JP5923364B2 - Thermally assisted magnetic head element inspection method and apparatus - Google Patents

Description

  The present invention relates to an inspection method and apparatus for inspecting a thin film thermally assisted magnetic head, and in particular, thermal assist capable of inspecting near-field light generated by a thin film thermally assisted magnetic head that cannot be inspected by a technique such as an optical microscope. The present invention relates to a magnetic head element inspection method and apparatus.

  As an apparatus for inspecting a magnetic head nondestructively, a method using an optical microscope, a method using a scanning electron microscope (SEM), a method using an atomic force microscope (AFM), a magnetic force There is a method using a microscope (Magnetic Force Microscope: MFM).

  Each of the above-described methods has advantages and disadvantages, but in that the magnetic field generated by the magnetic head for writing to the hard disk can be inspected nondestructively, a method using a magnetic force microscope (MFM) is another type of observation means. It is superior to the method using.

  Regarding the measurement of the effective track width of the write track in the state of the row bar before the magnetic head elements are individually separated using this magnetic force microscope (MFM), for example, Japanese Patent Application Laid-Open No. 2010-175534 (Patent Document 1). )It is described in. That is, in Patent Document 1, a magnetic field is generated by applying a current to a magnetic head circuit pattern of a rover as a sample, and the magnetic probe attached to the cantilever is brought close to the generated magnetic field to displace the probe of the cantilever. It is described that a magnetic field generated by a sample is measured two-dimensionally by detecting the quantity by two-dimensionally scanning a cantilever.

In the conventional magnetic head inspection, a recording signal (excitation signal) is input from a bonding pad to a thin film magnetic head in a magnetic head rover state, and a magnetic field generated from a recording head (element) included in the thin film magnetic head is observed. , By moving the scan at a position corresponding to the flying height of the magnetic head and directly observing with a magnetic force microscope (MFM), scanning Hall probe microscope (SHPM) or scanning magnetoresistive microscope (SMRM) As a method for measuring the generated magnetic field shape instead of the physical shape of the head (element) and enabling the magnetic effective track width inspection to be performed nondestructively, Patent Document 2 discloses an HGA state using a spin stand. Or, the effective track width that could only be inspected in the pseudo HGA state can be measured in the rover state by using a magnetic force microscope. The Rukoto is described in JP 2009-230845 (Patent Document 2), a method of magnetic recording by generating a near-field light as a recording method to realize high-density recording density exceeding 1 Tb / in ² The heat-assisted magnetic recording system has been proposed, but this heat-assisted magnetic recording head has a width in the direction perpendicular to the polarization direction of incident light that propagates through the waveguide gradually toward the apex where near-field light is generated. Conductive structure having a reduced cross-sectional shape and a shape in which the width gradually becomes smaller or stepwise toward the apex where near-field light is generated in the traveling direction of incident light Is used to generate near-field light. Japanese Patent Application Laid-Open No. 2011-146097 (Patent) discloses a configuration in which a waveguide is disposed beside a conductive structure and near-field light is generated through surface plasmons generated on the side surface of the conductive structure. Reference 3).

JP 2010-175534 A JP 2009-230845 A JP 2011-146097 A

Patent Document 1 describes that a two-dimensional distribution of a magnetic field formed by individual magnetic head elements formed on a row bar of a magnetic head is measured by two-dimensionally scanning a cantilever having a probe. The configuration and method for measuring the near-field light and magnetic field generated by the thermally-assisted magnetic head are not mentioned.
In conventional magnetic recording, since the size of the magnetic field generating portion of the head is the track width, the track width of the head can be inspected by measuring the magnetic field according to Patent Document 1, but the size of the generated near-field light is small. The thermal assist head that is the track width cannot be inspected.

  Also, in the magnetic head inspection device that inspects the magnetic execution track width by measuring the generated magnetic field shape in the state of the rover described in Patent Document 2, the near-field light and the magnetic field generated by the thermally-assisted magnetic head are detected. There is no mention of a configuration for measuring and its method.

  On the other hand, Patent Document 3 describes the structure of a thermally assisted magnetic recording head and a magnetic recording apparatus incorporating the head, and the actual operation in the HDD generated by adopting the thermally assisted magnetic recording head. Although suppression of the temperature rise is considered, the temperature rise during inspection of near-field light generated by the thermally-assisted magnetic recording head and inspection that generates near-field light for a long time is not considered.

  An object of the present invention is to prevent head element damage due to heat generation during inspection and to suppress the occurrence of misalignment during measurement due to thermal expansion, and to accurately measure the shape of the near-field light of the heat-assisted head without being affected by heat generation. A heat-assisted magnetic head element inspection method and apparatus thereof are provided.

