JP6475490B2 - Magnetic wire apparatus and method for manufacturing magnetic wire mounting board - Google Patents

Description

  The present invention relates to a magnetic wire apparatus and a method for manufacturing a magnetic wire mounting board.

  Liquid crystal is conventionally used as a spatial light modulator, but in recent years, magneto-optical spatial light modulation using a magneto-optical material, which is expected to be capable of high-speed processing and pixel miniaturization of 1 μm or less. Development of the vessel is in progress.

  In a magneto-optical spatial light modulator (hereinafter simply referred to as “spatial light modulator”), when light incident on a magnetic material is transmitted, the direction of polarization of the light is changed (rotated) and emitted. We are using. Further, when the light incident on the magnetic material is reflected, the Kerr effect is used in which the direction of the polarized light is changed (rotating) and emitted. Then, the magnetization direction of the light modulation element in the pixel (selected pixel) to be displayed brightly is different from the magnetization direction of the light modulation element in the other pixels (non-selected pixels). This causes a difference in the rotation angle (rotation angle) of the polarized light between the light emitted from the selected pixel and the light emitted from the non-selected pixel, and through a polarizer that transmits polarized light in a specific direction. Display only selected pixels brightly. As means for changing the magnetization direction of such a light modulation element, in addition to a magnetic field application method for applying a magnetic field to the light modulation element, in recent years, a spin injection method for injecting spin by supplying a current to the light modulation element is available. Are known.

  As such a spatial light modulator, one that uses a plurality of fine wire-like magnetic bodies (hereinafter simply referred to as “magnetic fine wires”) and generates a magnetic domain in the length direction is known. That is, when electrons are supplied by passing a current in the length direction, all the domain walls generated so as to separate the magnetic domains are moved equidistantly in the length direction of the magnetic wires, thereby shifting the magnetic domains. Can do. By this shift movement, the target pixel can be selected pixel or non-selected pixel.

  On the other hand, magnetic recording media such as hard disk drives (HDDs) have been increased in the recording density and the speed of recording and reproduction as the amount of information handled increases. As the recording density is increased, the tracks of recording media such as magnetic disks used for HDDs are narrowed, and the length of one data (1 bit) in the track is shortened. In order to detect magnetism, the recording / reproducing system is a magnetic system using a magnetic head composed of a magnetoresistive element such as a GMR (Giant MagnetoResistance) element or a TMR (Tunnel MagnetoResistance) element, or A magneto-optical method using laser light irradiation is applied.

  Recording and reproduction on such a magnetic disk are carried out along the track (in the circumferential direction of the disk) by rotating the disk with a spindle motor and moving the magnetic head or the laser beam irradiation spot only in the radial direction of the disk. ) Magnetize (record) in a predetermined direction, or detect (reproduce) magnetism. In order to increase the speed of recording and reproduction in such a disc, firstly, increasing the rotational speed of the disc is mentioned. However, there is a limit to increasing the rotational speed due to problems such as the time required for track magnetization during recording, the time required for magnetic detection during reproduction, and malfunctions due to disk vibration.

  Therefore, as a method for moving recorded data without driving a recording medium, a memory device is known in which the magnetic thin wires are formed in a ring shape or the like to form a track. This is because when a magnetic substance is formed in a thin line shape, magnetic domains are generated in the length direction, and when electrons (current) are further supplied in the length direction, all the domain walls generated so as to separate the magnetic domains are magnetic. It utilizes the characteristic of shifting by moving the same distance in the length direction of the thin line. That is, each recording and reproducing magnetic head is fixed at a predetermined position on a track (magnetic thin wire), and a desired magnetic domain sandwiched between domain walls is supplied to the magnetic head by reversibly supplying current from both ends of the track. It moves to the position which opposes (refer above patent document 1 grade | etc.,).

JP 2013-242940 A

A.Himeno, S.Kasai, and T.Ono, “Depinning fields of a magnetic domain wall from asymmetric notches”, JOURNAL OF APPLIED PHYSICS 99, 08G304 (2006)

  A device that achieves the intended purpose by shifting the magnetic domain using magnetic thin wires, such as the spatial light modulator and the magnetic recording medium, will be referred to as a “magnetic thin wire device”. In such a magnetic wire device, a device capable of shifting the magnetic domain in both directions in the length direction of the magnetic wire has been proposed, but here, one direction in the length direction of the magnetic wire is proposed. Consider a device that shifts the magnetic domain only.

  In such a magnetic wire device that shifts the magnetic domain only in one direction of the length of the magnetic wire, electrons are supplied only in one direction of the length of the magnetic wire, and the magnetic domain is moved in the direction of movement of the electron. Even if the magnetic domain is stopped after being shifted, the magnetic domain vibrates without immediately stopping completely. Since the energy of this vibration includes a component that attempts to return the magnetic domain in the direction opposite to the shift movement direction, the magnetic domain may shift in the direction opposite to the shift movement direction. Therefore, it is desirable to prevent the magnetic domain immediately after the shift movement from stopping in a desired position and to return in the opposite direction to the shift movement.

  On the other hand, Non-Patent Document 1 discloses that, in a plurality of magnetic thin wires formed in parallel, the width of the magnetic thin wires is changed in the parallel direction. That is, it is shown that a structure in which the width of the magnetic wire suddenly increases at a certain position in one direction along the length of the magnetic wire and then gradually decreases in width appears.

  In such a configuration, if electrons are supplied from the side where the width of the magnetic wire in the lengthwise direction of the magnetic wire suddenly increases (left side of the magnetic wire shown in the figure in the same document), the width of the magnetic wire It is possible to hold the magnetic domain in a range from a position where the diameter suddenly increases to a position where the width gradually decreases and becomes the narrowest. In this case, if the magnetic domain is shifted, the width gradually decreases from the position where the width of the next magnetic wire is suddenly increased to the position where the next width is the narrowest. The energy fluctuations in the magnetic field are slow and the magnetic domains move smoothly. In this case, even if the magnetic domain after the movement vibrates and tries to move in the opposite direction to the shift movement, the width of the magnetic fine line abruptly appears on the rear side of the magnetic domain (the left side of the magnetic fine line shown in the figure in the same document) Since it is large and the width is narrowest immediately after that, the energy barrier that must be overcome to move the magnetic domain is large and cannot be easily overcome, so the magnetic domain moves in the opposite direction to the shift movement. It is possible to prevent.

