JP5668236B2 - Near-field optical head manufacturing method, near-field optical head, and information recording / reproducing apparatus - Google Patents

Description

  The present invention relates to a manufacturing method of a near-field optical head, a near-field optical head, and an information recording / reproducing apparatus for recording information on the magnetic recording medium by a magnetic field while heating the magnetic recording medium with near-field light.

  In recent years, the recording density of information within a single recording surface has increased as the capacity of hard disks and the like in computer equipment has increased. For example, in order to increase the recording capacity per unit area of the magnetic disk, it is necessary to increase the surface recording density. However, as the recording density increases, the recording area occupied by one bit on the recording medium decreases. When this bit size is reduced, the energy of 1-bit information is close to that of room temperature, and the recorded information is reversed or lost due to thermal fluctuation, etc. Will occur.

  In the in-plane recording method that has been generally used, the magnetism is recorded so that the direction of magnetization is in the in-plane direction of the recording medium. In this method, the recorded information is lost due to the thermal demagnetization described above. Is likely to occur. Therefore, in order to solve such problems, in recent years, a perpendicular recording method for recording a magnetization signal in a direction perpendicular to the recording medium has been adopted. This method is a method for recording magnetic information on the principle of bringing a single magnetic pole closer to a recording medium. According to this method, the recording magnetic field is directed substantially perpendicular to the recording film. Information recorded by a perpendicular magnetic field is easy to maintain in energy stability because it is difficult for the N pole and the S pole to form a loop in the recording film surface. Therefore, this perpendicular recording method is more resistant to thermal demagnetization than the in-plane recording method.

  However, recent recording media are required to have a higher density in response to the need to record and reproduce a larger amount and higher density information. For this reason, in order to minimize the influence of adjacent magnetic domains and thermal fluctuations, those having a strong coercive force have begun to be adopted as recording media. For this reason, it is difficult to record information on a recording medium even in the above-described perpendicular recording system.

Therefore, in order to eliminate the above-described problems, the magnetic domain is locally heated using spot light that has collected light or near-field light to temporarily reduce the coercive force, and to the recording medium in the meantime. A hybrid magnetic recording type recording / reproducing head is provided.
Among such recording / reproducing heads, a recording / reproducing head using near-field light (hereinafter referred to as a near-field light head) is provided along the surface of a magnetic recording medium as shown in, for example, Patent Document 1 below. A movable slider, a recording element held at the tip of the slider, a near-field light generating element joined to the recording element, a light source that emits a light beam (laser light), and a light beam emitted from the light source. And an optical waveguide that leads to the near-field light generating element.

  The recording element described above is an element that generates a recording magnetic field from a facing surface facing the surface of the magnetic recording medium. This recording element is provided with a main magnetic pole and an auxiliary magnetic pole arranged opposite to each other, and a coil disposed between the main magnetic pole and the auxiliary magnetic pole. The main magnetic pole, the auxiliary magnetic pole, and the coil are respectively disposed substantially perpendicular to the surface of the magnetic recording medium, and the auxiliary magnetic pole is disposed on the base end side (slider side) and the main magnetic pole is disposed on the front end side ( It is arranged on the opposite side of the slider side.

  The near-field light generating element described above is an element that generates near-field light from a facing surface facing the surface of the magnetic recording medium. The near-field light generating element includes a core that propagates a light beam incident from the proximal end side while converging toward the distal end side, a clad that adheres to the side surface of the core and seals the core, and a distal end of the core And a metal film that generates near-field light from the light beam condensed on the side. The core described above extends in a direction perpendicular to the surface of the magnetic recording medium along the front end surface of the recording element, and is disposed with the front end facing the surface of the magnetic recording medium. Further, the leading end surface of the core is exposed to the outside from a facing surface facing the surface of the magnetic recording medium, and a metal film is in close contact with the side surface of the leading end portion of the core. The clad described above is bonded to the tip surface (the surface on the main magnetic pole side) of the recording element, and the near-field light generating element is disposed on the side opposite to the auxiliary magnetic pole side with respect to the main magnetic pole. In the near-field light generating element described above, when the light beam emitted from the light source passes through the optical waveguide and enters the core from the base end portion, the light beam incident on the core is Propagating while condensing toward the side, the light flux is converted into near-field light by the metal film at the tip of the core, and the magnetic recording medium is heated by the near-field light.

According to the near-field light head described above, various information is recorded on the recording medium by generating a near-field light and simultaneously applying a recording magnetic field. That is, the light beam emitted from the light source enters the core from the base end portion of the core via the optical waveguide. This light beam propagates in the core toward the tip side and reaches the metal film. Then, in the metal film, the internal free electrons are uniformly vibrated by the light flux, so that the plasmon is excited and the near-field light is generated in a localized state at the tip of the core. As a result, the magnetic recording layer of the magnetic recording medium is locally heated by near-field light, and the coercive force temporarily decreases.
Further, by supplying a drive current to the recording element simultaneously with the irradiation of the light beam described above, a recording magnetic field is locally applied to the magnetic recording layer of the magnetic recording medium adjacent to the tip of the main magnetic pole. As a result, various kinds of information can be recorded on the magnetic recording layer whose coercive force has temporarily decreased. That is, recording on the magnetic recording medium can be performed by the cooperation of the near-field light and the magnetic field.

  Incidentally, in the above-mentioned near-field optical head, it is preferable to heat a portion of the magnetic recording medium close to the main magnetic pole. Therefore, conventionally, for example, as shown in Patent Document 2 below, a structure in which a metal film (scatterer) is formed on the facing surface of the near-field light generating element facing the surface of the magnetic recording medium has been proposed. The metal film is formed in a triangular shape in plan view that is gradually reduced in width toward the main magnetic pole side. In the near-field optical head configured as described above, near-field light is generated at the corner on the main pole side of the metal film, so that a portion of the magnetic recording medium close to the main pole can be heated.

JP 2008-152897 A JP 2008-159192 A

  However, in the near-field optical head described above, the main magnetic pole, auxiliary magnetic pole and coil constituting the recording element, and the core and clad constituting the near-field light generating element are laminated in the direction along the surface of the magnetic recording medium. This is a laminated structure. For this reason, in the above-described conventional near-field optical head in which the metal film is formed on the facing surface facing the surface of the magnetic recording medium, the metal film is formed on the end surface orthogonal to the stacking direction of the stacked structure described above. Therefore, there is a problem that the work of forming the metal film is complicated.

  The present invention takes the above-described conventional problems into consideration, and a method for manufacturing a near-field optical head capable of easily forming a metal film on a facing surface facing the surface of a magnetic recording medium, and a near-field optical head And an information recording / reproducing apparatus.

  A method of manufacturing a near-field optical head according to the present invention includes a slider that can move along the surface of a magnetic recording medium that rotates in a certain direction, and is held by the slider, and has a main magnetic pole and an auxiliary magnetic pole, A recording element for generating a recording magnetic field from a facing surface facing the surface of the magnetic recording medium, and a near field from a facing surface facing the surface of the magnetic recording medium, disposed on the opposite side of the auxiliary magnetic pole side with respect to the main magnetic pole A near-field light generating element for generating light, and the near-field light generated from the opposing surface of the near-field light generating element heats the magnetic recording medium and generates from the opposing surface of the recording element A method of manufacturing a near-field optical head for recording information on the magnetic recording medium by causing magnetization reversal in the magnetic recording medium by a recording magnetic field, wherein the near-field light generating element includes a tip A core disposed toward the surface of the magnetic recording medium and propagating the light beam incident from the base end side while converging toward the tip end; and a side surface on the main magnetic pole side of at least the tip portion of the core And a metal film that generates near-field light from a light beam collected on the tip end side of the core, and the magnetic recording is provided between the metal film and the main magnetic pole. A near-field light generating element forming step of forming the near-field light generating element in a state where an intermediate layer having an opposing surface facing the surface of the magnetic recording medium exposed to the surface side of the medium is interposed; A light beam is incident from the base end side of the core to generate near-field light, the metal film is melted by the near-field light, and the metal film is melted on the opposite surface of the intermediate layer. Metal film melting step of forming an end of the metal film on the opposite surface of the metal film It is characterized in that it comprises.