In order to solve the above-described problems, in the present invention, a thermally assisted magnetic head element inspection apparatus is provided.
A tray unit for storing a row bar on which a large number of thermally-assisted magnetic head elements are formed and a mounting unit for mounting a row bar on which a large number of thermally-assisted magnetic head elements are formed are mounted on the mounting unit at the sample inspection position. Measuring means for measuring the intensity distribution of the magnetic field generated from the writing magnetic field generating unit of the thermally assisted magnetic head element formed on the row bar and the intensity distribution of the near-field light generated from the near-field light emitting unit; and Measuring means moving means for moving between the sample inspection position and the sample delivery position for transferring the row bar stored in the tray section to the measuring means, and removing the row bar from the tray section by the measuring means moving means a sample delivery means for mounting the row bar on the placing part of the measuring means is moved to the sample delivery position, the write magnetic field measured by said measuring means The heat-assisted magnetic head element by comparing the data of the intensity distribution of the magnetic field generated from the raw part and the data of the intensity distribution of the near-field light generated from the near-field light emitting part with reference data stored in advance constitute a data processing unit for checking the placement portion of the measuring means comprises a cooling mechanism for cooling the row bar near-field light-emitting portion generates heat by generating the near field light, wherein The measuring means includes a cantilever having a probe formed at the tip and capable of vibrating up and down, and a table for moving the mounting portion within a plane within a small range, and the cantilever is vibrated up and down near the surface of the row bar. The magnetic field intensity distribution generated from the writing magnetic field generating unit is measured by moving the mounting unit on which the row bar is mounted on the table while moving the moving unit within a small range within a plane. Both were so as to measure the intensity distribution of the near-field light generated from the near-field light-emitting portion by scanning the region including the near-field light-emitting portion while vibrating the cantilever up and down.

In order to solve the above-described problems, in the present invention, a row bar on which a large number of thermally-assisted magnetic head elements are formed is taken out of the tray portion and placed on the placement portion of the measuring means waiting at the sample delivery position. , Moving the measuring means on which the row bar is mounted on the mounting portion to the sample inspection position,
In the sample inspection position, the intensity distribution of the magnetic field generated from the writing magnetic field generation unit of the thermally assisted magnetic head element formed on the row bar mounted on the mounting unit and the intensity of the near field light generated from the near field light emitting unit. Data in which the measured distribution of the magnetic field intensity generated from the writing magnetic field generation unit and the near-field light intensity distribution data generated from the near-field light emitting unit are stored in advance. In the thermally assisted magnetic head element inspection method for inspecting the thermally assisted magnetic head element by comparing with a magnetic field generated from a write magnetic field generating part of a thermally assisted magnetic head element formed on a row bar placed on the placing part When measuring the intensity distribution of the near field light and the intensity distribution of the near field light generated from the near field light emitting part, the near field light emitting part is generated by generating the near field light. The rover measured while cooling the intensity distribution of the magnetic field and intensity distribution of the near-field light heat, to measure the intensity distribution of the intensity distribution of the magnetic field the near-field light, probe the tip By moving the mounting portion on which the row bar is mounted in a state where the cantilever on which the needle is formed is vibrated up and down within a plane, the probe of the cantilever moves the thermal assist magnetic head element. The scanning is performed by scanning the region including the writing magnetic field generation unit and the region including the near-field light emitting unit .

  According to the present invention, the shape of the near-field light of the thermally assisted head that cannot be measured and inspected by the conventional method can be measured without being affected by heat generation in the row bar state, so that the product yield of the thermally assisted magnetic head can be improved. be able to.

It is a block diagram which shows the system configuration | structure of the magnetic head element test | inspection apparatus in embodiment of this invention. It is a top view which shows the structure of the magnetic head element test | inspection apparatus in embodiment of this invention. It is a block diagram which shows the structure of the outline | summary of the test | inspection part of the thermally assisted magnetic head element in embodiment of this invention. It is a side view of the mounting part of the mounting part for positioning the Y-bar of the test | inspection part of the thermally-assisted magnetic head element which concerns on embodiment of this invention, and the row bar mounted in the Y stage. It is a side view of the probe unit which concerns on embodiment of this invention. It is a perspective view of the row bar made into the inspection object by the present invention. It is a top view of the magnetic head element which shows the state which made the front-end | tip part of the probe contact the electrode of the magnetic head element formed in the row bar in embodiment of this invention. FIG. 5 is a diagram for explaining the detection principle in the inspection unit of the thermally-assisted magnetic head element in the embodiment of the present invention, and shows a cross section of the cantilever and the row bar showing a state in which the magnetic field generated by the thermally-assisted magnetic head element formed on the row bar is measured FIG. FIG. 5 is a diagram for explaining the detection principle in the inspection unit of the thermally-assisted magnetic head element in the embodiment of the present invention, and a cantilever and a detection showing a state in which near-field light generated by the thermally-assisted magnetic head element formed on the row bar is measured FIG. It is a perspective view of the row bar mounting part provided with the cooling mechanism of the row bar in the embodiment of the present invention. It is a flowchart which shows the inspection procedure of the rover in embodiment of this invention.

Hereinafter, embodiments (embodiments) for carrying out the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a system configuration of a magnetic head element inspection apparatus 1000 according to an embodiment of the present invention. The magnetic head element inspection apparatus 1000 includes an inspection unit 100, a monitor unit 200, a transport unit 300, and a signal processing / control unit 400.

  The inspection unit 100, the monitor unit 200, and the transport unit 300 are covered with a soundproof box 600 and are configured to be sound-insulated so that sound from the outside does not affect the inspection.

FIG. 2 is a plan view showing the configuration of the magnetic head element inspection apparatus 1000 according to the embodiment of the present invention.
The magnetic head element inspection apparatus 1000 is configured by arranging an inspection unit 100 and a conveyance unit 300 on a vibration isolation table 500 covered with a soundproof box 600.

