JP2012160240A - Near-field light generating device, near-field light head, and manufacturing method of near-field light generating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a near-field light generating device of heat-assisted magnetic recording type capable of molding a near-field light generating element on a surface opposed to a medium of a light guide with ease and high accuracy, and a manufacturing method thereof.SOLUTION: A first light guide and a second light guide provided on an optical axis of the first light guide are provided. Next, at a boundary between the first light guide and the second light guide, in a cross section of the second light guide, a sacrificial layer is formed at an exposed portion other than a portion corresponding to a cross section of the first light guide, and the first light guide is removed using the sacrificial layer as a mask. Then, a metal film is formed at a portion of the sacrificial layer where the first light guide has been removed. Thus, the metal film is formed as a near-field light generating element on an optical axis of the second light guide.

Description

  The present invention relates to a near-field light generator, a near-field light head, and a method for manufacturing a near-field light generator.

  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-mentioned problems, the magnetic domain in which information is recorded by using near-field light is locally heated, the coercive force is temporarily reduced, and thermal recording is performed while writing to the recording medium in the meantime. A magnetic recording type information recording / reproducing apparatus has been devised and developed.

  Among the recording / reproducing heads of such an information recording / reproducing apparatus, a recording / reproducing head using near-field light (hereinafter referred to as a near-field optical head) includes a near-field on the bottom surface of the slider, as shown in Patent Document 1, for example. A scatterer having a planar triangular shape for generating light is formed, and a waveguide for introducing light is formed thereon. The region near the scatterer at the lower part of the waveguide is covered with a material different from that of the waveguide core so that the refractive index of the material is smaller than that of the waveguide core. Here, the lower portion of the waveguide means a portion close to the bottom surface of the slider. Thus, by reducing the refractive index of the material in the vicinity of the scatterer that generates near-field light, the magnitude of polarization generated in the material in the vicinity of the scatterer can be reduced. As a result, the scatterer It is disclosed that the intensity of near-field light generated therein can be increased.

JP 2007-280572 A

  However, the above-mentioned near-field optical head of the prior art is not disclosed with respect to a manufacturing method, and the main magnetic pole, auxiliary magnetic pole and coil constituting the recording element, and the core and the clad that propagate the light beam to the scatterer are magnetic recording. It is a laminated structure laminated in the direction along the surface of the medium. Therefore, in the above-described conventional near-field optical head that forms a scatterer on the surface facing the surface of the magnetic recording medium, the scatterer is formed on the end surface perpendicular to the stacking direction of the above-described stacked structure. Therefore, there is a problem that the work of forming the scatterer is complicated.

  Further, the apex and the film thickness of the near-field light generating element are required to have a processing accuracy of several nanometers to several tens of nanometers, and extremely advanced micromachining techniques such as an electron beam drawing apparatus and a focused ion beam apparatus are required. In this way, it is expected that applying advanced micromachining technology to recording head manufacturing is not suitable for mass production.

  Therefore, the present invention has been made in view of such circumstances, and the object thereof is to provide proximity of a thermally assisted magnetic recording system in which a near-field light generating element can be easily and accurately formed on the medium facing surface of an optical waveguide. It is providing the manufacturing method of a field light generator and a near field generator.

  In order to achieve the above object, the present invention proposes the following means. A method of manufacturing a near-field light generating device including a near-field light generating element that generates a light beam as near-field light, the first waveguide and a second waveguide provided on the optical axis of the first waveguide And at the boundary between the first waveguide and the second waveguide, a step of forming a sacrificial film on an exposed portion of the cross section of the second waveguide other than the portion corresponding to the cross section of the first waveguide And a waveguide removing step of removing the first waveguide using the sacrificial film as a mask, a step of forming a metal film on the removed portion of the first waveguide of the sacrificial film, and a step of removing the sacrificial film. The metal film is formed as a near-field light generating element on the optical axis of the second waveguide.