  A near-field optical head according to the present invention includes a slider that is movable along the surface of a magnetic recording medium that rotates in a predetermined direction, and is held by the slider, and has a main magnetic pole and an auxiliary magnetic pole, A recording element that generates a recording magnetic field from a facing surface facing the surface of the magnetic recording medium, and a near-field light disposed on the opposite side of the auxiliary magnetic pole side with respect to the main magnetic pole and facing the surface of the magnetic recording medium And a near-field light generating element for generating the recording medium, and the magnetic recording medium is heated by the near-field light generated from the opposing surface of the near-field light generating element and the recording generated from the opposing surface of the recording element A near-field optical head for recording information on the magnetic recording medium by causing magnetization reversal in the magnetic recording medium by a magnetic field, the tip of the near-field light generating element being the magnetic recording medium A core disposed toward the surface of the body and propagating while converging the light beam incident from the proximal end side toward the distal end side, and is in close contact with a side surface on the main magnetic pole side of at least the distal end portion of the core. And a metal film that generates near-field light from a light beam condensed on the tip end side of the core, and between the metal film and the main pole, on the surface side of the magnetic recording medium An intermediate layer having a facing surface that is exposed to face the surface of the magnetic recording medium is interposed, and the metal film is melted by the near-field light and melted on the facing surface of the intermediate layer. The end of the metal film is formed on the opposing surface of the intermediate layer.

  Due to such a feature, when a light beam having a higher output than the light beam when heating the magnetic recording medium is incident on the core from the base end side of the core, the light beam is condensed toward the tip end side of the core and the core. A strong near field light is generated in the metal film on the core tip side. The near-field light melts the metal film at a high temperature, and melts on the opposing surface of the intermediate layer facing the surface of the magnetic recording medium. As a result, the end of the metal film extends to the surface facing the surface of the magnetic recording medium, and the end of the metal film is gradually reduced toward the main magnetic pole. As a result, when the magnetic recording medium is heated, near-field light is generated at the tip portion of the end portion of the metal film, so that the portion of the magnetic recording medium close to the main magnetic pole is heated.

Also, the near-field optical head manufacturing method and the near-field optical head according to the present invention include a conductive film exposed on the surface side of the magnetic recording medium between the intermediate layer and the main pole. In this case, the near-field optical head manufacturing method according to the present invention detects the contact of the end of the metal film with respect to the current-carrying film during the metal film melting step, and includes the detection information in the detection information. Based on this, the light beam incident on the core is controlled.
Thereby, when a high-output light beam is incident on the core and the metal film is melted by the near-field light, the end portion of the metal film can be reliably extended to the position of the conductive film. For example, when the metal film is melted by near-field light, a high-output light beam is incident on the core until it is detected that the end of the metal film is in contact with the conductive film. And after detecting that the edge part of the metal film contacted the electricity supply film | membrane, incidence | injection of the light beam with respect to a core is stopped. Thereby, the dispersion | variation in the shape of the edge part of a metal film is suppressed.

The near-field optical head manufacturing method and the near-field optical head according to the present invention include an end on the opposite side of the metal film on the magnetic recording medium side and an end on the opposite side of the conductive film on the magnetic recording medium side. Are preferably extended to a position flush with the end surface opposite to the opposing surface of the recording element. In this case, the method of manufacturing a near-field optical head according to the present invention includes dissolving the metal film During the process, an electric circuit is formed to electrically connect the end of the metal film opposite to the magnetic recording medium side and the end of the conductive film opposite to the magnetic recording medium side.
As a result, when the metal film is melted by the near-field light when a high-power light beam is incident on the core, the end of the metal film on the magnetic recording medium side is not in contact with the conductive film. And the end of the energization film on the magnetic recording medium side are not electrically connected, and the electric circuit is disconnected. On the other hand, when the end of the metal film contacts the current-carrying film, the end of the metal film on the magnetic recording medium side and the end of the current-carrying film on the magnetic recording medium side are electrically connected, and the closed loop in which the electric circuit is closed It becomes. Therefore, it can be detected that the end portion of the metal film is in contact with the conductive film by detecting whether the electric circuit is cut or closed.

Further, the near-field optical head manufacturing method and the near-field optical head according to the present invention include a resistance portion in which the conductive film is exposed on a surface side of the magnetic recording medium, and the recording element from both ends of the resistance portion. And a pair of connecting portions each extending to a position flush with the opposite end surface of the opposite surface, and in this case, the method for manufacturing a near-field optical head according to the present invention Forms an electrical circuit that electrically connects the ends of the pair of connecting portions opposite to the magnetic recording medium during the metal film melting step, and detects the electrical resistance value of the electrical circuit .
This makes it possible to detect that the end portion of the metal film is in contact with the current-carrying film based on the electric resistance value of the electric circuit when the high-power luminous flux is incident on the core and the metal film is melted by the near-field light. it can. That is, the electric resistance value of the electric circuit is substantially constant when the end of the metal film is not in contact with the energizing film, but the electric resistance value of the electric circuit changes when the end of the metal film is in contact with the energizing film. To do. Based on the change in the electrical resistance value, it can be detected that the end of the metal film is in contact with the conductive film.

In the near-field optical head manufacturing method and the near-field optical head according to the present invention, it is preferable that the facing surface of the intermediate layer has higher wettability than the tip surface of the core.
As a result, when a high-power light beam is incident on the core and the metal film is dissolved by near-field light, the facing surface of the intermediate layer has higher wettability (hydrophilicity) than the end surface of the core. Since the tip surface has higher water repellency than the facing surface of the intermediate layer, the metal fluid in which the metal film has melted is less likely to flow to the tip surface side of the core having high water repellency, and on the facing surface side of the highly wettable intermediate layer. Easy to flow. For this reason, it is easy to form the end part of the metal film in a shape extending toward the main magnetic pole side.

Further, in the near-field optical head manufacturing method and the near-field optical head according to the present invention, the plurality of conductive films are laminated between the intermediate layer and the main magnetic pole via an insulating layer. Preferably, in this case, the near-field optical head manufacturing method according to the present invention detects the contact of the end portions of the metal film with respect to the plurality of current-carrying films during the metal film melting step, and uses the detected information as the detection information. Based on this, the output of the light beam incident on the core is reduced stepwise.
As a result, the end portion of the metal film formed on the facing surface facing the magnetic recording medium is surely formed in a pointed shape that is gradually reduced in diameter toward the main magnetic pole side. Further, since the output of the luminous flux is reduced stepwise, it is possible to prevent the end portion of the metal film from coming into contact with the main pole beyond the conductive film.

The information recording / reproducing apparatus according to the present invention can move in the direction parallel to the surface of the near-field optical head and the magnetic recording medium, and is parallel to the surface of the magnetic recording medium and orthogonal to each other. A beam that supports the near-field light head on the distal end side in a state of being rotatable about an axis, a light source that makes a light beam incident on the proximal end portion of the core, and a proximal end side of the beam, An actuator for moving the beam in a direction parallel to the surface of the magnetic recording medium, a rotation driving unit for rotating the magnetic recording medium in the fixed direction, and a control unit for controlling the operation of the recording element and the light source It is characterized by having.
With such a feature, it is possible to heat a portion of the magnetic recording medium that is close to the location where magnetic recording is performed, so that information can be efficiently magnetically recorded on the magnetic recording medium.

  According to the method for manufacturing a near-field optical head, the near-field optical head, and the information recording / reproducing apparatus according to the present invention, the metal film can be easily formed on the facing surface facing the surface of the magnetic recording medium.

It is a block diagram of the information recording / reproducing apparatus in embodiment of this invention. It is sectional drawing of the recording / reproducing head in embodiment of this invention. FIG. 4 is an enlarged cross-sectional view of the side surface on the outflow end side of the recording / reproducing head. It is the top view to which the lower surface of the outflow end side of a recording / reproducing head was expanded. It is an expanded sectional view which expanded the lower part by the side of the outflow end of a recording / reproducing head. FIG. 5 is a diagram corresponding to FIG. 4 and a process diagram for explaining a method of manufacturing a recording / reproducing head. FIG. 5 is a diagram corresponding to FIG. 4 and a process diagram for explaining a method of manufacturing a recording / reproducing head. It is a perspective view of a recording / reproducing head for explaining a manufacturing method of the recording / reproducing head. It is a perspective view of the recording / reproducing head for demonstrating a modification. It is the top view to which the lower surface by the side of the outflow end of the recording / reproducing head for demonstrating a modification is expanded.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Information recording / playback device]
First, the information recording / reproducing apparatus 1 shown in FIG. 1 as an example of the information recording / reproducing apparatus according to the present invention will be described.
As shown in FIG. 1, the information recording / reproducing apparatus 1 performs recording / reproducing on / from a disk (magnetic recording medium) D by a hybrid magnetic recording system in which near-field light and a recording magnetic field cooperate. It is. As shown in FIG. 1, the information recording / reproducing apparatus 1 includes a recording / reproducing head (near-field optical head) 2, a beam 3 that supports the recording / reproducing head 2, and a laser beam (light beam) L ( (See FIG. 2). A light beam incident mechanism 4 for making the light incident, an actuator 5 for moving the beam 3, a spindle motor (rotation drive unit) 6 for rotating the disk D in a fixed direction, and the above-described components are comprehensively controlled. And a housing 9 that houses each component.

