscillation element in the medium facing surface polishing process of the head is provided, and the width of the high-frequency oscillation element in the cross-track direction is moved away from the medium facing surface in the flying height direction. Form to be narrow.

  That is, the perpendicular magnetic recording head according to the present invention includes a main magnetic pole for generating a recording magnetic field, a trailing shield disposed on the trailing side of the main magnetic pole, and an electrical connection between the main magnetic pole and the trailing shield. A high-frequency oscillation element disposed; a coil for exciting the main magnetic pole; and a means for allowing a current to flow through the main magnetic pole, the high-frequency oscillation element, and the trailing shield. The high frequency oscillating element is electrically insulated at an upper position in the height direction, and has a shape in which the width in the cross-track direction becomes narrower as the distance from the medium facing surface increases in the flying height direction near the medium facing surface.

  For example, in the high-frequency oscillator, when the width in the cross-track direction at a position separated from the medium facing surface in the flying height direction by a distance x is W, the rate of change of W with respect to x (dW / dx) increases with x. It can be made into the shape to do. In the region far from the medium facing surface in the flying height direction, the width in the cross track direction may be constant.

  The method of manufacturing a perpendicular magnetic recording head according to the present invention includes a step of forming a main magnetic pole on a substrate, a step of forming a laminated film to be a high-frequency oscillation element on the main magnetic pole, and the laminated film from the medium facing surface. A step of processing into a shape in which the width in the cross-track direction becomes narrower with increasing distance in the flying height direction, a step of cutting the substrate into a stack including one or more perpendicular magnetic recording heads, A polishing step of polishing a surface corresponding to the medium facing surface. In the polishing step, the polishing proceeds while measuring the electric resistance value of the laminated film, and the polishing is terminated when the electric resistance value reaches the target value.

  According to the present invention, it is possible to detect with high sensitivity the change in electrical resistance of the high-frequency oscillation element accompanying the progress of slider polishing. As a result, it is possible to estimate the shape of the element from the electric resistance and determine the polishing amount, and to suppress the characteristic variation of the high-frequency oscillation element.

  Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

FIG. 3 is a schematic sectional view of a magnetic recording / reproducing head. The schematic diagram of a high frequency oscillation element and a main pole. The shape explanatory view of the high frequency oscillation element by the present invention. The figure which shows the lapping amount dependence of the electrical resistance of a high frequency oscillation element. The model figure of the oscillation frequency simulation of a high frequency oscillation element. The figure which shows the relationship between the oscillating frequency of the high frequency oscillation element, and the inclination angle (theta) of the cross-track direction edge part. The figure which shows the relationship between the electrical resistance change rate of a high frequency oscillation element, and a lapping process shift | offset | difference. The figure which shows the relationship between the oscillation frequency of a high frequency oscillation element, and a lapping process shift | offset | difference. The figure which shows the relationship between the angle (theta) of a high frequency oscillation element, and the variation of an oscillation frequency. The figure which shows the example of the planar shape of the high frequency oscillation element by this invention. The figure which shows the example of the planar shape of the high frequency oscillation element by this invention. FIG. 3 is an explanatory diagram illustrating an example of a medium facing surface polishing process of a magnetic head. The flowchart of a process.

Examples of the present invention will be described below, and will be described more specifically with reference to the drawings.
[Example 1]
FIG. 1 is a schematic cross-sectional view of a magnetic recording / reproducing head targeted by the present invention. This magnetic recording / reproducing head is a recording / reproducing separation head having a recording head unit 100 and a reproducing head unit 200. The recording head unit 100 includes a high-frequency oscillating element 110 for generating a high-frequency magnetic field, a main magnetic pole 120 for generating a recording head magnetic field, and a coil 160 for exciting a magnetic field in the main magnetic pole. A trailing shield 130 is provided in the trailing direction of the main magnetic pole 120. Here, the trailing direction is defined as the direction opposite to the traveling direction of the head with respect to the magnetic recording medium 170, and the leading direction is defined as the traveling direction of the head with respect to the medium facing surface. The main magnetic pole 120 and the trailing shield are electrically insulated by an insulating region 150 provided at an upper position in the flying height direction away from the medium facing surface. Although not shown in FIG. 1, a side shield may be provided outside the main magnetic pole 120 in the cross track direction. The side shields may be provided on both sides of the main magnetic pole 120, or may be provided only on one side. A current is applied to the high-frequency oscillator 110 from the power supply 140 connected across the insulating region 150 through the main magnetic pole 120 and the trailing shield 130. In the reproducing head unit 200, a reproducing element 210 such as a TMR element or a GMR element is disposed between the lower magnetic shield 220 and the upper magnetic shield 230. During recording, a recording magnetic field from the main magnetic pole 120 and a high-frequency magnetic field from the high-frequency oscillation element 110 are applied to the magnetic recording medium 170.