  However, in the technique of Non-Patent Document 1, the width of the magnetic wire varies in the parallel direction of the plurality of magnetic wires. For this reason, adjacent magnetic wires are moved closer to or away from each other depending on the position in the length direction of the magnetic wires. For this reason, the magnetic domains between the magnetic wires are strongly influenced magnetically at positions where adjacent magnetic wires are close to each other, and the magnetic domains between the magnetic wires are not so magnetically affected at other positions. Become. As described above, there is a problem that when the magnetic influence between the magnetic thin wires adjacent to each other is increased or decreased, the magnetic domain may not move smoothly. In this case, if it is attempted to reduce the magnetic influence between adjacent magnetic thin wires and keep the magnetic thin wires away from each other, it becomes difficult to form a large number of magnetic thin wires within a limited area. .

  The present invention provides a magnetic wire device in which a magnetic domain shifts only in one direction along the length of the magnetic wire, and the magnetic domain after the shift movement is reliably stopped at a desired position, and the magnetic wires of adjacent magnetic wires are magnetically moved. It is an object of the present invention to provide a magnetic wire apparatus that can move magnetic domains smoothly without being affected, and a method for manufacturing a magnetic wire mounting board.

One embodiment of the present invention is a magnetic wire apparatus including a magnetic wire, an electrode, and a recess.
According to the present invention, the magnetic thin film has a magnetic film formed in a thin line shape, a magnetic domain having a magnetization direction different from that of the other part can be formed in a part of the longitudinal direction, and a plurality of the magnetic wires are arranged in parallel. Yes. The electrode always supplies electrons from one of the magnetic wires in the longitudinal direction to the other when shifting the magnetic domain. The recesses are provided at a plurality of locations of each magnetic wire, and trap the magnetic domains that shift in the magnetic wire due to the movement of electrons. Further, the recess is formed on the upper surface of the magnetic wire, and has an inclined surface from the opening of the recess to the bottom so that the inclination on the downstream side is gentler than that on the upstream side of electron movement.
Therefore, according to the present invention, the shape of the recess is formed so that the slope on the downstream side becomes gentler than that on the upstream side of the electron movement, so that the magnetic domain after the shift movement is reliably stopped at a desired position. In addition, the magnetic domain moves smoothly without being affected by the magnetic influence of adjacent magnetic wires.

Another embodiment of the present invention is a method for manufacturing a magnetic wire mounting board comprising a first step and a second step.
According to the present invention, in the first step, a magnetic film is formed on a substrate in a thin line shape, a plurality of magnetic films are arranged in parallel, and a magnetic domain having a magnetization direction different from that of other portions in a part in the longitudinal direction. A magnetic fine wire is formed. In the second step, concave portions that are provided at a plurality of locations of each magnetic wire and trap magnetic domains that shift and move in the magnetic wire due to the movement of electrons are formed using the nanoimprint method. In the second step, the concave portion is formed on the upper surface of the magnetic wire, and has an inclined surface from the opening of the concave portion to the bottom so that the inclination on the downstream side becomes gentler than the upstream side of the electron movement. Form.
Therefore, according to the present invention, the shape of the recess can be formed so that the slope on the downstream side becomes gentler than the upstream side of the movement of electrons, so that the magnetic domain after the shift movement can be surely placed at a desired position. The movement of the magnetic domains is smooth without stopping and being affected by the magnetic influence of the adjacent magnetic wires.
Further, by the nanoimprint method, further miniaturization can be achieved when manufacturing the magnetic fine wire mounting substrate.

  According to the present invention, in a magnetic wire device in which a magnetic domain shifts only in one direction along the length of the magnetic wire, the magnetic domain after the shift movement is reliably stopped at a desired position, and the adjacent magnetic wire The magnetic domain can be moved smoothly without being affected by the magnetic field.

FIG. 1 is a plan view of a spatial light modulator according to an embodiment of the present invention. FIG. 2 is a perspective view illustrating the configuration of the spatial light modulator according to the embodiment of the present invention. FIG. 3 is a schematic diagram illustrating a configuration of a display device using the spatial light modulator illustrated in FIG. FIG. 4 is a detailed explanatory view of the recess. 4A is an enlarged perspective view of a magnetic wire cut in the longitudinal direction. FIGS. 4B and 4C are positions of electrons moving around the concave portion of the magnetic wire, and are necessary for the movement of the electrons. It is a graph which shows the relationship with various energy. FIG. 5 is an explanatory diagram of an example of a recess as a modification. (A)-(c) is drawing corresponding to FIG. 4 (a)-(c), respectively. FIG. 6 is an explanatory diagram of an example of a recess serving as a modification. (A)-(c) is drawing corresponding to FIG. 4 (a)-(c), respectively. FIG. 7 is an explanatory diagram of an example of a recess serving as a modification. (A)-(c) is drawing corresponding to FIG. 4 (a)-(c), respectively. FIG. 8 is a schematic diagram of a magnetic recording medium according to an embodiment of the present invention, where (a) is a plan view and (b) is a partially enlarged view of (a). FIG. 9 is a partial perspective sectional view of the magnetic recording medium shown in FIG. FIG. 10 is a flowchart for explaining an example of a method for manufacturing a magnetic wire mounting board. FIG. 11 is a drawing corresponding to FIG. 4 in a comparative example for one embodiment of the present invention. 11A and 11C are diagrams corresponding to FIG. 4A, respectively, and FIG. 11B is a graph corresponding to FIGS. 4B and 4C corresponding to FIG. 11A. is there. FIG. 11D is a graph corresponding to FIGS. 4B and 4C corresponding to FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

[Spatial light modulator]
First, an example in which the magnetic wire device of the present invention is applied to a spatial light modulator will be described.

(Schematic configuration of spatial light modulator)
FIG. 1 is a plan view of the spatial light modulator of this embodiment. FIG. 2 is a perspective view illustrating the configuration of the spatial light modulator. FIG. 3 is a schematic diagram illustrating a configuration of a display device using the spatial light modulator illustrated in FIG.

  As shown in FIG. 1, a spatial light modulator (magnetic wire device) 10 is formed by two-dimensionally arranging pixels 1b. The spatial light modulator 10 includes a substrate 2, eight striped magnetic wires 1 extending in the X direction on the substrate 2, an insulating layer 6 that insulates between the magnetic wires 1, 1, and a magnetic wire 1 is provided with a positive electrode 31 and a negative electrode 32 connected to one end and the other end. In the spatial light modulator 10 having such a configuration, a scanning current source 8 (see FIG. 2) is connected to each magnetic wire 1 with the positive electrode 31 and the negative electrode 32 serving as terminals of a pair of electrodes. A magnetic head for data writing (the main magnetic pole is shown in FIG. 2 as the data writing unit 50) is made to face the write area 1w and operated. In FIG. 2, the spatial light modulator 10 omits the substrate 2 and the like and shows only three magnetic thin wires 1, and further shows a part of the magnetic thin wire 1 omitted by broken lines.