  The transport unit 300 includes a handling robot 310 and a guide rail 320 that guides the movement of the handling robot 310 in the X direction, a supply tray 331 on which the row bar 40 before inspection and a non-defective product collection tray 332 on which a row bar after inspection is mounted, A tray mounting unit 330 for mounting the non-defective product collecting tray 333 is provided.

  In FIG. 2, H is a sample delivery station and M is a sample inspection station. The inspection unit 100 is structured to be movable along the guide rail 150 between the sample delivery station H and the sample inspection station M. The inspection unit 100 delivers row bars to and from the tray placement unit 330 by the handling robot 310 at the sample delivery station H, moves along the guide rail 150, and is formed on the row bars at the sample inspection station M. Inspect the thermally-assisted magnetic head element.

  FIG. 3A is a block diagram showing the configuration of the inspection unit 100 that inspects the thermally-assisted magnetic head element according to the present invention. The inspection unit 100 of the heat-assisted magnetic head element shown in FIG. 3A is a process before processing a wafer on which a large number of thin film magnetic head elements are formed and cutting out a single slider (thin film magnetic head chip) in the magnetic head element manufacturing process. It is possible to measure the intensity distribution of near-field light generated by the thermally-assisted magnetic head element in the state of the row bar 40 (a block in which a plurality of head sliders are arranged). Usually, the row bar 40 cut out from a wafer on which a large number of thin-film magnetic head elements are formed as an elongated block body of about 3 cm to 10 cm has a configuration in which about 40 to 90 head sliders (thin-film magnetic head elements) are arranged. It has become.

  The inspection unit 100 of the thermally-assisted magnetic head according to the present embodiment is configured to perform a predetermined inspection using the row bar 40 as a workpiece. The row bars 40 are accommodated in the supply tray 331 shown in FIG. 2 in an array of about 20 to 30 at predetermined intervals in the minor axis direction. The row bars 40 picked up one by one from the supply tray 331 using the handling robot 310 are transported to the inspection unit 100 waiting at the sample delivery station H, and placed on the placement unit 114 of the inspection unit 100. . The row bar 40 placed on the placement unit 114 is inspected in the following procedure.

  The inspection unit 100 of the magnetic head element inspection apparatus 1000 according to the present embodiment is based on a scanning probe microscope. The inspection unit 100 can be moved between the sample delivery station H and the sample inspection station M along the guide rail 150 and can be moved in the XY direction, and is placed on the inspection stage 101. Thus, the X-stage 106 and the Y-stage 105 are configured to be driven by a piezo element (not shown) capable of moving the row bar 40 by a minute distance in the X and Y directions.

  The row bar 40 has one side surface in the major axis direction abutted against a reference surface 1141 provided on the stepped portion 1142 of the positioning portion 114 for positioning the row bar 40 provided on the upper surface of the Y stage 105. Positioned in the direction. As shown in FIG. 3B, the row bar 40 is placed at a predetermined position in the Z direction and the X direction by contacting the side surface (reference surface) 1141 of the stepped portion 1142. The side surface (reference surface 1141) of the stepped portion 1142 is in contact with the rear side surface of the row bar 40 (the surface opposite to the surface on which the probe electrodes 41 and 42 of the thermally-assisted magnetic head element are formed). Positioning is performed.

  Above the Y stage 105, a camera 103 for measuring the amount of positional deviation of the row bar 40 is provided. The Z stage 104 is fixed to the column 1011 of the inspection stage 101, and moves the cantilever 10 in the Z direction. The X stage 106, the Y stage 105, and the Z stage 104 of the inspection stage 101 are each composed of a piezo stage that is driven by a piezo element (not shown).

  When the predetermined positioning of the row bar 40 is completed, the probe unit 140 is driven, and the tip portion of the probe 141 comes into contact with the probe electrodes 41 and 42 formed on the row bar 40.

  4A, the probe unit 140 includes a probe guard 141 and a probe 142 attached to the probe guard 141, and is supported on the inspection stage 101 by a support plate 144. On the other hand, the row bar 40 is a rectangular bar-shaped substrate on which a large number of magnetic head elements are formed as shown in FIG. 4B, and the probe electrode 41 formed inside the row bar 40 of the magnetic head element as shown in FIG. 4C. 42, the alternating current 143 is applied in a state where the tip portions 1421 and 1422 of the probe 142 are in contact with each other, thereby generating a magnetic field from the next write generation unit 502 (see FIG. 5A) of the write circuit unit 43. By setting the frequency of the alternating current applied to the row bar 40 to a frequency different from the resonance frequency of the cantilever 131, the distribution of the magnetic field generated from the row bar 40 can be measured at high speed, and the write execution track width can be measured.

  The probe guard 141 is configured to be movable in the Y direction by the drive unit 143, and the tip portions 1421 and 1422 of the probe 142 and the probe electrodes 41 and 42 formed on the row bar 40 perform contact and separation operations. To drive.