  The housing 9 is made of a metal material such as aluminum and has a quadrangular shape when viewed from above, and a recess 9a for accommodating each component is formed inside. Further, a lid (not shown) is detachably fixed to the housing 9 so as to close the opening of the recess 9a. A spindle motor 6 is attached to substantially the center of the recess 9a, and the disc D is detachably fixed by fitting a center hole into the spindle motor 6. In the present embodiment, the case where three disks D are fixed to the spindle motor 6 is described as an example. However, the number of disks D is not limited to three.

  An actuator 5 is attached to the corner of the recess 9a. A carriage 11 is attached to the actuator 5 via a bearing 10. The carriage 11 is formed by cutting, for example, a metal material, and a portion from the base end portion 11 a fixed to the actuator 5 via the bearing 10 toward the front end is disposed on the upper surface of the three disks D. Thus, it has a three-layer structure. That is, it is formed so as to be E-shaped when the carriage 11 is viewed from the side. The proximal end side of the beam 3 is fixed to each distal end of the carriage 11 divided into three layers. Therefore, the actuator 5 supports the base end side of the beam 3 via the carriage 11, and scans the beam 3 in the XY directions parallel to the disk surface (the surface of the magnetic recording medium) D1 (see FIG. 2). It can be moved.

  The beam 3 is movable in the XY direction together with the carriage 11 by the actuator 5 as described above, and is rotatable about two axes (X axis, Y axis) parallel to the disk surface D1 and orthogonal to each other. In this state, the recording / reproducing head 2 is supported on the tip side. The beam 3 and the carriage 11 are retracted from the disk D by driving the actuator 5 when the rotation of the disk D is stopped.

[Near-field optical head]
Next, the recording / reproducing head 2 shown in FIG. 2 as an example of the near-field optical head according to the present invention will be described.
As shown in FIGS. 2 and 3, the recording / reproducing head 2 is a head that records and reproduces various information on a rotating disk D using near-field light generated from laser light L. The recording / reproducing head 2 is opposed to the disk D in a state of floating by a predetermined distance H from the disk surface D1 and is movable along the disk surface D1, and a recording element 21 for recording information on the disk D. A reproducing element 22 that reproduces information recorded on the disk D, a near-field light generating element 26 that propagates while collecting the introduced laser light L, and generates the near-field light and then emits it to the outside. It is equipped with.

  The slider 20 is formed in a rectangular parallelepiped shape from a light transmissive material such as quartz glass, a ceramic such as AlTiC (altic), or the like. The slider 20 has a lower surface 20a on the disk D side parallel to the disk surface D1, and is supported so as to be suspended from the tip of the beam 3 via a gimbal portion 30 (see FIG. 2). The gimbal portion 30 is a component whose movement is restricted so as to be displaced only around the X axis and around the Y axis. As a result, the slider 20 is rotatable about two axes (X axis and Y axis) that are parallel to the disk surface D1 and orthogonal to each other as described above.

  Further, the lower surface 20a of the slider 20 is formed with a ridge portion 20b that generates a pressure for rising due to the viscosity of the air flow generated by the rotating disk D. The ridges 20b are formed so as to extend along the longitudinal direction (X direction), and two are formed on the left and right sides (Y direction) at intervals so as to be arranged in a rail shape. However, the ridge portion 20b is not limited to this case, and adjusts a positive pressure for separating the slider 20 from the disk surface D1 and a negative pressure for attracting the slider 20 to the disk surface D1, Any uneven shape may be used as long as the slider 20 is designed to float in an optimal state. In addition, the surface of this protruding item | line part 20b is called ABS (AIR BEARING SURFACE) 20c.

  The slider 20 receives a force that rises from the disk surface D1 by the two ridges 20b. On the other hand, the beam 3 is bent in the Z direction perpendicular to the disk surface D1, and absorbs the flying force of the slider 20. That is, the slider 20 receives a force pressed against the disk surface D1 side by the beam 3 when it floats. Therefore, the slider 20 floats in a state of being separated from the disk surface D1 by a predetermined distance H as described above due to the balance between the forces of the two. Moreover, since the slider 20 is rotated about the X axis and the Y axis by the gimbal portion 30, it always floats in a state where the posture is stable.

The air flow generated by the rotation of the disk D flows from the inflow end side (the X direction base end side of the beam 3) of the slider 20 and then flows along the ABS 20c, and flows out of the slider 20 (the beam 3). From the X direction tip side).
Hereinafter, the inflow end side (leading edge side) of the slider 20, that is, the right side in the X direction in FIG. 2 is referred to as “rear”, and the outflow end side (trailing edge side) of the slider 20, ie, the left side in the X direction in FIG. " Further, the disk surface D1 side with respect to the recording / reproducing head 2, that is, the lower side in the Z direction in FIG. 2, is referred to as “lower”, and the opposite side, that is, the upper side in the Z direction in FIG.

  The recording element 21 is an element for recording information by generating a recording magnetic field from the facing surface 21a facing the disk surface D1 shown in FIG. 2, and applying the recording magnetic field to the disk D. As shown in FIG. The slider 20 is held at the front end. The recording element 21 is connected to the auxiliary magnetic pole 31 via the auxiliary magnetic pole 31 fixed to the front end face (front end face) of the slider 20 and the front side of the auxiliary magnetic pole 31 via the magnetic circuit 32. The main magnetic pole 33 and a coil 34 that spirally winds around the magnetic circuit 32 around the magnetic circuit 32 are provided. That is, the auxiliary magnetic pole 31, the magnetic circuit 32 and the coil 34, and the main magnetic pole 33 are arranged in this order from the front end surface of the slider 20 toward the front side.

  Both the magnetic poles 31 and 33 and the magnetic circuit 32 are formed of a high saturation magnetic flux density (Bs) material (for example, a CoNiFe alloy, a CoFe alloy, etc.) having a high magnetic flux density. Further, the coil 34 is arranged so that there is a gap between adjacent coil wires, between the magnetic circuit 32 and between the magnetic poles 31 and 33 so as not to be short-circuited. Molded. The coil 34 is supplied with a current modulated according to information from the control unit 8 shown in FIG. That is, the magnetic circuit 32 and the coil 34 constitute an electromagnet as a whole. Further, the opposing surfaces 33a, 31a, and 35a (Z direction end surfaces) facing the disk surface D1 of the main magnetic pole 33, the auxiliary magnetic pole 31, and the insulator 35 are formed flush with the ABS 20c of the slider 20, respectively. . In the recording element 21 having the above-described configuration, when a current is supplied to the coil 34, a recording magnetic field is generated from the opposing surface 33a of the main magnetic pole 33 and entering the opposing surface 31a of the auxiliary magnetic pole 31a.

  The near-field light generating element 26 is an element that generates near-field light from the facing surface 26a facing the disk surface D1 shown in FIG. 2, and as shown in FIG. 3, the front side of the recording element 21 (shown in FIG. 3). The main magnetic pole 33 is disposed on the side opposite to the auxiliary magnetic pole 31 side. The near-field light generating element 26 is arranged in close contact with the core 23 extending vertically toward the disk surface D1 shown in FIG. 2 and the side surface (rear surface 23g) of the core 23 on the main magnetic pole 33 side. A plasmon-enhanced metal film 25 (metal film), a light-shielding film 27 that covers the lower end portion (tip portion) of the core 23, and a clad 24 that tightly contacts the side surface of the core 23 and seals the core 23. ing.

  The core 23 is a light flux propagating member that propagates the laser light L incident from the upper end side (base end side) while condensing the laser light L toward the lower end side (tip end side). The core 23 is gradually drawn from the upper end side to the lower end side so that the laser beam L can be propagated while being gradually condensed inside. More specifically, the core 23 has a reflective surface 23a, a light beam condensing unit 23b, and a near-field light generating unit 23c from the upper side, and is triangular when viewed from the propagation direction (Z direction) of the laser light L. Is formed.

  The reflecting surface 23a bends the laser light L introduced from an optical waveguide (light flux introducing means) 42, which will be described later. Specifically, the reflection is performed so that the laser light L is reflected so as to be bent approximately 90 degrees downward. Surface. The laser light L introduced from the optical waveguide 42 by the reflecting surface 23 a propagates toward the lower end side of the core 23 while repeating total reflection in the core 23. In addition, the bending angle by the reflective surface 23a can be changed as appropriate, and is appropriately set according to the incident direction of the laser light L.

  The light beam condensing unit 23b is a portion formed by drawing so that the cross-sectional area (the cross-sectional area in the XY direction) gradually decreases from the upper end side toward the lower end side, and is downward while condensing the introduced laser light L. To propagate. That is, the spot size of the laser beam L introduced into the light beam condensing unit 23b can be gradually reduced to a smaller size.