  The high-frequency oscillation element 110 of the magnetic head unit 100 includes an oscillation layer 111 that generates a high-frequency magnetic field, an intermediate layer 112 made of a material having high spin permeability, and a spin injection layer 113 for applying spin torque to the oscillation layer 111. As shown in FIG. 1, the high-frequency oscillation element 110 may be formed by laminating the oscillation layer 111, the intermediate layer 112, and the spin injection layer 113 in this order from the main magnetic pole 120 side, and conversely, the spin injection layer 113 from the main magnetic pole 120 side. The intermediate layer 112 and the oscillation layer 111 may be stacked in this order.

  As the material of the oscillation layer 111, for example, a ferromagnetic metal such as FeCo is used. In addition to the FeCo alloy, a NiFe alloy, a Heusler alloy such as CoFeGe, CoMnGe, CoFeAl, CoFeSi, CoMnSi, and CoFeSi, a Re-TM-based amorphous alloy such as TbFeCo, and a CoCr-based alloy may be used. In addition, it has been reported that efficient oscillation can be expected by using a material having negative perpendicular anisotropy energy such as CoIr (“Spin Torque Oscillator With Negative Magnetic Anisotropy Materials for MAMR” K. Yoshida et al. , IEEE trans. Magn., Vol.46, p.2466, 2010). For the intermediate layer 112, a non-magnetic conductive material such as Cu can be used, and for example, Au, Ag, Pt, Ta, Ir, Al, Si, Ge, Ti, or the like can be used. By using a material having perpendicular magnetic anisotropy for the spin injection layer 113, the oscillation of the oscillation layer 111 can be stabilized. For example, Co / Pt, Co / Ni, Co / Pd, CoCrTa / Pd, etc. It is preferable to use an artificial lattice magnetic material. Further, although the oscillation stability is slightly lost, the same material as that of the oscillation layer 111 can be used.

  FIG. 2 shows a schematic diagram of the high-frequency oscillation element 110 and the main magnetic pole 120 as seen from the recording medium direction. Here, for the sake of simplicity, the trailing shield 130 is not shown. The main magnetic pole 120 may have an inverted trapezoidal shape or a triangular shape whose width in the cross-track direction is wide on the trailing side and narrow on the leading side. Here, the width W in the cross-track direction of the high-frequency oscillation element 110 decreases as the distance from the medium facing surface decreases. Here, for the sake of simplicity, it is assumed that the outline of the track end portion of the high-frequency oscillator 110 is a straight line that forms an angle θ with the flying height direction.

  Hereinafter, effects obtained by the configuration of the present embodiment will be described. The current generated by the voltage applied by the power supply 140 flows from the main magnetic pole 120 to the trailing shield via the high frequency oscillation element 110 (or in the opposite direction). The electrical resistance at this time is expressed as ρ / A using the specific resistance ρ and the area A of the high-frequency oscillation element. Therefore, it is possible to detect the element shape in a non-destructive manner by measuring a change in electrical resistance accompanying lapping of the medium facing surface.

  As shown in FIG. 3, for example, consider an element in which the length in the flying height direction before lapping is L0 and the element width on the medium facing surface is W0. Considering the shape of the element when lapping is applied to the element and the element is cut in the flying height direction by x from the initial state. At this time, the length in the flying height direction is (L0−x). On the other hand, the width W of the element on the medium facing surface after processing is W0-2x · tan θ. Therefore, the area S of the element after processing is (L0−x) · (W0− (x + L0) · tan θ). At this time, the change dS of the area with respect to the minute processing amount dx is dS / dx = 2x · tan θ−W0. Therefore, the area change rate increases with increasing θ.