  The probe 141 of the probe unit 140 is driven by the drive unit 143, and the tip portions 1421 and 1422 of the probe 141 come into contact with the probe electrodes 41 and 42 formed on the row bar 40, respectively, so that the excitation output from the control unit PC30 The signal and the laser emission signal or directly the excitation laser 301 can be supplied to the heat-assisted magnetic head element formed on the row bar 40. In this state, the row bar 40 is provided on the mounting unit 114 in a state where the writing magnetic field generating unit 502 of the thermally-assisted magnetic head element can generate a magnetic field and the near-field light emitting unit 504 can emit light on the mounting unit 114. It is sucked and held by a suction means (not shown).

  The piezo driver 107 drives and controls piezo elements (not shown) that respectively drive the X stage 106, the Y stage 105, and the Z stage 104 mounted on the inspection stage 101. The control unit PC30 is configured by a control computer having a basic configuration of a personal computer (PC) including a monitor. As shown in the figure, a cantilever 10 capable of measuring both the near-field light and the magnetic field is disposed at an opposing position above the row bar 40 placed on the Y stage 105 of the inspection stage 101. The cantilever 10 is attached to a vibration unit 122 provided on the lower side of the Z stage 104. The excitation unit 122 is composed of a piezo element, and an alternating voltage having a frequency near the mechanical resonance frequency is applied by the excitation voltage from the piezo driver 107, and the probe 4 at the tip of the cantilever 10 is moved in the vertical direction (Z direction). Vibrated.

  The cantilever 10 can measure both near-field light and a magnetic field. As shown in FIGS. 5A and 5B, the probe 4 is formed in a tetrahedral structure at the tip of the plate-like lever 1 of the cantilever 10. The lever 1 and the probe 4 are made of silicon (Si). A thin magnetic film 2 (for example, Co, Ni, Fe, NiFe, CoFe, NiCo, etc.) is formed on the front side of the lever 1 and the probe 4 (left side in FIGS. 5A and 5B). Are formed with fine particles or a thin film 3 of a noble metal (for example, gold, silver or platinum) or an alloy containing the noble metal. Since the cantilever 10 includes the lever 1, the probe 4, the thin magnetic film 2, the noble metal particles or the thin film 3, both the near-field light and the magnetic field can be measured.

  That is, the thin magnetic film 2 formed on the surface of the probe 4 determines sensitivity and resolution when measuring the magnetic field, and senses the magnetic field of the object to be measured when measuring the magnetic field. The fine particles or thin film 3 of a noble metal (for example, gold or silver) or an alloy containing the noble metal amplifies the near-field light by the localized surface plasmon enhancement effect when the near-field light hits the probe 4. When the laser beam is irradiated from the outside, the fine particles or thin film 3 is excited and emits near-field light.

  As shown in FIG. 3A, the vibration in the Z direction of the probe 4 of the cantilever 10 is detected by a displacement detection unit 130 including a semiconductor laser element 109 and a displacement sensor 110 composed of a four-split optical detector element. The In this displacement detector 130, the laser emitted from the semiconductor laser element 109 is irradiated on the surface of the cantilever 1 opposite to the surface on which the probe 4 is formed, and the laser reflected by the cantilever 1 is incident on the displacement sensor 110. To do. The displacement sensor 110 is a four-divided sensor in which the light receiving surface is divided into four regions, and the laser incident on each of the divided light receiving surfaces of the displacement sensor 110 is photoelectrically converted and output as four electric signals. .

  Here, the displacement sensor 110 has a light receiving surface divided into four parts, and when the laser beam is irradiated from the semiconductor laser element 109 in a state where the cantilever 10 is not vibrated by the vibration unit 122, that is, in a stationary state. In addition, the reflection light from the cantilever 10 is installed at a position where it is equally incident on each of the four light receiving surfaces. The differential amplifier 111 performs predetermined arithmetic processing on the difference signal of the four electrical signals output from the displacement sensor 110 and outputs the result to the DC converter 112.

  That is, the differential amplifier 111 outputs a displacement signal corresponding to the difference between the four electrical signals output from the displacement sensor 110 to the DC converter 112. Therefore, in a state where the cantilever 10 is not vibrated by the vibration unit 122, the output from the differential amplifier 111 becomes zero. The DC converter 112 is configured by an RMS-DC converter (Root Mean Squared to Direct Current converter) that converts a displacement signal output from the differential amplifier 111 into an effective DC signal.

  The displacement signal output from the differential amplifier 111 is a signal corresponding to the displacement of the cantilever 10 and is an AC signal because the cantilever 10 vibrates. A signal output from the DC converter 112 is output to the feedback controller 113. The feedback controller 113 outputs a signal output from the DC converter 112 to the control unit PC30 as a signal for monitoring the current magnitude of the cantilever 10 and adjusts the magnitude of the excitation of the cantilever 10. A signal output from the DC converter 112 is output to the piezo driver 107 through the control unit PC 30 as a control signal for the Z stage 104. This signal is monitored by the control unit PC30, and the piezo driver 107 controls the piezo element (not shown) that drives the Z stage 104 in accordance with the value, so that the initial position of the cantilever 10 is determined before the measurement is started. I try to adjust it.

  In this embodiment, the head flying height of the hard disk drive is set as the initial position of the cantilever 10. The transmitter 102 supplies an oscillation signal for exciting the cantilever 10 to the piezo driver 107. The piezo driver 107 drives the excitation unit 122 based on the oscillation signal from the transmitter 102 to vibrate the cantilever 10 at a predetermined frequency.