  With such a manufacturing method, the first waveguide and the metal film can be formed to have the same cross-sectional shape. Therefore, by controlling the shape and size of the first waveguide, a desired shape and size of the metal film can be formed.

  In the method for manufacturing a near-field light generating device of the present invention, the waveguide removing step removes the first waveguide and a part of the second waveguide using the sacrificial film as a mask. Thereby, the position of the metal film with respect to the second waveguide can be controlled.

  In the method for manufacturing a near-field light generating device of the present invention, the step of forming the sacrificial film uses a photolithography technique.

  In the method for manufacturing a near-field light generating device of the present invention, in the patterning step, the first waveguide includes a sacrificial structure, and the sacrificial structure is made of the same material as the second waveguide. Alternatively, the sacrificial structure is made of a material different from that of the second waveguide.

Moreover, in the manufacturing method of the near-field light generator of this invention, the cross-sectional shape of a 1st waveguide is a triangle.
Moreover, in the manufacturing method of the near-field light generator of this invention, the cross-sectional shape of a 2nd waveguide is a square.
Moreover, this invention provides the near-field light generator manufactured using the above manufacturing method.

  In addition, the present invention includes the above near-field light generator, 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. And a recording element for generating a recording magnetic field from a surface facing the surface of the magnetic recording medium, heating the magnetic recording medium by near-field light, and reversing the magnetization in the magnetic recording medium by the recording magnetic field generated from the recording element By providing the above, a near-field optical head characterized by recording information on a magnetic recording medium is provided.

  According to the present invention, the near-field light can be easily applied to the medium facing surface of the optical waveguide because it can be manufactured by an existing film forming technique without requiring an advanced fine processing technique such as an electron beam drawing apparatus or a focused ion beam apparatus. A generating element can be formed. In addition, since the positional deviation is not generated with respect to the optical waveguide and the size and thickness can be controlled, the near-field light generating device, the near-field light head, and the near-field light generating device capable of forming the near-field light generating element with high accuracy Can provide a manufacturing method

It is a block diagram which shows the information recording / reproducing apparatus which has a near-field optical head based on this invention. It is an expanded sectional view of the near-field light head concerning the present invention. FIG. 3 is a diagram of the near-field optical head shown in FIG. 2 viewed from the disk surface side. FIG. 3 is a cross-sectional view of the near-field optical head shown in FIG. It is the perspective view which expanded and displayed the core of the optical waveguide, and the near field light generation element. (A)-(F) It is the figure which showed the manufacturing process of 1st Embodiment of the recording head from each of the AA 'cross section and B side surface shown in FIG. (G)-(I) It is the figure which showed the manufacturing process of 1st Embodiment of the recording head following FIGS. 6-1 from each of AA 'cross section and B side surface shown in FIG. (A)-(F) It is the figure which showed the manufacturing process of 2nd Embodiment of a recording head from each of the AA 'cross section and B side surface shown in FIG. (G)-(I) It is the figure which showed the manufacturing process of 2nd Embodiment of the recording head following FIG. 7-1 from each of AA 'cross section and B side surface shown in FIG.

(First embodiment)
A first embodiment of a recording head manufacturing method for an information recording / reproducing apparatus according to the present invention will be described below with reference to FIGS.

  First, the structure of the information recording / reproducing apparatus 1 and the recording head 2 will be described with reference to FIGS. As shown in FIG. 1, the information recording / reproducing apparatus 1 in the present embodiment is movable in the XY directions parallel to the recording head 2 and the disk surface (the surface of the magnetic recording medium) D1, and is parallel to the disk surface D1. In addition, the suspension 3 that supports the recording head 2 on the front end side so as to be rotatable about two axes (X axis, Y axis) orthogonal to each other, and the light flux introducing means 4 from the base end side to the light flux introducing means 4 An optical signal controller (light source) 5 that makes the light beam L incident thereon, an actuator 6 that supports the base end side of the suspension 3 and scans the suspension 3 in the XY directions parallel to the disk surface D1, and the disk D A spindle motor (rotation drive unit) 7 that rotates the motor in a fixed direction, a control unit 8 that controls the operation of a recording element 21 and an optical signal controller 5, which will be described later, and these components. And a housing 9 for housing therein.