As shown in FIG. 1, the magnetic wire 1, a region separated by a predetermined unit length in the fine line direction L _b as one pixel, eight pixels 1b in this example are arranged continuously in the fine line direction And each of the pixels 1b shows one of two directions of magnetization, here, upward or downward magnetization (see FIG. 2). That is, as shown in FIG. 2, the magnetic fine wire 1 is generated by dividing the magnetic domain in the fine wire direction. In the magnetic wire 1, a region in which all (eight in the present embodiment) pixels are provided is referred to as a pixel region 1 px. Since the spatial light modulator 10 includes eight magnetic thin wires 1 in this example, the spatial light modulator 10 includes pixels 1b (pixel array) arranged in a matrix of 64 columns of 8 columns × 8 rows. In this specification, the spatial light modulator 10 (pixel array) uses the row direction (X direction) as the fine line direction (length direction) of the magnetic fine wire 1, but the row and column may be interchanged. Note that a pixel array of a general spatial light modulator has, for example, about 2.70 million pixels in the horizontal (X) direction 1920 × vertical (Y) direction 1080 in full high vision, but is described in a simplified manner in this specification for the sake of convenience. Therefore, it is illustrated by 8 columns × 8 rows.

Here, the pixel 1b in the spatial light modulator 10 is a region including a gap (insulating layer 6) between the magnetic fine wires 1 and 1, as indicated by a broken line frame in FIG. unit refers to a region separated by a length L _b. In general, a pixel is the smallest unit capable of displaying tone and gradation with one pixel. For example, in order to display full color (RGB 3 colors × 256 gradations), each pixel has a lot of information of 24 bits. However, the pixel in the present specification indicates, as an example, means for presenting light / dark binary (1 bit) as information in the minimum unit of display by the spatial light modulator 10.

(Light modulation operation of spatial light modulator)
The light modulation operation of the spatial light modulator 10 shown in FIGS. 1 and 2 will be described with reference to FIG. 3 using the display device 100 using the spatial light modulator 10. The display device 100 may have the same configuration as that using a conventional magneto-optical spatial light modulator or a device using a spin-injection magnetization reversal element as a light modulation element. The spatial light modulator 10 according to the present embodiment is a reflection type, and the magnetic thin wire 1 to be modulated is made of a perpendicular magnetic anisotropic material, and the magnetization direction (indicated by an arrow 40 in FIG. 2) is upward. Alternatively, the display device 100 preferably has the following configuration because the substrate 2 transmits light and the substrate 2 transmits light. Immediately below the spatial light modulator 10 (pixel array), an optical system OPS having a light source or the like that irradiates light (laser light) toward the spatial light modulator 10, and light emitted from the optical system OPS is spatial light. A polarizer PFi that makes light of one polarization component (polarized light in one direction, hereinafter referred to as appropriate polarization) before entering the modulator 10 (magnetic wire 1), and enters the spatial light modulator 10 from below. A half mirror HM that transmits polarized light (incident polarized light) and reflects light emitted from the spatial light modulator 10 (magnetic wire 1) to the side is disposed. Then, to the side of the half mirror HM below the spatial light modulator 10, the polarizer PFo that shields light of a specific polarization component from the light that is reflected by the half mirror HM and transmitted through the polarizer PFo. A detector PD for detecting light is arranged.

  The optical system OPS includes, for example, a laser light source, a beam expander that is optically connected to the laser light source and expands the laser light onto the entire surface of the pixel array of the spatial light modulator 10, and further expands the laser light. It is composed of a lens that makes parallel light (not shown). Since the light (laser light) emitted from the optical system OPS includes various polarization components, this light is transmitted through the polarizer PFi in front (lower) of the spatial light modulator 10 to obtain one polarization component. Use light (polarized light). The polarizers PFi and Pfo are polarizing plates, respectively, and the detector PD is an image display means such as a screen.

  The optical system OPS irradiates parallel laser light so as to enter the spatial light modulator 10 perpendicularly to the film surface (at an incident angle of 0 °). The laser light passes through the polarizer PFi to become polarized light (incident polarized light), passes through the half mirror HM, and enters from the lower side of the spatial light modulator 10 toward all the pixels 1b, that is, the magnetic thin wires 1. The incident polarized light passes through the substrate 2 and is reflected by the magnetic wire 1 and is emitted from the spatial light modulator 10 as outgoing polarized light. Since the incident angle is 0 °, the outgoing polarized light has the same optical path as the incident polarized light. Therefore, by arranging a half mirror HM inclined by 45 ° with respect to the spatial light modulator 10 between the polarizer PFi and the spatial light modulator 10, only the outgoing polarization is reflected by reflecting the outgoing polarization to the side. To the polarizer PFo. The polarizer PFo shields specific polarized light out of all outgoing polarized light, and light transmitted through the polarizer PFo enters the detector PD. The configuration may be such that the incident polarized light is tilted and incident on the spatial light modulator 10 (incident angle> 0 °), the outgoing polarized light and the optical path do not overlap, and the half mirror HM is not disposed. However, since the magneto-optical effect is higher as the incident direction is closer to the magnetization direction, the incident angle is preferably within about 30 °.

  When the light is reflected or transmitted by the magnetic wire 1, the direction of polarization is one direction and the opposite direction corresponding to the magnetization direction in the region where the light of the magnetic wire 1 is incident due to the magneto-optic effect. Rotate at the same angle. In FIG. 3, the light is rotated at an angle θk due to the Kerr effect when reflected by the magnetic thin wire 1, the light reflected by the region showing the upward magnetization direction is + θk, and the light reflected by the region showing the downward magnetization direction is -Θk rotation. The polarizer PFo shields light that has been rotated by -θk with respect to incident polarized light. Therefore, the outgoing polarized light reflected by the downward magnetization direction region (magnetic domain) is shielded by the polarizer PFo, while the outgoing polarized light reflected by the upward magnetic direction magnetic domain passes through the polarizer PFo and passes through the detector PD. Is irradiated. Therefore, the light emitted from one magnetic wire 1 is displayed on the detector PD in a pattern that is divided into bright and dark (black and white) for each magnetic domain generated in the magnetic wire 1. Therefore, in one magnetic thin wire 1, a magnetic domain is generated as a desired magnetization direction, either upward or downward, for each pixel segmented in the thin line direction, so that light / dark (white / black) is generated for each pixel. It is possible to display an image that has been cut.