  The near-field light generating unit 23c is a portion that is further drawn from the lower end of the light beam condensing unit 23b downward. Specifically, it is drawn by an inclined surface 23h formed so as to face the reproducing element 22 while being inclined with respect to the optical axis (Z direction) of the laser beam L propagating inside. Due to the inclined surface 23h, the lower end portion of the core 23 is pointed.

  In the present embodiment, the light beam condensing unit 23b and the near-field light generating unit 23c are formed to have three side surfaces, and the rear side surface (rear surface 23g) is shown in FIGS. As shown, the recording element 21 (main magnetic pole 33) is formed in parallel with the front end face. In this case, as shown in FIG. 4, a pair of side surfaces 23d are formed from both ends (Y direction both ends) of the rear surface 23g toward the front side (reproducing element 22 side shown in FIG. 3). It is formed in a triangular shape that tapers toward the front side when viewed from the Z direction. Therefore, the lower end surface 23e exposed to the outside at the lower end of the near-field light generating unit 23c is formed in a triangular shape. Further, as shown in FIG. 5, the lower end surface 23e is a facing surface 21a of the recording element 21 (the facing surfaces 33a, 31a, 35a of the main magnetic pole 33, the auxiliary magnetic pole 31 and the insulator 35) or the slider shown in FIG. It is formed flush with 20 ABS 20c.

  The clad 24 is a mold member that seals the core 23, and is formed of a material having a refractive index lower than that of the core 23. As shown in FIGS. 3 to 5, the clad 24 embeds the core 23 in a state where the lower end surface 23 e and the rear surface 23 g of the core 23 are exposed. That is, the clad 24 is in close contact with the reflecting surface 23a and both side surfaces 23d of the core 23, the rear end surface of the clad 24 is formed flush with the rear surface 23g of the core 23, and the lower end surface 24a ( The end surface facing the disc surface D1 is formed flush with the lower end surface 23e of the core 23.

An example of a combination of materials used for the clad 24 and the core 23 is described, for example, a combination in which the core 23 is formed of quartz (SiO ₂ ) and the clad 24 is formed of quartz doped with fluorine. In this case, when the wavelength of the laser beam L is 400 nm, the refractive index of the core 23 is 1.47 and the refractive index of the clad 24 is less than 1.47, which is a preferable combination.
A combination in which the core 23 is formed of quartz doped with germanium and the clad 24 is formed of quartz (SiO ₂ ) is also conceivable. In this case, when the wavelength of the laser beam L is 400 nm, the refractive index of the core 23 becomes larger than 1.47 and the refractive index of the cladding 24 becomes 1.47, which is also a preferable combination.
In particular, as the difference in refractive index between the core 23 and the clad 24 increases, the force for confining the laser light L in the core 23 increases. Therefore, when the core 23 has tantalum oxide (Ta ₂ O ₅ : wavelength is 550 nm) 2.16) and quartz or alumina (Al ₂ O ₃ ) or the like is used for the clad 24 to increase the refractive index difference between the two. In addition, when using the laser light L in the infrared region, it is also effective to form the core 23 with silicon (Si: refractive index is about 4) which is a material transparent to infrared light.

  As shown in FIG. 3, the plasmon-enhanced metal film 25 generates near-field light from the laser light L propagating through the core 23, and the near-field light is generated on the opposing surface 26a of the near-field light generating element 26 and For example, it is made of gold (Au), platinum (Pt), or the like. The plasmon enhancing metal film 25 extends from a position flush with the facing surface 21a of the recording element 21 to a position flush with the upper end surface of the recording element 21 (end surface opposite to the facing surface 21a). It is formed over a range corresponding to the entire Z direction of the front end face of 21. That is, the upper end of the plasmon enhancing metal film 25 is formed below the upper end of the core 23, and the upper end portion of the rear surface 23 g of the core 23 is not covered with the plasmon enhancing metal film 25.

  As shown in FIG. 4, the plasmon enhancing metal film 25 is formed in an isosceles trapezoidal shape that tapers toward the front side (the reproducing element 22 side shown in FIG. 3) when viewed from the Z direction. At this time, the width in the Y direction of the front surface 25a of the plasmon enhancing metal film 25 in close contact with the rear surface 23g of the core 23 is formed to be the same width as the rear surface 23g of the core 23. Further, the side surface 25 b of the plasmon enhancing metal film 25 inclined with respect to the front surface 25 a is formed flush with the side surface 23 d of the core 23.

  As shown in FIGS. 4 and 5, the light shielding film 27 is a film body for blocking light incident on the near-field light generating unit 23 c from the outside, and is made of a highly reflective material such as aluminum (Al). Become. The light shielding film 27 is laminated on the surface of the separation film 28 which is in close contact with the side surface 23d of the near-field light generating portion 23c and the side surface 25b of the lower end portion of the plasmon enhancing metal film 25. The separation film 28 is a film body for separating the light shielding film 27 and the plasmon enhancement metal film 25, and covers the side surface 23d of the near-field light generation unit 23c and the side surface 25b of the lower end portion of the plasmon enhancement metal film 25, respectively. It is formed as follows. The light shielding film 27 and the separation film 28 described above are formed in a wider range than the near-field light generation unit 23c in the Z direction. More specifically, the upper portions of the light shielding film 27 and the separation film 28 cover the lower end portion of the light beam condensing portion 23 b, and the lower end surfaces 27 a and 28 a of the light shielding film 27 and the separation film 28 are respectively below the core 23. It is formed flush with the end face 23e.

  2 and 3, between the recording element 21 (main magnetic pole 33) and the near-field light generating element 26 (plasmon enhanced metal film 25), a magnetic shield 50 (intermediate layer) and A laminated structure 52 in which a current-carrying metal film 51 (electric current film) is laminated is interposed. The magnetic shield 50 is laminated on the rear surface of the plasmon enhancing metal film 25, and the energizing metal film 51 is laminated on the rear surface of the magnetic shield 50 and is interposed between the magnetic shield 50 and the main magnetic pole 33. Yes. That is, the current-carrying metal film 51 and the magnetic shield 50 are laminated in this order from the main magnetic pole 33 side (rear side) toward the plasmon enhancing metal film 25 side (front side).

  The magnetic shield 50 is a shield material that blocks the magnetism between the plasmon enhancing metal film 25 and the main magnetic pole 33, and is interposed between the plasmon enhancing metal film 25 and the main magnetic pole 33. The magnetic shield 50 has an upper end surface of the plasmon enhancing metal film 25 and an upper end surface of the recording element 21 (on the opposite side of the opposing surface 21a) from a position flush with the lower end surface 23e of the core 23 and the opposing surface 21a of the recording element 21. It extends to a position flush with the (end face), and is formed over the entire Z direction of the front end face of the recording element 21 (the rear face of the magnetic shield 50). That is, as shown in FIGS. 4 and 5, the magnetic shield 50 has a facing surface 50a that is exposed toward the disk surface D1 and is disposed to face the disk surface D1 shown in FIG. The facing surface 50 a is formed flush with the facing surfaces 26 a and 21 a of the near-field light generating element 26 and the recording element 21. As shown in FIG. 3, the upper end surface of the magnetic shield 50 is formed flush with the upper end surface of the plasmon enhancing metal film 25.

  The magnetic shield 50 is formed of a material having high wettability with respect to a metal fluid (a fluid in which the plasmon enhancing metal film 25 is dissolved), and is made of, for example, permalloy (Fe—Ni alloy) or a soft magnetic ferrite material. . Thereby, the facing surface 50 a of the magnetic shield 50 shown in FIG. 5 has higher wettability (hydrophilicity) than the lower end surface 23 e of the core 23. In other words, the lower end surface 23 e of the core 23 has higher water repellency than the facing surface 50 a of the magnetic shield 50.

  The current-carrying metal film 51 is a current-carrying current film, and is made of, for example, chromium (Cr). The current-carrying metal film 51 is interposed between the magnetic shield 50 and the main magnetic pole 33 as shown in FIG. The energizing metal film 51 extends from a position flush with the opposing surface 21 a of the recording element 21 to a position flush with the upper end face of the recording element 21, and the front end face (magnetic shield 50) of the recording element 21. The rear surface is formed over the entire Z direction. That is, as shown in FIG. 5, the current-carrying metal film 51 has a facing surface 51a that is exposed toward the disk surface D1 and is disposed to face the disk surface D1 shown in FIG. The facing surface 51 a is formed flush with the facing surfaces 26 a and 21 a of the near-field light generating element 26 and the recording element 21 and the facing surface 50 a of the magnetic shield 50. As shown in FIG. 3, the upper end surface of the energizing metal film 51 is formed flush with the upper end surface of the magnetic shield 50 and the upper end surface of the recording element 21.