  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.

  The spindle motor 7 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 7. The actuator 6 is attached to the corner of the recess 9a. A carriage 11 is attached to the actuator 6 via a bearing 10, and a suspension 3 is attached to the tip of the carriage 11. The carriage 11 and the suspension 3 are both movable in the XY directions by driving the actuator 6.

  The carriage 11 and the suspension 3 are retracted from the disk D by driving the actuator 6 when the rotation of the disk D is stopped. The recording head 2 and the suspension 3 constitute a head gimbal assembly 12. The optical signal controller 5 is mounted in the recess 9 a so as to be adjacent to the actuator 6. The control unit 8 is attached adjacent to the actuator 6.

  The recording head 2 heats the rotating disk D and applies a recording magnetic field perpendicular to the disk D to cause magnetization reversal and record information.

  As shown in FIGS. 2 and 3, the recording head 2 is disposed so as to face the disk D in a state where it floats by a predetermined distance H from the disk surface D1, and has a slider 20 having a facing surface 20a facing the disk surface D1, A recording element 21 fixed to the front end surface of the slider 20 (hereinafter referred to as a side surface on the inflow end side), an optical waveguide 22 fixed adjacent to the recording element 21, and the optical waveguide 22 will be described later. The core 40 is provided with a light beam introducing means 4 for introducing the light beam L from the optical signal controller 5. Further, the recording head 2 of the present embodiment includes a reproducing element 23 fixed adjacent to the optical waveguide 22.

  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 is supported so as to hang from the tip of the suspension 3 via the gimbal portion 24 with the opposing surface 20a facing the disk D. The gimbal portion 24 is a component whose movement is restricted so as to be displaced only around two axes (X axis and Y axis) that are parallel to the disk surface D1 and orthogonal to each other. 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 suspension 3 bends 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 suspension 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 24, the slider 20 always floats in a stable posture.

  The air flow generated along with the rotation of the disk D flows from the inflow end side of the slider 20 (X direction base end side of the suspension 3), then flows along the ABS 20c, and flows out of the slider 20 (suspension 3 side). 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.

  Next, the structure of the recording head 2 will be described. FIG. 4 is a sectional view of the recording head 2. The recording head 2 includes a light guide 12, a slider 20, an optical waveguide 22 that is in contact with the slider 20, a core 40 and a cladding 41, a near-field light generating element 50, and a main magnetic pole adjacent to the optical waveguide 22. 32, a coil 33, a magnetic circuit 31, an auxiliary magnetic pole 30, and a reproducing element 23. The auxiliary magnetic pole 30, the main magnetic pole 32, and the magnetic circuit 31 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 coils 33 are arranged so that there is a gap between the adjacent coils 33, the magnetic circuit 31, and the auxiliary magnetic pole 30 and the main magnetic pole 32 so as not to be short-circuited. 34 is molded. The magnetic circuit 31 and the coil 33 constitute an electromagnet as a whole.

FIG. 5 shows an enlarged view of the near-field light generating element 50 facing the disk surface D1 of the recording head 2 and the core 40 of the optical waveguide 22. A triangular columnar near-field light generating element 50 is formed on the end surface of the quadrangular columnar core 40 on the disk D1 side. The material of the core 40 is Ta ₂ O ₅ having a high refractive index, and the length of one side is 500 nm. The near-field light generating element 50 is made of Au, Hg, and Pt, which are materials that generate plasmons, the cross-sectional shape is a triangle, the length of one side is 500 nm, and the thickness is 50 nm.