  5A and 5B are diagrams schematically showing the principle of detection of the magnetic field and near-field light by the inspection unit 100 of the thermally-assisted magnetic head element shown in FIG. 3A, and the thermally-assisted magnetic head element formed on the row bar 40. FIG. 5 is an enlarged view of the configuration of a writing magnetic field generation unit 502 and a thermal assist light (near-field light) light emitting unit 504 of the unit 501 together with the cantilever 10.

  As shown in FIG. 5A, the cantilever 10 has a magnetic film 2 and a noble metal (for example, gold or the like) of the cantilever 10 at a height corresponding to the head flying height Hf from the surface of the heat-assisted magnetic head element portion 501 formed on the row bar 40. It is positioned by the Z stage 104 so that the tip 5 of the probe 4 on which the fine particles of the alloy containing silver or the like or the thin film 3 are formed is positioned. The cantilever 10 is scanned within a range of several hundred nm to several μm on a plane parallel to the recording surface 510 of the head of the row bar 40.

  In this embodiment, the row bar 40 is moved by the X stage 106 and the Y stage 107. At this time, the heat-assisted magnetic head element unit 501 is supplied with the excitation signal output from the control unit PC30 and the light emission signal 301 shown in FIG. The magnetic field generator 502 generates a writing magnetic field (alternating magnetic field) 503, and the near-field light emitting unit 504 emits heat assist light (near-field light) 505.

  The probe 4 has a magnetic body 2 and a noble metal (for example, gold or silver) or a fine particle of an alloy containing a noble metal or a thin film 3 formed on the surface.

  While the cantilever 10 is vibrated by the vibration unit 122, the X stage 106 on which the row bar 40 is mounted is moved in the X direction at a constant speed by a piezo element (not shown) controlled by a piezo driver 107. . On the other hand, when the alternating current 143 is applied while the tip portions 1421 and 1422 of the probe 142 are in contact with the electrodes 41 and 42 formed on the row bar 40 by being driven by the driving unit 143 of the probe unit 140, the writing circuit unit A write magnetic field 503 is generated from the 43 write magnetic field generator 502.

  When the probe 4 of the cantilever 10 enters the write magnetic field 503 generated by the write magnetic field generator 502, the thin film magnetic body 2 formed on the surface of the probe 4 is magnetized, and the probe 4 receives magnetic force. As a result, the vibration state of the cantilever 10 changes. This change in vibration is detected by the displacement sensor 110 in FIG. 3A. That is, when the vibration state of the cantilever 10 changes, the incident position on the light receiving surface divided into four of the displacement sensor 110 of the laser emitted from the semiconductor laser element 109 and reflected by the cantilever 10 changes.

  A change in the vibration state of the cantilever 10 can be detected by detecting the output of the displacement sensor 110 with the differential amplifier 111. By processing the detected signal by the control unit PC30, it is possible to detect the intensity distribution of the write magnetic field 503 generated by the magnetic field generation unit 502 of the thermally-assisted magnetic head element unit 501. The quality of the write magnetic field generated from the write magnetic field generator 502 can be determined by comparing the detected write magnetic field intensity distribution with a preset reference value.

  On the other hand, as shown in FIG. 5B, the X stage 106 on which the row bar 40 is placed in a state where the cantilever 10 is vibrated in the vertical direction with respect to the surface (recording surface) 510 of the row bar 40 by the vibrating unit 122. When the probe 4 reaches the region where the near-field light 505 is generated by the near-field light generator 504 by moving in the X direction at a constant speed, it is formed on the magnetic film 3 on the surface of the probe 4. The scattered light 506 of the near-field light 505 is amplified by the local surface plasmon enhancement effect by the noble metal (for example, gold, silver, etc.) or the fine particles of the alloy containing the noble metal or the thin film 3. The amplified scattered light 506 is detected by the photodetector 115 disposed in the vicinity of the cantilever 10.

  After driving the X stage 106 and moving the probe 4 a certain distance including the near-field light generator 504, the driving of the X stage 106 is stopped, and the Y stage 107 is driven to move the probe 4 in the Y direction. By moving the X stage 106 by one pitch and driving the X stage 106 in the direction opposite to the previous time to move the probe 4 a certain distance including the near-field light generator 504, the probe 4 moves the near-field light generator. The region including 504 is scanned.

  In this way, the near-field light generated from the near-field light generating unit 504 of the thermally-assisted magnetic head element unit 501 in the region near the near-field light generating unit 504 is relatively separated from the near-field light generating unit 504. It becomes possible to detect in the place. By processing the detected signal by the control unit PC30, the distribution of the intensity of the near-field light generated from the near-field light generation unit 504 can be obtained. The quality of the near-field light emission from the near-field light generator 504 can be determined by comparing the obtained near-field light intensity distribution with preset reference data.

  Further, the positional relationship between the write magnetic field (alternating magnetic field) 503 generated by the magnetic field generation unit 502 of the heat-assisted magnetic head element unit 501 and the thermal assist light (near-field light) 505 generated from the near-field light generation unit 504 is also measured. It becomes possible. Thereby, it is possible to inspect the intensity distribution of the write magnetic field and the near-field light of the thermally-assisted magnetic head element and measure the positional relationship between them at the earliest possible stage during the manufacturing process.