  Incidentally, as shown in FIG. 5, an elution portion 25 a eluted on the opposing surface 50 a of the magnetic shield 50 is formed at the lower end of the plasmon enhancing metal film 25 described above. The elution portion 25 a is a portion formed by melting the plasmon enhancing metal film 25 and dissolving it on the opposing surface 50 a of the magnetic shield 50. More specifically, strong near-field light is generated at the lower end portion of the plasmon enhancing metal film 25 by making high-power laser light enter the upper end of the core 23, and the lower end portion of the plasmon enhancing metal film 25 is caused by this near-field light. By being heated and melted, the metal fluid melts along the facing surface 50a of the magnetic shield 50, and the elution portion 25a is formed. The elution portion 25a protrudes rearward from the rear surface of the plasmon enhancing metal film 25 and is formed in a shape gradually reduced in diameter toward the rear side in plan view as shown in FIG. . The protruding end (rear end) of the elution portion 25a extends to the opposing surface 51a of the energizing metal film 51, and the elution portion 25a and the opposing surface 51a of the energizing metal film 51 are electrically connected. Has been.

  An optical waveguide 42 is fixed on the upper surface of the slider 20. The optical waveguide 42 includes a core 42a extending from the rear end side to the front end side of the slide 20 and a clad 42b formed so as to cover the core 42a, and the laser light L propagates in the core 42a. It is supposed to be. The front end (tip) of the optical waveguide 42 is connected to the upper end portion of the rear surface 23g of the core 23 of the near-field light generating element 26, and emits the laser light L toward the reflection surface 23a. The core 42 a and the clad 42 b of the optical waveguide 42 are made of the same material as the core 23 and the clad 24 of the near-field light generating element 26.

  On the other hand, the rear end side (base end side) of the optical waveguide 42 is drawn out along the beam 3 and the carriage 11 and then connected to a laser light source (light source) 43 as shown in FIG. The laser light source 43 is mounted on a control board 44 attached to the side surface of the base end portion 11a of the carriage 11 together with various electronic components such as an IC chip (not shown). In particular, the laser light source 43 emits the laser light L in a linearly polarized state. That is, the laser light source 43 and the optical waveguide 42 function as a light beam incident mechanism 4 that causes the laser light L to enter the recording / reproducing head 2 in a linearly polarized state.

  The control board 44 on which the laser light source 43 is mounted is connected to the control unit 8 by a flexible flat cable (flexible board) 45. Thus, the control unit 8 performs an overall control by sending an electrical signal to each component. In particular, the timing at which the laser light source 43 emits the laser light L is controlled by the control unit 8.

  As shown in FIG. 2, the reproducing element 22 is a magnetoresistive film whose electric resistance is converted according to the magnitude of the magnetic field leaking from the perpendicular recording layer d2 of the disk D, and the near-field light generating element 26 ( It is held on the front end face of the cladding 24). A bias current is supplied to the reproducing element 22 from the control unit 8 shown in FIG. 1 via a lead film (not shown). Thus, the control unit 8 can detect a change in the magnetic field leaking from the disk D as a change in voltage, and can reproduce a signal from the change in voltage.

As shown in FIG. 2, the disk D of this embodiment has at least two of a perpendicular recording layer d2 having an easy axis of magnetization in a direction perpendicular to the disk surface D1, and a soft magnetic layer d3 made of a high magnetic permeability material. A vertical two-layer film disc D composed of layers is used. As such a disk D, for example, a disk in which a soft magnetic layer d3, an intermediate layer d4, a perpendicular recording layer d2, a protective layer d5, and a lubricating layer d6 are sequentially formed on a substrate d1 is used. .
Examples of the substrate d1 include an aluminum substrate and a glass substrate. The soft magnetic layer d3 is a high magnetic permeability layer. The intermediate layer d4 is a crystal control layer of the perpendicular recording layer d2. The perpendicular recording layer d2 is a perpendicular anisotropic magnetic layer, and for example, a CoCrPt alloy is used. The protective layer d5 is for protecting the perpendicular recording layer d2, and for example, a DLC (Diamond Like Carbon) film is used. For the lubrication layer d6, for example, a fluorine-based liquid lubricant is used.

[Information recording / playback method]
Next, a case where various kinds of information are recorded on and reproduced from the disk D by the information recording / reproducing apparatus 1 described above will be described below.
First, as shown in FIG. 1, the spindle motor 6 is driven to rotate the disk D in a certain direction. Next, the actuator 5 is actuated to scan the beam 3 in the XY directions via the carriage 11. Thereby, the recording / reproducing head 2 can be positioned at a desired position on the disk D. At this time, the recording / reproducing head 2 receives a force that rises by the two ridges 20b formed on the opposing surface 20a of the slider 20, and is pressed against the disk D by a predetermined force by the beam 3 or the like. The recording / reproducing head 2 floats to a position separated from the disk D by a predetermined distance H as shown in FIG.

  Further, even if the recording / reproducing head 2 receives wind pressure generated due to the undulation of the disk D, the displacement in the Z direction is absorbed by the beam 3 and can be displaced around the XY axis by the gimbal portion 30. Since it has become possible, it can absorb the wind pressure caused by the swell. Therefore, the recording / reproducing head 2 can be floated in a stable state.

Next, when recording information, the control unit 8 shown in FIG. 1 activates the laser light source 43 to emit linearly polarized laser light L (shown in FIG. 3) and generates a current modulated according to the information. The recording element 21 is operated by supplying the coil 34.
First, the laser light L is incident on the optical waveguide 42 from the laser light source 43 to guide the laser light L to the slider 20 side. As shown in FIG. 3, the laser light L emitted from the laser light source 43 travels in the core 42 a of the optical waveguide 42 toward the tip (outflow end) side and propagates into the core 23 of the near-field light generating element 26. To do. The laser beam L that has propagated into the core 23 is reflected by approximately 90 degrees on the reflecting surface 23a, and then propagates in the light beam condensing part 23b. The laser light L propagating through the light beam condensing unit 23b propagates downward while repeating total reflection between the core 23 and the clad 24. Particularly, since the clad 24 is in close contact with the side surface 23d of the core 23 shown in FIG. 4 and the plasmon enhancing metal film 25 is in close contact with the rear surface 23g of the core 23, light does not leak outside the core 23. Therefore, the introduced laser beam L can be propagated to the other end side without being wasted and made incident on the near-field light generating unit 23c.
At this time, the core 23 is drawn so that the cross-sectional area gradually decreases downward. Therefore, the laser beam L is gradually narrowed as it propagates in the light beam condensing part 23b, and the spot size is reduced.

  Subsequently, the laser beam L having a reduced spot size is incident on the near-field light generator 23c. The near-field light generating unit 23c is further drawn downward and has a lower end surface 23e having a size equal to or smaller than the wavelength of light. In this case, the two side surfaces 23d (shown in FIG. 4) of the near-field light generating unit 23c are shielded by the light shielding film 27. Therefore, the laser light L incident on the near-field light generation unit 23 c does not leak to the clad 24 side and propagates while being reflected at the interface between the light shielding film 27 and the separation film 28. When the laser light L propagating through the near-field light generating unit 23 c is incident on the plasmon enhanced metal film 25, surface plasmons are excited in the plasmon enhanced metal film 25. The excited surface plasmon propagates toward the lower end side of the core 23 along the interface between the plasmon enhancing metal film 25 and the core 23 (near-field light generating part 23c) while being enhanced by the resonance effect. And it leaks outside from the lower end part of the plasmon enhancement metal film 25 as near-field light with a strong light intensity. That is, the near-field light can be localized between the facing surface 26a of the near-field light generating element 26 and the disk surface D1. Then, the disk D is locally heated by the near-field light, and the coercive force is temporarily reduced. Further, in the recording / reproducing head 2 described above, strong near-field light is generated and heated at the protruding end (rear end) of the elution portion 25a of the plasmon enhancing metal film 25, so that it is close to the main magnetic pole 33 of the disk D. The coercive force of the part temporarily decreases.

  On the other hand, when a current is supplied to the coil 34 by the control unit 8 shown in FIG. 1, a current magnetic field is generated in the magnetic circuit 32 by the principle of an electromagnet, so that a disk is interposed between the main magnetic pole 33 and the auxiliary magnetic pole 31. A recording magnetic field perpendicular to D can be generated. Then, the magnetic flux generated from the main magnetic pole 33 side passes straight through the perpendicular recording layer d2 of the disk D and reaches the soft magnetic layer d3. As a result, recording can be performed in a state where the magnetization of the perpendicular recording layer d2 is directed perpendicular to the disk surface D1. The magnetic flux reaching the soft magnetic layer d3 returns to the auxiliary magnetic pole 31 via the soft magnetic layer d3. At this time, when returning to the auxiliary magnetic pole 31, the direction of magnetization is not affected. This is because the area of the auxiliary magnetic pole 31 facing the disk surface D1 is larger than that of the main magnetic pole 33, so that the magnetic flux density is large and a force sufficient to reverse the magnetization does not occur. That is, recording can be performed only on the main magnetic pole 33 side.