  Next, when recording information, the control unit 8 shown in FIG. 1 operates the optical signal controller 5 to emit laser light L (shown in FIG. 4), and the coil 33 generates a current modulated according to the information. And the recording element 21 is operated.

  First, after the laser beam L incident and propagated from the optical signal controller 5 is reflected by approximately 90 degrees on the reflecting surface 25, it propagates in the core of the optical waveguide 22 from the upper side to the lower side of the slider.

  Subsequently, the laser light L is incident on the near-field light generating element 50. When the laser light L reaches the near-field light generating element 50, surface plasmons are excited in the near-field light generating element 50. The near-field light generating element 50 has a triangular shape, and particularly strong surface plasmon is generated at the apex thereof.

[Production method]
Now, a method for manufacturing the above-described recording head 2 will be described with reference to FIGS.

First, the slider side cladding 100 is formed on the substrate. Specifically, an insulating material such as Al ₂ O ₃ or SiO ₂ is used. Next, a Ta ₂ O ₅ layer that is a material of the core 40 is formed on the slider-side clad 100. The film forming method is not particularly limited, and magnetron RF sputtering, ion beam sputtering, or the like is used.

  Next, as shown in FIG. 6A, a mask pattern (not shown) having an opening to be removed is formed on the core 40 using a photolithography technique, and reactive ion etching is performed through the mask pattern. (RIE) is performed (vertical etching). After the excess film is removed by vertical etching, the mask pattern is removed to form a square columnar core 40 having a predetermined size.

Next, as shown in FIG. 6B, an etching mask 101 is formed at a predetermined position on the core 40 using a photolithography technique in a state where the quadrangular prism-shaped core 40 is formed. The etching mask 101 is not particularly limited, and Cr or the like, which is a material having a selection ratio when etching the Ta ₂ O ₅ layer, is used. The etching mask 101 is formed on the right side of the section AA ′ in FIG. 6B by a distance h from the end face of the core 40. However, the etching mask 101 can be arranged at an arbitrary position. In addition, the etching mask 101 does not cover the side surface of the core 40 in the drawing, but may actually cover the side surface of the core.

  Subsequently, as shown in FIG. 6C, the triangular prism core 40a is formed by Ar etching. When the quadrangular column core 40 is sputter-etched, the corners of the quadrangular column are selectively etched to form inclined surfaces. If etching is further continued in this state, the inclined surface is etched while maintaining a certain angle with respect to the bottom, thereby forming the triangular prism core 40a.

  Thereafter, when the triangular prism core 40a is further etched, the width and height of the cross section of the triangular prism core 40a are reduced while maintaining a similar shape. Therefore, if the etching time is adjusted, the triangular prism core 40a having a desired dimension can be formed.

  After that, as shown in FIG. 6D, the etching mask 101 is removed to form a core having a structure in which the triangular prism core 40a and the quadrangular prism core 40 are connected.

  Next, as shown in FIG. 6E, a sacrificial film 103 is formed on the exposed end face of the core 40 located outside the triangular prism core 40a in the B side view at the joint between the triangular prism core 40a and the quadrangular prism core 40. Form. First, a photoresist is applied so as to cover the entire surface of the triangular prism core 40 a and the core 40, and an exposure light beam L 1 is incident on the core 40. Here, the exposure light beam L1 propagates through the core 40, and when it reaches the connecting portion between the core 40 and the triangular prism core 40a, the cross-sectional shape changes greatly from a square to a triangle. Leaks from exposed end face. The leaked exposure light beam L1 sensitizes the photoresist applied to the exposed end face of the core 40 for an exposure distance g1. A negative photoresist is used as the photoresist. Next, the sacrificial film 103 can be formed on the exposed end surface of the core 40 by developing with a developer for a predetermined time and removing the unexposed photoresist.