  In a spatial light modulator or the like in which a magnetic body (light modulation element) that performs light modulation operation is separated for each pixel, each light modulation element is individually connected to a pair of different combinations, etc. Bright / dark rewriting is possible, and since the position of each light modulation element is fixed, the position of each pixel in the pixel array is not shifted. On the other hand, in the spatial light modulator 10 according to the present embodiment, as shown in FIG. 1, one magnetic wire 1 is shared by a plurality of pixels continuous in the X (row) direction, and Y (column ) Is separated by one pixel only in the direction. Therefore, individual rewriting cannot be performed between the pixels 1b in the same row.

As shown in FIG. 2, such a spatial light modulator 10 is applied with a magnetic field applied by, for example, a data writing unit 50 (magnetic head) in the writing region 1w of the magnetic wire 1 (data writing). After the magnetic domain having a desired magnetization direction for indicating light / dark (written) is set (written), the magnetic domain is moved from the writing area 1w to the predetermined magnetic thin line 1 by the domain wall movement. To the position (pixel 1b) (the movement direction is indicated by an arrow 42 in FIG. 2). The magnetic thin wire 1 is supplied with current in the direction of the thin wire from one end to the other end through a pair of electrodes 31 and 32 (see FIG. 1) connected to both ends (in FIG. 1, the current flows from the right side to the left side). The electrons move in the direction of the thin line opposite to the current flow (in FIG. 1, the electrons move from the left side to the right side), and the domain wall moves in the same direction. In the magnetic wire 1, since the size (volume) of each generated magnetic domain is maintained, so-called shift movement is performed in which all magnetic domains move equidistantly as the domain wall moves. Since the moving speed of the domain wall depends on the current density, the magnetic domain can be moved by a desired distance depending on the supply time by supplying a constant current to the magnetic wire 1. Then, since the stop when stopping the supply of current is also domain wall motion, by supplying the pulse current to the magnetic nanowire 1 at a scanning current source 8, it is possible to shift movement intermittently magnetic domains in unit length L _b increments .

(Magnetic wire)
The magnetic wire 1 is formed by forming a magnetic body (magnetic film) into a thin wire shape that is sufficiently long with respect to the thickness and width. As shown in FIG. 1, in the spatial light modulator 10, the magnetic fine wires 1, 1,... Are formed on the substrate 2 in parallel with each other with the insulating layer 6 interposed therebetween in a plan view. As described above, the magnetic thin line 1 includes a region to be a pixel, and the pixel region 1px in which a predetermined number (eight in this example) of pixels are continuously provided in the thin line direction is a portion that performs light modulation. The pixel region 1px is an incident region of light in the magnetic thin wire 1, and when light incident on the pixel region 1px is transmitted through or reflected from the magnetic thin wire 1, the pixel region 1px differs depending on the magnetization direction in the pixel 1b for each pixel. Modulated into light rotated at one of two angles. In addition, the magnetic thin line 1 is provided with a writing region 1w in a region partitioned in the thin line direction outside the pixel region 1px (left side of the pixel region 1px in FIG. 1). The write region 1w is a region that is changed by the data writing unit 50 in the same magnetization direction as that of one of the pixels 1b provided on the magnetic wire 1. The magnetic thin line 1 generates a magnetic domain having the same magnetization direction as the upward or downward magnetization direction of a certain pixel 1b in the writing area 1w, and this magnetic domain is moved in the thin line direction to reach the pixel 1b in the pixel area 1px. Thus, the pixel 1b has a desired magnetization direction. In the spatial light modulator 10, such an operation (pixel driving) is executed in parallel for each magnetic wire 1 as shown in FIG.

  The magnetic wire 1 is made of a magneto-optical material having perpendicular magnetic anisotropy. As such a material, a known ferromagnetic material can be applied. Specifically, a multilayer film such as a Co / Pd multilayer film in which transition metals such as Co and Pd, Pt, and Cu are repeatedly laminated, and Tb- An alloy (RE-TM alloy) of a rare earth metal such as Fe—Co, Gd—Fe and a transition metal can be used. These materials are formed into a film by a known method such as a sputtering method, and are formed into the following fine wire shape by photolithography and etching or lift-off to form the magnetic wire 1. In the present embodiment, since the magnetic wire 1 is a perpendicular magnetic anisotropic material, it indicates an upward or downward magnetization direction as indicated by an arrow in FIGS.

(Outline of the recess)
As shown in FIGS. 2 and 3, the magnetic thin wire 1 has recesses 1c, 1c,... Formed on the upper surface so as to be locally thin in the pixel region 1px. Since a domain wall is likely to be generated at such a location where the cross-sectional area (cross section perpendicular to the fine line direction) is locally small, the magnetic fine wire 1 is likely to be in a state where a magnetic domain is generated so as to be separated at the location where the recess 1c is formed. . Further, since the domain wall is easily locked (trapped) when the supply of current to the magnetic wire 1 is stopped, the domain wall that has reached the vicinity when the pulse current is stopped (base period) moves to the recess 1c. Then stop. As described above, since the concave portion 1c is formed at the boundary that divides the pixels of the magnetic thin wire 1, the magnetic domain generated in the writing area 1w can easily reach each pixel accurately.

The groove width of the recess 1c (the length in the direction of the thin line in the opening of the recess 1c) is preferably not less than the thickness of the domain wall and not more than 10 times. On the other hand, if the groove width of the recess 1c is too wide, the error range of the domain wall trap position becomes large. Specifically, fine line direction length of the recess 1c is 1 / 10-2 times the width of the magnetic wire 1 and 1/2 or less is preferably a unit length _{L b.}

  In the magnetic wire 1, the amount of change is preferably set to 2% or more in order to trap the domain wall appropriately in the deformed portion such as the recess 1 c. Specifically, if the thickness of the magnetic wire 1 is 50 nm, the depth of the recess 1c is preferably 1 nm or more (the thickness of the thinnest part is 49 nm or less). On the other hand, if the amount of change is too large, a high current density is required to move the trapped domain wall again, and if the cross-sectional area is reduced as the recess 1c, if the cross-sectional area is reduced, the magnetic wire 1 is pulsed. Since the resistance at the time of supplying current increases, the amount of change is preferably 40% or less (the cross-sectional area is 60% or more outside the recess 1c). That is, if the thickness of the magnetic wire 1 is 50 nm, the depth of the recess 1c is preferably 20 nm or less.

In the spatial light modulator 10, the magnetic thin wire 1 is formed with recesses 1c at the boundaries between all the pixels including the end of the pixel region 1px, that is, at nine locations with 8 + 1 pixels. However, the present invention is not limited to this, and the recess 1c may be formed for every two or more pixels, or only at the end of the pixel region 1px. Also, outside the pixel region 1px, by forming a recess in between the write area 1w, for example magnetic wall generated with the generation of the magnetic domain in the write area 1w is, the distance between the unit length L _b You may make it trap stably in the position which shifts and arrives. However, in any case, the recesses 1c are aligned at the same position in the thin line direction for all the eight magnetic thin lines 1 provided in the spatial light modulator 10. That is, as shown in FIG. 1, in the entire spatial light modulator 10, the concave portion 1c of each magnetic wire 1 is provided on a straight line along the Y direction (thin wire width direction). The spatial light modulator 10 is easily manufactured by the manufacturing method described later by providing the concave portion 1c with the magnetic fine wire 1 aligned in position.