  As a result, information can be recorded by a hybrid magnetic recording method in which near-field light and the recording magnetic field generated by both magnetic poles 31 and 33 cooperate. In addition, since the recording is performed by the vertical recording method, it is difficult to be affected by the thermal fluctuation phenomenon and the like, and stable recording can be performed. Therefore, writing reliability can be improved. In particular, in the recording / reproducing head 2 described above, near-field light is generated in a portion of the disk D close to the main magnetic pole 33, so that the coercive force of the portion to be recorded by the recording magnetic field can be greatly reduced, and particularly stable. Recording can be performed.

  Further, when reproducing information recorded on the disk D, the reproducing element 22 receives a magnetic field leaking from the perpendicular recording layer d2 of the disk D when the coercive force of the disk D is temporarily reduced. Thus, the electrical resistance changes according to the size. Therefore, the voltage of the reproducing element 22 changes. Thereby, the control unit 8 can detect a change in the magnetic field leaking from the disk D as a change in voltage. The control unit 8 can reproduce information recorded on the disk D by reproducing a signal from the change in voltage.

[Method of manufacturing recording / reproducing head]
Next, a method for manufacturing the recording / reproducing head 2 described above will be described. 6 and 7 are partial cross-sectional views corresponding to FIG. 4, and are process diagrams for explaining a method of manufacturing the recording / reproducing head 2.
In the present embodiment, the recording element 21, the near-field light generating element 26, and the reproducing element 22 are sequentially formed on a substrate 120 (for example, AlTiC (altic), etc.) to be the slider 20, and then dicing is performed to perform recording and reproduction. The head 2 is manufactured. 6 and 7, the description of the auxiliary magnetic pole 31, the magnetic circuit 32, and the coil 34 in the recording element 21 formed on the substrate 120 is omitted for easy understanding.

  First, after forming the recording element 21 on the substrate 120, a near-field light generating element forming step for forming the near-field light generating element 26 on the recording element 21 is performed. At this time, the laminated structure 52 including the magnetic shield 50 and the energizing metal film 51 is interposed between the plasmon enhancing metal film 25 and the main magnetic pole 33.

  More specifically, first, as shown in FIG. 6A, a current-carrying metal film 51, a magnetic shield 50, a plasmon enhancing metal film 25, and a plasmon-enhancing metal film 25 shown in FIG. 4 are formed on the recording element 21 formed on the substrate 120. The base materials of the core 23 are sequentially stacked (base material film forming step). That is, first, the base material of the current-carrying metal film 51 (the current-carrying metal film base material 151) is formed on the recording element 21 formed on the substrate 120. Subsequently, the base material of the magnetic shield 50 (magnetic shield base material 150) is formed on the energizing metal film base material 151. Next, a base material of the plasmon enhanced metal film 25 (plasmon enhanced metal film base material 125) is formed on the magnetic shield base material 150. Thereafter, the base material of the core 23 (core base material 123) is formed on the plasmon enhancing metal film base material 125. Note that after the above-described base materials 151, 150, 125, and 123 are formed, the respective surfaces are polished by CMP (Chemical Mechanical Polishing) or the like to obtain flat surfaces.

  Next, as shown in FIG. 6B, a mask pattern (not shown) in which a region where the core base material 123 is to be removed is formed on the core base material 123 using a photolithography technique is formed. Reactive ion etching (RIE) is performed through (Vertical etching process). Thereby, the core base material 123 in the region where the mask pattern is opened is etched, and a rectangular core base material 123a is formed as viewed from the Z direction. Further, the core base material 123a is formed in a trapezoidal shape that tapers from one end side to the other end side in a plan view (A arrow shown in FIG. 6). In the vertical etching process, it is preferable that the core base material 123a in the region where the mask pattern is opened is slightly left without being completely removed to form the remaining portion 123b.

  Next, as shown in FIG. 6C, the core base material 123a and the metal film base material 151 are sputter-etched in a plasma such as argon (Ar) (gradient etching step). In the inclined etching process, when the core base material 123a having a rectangular cross section is sputter-etched, the corners of the core base material 123a are selectively etched to form a slope. If the etching is further continued in this state, the slope is etched while maintaining a certain angle with respect to the bottom surface (corresponding to the rear surface 23g shown in FIG. 4), so that the core base material shown in FIG. 6B is obtained. 123a is formed in a triangular cross section. Thereafter, when the etching is further continued, the core base material 123a shown in FIG. 6B is reduced in width (dimension in the horizontal direction in FIG. 6) and height (dimension in the vertical direction in FIG. 6) while maintaining a similar shape. At the same time, the remaining portion 123b shown in FIG. 6B is removed. As a result, a triangular core 23 having two side surfaces 23d and a rear surface 23g is formed. Thus, by performing sputter etching on the core base material 123a formed in a rectangular shape in the vertical etching step, the core 23 can be formed in an arbitrary width and height.

  Next, as shown in FIG. 7A, when the etching is further continued, the core 23 is etched while maintaining the similar shape, and the plasmon enhancing metal film base material 125 is etched. In this case, both end portions in the width direction of the plasmon enhancing metal film base material 125 (corresponding to the side surface 25b in FIG. 4) are etched at the same angle as the angle formed between the side surface 23d of the core 23 and the rear surface 23g. Thus, the plasmon enhancing metal film 25 ′ is formed. The plasmon enhancing metal film 25 ′ is a metal film in which the above-described extraction portion 25 a is not formed, and the lower end surface of the plasmon enhancing metal film 25 ′ is the opposite surface of the lower end surface 23 e of the core 23 and the magnetic shield 50. It is formed flush with 50a.

  In order to completely remove the plasmon enhancing metal film base material 125 in the region other than the core 23, the magnetic shield base material 150 is also slightly etched. As a result, the magnetic shield 50 is formed. In this case, by forming the remaining portion 123b of the core base material 123 in the vertical etching process described above, it is possible to prevent the magnetic shield base material 150 from being over-etched in the tilt etching process.

Next, as shown in FIG. 7A, a separation film 28 is formed so as to cover the core 23 and the plasmon enhancing metal film 25 (a separation film forming step). Specifically, the separation film 28 is patterned in a region corresponding to the near-field light generation unit 23 c on the side surface 23 d of the core 23.
Next, as shown in FIG. 7B, a light shielding film 27 is formed so as to cover the separation film 28 (light shielding film forming step). Specifically, the light shielding film 27 is patterned on the upper surface of the separation film 28.

Next, as shown in FIG. 7C, the clad 24 is formed so as to cover the core 23 and the light shielding film 27 (clad forming step). Thereafter, the surface of the clad 24 is polished by CMP or the like to form a flat surface.
Next, the reproducing element 22 shown in FIG. 3 is formed on the clad 24. Thus, the recording element 21, the near-field light generating element 26, and the reproducing element 22 are formed on the substrate 120 in a stacked state.

  Next, as shown in FIG. 8, high-power laser light L ′ is incident from the upper end side of the core 23 to generate strong near-field light at the lower end portion of the plasmon enhancing metal film 25, and the plasmon is generated by the near-field light. A metal film melting step is performed in which the lower end portion of the enhancement metal film 25 is melted to melt the plasmon enhancement metal film 25 on the facing surface 50a of the magnetic shield 50, and the elution portion 25a is formed on the facing surface 50a of the magnetic shield 50. .

  Specifically, first, a laser light source 143 that irradiates a high-power laser beam L ′ is installed on the slider 20, and a control unit 108 that controls the laser light source 143 is installed on the front end surface of the reproducing element 22. The laser light source 143 is a light source that emits high-power laser light L ′ toward the reflecting surface 23 a of the core 23. The control unit 108 detects that the current-carrying metal film 51 and the plasmon enhancing metal film 25 ′ are electrically connected to each other so that a later-described extraction unit 25 a comes into contact with the opposing surface 51 a of the current-carrying metal film 51. It is a control means which detects this and controls the laser light source 143 based on the detection information. The control unit 108 is electrically connected to the upper end portion of the plasmon enhancing metal film 25 ′ and the upper end portion of the energizing metal film 51 via the electric wiring 101, thereby forming the electric circuit 100. .