  Next, as shown in FIG. 6F, the triangular prism core 40a is removed using the sacrificial film 103 as a mask by anisotropic etching from a direction in which the upper part of the quadrangular prism core 40 cannot be seen when viewed from the B side. Alternatively, a mask (not shown) may be formed on all exposed surfaces of the quadrangular prism core 40 and etched. The removal method is not particularly limited, and wet etching, dry etching, ion milling, or the like may be used. Further, the etching is continued so that the left side cross section of the triangular prism core 40a in the AA 'cross section is flush with the cross section of the sacrificial film 103. In the present embodiment, the left cross section of the triangular prism core 40 a and the cross section of the sacrificial film 103 are perpendicular to the slider-side clad 100, but may be oblique or curved with respect to the clad 100. Thereafter, when the etching is further continued, the etching proceeds using the sacrificial film 103 as a mask, and the triangular prism is removed from the left end face of the sacrificial film 103 by an etching distance g2. In this embodiment, etching is performed so that the etching distance g2 is longer than the exposure distance g1 of the sacrificial film 103. As a result, a triangular plate-shaped depression is formed on the end face of the core 40 having a quadrangular prism shape. Here, the etching distance g2 can be controlled by managing the etching amount.

  Thereafter, as shown in FIG. 6G, a metal film 110 is formed from the left side in the vertical cross section of the core 40 and the sacrificial film 103 in the AA ′ cross section. The thickness of the metal film 110 can be controlled by the film formation speed, the film formation angle, and the film formation time.

  Subsequently, as shown in FIG. 6H, the sacrificial film 103 is removed. There is no particular limitation on a removal method, but wet etching or the like that can peel only the sacrificial film 103 may be used. In this step, the triangular plate-shaped near-field light generating element 50 can be formed in the state where the square-column-shaped core 40 is embedded in the end face of the square columnar core 40. Further, since the embedding amount can be expressed by the difference between the etching distance g2 and the exposure distance g1, it can be controlled by managing the etching amount g2 in the step of FIG.

Thereafter, as shown in FIG. 6I, a clad 41 made of an insulating material such as Al ₂ O ₃ or SiO ₂ is formed so as to cover the entire surface. Thereafter, if necessary, the surface of the clad 41 is polished by CMP (Chemical Mechanical Polishing) or the like to form a flat surface. A main magnetic pole 32, a magnetic circuit 31 (not shown), an insulator 34, a coil 33, and a reproducing element 23 are formed on the clad 41 by a conventional method.

  Next, the substrate is diced to form a bar (not shown) in which a plurality of sliders 20 are connected in one direction (X direction). Thereafter, the medium facing surface F is removed by a predetermined distance. The removal method is not particularly limited. For example, lapping (polishing) methods such as mechanical polishing and chemical mechanical polishing (CMP), ion beam etching, plasma etching, reactive ion etching, etching methods such as chemical etching, and any of these methods The surface on the medium facing surface side may be removed by a predetermined thickness by a method such as combination. If the polishing method is used as the removal method, the position of the exposed surface of the near-field light element 50 may be determined using an electro-wrapping guide (ELG). Conventionally, a magnetic head performs polishing amount control (polishing end detection) using ELG. Similarly, in this embodiment, if ELG is used and the end of the polishing is aligned with the position of the near-field light generating element 50, the polishing can be stopped at the position of the near-field light generating element 50 as in the case of polishing the magnetic head.

Thereafter, the bar is cut to form the slider 20.
According to the process described above, the recording head 2 described with reference to FIG. 5 can be manufactured.
According to the manufacturing method of the recording head 2 described above, the near-field light generating element 50 can be easily and highly accurately formed on the medium facing surface of the optical waveguide 22 by using an existing process technique.