FIG. 4A shows the lap processing amount dependency of the electrical resistance of the high-frequency oscillation element when L0 = 100 and W0 = 100. The horizontal axis is the lapping amount x, and the vertical axis is the electrical resistance. Here, it is assumed that a tunnel type magnetoresistive element structure is used for the high-frequency oscillation element, and the specific resistance is set to 0.6 Ωμm ^{2 in} consideration of an element generally used in a magnetic recording / reproducing head. FIG. 4B is normalized by the electric resistance value before processing. The change in electrical resistance with respect to the lapping amount increases with θ. Therefore, when determining the lapping amount while detecting this electrical resistance, it is possible to control the amount of machining with high accuracy by increasing θ.

On the other hand, increasing θ means changing the outer shape of the high-frequency oscillation element from a rectangle to a trapezoid. Therefore, the symmetry of the shape may decrease as θ increases. In the following, a range of θ appropriate for realizing sufficient oscillation magnetic field strength and oscillation frequency will be described. The magnetization behavior of a high-frequency oscillator is calculated using the following LLG equation ("Magnetization dynamics with a spin-transfer torque" Z. Li and S. Zhang, Phys. Rev. B, vol. 68, p. 024404, 2003). Calculated.
(1 + α ² ) dM / dt = −γM (H _eff −αH _st ) −λ / M _s · M ² (αH _eff + H _st )
H _st = hηJM _p / 2eM _s d
α: Damping constant (0.02)
M: magnetization vector γ: gyromagnetic constant H _eff : sum of anisotropic magnetic field, static magnetic field, exchange coupling magnetic field, Zeeman energy, and current magnetic field H _st : spin torque magnetic field λ: loss constant M _s : saturation magnetization h: Planck constant η: Spin polarizability J: Current density M _p : Unit magnetization vector of spin injection layer d: Film thickness of FGL e: Unit charge

The model used for the calculation is shown in FIG. The basic shape was a square with a width of 40 nm and a height of 40 nm, and the magnetization was calculated for each unit cell divided into 24 in the cross track direction and the flying height direction. The change in oscillation frequency was estimated by using this as a trapezoidal shape with an increase in θ. Table 1 shows physical property values of the oscillation layer, the intermediate layer, and the spin injection layer used in the calculation. The current density between the main magnetic pole and the shield was 1.8 A / cm ^2, and a uniform external magnetic field of 10 kOe was assumed in the down track direction.

  FIG. 6 shows the relationship between the oscillation frequency and θ obtained by calculation. The oscillation frequency decreases as θ increases. This is considered to be caused by the fact that the element becomes smaller, the influence of the demagnetizing field generated at the peripheral edge of the element becomes stronger, and the oscillation becomes unstable. At this time, the oscillation continues relatively stably when θ is in the range of 7 ° to 18 °. However, when θ exceeds 20 °, the oscillation frequency greatly decreases, and θ should be used in the range of 7 to 20 °. Is desirable from the viewpoint of maintaining performance.

  Next, the characteristic variation reducing effect of the high frequency oscillation device according to the present invention will be described. First, FIG. 7 shows the dependence of the resistance change rate 1 / R (x) · dR (x) / dx deviation of the lapping amount calculated based on the electrical resistance lapping dependence of the element shown in FIG. R (x) is the electrical resistance of the element after lnm lapping. Here, it is assumed that the final target size of the high-frequency oscillation element is 40 nm, and the horizontal axis indicates the processing deviation from x = 40 as Δx.

  Similar to FIG. 4B, the rate of change in resistance increases as θ increases. Assuming that the resistance change rate ± 0.5% is the detection limit of the resistance detection system, the final dimension of the high-frequency oscillation element has a variation in length in the horizontal axis (σx) surrounded by a square in the figure. . As can be seen from the figure, σx decreases as θ increases.