  Next, the power source of the laser light source 143 is turned on to irradiate high-power laser light L ′. The high-power laser light L ′ enters the core 23 from the rear surface 23g of the upper end portion of the core 23, is reflected by the reflecting surface 23a by approximately 90 degrees, and then propagates through the light beam condensing unit 23b. The high-power laser beam L ′ propagating through the light beam condensing unit 23b propagates downward while repeating total reflection between the core 23 and the clad 24, and is gradually narrowed down to reduce the spot size. , And enters the near-field light generating unit 23c. When the high-power laser beam L ′ incident on the near-field light generating unit 23c is incident on the plasmon enhanced metal film 25 ′, surface plasmon is excited in the plasmon enhanced metal film 25 ′, and the lower end of the plasmon enhanced metal film 25 ′. Strong near-field light is generated from the part. At this time, the near-field light dissolves the lower end portion of the plasmon enhancing metal film 25 ′ to become a metal fluid and form the elution portion 25 a. At this time, since the facing surface 50 a of the magnetic shield 50 has higher wettability than the tip surface 23 e of the core 23, the above-described metal fluid flows to the facing surface 50 a side of the magnetic shield 50. Moreover, since the center part of the width direction (Y direction in FIG. 4) in the lower end part of the plasmon enhancement metal film 25 ′ has the highest temperature, the center part in the width direction of the lower end part of the plasmon enhancement metal film 25 ′. The metal fluid flows out from.

  When the metal fluid (eluting portion 25a) flows to the facing surface 51a of the energizing metal film 51, the plasmon enhancing metal film 25 and the energizing metal film 51 are electrically connected via the elution portion 25a. The As a result, the electric circuit 100 becomes a closed circuit, and a current flows. When the control unit 108 detects that a current flows in the electric circuit 100, the laser light source 143 electrically connected to the control unit 108 is turned off. As a result, the above-mentioned near-field light disappears, the distraction of the elution portion 25a of the plasmon enhancement metal film 25 stops, and the elution portion 25a of the plasmon enhancement metal film 25 having a desired size is formed on the opposing surface 50a of the magnetic shield 50. It is formed.

Next, the substrate 120 is diced to form a bar (not shown) in which a plurality of sliders 20 are connected in one direction (Y direction). Thereafter, the side surface (cut surface) of the diced bar is polished (polishing step). In this polishing process, the side of the bar is positioned using ELG (electro wrapping guide). ELG is for controlling the amount of polishing by polishing while checking the resistance value of the ELG element. In this embodiment, for example, an ELG element and a pair of pads connected to both ends of the ELG element are formed in the ELG area of a bar (dicing allowance in a slider process described later), and the ELG element is energized through the pad. While polishing. Then, the ELG element is polished together with the side surface of the bar, the width of the ELG element in the Z direction is reduced, and the electric resistance is increased. Therefore, a correlation between the electrical resistance of the ELG element and the polishing amount is obtained in advance, and polishing is performed while monitoring the resistance value of the ELG element. When the resistance value reaches a predetermined value, a desired polishing amount is obtained. It is determined that polishing has been completed. Note that ELG elements and pads have a basic function of detecting a change in electrical resistance during polishing, and thus do not need to have an extremely fine structure.
Thereafter, the bar is cut so as to have a size for each slider 20 (slider forming step).
Thus, the recording / reproducing head 2 is completed.

  According to the recording / reproducing head 2 and the manufacturing method thereof described above, the end portion (eluting portion 25a) of the plasmon enhancing metal film 25 can be easily formed on the facing surface 50a facing the disk surface D1.

  Further, according to the recording / reproducing head 2 and the manufacturing method thereof, since the energizing metal film 51 is interposed between the main magnetic pole 33 of the magnetic shield 50, the high-power laser beam L ′ is applied to the core 23. When the elution portion 25a is formed by dissolving the lower end portion of the plasmon enhancing metal film 25 by strong near-field light and the elution portion 25a can be reliably extended to the position of the energizing metal film 51. Thereby, the variation in the shape of the elution portion 25a of the plasmon enhancing metal film 25 can be suppressed, and the recording / reproducing head 2 with stable quality can be mass-produced.

  In particular, according to the recording / reproducing head 2 and the manufacturing method thereof, the upper ends of the plasmon enhancing metal film 25 and the energizing metal film 51 are extended to the position of the upper end surface of the recording element 21. An electric circuit 100 is formed in which the upper ends of the metal film 25 and the current-carrying metal film 51 are electrically connected to each other. When it is detected that a current flows through the electric circuit 100, the laser light source 143 is turned off. Therefore, it can be easily detected that the elution portion 25a is extended to the energizing metal film 51.

  Further, according to the recording / reproducing head 2 and the manufacturing method thereof described above, the facing surface 50a of the magnetic shield 50 has higher wettability to the metal fluid than the lower end surface 23e of the core 23. As described above, when the lower end portion of the plasmon enhancing metal film 25 ′ is dissolved by the near-field light, the metal fluid in which the lower end portion of the plasmon enhancing metal film 25 ′ is melted is the lower end surface 23 e of the core 23 having high water repellency. It tends to flow to the opposite surface 50 a side of the magnetic shield 50 having high wettability. For this reason, the elution part 25a of the plasmon enhancing metal film 25 can be easily and reliably formed in a shape extending toward the main magnetic pole 33 side.

  Further, according to the information recording / reproducing apparatus 1 described above, since the portion of the disk D close to the magnetic recording location can be heated, it is possible to increase the density of information recording / reproduction and It is possible to improve the reliability of recording / reproducing information with less difficulty in recording / reproducing.

  Next, a modified example of the embodiment of the near-field optical head according to the present invention and the manufacturing method thereof will be described.

[Modification 1]
In the recording / reproducing head 202 according to the first modification shown in FIG. 9, a U-shaped energization metal film 251 is interposed between the magnetic shield 50 and the main magnetic pole 33. The energizing metal film 251 includes a resistor 251a exposed on the disk D1 side and a pair of connecting portions 251b and 251b extending from both ends of the resistor 251a to a position flush with the upper end surface of the recording element 21. And. The resistance portion 251 a is a band-shaped metal film extending along the facing surface 50 a of the magnetic shield 50, and the lower end surface of the resistance portion 251 a is formed flush with the facing surface 50 a of the magnetic shield 50. The pair of connection portions 251b and 251b are band-like metal films wider than the resistance portion 251a, and extend substantially perpendicular to the resistance portion 251a. In this case, the plasmon enhancing metal film 225 does not need to be extended to the upper end surface of the recording element 21, and may be formed only on the lower end portion of the core 23.

  In the manufacturing method of the recording / reproducing head 202 described above, the upper ends of the pair of connection portions 251b and 251b are connected to the electric wiring during the metal film dissolution step of dissolving the plasmon enhancing metal film 25 to form the elution portion 25a. It is electrically connected to the control unit 208 via 201. Thereby, the upper ends of the pair of connection portions 251b and 251b are electrically connected to each other via the control unit 208, and the closed electric circuit 200 is formed. And the electrical resistance value of this electric circuit 200 is detected by the control part 208, and it detects that the elution part 25a extended | stretched to the resistance part 251a based on the detected value. That is, the electric resistance value of the electric circuit 200 is substantially constant when the elution portion 25a is not in contact with the resistance portion 251a, but when the elution portion 25a is in contact with the resistance portion 251a, the electric resistance value of the electric circuit 200 changes. To do. Based on the change in the electrical resistance value, it can be detected that the elution portion 25a has come into contact with the resistance portion 251a.

[Modification 2]
In the recording / reproducing head 302 according to the first modification shown in FIG. 9, a plurality of current-carrying metal films 51A to 51B are laminated between the magnetic shield 50 and the main magnetic pole 33 via insulating layers 53A and 51B. An elution portion 325 a that is gradually reduced toward the main magnetic pole 33 is formed at the lower end of the plasmon enhancing metal film 25. Eluate 325a includes, in order from the core 23 side, the first elution portion 325a ₁ formed on the opposing surface 50a of the magnetic shield 50, the second eluate portion 325a formed on the opposite surface 53a of the core 23 side of the insulating layer 53A ₂ and a third elution portion 325a ₃ formed on the opposing surface 53b of the insulating layer 53B on the main magnetic pole 33 side.

  As a manufacturing method of the recording / reproducing head 302 described above, the elution portion 325a with respect to the plurality of energizing metal films 51 is formed in the metal film dissolution step of dissolving the lower end portion of the plasmon enhancing metal film 25 to form the elution portion 325a. Each contact is detected, and the output of the laser beam incident on the core 23 is reduced stepwise based on the detection information. That is, when it is detected that the elution portion 325a has been extended to the first energization metal film 51A on the core 23 side, the output of the laser beam is lowered by one step. Thereafter, when it is detected that the elution portion 325a has been extended to the middle second energizing metal film 51B, the output of the laser beam is further lowered by one step. Thereafter, when it is detected that the elution portion 325a has been extended to the third energization metal film 51C on the main magnetic pole 33 side, the irradiation of the laser beam is stopped.