  First, since the triangular prism core 40a is a part of the core 40, the positional relationship between the triangular prism core 40a and the core 40 is coaxial. Utilizing the fact that the cross-sectional shapes of the triangular prism core 40a and the core 40 are different, the sacrificial film 103 is formed in the portion where the core 40 is exposed in the B side view. Thereafter, using the sacrificial film 103 as a mask, the triangular prism core 40a is etched by a predetermined distance, and a metal film 110 is formed on the entire surface facing the medium. Next, the metal film 110 formed on the end face of the sacrificial film 103 is removed together with the sacrificial film 103, thereby forming the near-field light generating element 50 having the same shape as the triangular prism core 40a. Therefore, alignment (alignment) between the core 40 and the near-field light generating element 50 becomes unnecessary.

  In the formation of the sacrificial film 103, the cross section of the sacrificial film 103 is a portion obtained by removing the cross section of the triangular prism core 40 a from the cross section of the core 40. Further, after the triangular prism core 40a is etched by a predetermined distance, the metal film 110 is formed on the entire surface facing the medium, and the metal film 110 formed on the end face of the sacrificial film 103 is removed. From the above steps, the triangular prism core 40a and the near-field light generating element 50 have the same shape. Therefore, since the shape and size of the triangular prism core 40a can be controlled, the near-field light element 50 having a desired shape and size can be formed. Furthermore, the thickness of the near-field light generating element 50 can be controlled by the film thickness when the metal film 110 is formed. In the step of etching the triangular prism core 40a by a predetermined distance, the near-field light generating element 50 can be formed at a position embedded in the core 40 by a predetermined distance by managing the etching amount.

Therefore, since it can manufacture with the existing process technology, it can manufacture easily. Moreover, there is no position shift with respect to the core 40, and a desired dimension and thickness can be controlled. The near-field light generating element 50 can be formed at a position embedded in the core 40 by a predetermined distance. Therefore, it can be said that this is a manufacturing method with high accuracy and a high degree of freedom in the arrangement position of the near-field light generating element. As described above, the near-field light generating element 50 can be manufactured easily and with high accuracy.
From the above, the manufacturing method of this embodiment is a recording head manufacturing method suitable for mass production.

(Second Embodiment)
A second embodiment of the recording head manufacturing method for the information recording / reproducing apparatus according to the present invention will be described below with reference to FIG. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  First, a method for manufacturing the recording head 2 having the quadrangular prism-shaped core 40 and the triangular plate-shaped near-field light generating element 50 as shown in FIGS. 4 and 5 will be described.

[Production method]
In the second embodiment, description of FIGS. 7H to 7I, which are the same steps as those in the first embodiment, is omitted.

First, as shown in FIG. 7A, the quadrangular prism core 40 and the sacrificial structure 104 are formed so as to be connected to the clad 100 in a vertical plane. Although the formation method is not particularly limited, the formation method may be as follows. Ta ₂ O ₅ which is a material of the quadrangular column core 40 is formed on the entire surface. The film forming method is not particularly limited, and magnetron RF sputtering, ion beam sputtering, or the like is used. After etching so that a substantially vertical cross section is formed with respect to the clad 100 at a certain position, the material of the sacrificial structure 104 is formed so as to cover the entire surface. However, although a vertical cross section is formed in FIG. 7, the cross section may be inclined or curved with respect to the clad 100 as long as the cross section is formed. Next, the material of the sacrificial structure 104 covering the surface of the quadrangular column core 40 is removed from the upper side of the AA ′ sectional view by a method such as etching or polishing. At this time, the etched or polished surface becomes an optically smooth surface, and the upper surface of the connection portion in the AA ′ cross-sectional view of the sacrificial structure and the core 40 is in the same plane. Thereafter, a mask pattern (not shown) having an opening to be removed is formed on each material of the core 40 and the sacrificial structure 104 by using a photolithography technique, and reactive ion etching (RIE) is performed through the mask pattern. ) (Vertical etching). Next, the mask pattern is removed, and a quadrangular prism-shaped core 40 and a sacrificial structure 104 having predetermined dimensions are formed.