  The effect of this variation on the oscillation frequency is shown in FIG. FIG. 8 shows the relationship between the oscillation frequency and the deviation of the high-frequency oscillation element from the final target size of 40 nm. At every θ, the oscillation frequency decreases as Δx increases. Here, when the lapping amount fluctuates around Δx = 0 in accordance with σx shown in FIG. 7, the change in oscillation frequency Δf is expressed by the length of the rectangular line in the vertical axis direction shown in the figure. .

  FIG. 9 summarizes the relationship between θ and Δf based on FIG. Δf decreases as θ increases. For example, by setting θ = 20 °, fluctuations in the oscillation frequency can be suppressed to about ¼ that in the case of θ = 0 °.

[Example 2]
Hereinafter, various planar shapes of the high-frequency oscillation element that can obtain the same effects as those described in the first embodiment will be described.

  The essence of the present invention is that the lapping of the medium facing surface proceeds, the width of the high-frequency oscillation element in the cross-track direction is reduced, and the area, that is, the rate of change in electrical resistance increases. Therefore, even if the rate of change in the width in the cross track direction is not uniform, the same effect can be obtained. That is, as shown in FIGS. 10A and 10B, the same effect can be obtained even if the side surface of the track end is curved. In particular, as shown in FIG. 10B, a shape in which the rate of change in the width in the cross-track direction increases with increasing distance from the medium facing surface in the flying height direction is desirable for improving the resistance change rate. It is. In other words, when the width in the cross-track direction at a position separated by a distance x in the flying height direction from the medium facing surface is W, the rate of change of W with respect to x (dW / dx) increases with x. Shape. Alternatively, the resistance change rate can be improved in the same manner even in the shape shown in FIG. 10C in which the change in width changes in several steps, and is within the scope of the present invention.

  In such a form, the angle θ formed by the outline of the track end and the flying height direction described in the first embodiment is an approximate straight line drawn by the least square method on the outline as indicated by a broken line in the figure. It is defined by the angle formed by the flying height direction. It is clear that the resistance change rate accompanying the lapping amount increases with the increase in θ defined as described above.

  Also, the relationship between the oscillation frequency and θ does not change greatly depending on whether the outline at the track end is a straight line or a curved line.

Example 3
Another embodiment of the planar shape of the high-frequency oscillation element will be described.
It is not always necessary to change the length in the cross-track direction in the entire high-frequency oscillation element. For example, as shown in FIGS. 11A to 11E, the effect of the present invention can be obtained as long as it has a region in which the length in the cross-track direction changes in the vicinity of the medium facing surface after lapping. . Therefore, the shape as shown in FIGS. 11A, 11B, 11C, and 11D having a region having a constant width in the cross-track direction on the end face side of the high-frequency oscillation element far from the medium facing surface is also used. This is the category of the present invention.

  Further, as described in the second embodiment, the rate of change in the width in the cross track direction has a portion on the medium facing surface side that increases as the distance from the medium facing surface increases, and the rate of change at a position away from the medium facing surface. The effect of the present invention can be obtained even when the shape of the high-frequency oscillation element as shown in FIG.

Example 4
An example of the medium facing surface polishing process of the perpendicular magnetic recording head according to the present invention will be described.
A plurality of perpendicular magnetic recording head elements are formed in an array on a substrate by a normal process. Here, a characteristic process for manufacturing the high-frequency magnetic field-assisted perpendicular magnetic recording head element of the present invention is that the main film is formed and then a laminated film that becomes a high-frequency oscillation element in a state of being electrically connected to the main pole. Forming a high-frequency oscillation element by processing the laminated film into a shape in which the width in the cross-track direction becomes narrower as the distance from the medium facing surface increases in the flying height direction.

  The medium facing surface of the perpendicular magnetic recording head thus formed on the substrate is then polished by a predetermined amount. As shown in FIG. 12A, the perpendicular magnetic recording head element including the high-frequency oscillation element formed on the substrate 310 is first cut into a stack 311 for each or a plurality of elements. Next, the surface orthogonal to the surface on the substrate on which the perpendicular magnetic recording head element is formed (that is, the medium facing surface) is polished using the rotary polishing surface plate 312 and the polishing liquid 313. FIG. 12C is an enlarged view of the support portion of the stack 311. The stack 311 is fixed to the stack support portion 314 via the elastic body 315. Here, terminals 316 and 317 provided on the support portion 314 and the stack 311 are connected by a gold wire 318.