  Here, when inspecting the near-field light generating unit 504 of the thermally-assisted magnetic head element unit 501, the X stage 106 and the Y stage 105 are driven by a piezo element (not shown) while vibrating the cantilever 10, and the probe 4 is scanned over the region including the region where the near-field light 505 is emitted. During this inspection, the near-field light generator 504 continues to emit the near-field light 505. In order to emit the near-field light 505 from the near-field light generating unit 504, a laser light source unit (not shown) formed from outside the thermally-assisted magnetic head element unit 501 or inside the thermally-assisted magnetic head element unit 501. It is necessary to continue irradiating the near-field light generating unit 504 with the laser emitted from. This laser irradiation is continued while scanning the upper part of the region including the near-field light generating unit 504 with the probe 4.

  The light emission efficiency of the laser at this time is about several percent with respect to the laser irradiation energy, and the rest is converted into thermal energy, and the near-field light generating unit 504 and its vicinity generate heat. Since the laser irradiation time for inspecting the region including the near-field light generating unit 504 is relatively long, for example, a laser is generated by applying 50 W power to a laser light source unit (not shown). In this case, the temperature of the near-field light generating unit 504 and the vicinity thereof increases to about 200 to 300 ° C. As a result, the row bar 40 is thermally expanded during the inspection to cause a displacement of the inspection position, and the cantilever 10 is also thermally deformed, which may reduce the inspection accuracy.

  Therefore, in the present embodiment, the mounting portion 114 on which the row bar 40 is mounted has a row bar holder portion 1145 formed of a conductive material (for example, silicon carbide) having good thermal conductivity as shown in FIG. A cooling part 1146 for cooling the rover holder part 1145 located at the lower part of the rover holder part 1145 and a temperature sensor 1157 embedded in the rover holder part 1145 to detect the temperature of the rover holder part 1145 are provided. . The row bar holder portion 1145 has a mounting portion 1142 on which the row bar 40 is mounted, and an exhaust port 1147 for holding the row bar 40 mounted on the mounting portion 1142 by vacuum suction (not shown). . The cooling unit 1146 is provided with a cooling water introduction port 1148 and a discharge port 1149 for discharging the cooling water introduced inside to the outside, and the cooling water supplied by a pipe (not shown) is introduced into the introduction port 1148. Is supplied to the inside of the cooling unit 1146 from the discharge port 1149 through a water channel (not shown) inside the cooling unit 1146.

  The mounting unit 114 is configured as shown in FIG. 6 so that the temperature sensor 1157 embedded in the rover holder unit 1145 monitors the temperature of the rover holder unit 1145 with the control unit PC30 and the cooling unit 1146 uses the rover holder. By cooling the portion 1145, the near-field light 505 can be detected from the near-field light generating portion 504 using the probe 4 while the row bar 40 placed on the row bar holder portion 1145 is maintained at a constant temperature. It becomes possible.

  As a result, it is possible to prevent occurrence of an inspection position shift due to thermal expansion of the row bar 40 during inspection, and it is possible to suppress the occurrence of thermal deformation of the cantilever 10, and thus it is possible to maintain high inspection accuracy. become.

  FIG. 7 is a flowchart showing an operation procedure for inspecting the row bar 40 using the inspection unit 100 of the above-described heat-assisted magnetic head.

  First, one row bar 40 is taken out from the supply tray 331 of the tray mounting unit 330 by the handling unit 310, and the reference surface 1141 of the mounting unit 114 of the inspection unit 100 of the thermally-assisted magnetic head element waiting at the sample delivery station H. The row bar 40 is placed on the placement unit 114 in a state where the row bar 40 is pressed against the placement unit 114 (S701). Next, the inspection stage 101 moves along the guide rail 150 and reaches the sample inspection station M (S702).

  In the sample inspection station M, the camera 103 of the inspection unit 100 of the thermally assisted magnetic head images the row bar 40 placed on the placement unit 114 to obtain the position information of the row bar 40, and based on the obtained position information. The controller PC30 controls the piezo driver 107 to drive the X stage 106 or the Y stage 105, thereby performing alignment for adjusting the position of the row bar 40 (S703), and moving the row bar 40 to the measurement position to measure heat. The assist magnetic head element portion 501 is positioned (S704).

  Next, the drive unit 143 of the probe unit 140 is operated to advance the probe 141, and the tip portions 1411 and 1412 of the probe 141 are moved to the probe electrodes 41 and 42 of the heat-assisted magnetic head element unit 501 formed on the row bar 40. The excitation signal 301 is supplied to the heat-assisted magnetic head element unit 501 and, at the same time, a light emission signal or direct excitation laser light is supplied to the heat-assisted magnetic head element unit 501 by means not shown (S705). . As a result, a writing magnetic field (alternating magnetic field) 503 is generated from the magnetic field generation unit 502, and light assist light (near field light) 505 is generated from the near-field light issuing unit 504.

  Next, the cantilever 10 is approached to the recording surface 510 of the thermally-assisted magnetic head element unit 501 by controlling a piezo element (not shown) that drives the Z stage 104 by the piezo driver 107 controlled by the control unit PC30. (S706).