  Next, as shown in FIG. 7B, an etching mask 101 is formed at a predetermined position on the core 40 by using a photolithography technique. The etching mask 101 is formed so that the connection portion between the core 40 and the sacrificial structure 104 and the end face of the etching mask 101 itself are at the same position.

  Next, as shown in FIG. 7C, the sacrificial structure 104 is formed into a triangular cross section by Ar etching. When the rectangular columnar sacrificial structure 104 is sputter-etched, the corners of the quadrangular column are selectively etched to form inclined surfaces. Then, further etching is continued in this state, and the inclined surface is etched while maintaining a certain angle with respect to the bottom, thereby forming a triangular prism. Etching is then continued, and the width and height of the cross section of the triangular prism-shaped sacrificial structure 104 are reduced while maintaining a similar shape. By managing the etching amount, the size of the cross section of the sacrificial structure 104 can be controlled.

  After that, as shown in FIG. 7D, the etching mask 101 is removed, and a triangular prism-shaped sacrificial structure 104 and a quadrangular prism-shaped core 40 are formed in a connected state.

  Next, as shown in FIG. 7E, a sacrificial film 103 is formed on the exposed end face of the core 40 located outside the triangular prism core 40a in the B side view at the connecting portion of the triangular prism core 40a and the quadrangular prism core 40. Form. First, a photoresist is applied so as to cover the entire surface of the triangular prism core 40 a and the core 40, and an exposure light beam L 1 is incident on the core 40. Here, the exposure light beam L1 propagates through the core 40, and when it reaches the connecting portion between the core 40 and the triangular prism core 40a, the cross-sectional shape changes greatly from a square to a triangle. Leaks from exposed end face. The leaked exposure light beam L1 sensitizes the photoresist applied to the exposed end face of the core 40 for an exposure distance g. A negative photoresist is used as the photoresist. Next, although not particularly limited, the sacrificial film 103 can be formed on the exposed end face of the core 40 by developing with a developer for a predetermined time and removing the unexposed photoresist.

Next, as shown in FIG. 7F, the sacrificial structure 104 is removed by etching. The removal method is not particularly limited, and may be wet etching, dry etching, or the like. Etching is preferably a method in which only the sacrificial structure 104 can be selectively removed without etching progressing with respect to Ta ₂ O ₅ which is the material of the core 40.

In addition, when the end face of the core 40 is desired to be recessed in a triangular plate shape, etching is performed so that etching proceeds with respect to Ta ₂ O ₅ which is a material of the core 40.

  After that, as shown in FIG. 7G, the metal film 110 is formed from the left side in the vertical cross section of the core 40 and the sacrificial film 103 in the AA ′ cross section. The thickness of the metal film 110 can be controlled by the film formation speed, the film formation angle, and the film formation time.

  According to the manufacturing method of the second embodiment described above, the recording head 2 in which the optical waveguide 22 and the near-field light generating element 50 are formed can be manufactured easily and with high accuracy.

  First, in FIG. 7F, the material of the sacrificial structure 104a is removed, and etching is performed so that the material of the sacrificial film 103 is not removed, so that the near-field light generating element 50 is left on the AA ′ cross section of the core 40. It can be reliably formed on the end face.

  The triangular prism sacrificial structure 104a and the near-field light generating element 50 have the same shape. Therefore, since the shape and size of the triangular prism sacrificial structure 104a can be controlled, the near-field light element 50 having a desired shape and size can be formed.

  Furthermore, the thickness of the near-field light generating element 50 can be controlled by the film thickness when the metal film 110 is formed.

From the above, the near-field light generating element 50 can be formed on the end face of the core 40 easily and with high accuracy.
From the above, the manufacturing method of this embodiment is a recording head manufacturing method suitable for mass production.

  It should be noted that the technical scope of the present invention is not limited to the above-described embodiments, and includes those in which various modifications are made to the above-described embodiments without departing from the spirit of the present invention. In other words, the configuration described in the above-described embodiment is merely an example, and can be changed as appropriate. Moreover, it is also possible to employ | adopt combining each embodiment mentioned above suitably.