(Detailed shape and action of recess)
FIG. 4 is a detailed explanatory view of the recess 1c. 4A is an enlarged perspective view of the magnetic wire 1 cut in the longitudinal direction, and FIGS. 4B and 4C show the position (horizontal axis) of electrons moving around the concave portion 1c of the magnetic wire 1. FIG. FIG. 6 is a graph showing a relationship with energy (vertical axis) necessary for movement of the electrons.
In FIG. 4A, the right side is the positive electrode 31 side, and the left side is the negative electrode 32 side. Since the current flows from the positive electrode 31 side (right side) to the negative electrode 32 side (left side), the electrons moving on the magnetic wire 1 move from the negative electrode 32 side (left side) to the positive electrode 31 side (right side). Since the positive electrode 31 and the negative electrode 32 are fixed, in each magnetic wire 1, when the magnetic domain is shifted by the positive electrode 31 and the negative electrode 32, the magnetic wire 1 always starts from one side (left side) in the longitudinal direction. Electrons are supplied toward the other side (right side).

As described above, the recesses 1c are provided at a plurality of locations (9 locations in the above example) of each magnetic wire 1 and trap magnetic domains that shift in the magnetic wire 1 due to the movement of electrons. in this example, for convenience, the width L1 of the lateral direction of the recess 1c, are exaggerated compared to the length between the adjacent recess 1c L2 (substantially corresponding to the unit length L _b) of the magnetic wire 1 ( The same applies to the following figures).

  As shown in FIGS. 1 and 2, the recess 1 c is formed on the upper surface of the magnetic wire 1, and the parallel direction of the plurality of magnetic wires 1 is parallel to the parallel direction and intersects in a top view. A direction (preferably a direction parallel to the parallel direction and substantially orthogonal to the top view) is defined as a longitudinal direction. The concave shape of the concave portion 1c is such that the slope (surface) 1e on the downstream side (right side in FIG. 4A) is higher than the slope (surface) 1d on the upstream side (left side in FIG. 4A) of electron movement. An inclined surface is formed from the opening of the recess 1c to the bottom so as to be gentle.

In the example of FIG. 4A, the cross-sectional shape of the recess 1c cut vertically (in the XZ plane) in the longitudinal direction of the magnetic wire 1 is a substantially right triangle. Therefore, in the concave portion 1 c, the surface 1 d on the upstream side of the electron flow is inclined in the substantially thickness direction (Z direction) of the magnetic wire 1.
4B and 4C, the horizontal direction of the “position” on the horizontal axis corresponds to the horizontal position of 4 (a). Further, the direction of electrons moving along the magnetic wire 1 is shown by adding an arrow to the image of the reference numeral 59. The graph line 51 indicates the energy required to move the electrons when passing through the concave portion 1c of the magnetic fine wire 1 and the front and rear thereof.

  FIG. 4B shows a case where electrons move from the left side to the right side in FIG. 4A due to the current flowing through the positive electrode 31 and the negative electrode 32. That is, the energy level necessary for shifting the magnetic domain in the magnetic wire 1 from the trap by the recess 1c and shifting from one pixel 1b to the adjacent pixel 1b is shown. When the magnetic domain (domain wall) is trapped by the recess 1c, the necessary energy level rapidly drops on the surface 1d (arrow 52), so that it is easily trapped. However, when the magnetic domain (domain wall) escapes from the trap, the required energy level gradually rises (arrow 53) because the surface 1e has a gentle inclination. Also, the energy level immediately after exiting the trap (the difference between the two is the energy barrier difference E) is lower than the energy level immediately before trapping. Therefore, the magnetic domain can be removed from the trap by the recess 1c relatively easily. Therefore, the magnetic domain shift in the magnetic wire 1 can be performed relatively smoothly.

  However, the magnetic domain that has just shifted and moved to the adjacent pixel 1b vibrates at the position of the pixel 1b. The energy of this vibration includes a component that attempts to return the magnetic domain in the direction opposite to the direction of shift movement (leftward in the example of FIG. 4A), so the magnetic domain is in the direction opposite to the shift movement direction. There is a risk of shifting. FIG. 4C shows the energy level necessary for the movement of the magnetic domain in the opposite direction.

  In FIG. 4 (c), when the magnetic domain (domain wall) moves down the surface 1e, the required energy level also gradually decreases (arrow 54) because the surface 1e has a gentle inclination. However, when the magnetic domain (domain wall) goes over the surface 1d and returns to the original pixel 1b, the necessary energy level rises sharply (arrow 55) because the surface 1d is steep. Moreover, the energy level when returning to the original pixel 1b (the difference between the two is the energy barrier difference E) is higher than the energy level immediately before going down the surface 1e. Therefore, it can be seen that even if the magnetic domain vibrates, it is difficult for the magnetic domain to deviate in the direction opposite to the shift movement direction (this is indicated by an X symbol).

  FIG. 11 is a drawing corresponding to FIG. 4 in a comparative example of the present embodiment. 11 (a) and 11 (c) are diagrams corresponding to FIG. 4 (a), respectively, and the shape of the concave portion 201c (corresponding to the concave portion 1c) of the magnetic wire 201 is different between (a) and (c). . The surfaces 201d and 201e correspond to the surfaces 1d and 1e, respectively. In the example of FIGS. 11A and 11C, a bottom surface 201f is also formed between the surface 201d and the surface 201e. FIG. 11B is a graph corresponding to FIGS. 4B and 4C corresponding to FIG. FIG. 11D is a graph corresponding to FIGS. 4B and 4C corresponding to FIG.

  In this comparative example, the point that the surface 201d and the surface 201e are formed with the same inclination is different from the example of the surfaces 1d and 1e of the above-described embodiment. In the example of FIG. 11A, the surfaces 201d and 201e are surfaces in the thickness direction (Z direction) of the magnetic thin wire 201. In the example of FIG. 11D, the surface 201d and the surface 201e are respectively formed on a plane such that the distance between the surfaces 201d and 201e gradually decreases as the surface approaches the bottom surface 201f.