  A flowchart of the machining process is shown in FIG. The electrical resistance of the high-frequency oscillation element is measured during processing or between intermittent processing, and the polishing process is terminated when the target electrical resistance value is reached. The target electric resistance value is determined using an electric resistance such as a GMR film in a wafer process for forming a final target shape and a high-frequency oscillation element. According to this method, it is possible to manufacture a high-frequency magnetic field assisted perpendicular magnetic recording head having desired performance while suppressing variation in characteristics of the high-frequency oscillation element with a high yield.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. In addition, a part of the configuration of a certain embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of a certain embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

100 recording head 110 high frequency oscillation element 111 oscillation layer
112 Intermediate layer 113 Spin injection layer 120 Main magnetic pole 130 Trailing shield 140 Power supply 150 Insulating region 160 Coil 170 Magnetic recording medium 200 Playback head 210 Playback element 220 Lower magnetic shield 230 Upper magnetic shield 310 Substrate 311 Stack 312 Rotating polishing surface plate 313 Polishing Liquid 314 Stack support part 315 Elastic body 316 Terminal 317 Terminal 318 Gold wire

Claims (7)

A main magnetic pole for generating a recording magnetic field;
A trailing shield disposed on the trailing side of the main pole;
A high-frequency oscillation element arranged in electrical connection between the main pole and the trailing shield;
A coil for exciting the main magnetic pole;
Means for passing a current through the main pole, the high-frequency oscillation element and the trailing shield;
The main magnetic pole and the trailing shield are electrically insulated at an upper position in the flying height direction,
The perpendicular magnetic recording head according to claim 1, wherein the high-frequency oscillation element has a shape in which the width in the cross-track direction becomes narrower as the distance from the medium facing surface increases in the flying height direction near the medium facing surface.   2. The perpendicular magnetic recording head according to claim 1, wherein the high-frequency oscillation element has a width in the cross-track direction at a position separated from the medium facing surface by a distance x in the flying height direction, where W A perpendicular magnetic recording head characterized in that the rate of change (dW / dx) increases with x.   2. The perpendicular magnetic recording head according to claim 1, wherein the high-frequency oscillation element has a first region in which the width in the cross-track direction becomes narrower as the distance from the medium facing surface increases in the flying height direction. A second region having a constant range in the flying height direction and having a constant width in the cross-track direction is located farther from the medium facing surface in the flying height direction than the first region. Perpendicular magnetic recording head.   2. The perpendicular magnetic recording head according to claim 1, wherein the high-frequency oscillation element has a width in the cross-track direction at a position separated from the medium facing surface by a distance x in the flying height direction, where W The first region in which the rate of change (dW / dx) increases with x is in a certain range in the flying height direction from the medium facing surface, and the second region in which the rate of change is constant is the first region. A perpendicular magnetic recording head having a position farther in the flying height direction from the medium facing surface than the area.   5. The perpendicular magnetic recording head according to claim 4, wherein the rate of change is zero in the second region.   2. The perpendicular magnetic recording head according to claim 1, wherein an angle formed by an approximate straight line drawn by a least-squares method on an outline of a cross-track direction end of the high-frequency oscillation element and a flying height direction is 20 ° or less. A perpendicular magnetic recording head. In a method of manufacturing a perpendicular magnetic recording head having a main magnetic pole, a high-frequency oscillation element electrically connected to the main magnetic pole, and a trailing shield electrically connected to the high-frequency oscillation element,
Forming the main pole on a substrate;
Forming a laminated film to be the high-frequency oscillation element on the main pole;
Processing the laminated film into a shape in which the width in the cross-track direction becomes narrower as it moves away from the medium facing surface in the flying height direction;
Cutting the substrate into a stack including one or more perpendicular magnetic recording heads;
Polishing a surface corresponding to a medium facing surface of the perpendicular magnetic recording head of the stack,
In the polishing step, the polishing proceeds while measuring the electric resistance value of the laminated film, and the polishing is finished when the electric resistance value reaches a target value.

Images