  For example, the boundary between the first waveguide and the second waveguide is a separated state in which the end portions of the first waveguide and the second waveguide are slightly separated, or the first waveguide and the second waveguide. Including the contact state in which is in contact. In this contact state, it is more preferable that the first waveguide and the second waveguide constitute the same optical waveguide. Thereby, since the first waveguide and the second waveguide can be provided coaxially more reliably, the positioning accuracy of the near-field light generating element provided at the boundary between them can be further improved.

D disk (magnetic recording medium)
D1 Disc surface E Vertical section F Medium facing surface L Light beam L1 Exposure light beam R Near-field light 1 Information recording / reproducing apparatus 2 Recording head 3 Suspension 4 Light beam introduction means 5 Optical signal controller (light source)
6 Actuator 7 Spindle motor (rotary drive)
DESCRIPTION OF SYMBOLS 8 Control part 9 Housing 10 Bearing 11 Carriage 12 Head gimbal assembly 20 Slider 21 Recording element 22 Optical waveguide 23 Playback element 24 Gimbal part 25 Reflecting surface 26 Substrate 30 Auxiliary magnetic pole 31 Magnetic circuit 32 Main magnetic pole 33 Coil 34 Insulator 40 Core 40a Triangular prism Core 41 Clad 42 Low refractive material 50 Near-field light generating element 100 Slider side clad 101, 102 Etching mask 103 Sacrificial film 104 Sacrificial structure 104a Triangular prism sacrificial structure 110 Metal film h Distance g1 Exposure distance g2 Etching distance

Claims (9)

A method of manufacturing a near-field light generating device including a near-field light generating element that generates a light beam as near-field light,
Providing a first waveguide and a second waveguide provided on an optical axis of the first waveguide;
Forming a sacrificial film at an exposed portion other than a portion corresponding to a cross section of the first waveguide in a cross section of the second waveguide at a boundary between the first waveguide and the second waveguide;
A waveguide removal step of removing the first waveguide using the sacrificial film as a mask;
Forming a metal film on the removed portion of the first waveguide of the sacrificial film;
Removing the sacrificial film,
The method of manufacturing a near-field light generating device, wherein the metal film is formed as the near-field light generating element on the optical axis of the second waveguide.   2. The method of manufacturing a near-field light generating device according to claim 1, wherein the waveguide removing step removes the first waveguide and a part of the second waveguide using the sacrificial film as a mask. A manufacturing method of a near-field light generating device.   3. The method of manufacturing a near-field light generating device according to claim 1, wherein the step of forming the sacrificial film uses a photolithography technique. In the manufacturing method of the near-field light generator in any one of Claim 1 to 3,
The method of manufacturing a near-field light generating device, wherein the first waveguide includes a sacrificial structure, and the sacrificial structure is made of the same material as the second waveguide. In the manufacturing method of the near-field light generator in any one of Claim 1 to 3,
The method of manufacturing a near-field light generating device, wherein the first waveguide includes a sacrificial structure, and the sacrificial structure is made of a material different from that of the second waveguide.   6. The method for manufacturing a near-field light generating device according to claim 1, wherein a cross-sectional shape of the first waveguide is a triangle.   7. The method of manufacturing a near-field light generating device according to claim 1, wherein the second waveguide has a quadrangular cross-sectional shape.   A near-field light generating device manufactured using the method for manufacturing a near-field light generating device according to claim 1. The near-field light generating device according to claim 8,
A slider movable along the surface of the magnetic recording medium rotating in a certain direction;
A recording element which 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,
The magnetic recording medium is heated by the near-field light, and information is recorded on the magnetic recording medium by causing magnetization reversal in the magnetic recording medium by the recording magnetic field generated from the recording element. Near-field light head.

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