  11 (b) and 11 (d), as in FIGS. 4 (b) and 4 (c), the graph line 63 shows the fluctuation of the energy level that varies depending on the position. The direction of energy level fluctuation corresponding to FIG. 4B is indicated by reference numeral 61, and the direction of energy level fluctuation corresponding to FIG. 4C is indicated by reference numeral 62. In the example of FIGS. 11B and 11D, since the surface 201d and the surface 201e are surfaces having the same inclination, there is no energy barrier difference E as shown in FIG. The action of oscillating the magnetic domain to stop the magnetic domain trying to return to the original position is not as strong as the example of FIG. That is, it can be seen that the energy level for stopping the magnetic domain to return to the original position is not different from the energy level required for shifting the magnetic domain.

  Further, in Non-Patent Document 1 described above, in a plurality of magnetic thin wires formed in parallel, the width of the magnetic thin wires is varied in the parallel direction. Therefore, the adjacent magnetic wires are moved closer or away depending on the position of the magnetic wires in the length direction. For this reason, the magnetic domains between the magnetic wires are strongly influenced magnetically at positions where adjacent magnetic wires are close to each other, and the magnetic domains between the magnetic wires are not so magnetically affected at other positions. Become. As described above, in Non-Patent Document 1, there is a problem in that the magnetic effect of the magnetic domain does not move smoothly because the magnetic influence between the magnetic thin wires adjacent to each other occurs. In this case, it is difficult to form several other magnetic wires within a limited area if the magnetic wires are moved away from each other in order to reduce the magnetic influence between adjacent magnetic wires. End up.

  On the other hand, as shown in FIG. 4, the recess 1c in the present embodiment is formed on the upper surface of the magnetic wire 1 and is parallel to the parallel direction (Y direction) of the magnetic wire 1 and intersects in a top view. The (orthogonal) direction (X direction) is the longitudinal direction. In the present embodiment, in order to achieve the effect as described above with reference to FIG. 4C, the inclination inside the recess 1c is devised. In the magnetic wire 1 formed in parallel, The width of the magnetic wire 1 does not vary in the parallel direction (Y direction). Therefore, the magnetic domains between the magnetic wires 1 do not affect each other magnetically. Therefore, in the present embodiment, the magnetic domain moves smoothly compared to the configuration of Non-Patent Document 1. Therefore, in this embodiment, since it is not necessary to keep the magnetic thin wires 1 away from each other, it is possible to form a large number of magnetic thin wires 1 within a limited area.

Further, the recess 1c has an inclined surface extending from the opening of the recess 1c to the bottom so that the recess (surface) 1e is gentler than the inclination (surface) 1d on the upstream side of the electron movement. If it is formed, it can be made into various shapes.
Furthermore, the surface 1d on the upstream side of the flow of electrons is inclined so as to be substantially in the thickness direction (Z direction) of the magnetic wire 1. This is a configuration that can make the surface 1d steepest, maximize the energy barrier difference E, and can strongly prevent the return of the magnetic domain due to the vibration immediately after the shift of the magnetic domain.

5-7 has shown the example of the recessed part 1c of a respectively different shape. 5 to 7, (a) to (c) are drawings corresponding to FIGS. 4 (a) to (c), respectively. 5 to 7, the same reference numerals as those in FIG.
The example of FIG. 5 is different from the example of FIG. 4 in that the surface 1e on the downstream side of the electron flow is formed in a plurality of steps. That is, the concave portion 1c is fine, and, for example, it is assumed that the width is 10 to 300 nm and the depth is about 1 to 10 nm. When the depth of the recess 1c is 1 to 10 nm, only about 6 to 60 atoms are arranged in this range, and it is actually difficult to form a smooth slope like the surface 1e in FIG. There is also. Therefore, in the example of FIG. 5, the surface 1 e is configured in a plurality of steps, and such a configuration is easy to manufacture by a manufacturing method described later. When the surface 1e is formed in a stepped shape, a flat (X direction) surface and a vertical (Z direction) surface alternately appear. Therefore, if only the vertical (Z direction) plane is viewed, it cannot be said that the plane 1e is gentler than the plane 1d. However, in the present invention, that the surface 1e is gentle compared to the surface 1d means that the entire surface 1e is gentle compared to the entire surface 1d. Is as gentle as

  The example of FIG. 6 is different from the example of FIG. 4 in that a bottom surface 1f is formed between the surface 1d and the surface 1e. The example of FIG. 7 is obtained by further smoothing the slope of the surface 1d in the example of FIG. In addition to these examples, the shape of the recess 1c can be variously selected.

[Magnetic recording medium]
An example in which the magnetic wire device of the present invention is applied to a magnetic recording medium will be described.
The magnetic recording medium of this embodiment is a so-called magnetic disk having a disk shape. FIG. 8 is a schematic diagram of a magnetic recording medium, where (a) is a plan view and (b) is a partially enlarged view of (a). FIG. 9 is a partial perspective sectional view of the magnetic recording medium shown in FIG. In addition, the same code | symbol is used for the member similar to the spatial light modulator 10, and detailed description may be abbreviate | omitted.

As shown in FIG. 8, the magnetic recording medium 10B includes, on a disk-shaped substrate 2B, an arc-shaped magnetic wire 1D concentric with the substrate 2B as a data recording (storage) area. FIG. 8B shows the vicinity of the electrodes 31 and 32 of the four magnetic wires 1D on the outermost periphery of the magnetic recording medium 10B. In this magnetic thin wire 1D, binary data, that is, “0” or “1” data is recorded as upward or downward magnetization continuously in the thin wire direction of the magnetic thin wire 1D, that is, in the circumferential direction. An area in which one piece of data of the magnetic thin line 1D is recorded is referred to as one data area, and the length in the direction of the fine line is a unit length (bit length L _b ). That is, the magnetic wire 1D is a so-called track of the magnetic recording medium 10B. In the magnetic thin line 1D, when data of the same value (either “0” or “1”) is continuously recorded in one data area, each magnetic domain has one magnetic domain in the continuous data area. Generate.

The magnetic recording medium 10B and the magnetic wire 1D can have the same configuration as the spatial light modulator 10 and the magnetic wire 1 (see FIGS. 1 to 7) of the embodiment except for the shape in plan view. However, the magnetic thin wire 1 of the spatial light modulator 10 is a pixel region 1 px that optically modulates most of the region based on the written data, in other words, the pixel region 1 px that is read simultaneously, whereas the magnetic thin wire 1D of the magnetic recording medium 10B is The data is normally read (reproduced) one by one (1 bit) per one. Therefore, the magnetic thin line 1D is equivalent to the read area 1r corresponding to the pixel area 1px of the magnetic thin line 1, and the length L _b of one bit (the unit length L _b in the spatial light modulator 10 (see FIGS. 1 to 3)). Equivalent to). Similarly to the magnetic thin wire 1 of the spatial light modulator 10, the magnetic thin wire 1D is supplied with current in the thin wire direction only from one end to the other end thereof, so that all the magnetic domains in the magnetic thin wire 1D, that is, the magnetic thin wire 1D. A series of data recorded on the screen sequentially moves. Accordingly, by supplying a pulse current to the magnetic wire 1D from an external current source (corresponding to the scanning current source 8 in FIG. 2) provided in a recording / reproducing apparatus (not shown) of the magnetic recording medium 10B, for example, the magnetic recording medium Without rotating 10B, all the data stored in the magnetic wire 1D move intermittently with the domain wall, and sequentially reach the reading area 1r provided at a fixed position in the magnetic wire 1D. Similarly, the data written in the writing area 1w of the magnetic wire 1D is also moved sequentially and stored in the magnetic wire 1D in order.