  Next, driving the piezo element (not shown) by the piezo driver 107 to move the X stage 106 at a constant speed in the X direction, the cantilever 10 is vibrated by the vibration unit 122 in the Y direction. The cantilever 10 is scanned within a plane parallel to the recording surface 510 of the thermally-assisted magnetic head element portion 501 in a range of several hundreds of nanometers to several micrometers in length and width respectively (S707). ).

  By this scan, a change in vibration of the cantilever 10 due to the write magnetic field 503 generated from the magnetic field generation unit 502 of the thermally-assisted magnetic head element unit 501 is detected from the displacement detection unit 130 including the semiconductor laser element 109 and the position sensor 110. The position information of the magnetic field generation unit 502 and the distribution information of the magnetic field generated by the magnetic field generation unit 502 are obtained by processing by the control unit PC30.

  On the other hand, the near-field light 505 generated from the near-field light emitting unit 504 is precious metal (for example, gold or silver) formed on the surface of the probe 4 of the cantilever 10 that has reached the near-field light 505 generation region by scanning. Alternatively, it is amplified by the localized surface plasmon enhancement effect by the fine particles of the alloy containing noble metal or the thin film 3 and detected by the detector 115. The detection signal 302 from the detector 115 that has detected the amplified near-field light is processed by the control unit PC 30 to obtain each intensity distribution of the heat assist light (near-field light) 505, and the near-field light emitting unit 504 Obtain position information and surface shape information. Then, the positional relationship between the magnetic field generator 502 and the near-field light emitter 504 is measured (side length) from the position information of the magnetic field generator 502 and the position information of the near-field light emitter 504 (S708). It is checked whether the interval between 502 and the near-field light emitting unit 504 is formed at a predetermined interval.

  Next, the drive unit 143 of the probe unit 140 is operated to retract the probe 141, and the tip 1411 and 1412 of the probe 141 are separated from the probe electrodes 41 and 42 and further measured on the row bar 40. If there is a part to be further measured, the cantilever 10 is lifted by the Z stage 104 and moved to the next head measurement position (S710), and the operation from S705 is performed. Repeat. On the other hand, if there is no further measurement point, the inspection stage 101 is moved along the guide rail 150 to the sample delivery station H with the cantilever 10 raised by the Z stage 104 (S711), and the measurement is completed. 40 is taken out by the handling unit 310 and stored in the non-defective product collecting tray 332 or the defective product collecting tray 333 according to the inspection result (S712).

  Next, it is checked whether or not there is an uninspected row bar 40 in the supply tray 331 (S713). If there is an uninspected row bar 40, the process returns to S701 to take out the uninspected row bar 40 from the supply tray 331. , Transport to the inspection stage 101 and execute the steps from S701. On the other hand, when there is no uninspected row bar 40 in the supply tray, the measurement ends (S714).

  After the measurement is completed, the row bar determined to be a non-defective product stored in the non-defective product storage tray 332 is conveyed and processed in the next process of manufacturing the magnetic head. On the other hand, the row bar 1 determined to be defective stored in the defective product storage tray 333 is discarded without being sent to the next process, or is conveyed to a defect analysis process for investigating the cause of the defect.

  According to this embodiment, the write magnetic field (alternating magnetic field) and the heat assist light (near field light) generated from the heat assist magnetic head element 501 formed on the row bar 40 by the inspection unit 100 of the heat assist magnetic head can be converted into the cantilever 10. Can be detected by one scan, and inspection can be performed in a relatively short time upstream of the manufacturing process.

  In the embodiment described above, a state where a magnetic field is generated from the write magnetic field generation unit 502 of the write circuit unit 43 by applying an alternating current from the probe 141 to the electrodes 41 and 42 of the elements formed on the row bar 40. In this method, the cantilever 10 having the probe 4 formed in the vicinity of the tip thereof is vibrated and the state of the vibration is measured, that is, a thermally assisted magnetic head formed on the rover 40 by an MFM (Magnetic Force Microscope) method. Although the method for measuring the state of the element 501 has been described, an alternating current is not applied from the probe 141 to the probe electrodes 41 and 42 of the element formed on the row bar 40, and the magnetic field is generated from the write magnetic field generation unit 502 of the write circuit unit 43. The cantilever 10 is vibrated in contact with the row bar 40 in a state where no The present invention can also be applied to the case where the surface shape of the row bar 40 is measured by a method of measuring the vibration state, that is, an AFM (Atomic Force Microscope) method.

  DESCRIPTION OF SYMBOLS 1 ... Lever 4 ... Probe 10 ... Cantilever 30 ... Control part PC 40 ... Rover 100 ... Inspection part 101 ... Inspection stage 104 ... Z stage 105 ... Y stage 106 ... X stage 107 ... piezo driver 111 ... differential amplifier 114 ... mounting unit 115 ... photodetector 130 ... displacement detecting unit 140 ... probe unit 300. ..Conveying unit 310... Handling robot 330... Tray mounting unit 400.