As a result, first to third eluting portions 325a _{1 to} 325a _{3 that} are stepwise reduced in width are formed at the lower end portion of the plasmon enhancing metal film 25, so that the shape of the eluting portion 325a is directed toward the main magnetic pole 33 side. Thus, it is surely formed into a pointed shape gradually reduced in diameter. Thereby, near-field light can be reliably generated at the protruding end of the elution part 325a. Further, since the output of the laser beam is decreased stepwise, it is possible to prevent the elution portion 325a of the plasmon enhancing metal film 25 from coming into contact with the main magnetic pole 33 beyond the third energizing metal film 51C.

As mentioned above, although the manufacturing method of the near-field optical head concerning this invention, the near-field optical head, and embodiment of the information recording / reproducing apparatus were demonstrated, this invention is not limited to above-described embodiment, The Changes can be made as appropriate without departing from the spirit of the invention.
For example, in the above-described embodiment, the core 23 is formed in a triangular shape in cross-sectional view, but a core having a rectangular shape in cross-sectional view or other cross-sectional shapes can also be used.

  In addition, in the range which does not deviate from the main point of this invention, it is possible to replace suitably the component in above-mentioned embodiment with a well-known component, and you may combine the above-mentioned modification suitably.

DESCRIPTION OF SYMBOLS 1 ... Information recording / reproducing apparatus 2,201,301 ... Recording / reproducing head (near-field optical head) 3 ... Beam 5 ... Actuator 6 ... Spindle motor (rotation drive part) 8 ... Control part 20 ... Slider 21 ... Recording element 23 ... Core DESCRIPTION OF SYMBOLS 24 ... Cladding 25,225 ... Plasmon enhancement metal film (metal film) 25a, 325a ... Elution part (edge part of metal film) 26 ... Near field light generating element 31 ... Auxiliary magnetic pole 33 ... Main magnetic pole 42 ... Optical waveguide (light beam introduction) Means) 43 ... Laser light source (light source) 50 ... Magnetic shield (intermediate layer) 51 251 ... Metal film 51 for energization (energization film) 100, 200 ... Electric circuit 251a ... Resistance part 251b ... Connection part D ... Disk (magnetic recording) Medium)

Claims (13)

A slider movable along the surface of the magnetic recording medium rotating in a certain direction;
A recording element that is held by the slider, has a main magnetic pole and an auxiliary magnetic pole, and generates a recording magnetic field from a facing surface facing the surface of the magnetic recording medium;
A near-field light generating element that is arranged on the opposite side of the auxiliary magnetic pole side with respect to the main magnetic pole and generates near-field light from a facing surface facing the surface of the magnetic recording medium;
With
Heating the magnetic recording medium by near-field light generated from the opposing surface of the near-field light generating element, and causing magnetization reversal in the magnetic recording medium by a recording magnetic field generated from the opposing surface of the recording element, A method of manufacturing a near-field optical head for recording information on the magnetic recording medium, comprising:
In the near-field light generating element,
A core that is disposed with the distal end directed toward the surface of the magnetic recording medium, and that propagates while collecting the light beam incident from the proximal end side toward the distal end side;
A metal film that is disposed in close contact with a side surface on the main magnetic pole side of at least a tip portion of the core, and generates near-field light from a light beam condensed on the tip side of the core;
Is provided,
The near field is interposed between the metal film and the main magnetic pole with an intermediate layer having an opposing surface exposed to the surface side of the magnetic recording medium and facing the surface of the magnetic recording medium. A near-field light generating element forming step for forming the light generating element;
A light beam is incident from the base end side of the core to generate near-field light, the metal film is melted by the near-field light, and the metal film is melted on the opposite surface of the intermediate layer. And a metal film melting step of forming an end portion of the metal film on the opposite surface of the substrate. In the manufacturing method of the near-field optical head according to claim 1,
Between the intermediate layer and the main magnetic pole, an energization film exposed on the surface side of the magnetic recording medium is interposed,
A near-field optical head characterized in that, during the metal film melting step, contact of the end of the metal film with the energization film is detected, and a light beam incident on the core is controlled based on the detection information. Production method. In the manufacturing method of the near-field optical head according to claim 2,
The opposite end of the metal film on the magnetic recording medium side and the opposite end of the energization film on the magnetic recording medium side are flush with the opposite end face of the recording element. Extended,
During the metal film melting step, an electric circuit is formed to electrically connect the end of the metal film opposite to the magnetic recording medium side and the end of the conductive film opposite to the magnetic recording medium side. A method of manufacturing a near-field optical head. In the manufacturing method of the near-field optical head according to claim 2,
The energization film has a resistor portion exposed on the surface side of the magnetic recording medium, and a pair of extended portions extending from both ends of the resistor portion to a position flush with an end surface opposite to the opposing surface of the recording element. A connecting portion, and
Forming an electric circuit for electrically connecting the opposite ends of the pair of connecting portions on the magnetic recording medium side during the metal film melting step, and detecting an electric resistance value of the electric circuit; A method of manufacturing a near-field optical head, which is characterized. In the manufacturing method of the near-field optical head according to any one of claims 1 to 4,
A method of manufacturing a near-field optical head, wherein the facing surface of the intermediate layer has higher wettability than the end surface of the core. In the manufacturing method of the near-field optical head according to any one of claims 1 to 5,
A plurality of the current-carrying films are stacked between the intermediate layer and the main magnetic pole via an insulating layer,
In the metal film melting step, the contact of the end portions of the metal film with respect to the plurality of conductive films is detected, respectively, and the output of the light beam incident on the core is reduced stepwise based on the detection information. A method of manufacturing a near-field optical head, which is characterized. A slider movable along the surface of the magnetic recording medium rotating in a certain direction;
A recording element that is held by the slider, has a main magnetic pole and an auxiliary magnetic pole, and generates a recording magnetic field from a facing surface facing the surface of the magnetic recording medium;
A near-field light generating element that is arranged on the opposite side of the auxiliary magnetic pole side with respect to the main magnetic pole and generates near-field light from a facing surface facing the surface of the magnetic recording medium;
With
Heating the magnetic recording medium by near-field light generated from the opposing surface of the near-field light generating element, and causing magnetization reversal in the magnetic recording medium by a recording magnetic field generated from the opposing surface of the recording element, A near-field optical head for recording information on the magnetic recording medium,
In the near-field light generating element,
A core that is disposed with the distal end directed toward the surface of the magnetic recording medium, and that propagates while collecting the light beam incident from the proximal end side toward the distal end side;
A metal film that is disposed in close contact with a side surface on the main magnetic pole side of at least a tip portion of the core, and generates near-field light from a light beam condensed on the tip side of the core;
Is provided,
Between the metal film and the main magnetic pole, an intermediate layer having an opposing surface that is exposed toward the surface side of the magnetic recording medium and faces the surface of the magnetic recording medium is interposed.
The near field is characterized in that the metal film is melted by the near-field light and melted on the facing surface of the intermediate layer, so that an end portion of the metal film is formed on the facing surface of the intermediate layer. Light head. The near-field optical head according to claim 7,
A near-field optical head characterized in that a conductive film exposed on the surface side of the magnetic recording medium is interposed between the intermediate layer and the main magnetic pole. The near-field optical head according to claim 8,
The opposite end of the metal film on the magnetic recording medium side and the opposite end of the energization film on the magnetic recording medium side are flush with the opposite end face of the recording element. A near-field optical head characterized by being extended. Oite the near-field light heads according to claim 8,
The energization film has a resistor portion exposed on the surface side of the magnetic recording medium, and a pair of extended portions extending from both ends of the resistor portion to a position flush with an end surface opposite to the opposing surface of the recording element. A near-field optical head, comprising: a connecting portion; The near-field optical head according to any one of claims 7 to 10,
The near-field optical head, wherein the facing surface of the intermediate layer has higher wettability than the end surface of the core. The near-field optical head according to any one of claims 7 to 11,
A near-field optical head, wherein a plurality of current-carrying films are laminated between the intermediate layer and the main magnetic pole via an insulating layer. The near-field optical head according to any one of claims 7 to 12,
The near-field optical head is supported on the front end side so as to be movable in a direction parallel to the surface of the magnetic recording medium and rotatable about two axes parallel to the surface of the magnetic recording medium and orthogonal to each other. With the beam,
A light source that makes a light beam incident on a base end portion of the core;
An actuator for supporting the base end side of the beam and moving the beam in a direction parallel to the surface of the magnetic recording medium;
A rotation drive unit for rotating the magnetic recording medium in the fixed direction;
A control unit for controlling the operation of the recording element and the light source;
An information recording / reproducing apparatus comprising:

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