  As in the known magnetic recording medium, the magnetic recording medium 10B is written by a magnetic head (corresponding to the data writing unit 50 in FIG. 2) provided in the recording / reproducing apparatus, and the writing area 1w of the magnetic wire 1D. Writing may be performed by applying a magnetic field to the electrode, or a current may be supplied separately from data movement by using the writing region 1w as a spin-injection magnetization switching element structure. On the other hand, in the reading method, similarly to a known magnetic recording medium, a magnetic head made of a magnetoresistive effect element such as a GMR element or a TMR element is opposed to the reading region 1r of the magnetic wire 1D to detect its magnetization. Can do. Alternatively, the magnetic recording medium 10B may be a magneto-optical disk, and similarly to the spatial light modulator 10, the readout region 1r of the magnetic wire 1D may be irradiated with laser light or the like, and the magnetization may be detected from the polarization of the reflected light. . Accordingly, the recording / reproducing apparatus for the magnetic recording medium 10B includes a recording magnetic head, a reproducing magnetic head, a laser light source, or the like, similar to a known magnetic disk, but does not rotate the magnetic recording medium 10B. Therefore, a spindle motor or the like is unnecessary, and instead, as described above, a current source for supplying a pulse current for data movement is provided.

  For example, if the magnetic recording medium 10B has a diameter of 120 mm, the number of data stored in one magnetic wire 1D (one track) is larger than the number of pixels in one row of a general spatial light modulator. Since there are much more, even if there is a slight error in the shift movement for one data, the shift is accumulated and becomes large. Accordingly, the magnetic thin wire 1D is formed with a recess 1c for trapping the domain wall, like the magnetic thin wire 1 of the spatial light modulator 10. Since the magnetic thin wire 1D has a circular arc shape concentric with the outer shape of the magnetic recording medium 10B (substrate 2B) in plan view, the radial direction of the outer shape of the magnetic recording medium 10B is the thin line width direction, and the recess 1c extends in this direction. It is formed in the groove shape provided. In the magnetic recording medium 10B, the positions of the recesses 1c of two or more adjacent magnetic thin wires 1D are arranged in a line along the radial direction.

  Here, each of the magnetic wires 1D has different lengths on the outer peripheral side and the inner peripheral side of the magnetic recording medium 10B. Therefore, if the concave portions 1c are provided on the same straight line along the radial direction in all the magnetic wires 1D, the number of data (number of bits) that can be stored per magnetic wire 1D is the same, and the magnetic wires 1D on the outer peripheral side are the same. The longer the bit length. In the magnetic recording medium 10B configured as described above, in order to make the angular velocity of domain wall movement uniform, it is necessary to supply a high density current to the magnetic fine wire 1D on the outer peripheral side to increase the circumferential speed of domain wall movement. Recording density decreases. Therefore, the magnetic recording medium 10B employs a ZBR (Zone Bit Recording) method in which the number of sectors of the magnetic thin wire 1D on the outer periphery is increased, as shown in FIG. Furthermore, it is preferable to divide into a plurality of zones (five in the example of FIG. 8) from the outer peripheral side to the inner peripheral side. In FIG. 8 (a), a region radially divided by a straight line along the radial direction represents a sector, and the number of sectors is set to a different number of 16 to 9 depending on each zone from the outer peripheral side to the inner peripheral side. Has been.

  In the magnetic recording medium 10B, since the number of bits (bytes) in one sector is standardized, the magnetic wire 1D in the same zone does not completely match the wire length (circumference length), but FIG. As shown in FIG. 3, the concave portion 1c can be provided on a common straight line along the diameter. In such a magnetic recording medium 10B, each of the magnetic thin wires 1D in the same zone has the distance between the recesses 1c and 1c, that is, the bit lengths are slightly different from each other, but the same magnitude of current is supplied to shift the magnetic domains. In this case, the domain wall can be trapped by the recess 1c. Further, as shown in FIG. 9, in the magnetic recording medium 10B, the positions of the concave portions 1c of the adjacent magnetic fine wires 1D and 1D are shifted in the fine wire direction (circumferential direction) across the zone switching portion. . FIG. 9 shows an enlarged zone switching portion of the magnetic recording medium 10B, and the zones are different between the two inner magnetic thin wires 1D and the two outer magnetic thin wires 1D. With such a configuration, the magnetic recording medium 10B can have a simple structure without malfunction such as a reproduction error while ensuring a recording density.

Further, as shown in FIG. 8A, in the magnetic recording medium 10B, the connection positions, that is, both ends of the reading area 1r, the writing area 1w, and the electrodes 31 and 32 of all the magnetic thin wires 1D are each one line. It is preferable to provide along. As a result, in the recording / reproducing apparatus for the magnetic recording medium 10B, it is only necessary to move the magnetic head or the like only in the radial direction of the magnetic recording medium 10B, so that the structure is not complicated. In addition, since the position of the reading region 1r is linearly aligned between two or more predetermined numbers of adjacent magnetic thin wires 1D, these magnetic thin wires 1D can be reproduced simultaneously (parallel reproduction).
The outline, detailed shape, and action of the recess 1c are the same as those of the spatial light modulator 10 described above, and a description thereof is omitted.

[Manufacturing method of magnetic wire mounting board]
The substrate 2 on which the magnetic wire 1 is formed, the substrate 2B on which the magnetic wire 1D is formed, and the like are hereinafter referred to as “magnetic wire mounting substrate”. The manufacturing method of the magnetic wire mounting board of this embodiment is a technique suitable for manufacturing these magnetic wire mounting boards.

(Outline of manufacturing method)
Although the manufacturing method of the magnetic wire mounting substrate of this embodiment can be implemented in various ways, each includes the following steps.
<First step>
A magnetic film in which a magnetic film is formed in a thin line shape on a substrate to be the substrate 2 or 2B, a plurality of magnetic films are arranged in parallel, and a magnetic domain having a different magnetization direction from other portions is formed in a part of the longitudinal direction. A thin wire 1 or 1D is formed.