Claims (8)

A tray portion for storing a row bar on which a large number of thermally-assisted magnetic head elements are formed;
Generated from the write magnetic field generating section of the heat-assisted magnetic head element formed on the row bar mounted on the mounting section at the sample inspection position, with a mounting section for mounting a row bar on which a large number of heat-assisted magnetic head elements are formed Measuring means for measuring the intensity distribution of the magnetic field and the intensity distribution of the near-field light generated from the near-field light emitting unit;
Measuring means moving means for moving the measuring means between the sample inspection position and a sample delivery position for delivering the row bar stored in the tray section to the measuring means;
A sample delivery means for placing the row bar on the placement portion of the measurement means taken out from the tray portion and moved to the sample delivery position by the measurement means moving means;
Compared with reference data stored in advance, data on the intensity distribution of the magnetic field generated from the writing magnetic field generation unit measured by the measuring means and data on the intensity distribution of the near-field light generated from the near-field light emitting unit And a data processing unit for inspecting the thermally-assisted magnetic head element,
The mounting unit of the measuring unit includes a cooling mechanism that cools the row bar that generates heat from the near-field light emitting unit by generating the near-field light,
The measuring means includes a cantilever having a probe formed at the tip and capable of vibrating up and down, and a table for moving the mounting portion within a plane within a small range, and the cantilever is moved up and down in the vicinity of the surface of the row bar. The magnetic field intensity distribution generated from the writing magnetic field generating unit is measured and the cantilever is vibrated up and down by moving the mounting unit on which the row bar is mounted on the table while being vibrated, within a plane within a minute range. A thermal-assisted magnetic head element inspection apparatus for measuring an intensity distribution of near-field light generated from the near-field light emitting unit by scanning a region including the near-field light emitting unit . The probe formed at the tip of the cantilever has a magnetic film formed on the surface, and a fine particle or thin film of a noble metal such as gold, silver or platinum or an alloy containing the noble metal is formed on the magnetic film. The heat-assisted magnetic head element inspection apparatus according to claim 1 . The mounting unit of the measuring means supplies the refrigerant to the row bar holder cooling unit for cooling the row bar holder unit, the row bar holder cooling unit for cooling the row bar holder unit, the row bar holder unit for mounting the row bar and determining the position of the row bar. thermally assisted magnetic head element inspecting device according to claim 1 or 2, characterized in that it comprises a coolant supply portion for discharging. The thermally assisted magnetic head element inspection apparatus according to claim 3 , wherein the mounting unit of the measuring unit further includes a temperature monitoring unit that monitors the temperature of the row bar holder unit. A row bar on which a large number of thermally-assisted magnetic head elements are formed is taken out of the tray portion and placed on the placement portion of the measuring means waiting at the sample delivery position,
Move the measuring means on which the row bar is mounted on the mounting portion to the sample inspection position,
In the sample inspection position, the intensity distribution of the magnetic field generated from the writing magnetic field generation unit of the thermally assisted magnetic head element formed on the row bar mounted on the mounting unit and the intensity of the near field light generated from the near field light emitting unit. Measure the distribution and
By comparing the measured data of the intensity distribution of the magnetic field generated from the writing magnetic field generating unit and the data of the intensity distribution of the near-field light generated from the near-field light emitting unit with the data stored in advance. A method for inspecting a thermally assisted magnetic head element, comprising:
When measuring the intensity distribution of the magnetic field generated from the writing magnetic field generating part and the intensity distribution of the near-field light generated from the near-field light emitting part of the heat-assisted magnetic head element formed on the row bar mounted on the mounting part. And measuring the intensity distribution of the magnetic field and the intensity distribution of the near-field light while cooling the row bar that generates heat by generating the near-field light ,
A probe is formed at the tip to measure the intensity distribution of the magnetic field and the intensity distribution of the near-field light.
The mounting portion on which the row bar is mounted in a state where the formed cantilever is vibrated up and down is flattened.
By moving a small range in the plane, the probe of the cantilever is moved to the thermally assisted magnetic field.
A method for inspecting a thermally-assisted magnetic head element , comprising: scanning a region including a write magnetic field generation unit and a region including a near-field light emitting unit of a magnetic head element. The probe formed at the tip of the cantilever has a magnetic film formed on the surface, and a fine particle or thin film of a noble metal such as gold, silver or platinum or an alloy containing the noble metal is formed on the magnetic film, The magnetic field distribution is measured by a magnetic film formed on the surface of the probe when the probe of the cantilever is scanned over a region including a write magnetic field generation unit of the thermally assisted magnetic head element, and the probe of the cantilever is measured. the noble metal or the noble metal such as gold or silver or platinum on the magnetic film formed on the surface of the probe when査 run a region including the near-field light-emitting portion of the thermally assisted magnetic head element 6. The heat-assisted magnetic head element inspection method according to claim 5 , wherein a distribution of the near-field light is measured by a fine particle or a thin film of an alloy including the alloy. Measuring the intensity distribution of the magnetic field and the intensity distribution of the near-field light while cooling the row bar is characterized by cooling while supplying and discharging the refrigerant to the mounting portion on which the row bar is mounted. The thermally assisted magnetic head element inspection method according to claim 5 or 6 . The measurement of the intensity distribution of the magnetic field and the intensity distribution of the near-field light while cooling the row bar is performed by monitoring the temperature of the placement unit on which the row bar is placed. 5. The heat-assisted magnetic head element inspection method according to 5 or 6 .

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