<Second step>
Recesses 1c that are provided at a plurality of locations of each magnetic wire 1 or 1D and trap magnetic domains that shift in the magnetic wire 1 or 1D by the movement of electrons are formed using the nanoimprint method.
In the second step, the concave portion 1c is formed on the upper surface of the magnetic wire 1 or 1D, and the parallel direction of the magnetic wire 1 or 1D is parallel to the direction and intersects in a top view (desirably, the The direction is parallel to the direction and substantially orthogonal to the top view). Further, the shape of the concave portion 1c is such that the inclination on the other side (the positive electrode 31 side) is gentler than one side (the negative electrode 32 side) in the longitudinal direction of the magnetic wire 1 or 1D. An inclined surface is formed from the opening of 1c to the bottom.

  It can be implemented in various ways as to what specific steps are used for manufacturing. For example, the magnetic thin wire 1 or 1D can be formed on the substrate 2 or 2B first, and then the recess 1c can be formed. Alternatively, the resin film for forming the magnetic wire 1 or 1D is prepared in advance by thinning the resin film, and then a plurality of magnetic films are obtained through a predetermined process using the resin film. The fine wire 1 or 1D may be generated from a magnetic film.

(Concrete example)
Next, a specific example of a method for manufacturing a magnetic wire mounting board will be described. FIG. 10 is a flowchart for explaining an example of a method for manufacturing a magnetic wire mounting board.
The magnetic fine wire mounting substrate includes a magnetic fine wire forming step (magnetic film forming step S10, magnetic fine wire processing step S20) for forming the magnetic fine wire 1 or 1D on the substrate 2 or 2B, and a recess 1c on the upper surface of the magnetic fine wire 1 or 1D. Are manufactured by performing a mask forming step S31 for forming a magnetic wire and a magnetic wire surface etching step S32 (surface processing step S30) and an electrode forming step S40 for forming electrodes 31 and 32 connected to the upper surfaces of both ends of the magnetic wire 1 or 1D. The

<Magnetic wire forming process>
The magnetic wire 1 or 1D can be formed by a known method. Hereinafter, an example will be described.
A material for forming the magnetic wire 1 or 1D (magnetic film) and a material for forming a protective film (not shown) are continuously formed on the substrate 2 or 2B (magnetic film forming step S10. Only the reference numerals are shown below. .) In the case of providing a base film, the film is formed first, and the magnetic fine wire 1 or 1D is subsequently formed. Next, a resist mask that covers the magnetic thin wire 1 or 1D region is formed on the protective film by photolithography (resist application, exposure, development, baking) (S21). Etching removes the thin magnetic wire 1 or 1D from the protective film to expose the substrate 2 or 2B (S22). Next, an insulating film (insulating layer 6) is formed to the height of the upper surface of the protective film (S23), and the resist is removed together with the insulating film (lift-off) (S24). As a result, a plurality of magnetic wires 1 or 1D are formed on the substrate 2 or 2B, the space between the magnetic wires 1 and 1 (between 1D and 1D) is filled with the insulating layer 6, and the magnetic wires 1 or 1D (protective film). The upper surfaces of the insulating layers 6 are flush with each other.

<Mask formation process>
A resin film having a plurality of grooves (concave grooves) provided in the Y direction so as to be orthogonal to the thin wire direction of the magnetic wire 1 or 1D is formed on the magnetic wire 1 or 1D and the insulating layer 6 by a nanoimprint method. Form (S31). First, a resin coating is formed on the magnetic wires 1 or 1D and the insulating layer 6 (the entire upper surface) to form a resin coating film. As the type of resin, as will be described later, a material corresponding to the curing method is selected. Next, the mold (mold) is pressed against the resin coating, the bottom (transfer surface) shape of the mold is transferred to the surface of the resin coating, the resin coating is cured as it is, and a resin film is formed. Is released from the resin film 9.

<Magnetic wire surface etching process>
Next, anisotropic etching is performed on the resin film by dry etching such as RIE (S32). As a result, the entire resin film is uniformly thinned, so that the resin film is removed from the groove portion, and the protective film immediately below it is further etched to thin the magnetic wire 1 or 1D. Therefore, the shape of the groove of the resin film is designed according to the shape of the recess 1c formed in the magnetic wire 1 or 1D and the difference in etching rate between the resin film and the magnetic wire 1 or 1D. Specifically, for example, when the etching rate of the magnetic wire 1 or 1D is slower than that of the resin film, the groove portion of the resin film is formed deeper than the recess 1c.

Next, the resin film remaining on the protective film is removed by O ₂ plasma ashing or acidic stripping solution (S34). Alternatively, the resin film may be completely removed by switching the gas species to O ₂ following the dry etching (S32). As a result, a plurality of groove-like recesses 1c are formed on the upper surface of the magnetic fine wire 1 or 1D, which are orthogonal to the fine wire direction, that is, provided so as to extend in the fine wire width direction. In the recess 1c, the protective film is removed and the magnetic wire 1 or 1D is exposed on the surface. Therefore, before removing the remaining resin film (S34), an insulating film is laminated or a protective film is formed. It is preferable to additionally form a film.

<Electrode formation process>
The positive electrode 31 and the negative electrode 32 can be formed by a known method. As an example, first, an insulating film is laminated on the magnetic thin wire 1 or 1D and the insulating layer 6 (entire surface), and the insulating film is removed by photolithography and etching on both end portions of the magnetic thin wire 1 or 1D to obtain magnetic properties. The thin wire 1 or 1D (protective film) is exposed, and a metal electrode material is formed to form electrodes 31 and 32. The magnetic thin wire mounting substrate is completed by the above procedure.

  Here, the nanoimprint method used in the mask formation step S31 will be described in detail. The curing of the resin can be performed by a heat method by heating or a UV curing method by ultraviolet irradiation, and a resin generally used in each method may be applied. In the thermal type, thermoplastic resins such as polycarbonate, PMMA (polymethyl methacrylate resin) and acrylic resin, or thermosetting resins such as epoxy, silicone, and polyimide can be used. A material having a sufficiently low glass transition point for a thermoplastic resin and a sufficiently low curing temperature for a thermosetting resin is selected so that the magnetic fine wire 1 or 1D is not affected by heating. Specifically, a resin having a heating temperature of 200 ° C. or lower is preferable. In the UV curing method, resins such as urethane and epoxy are listed. The thermal method has more choices of resin, while the UV curing method is suitable for processing with higher dimensional accuracy because there is no volume change of the resin due to heat.

  In the present embodiment, in order to form a plurality of groove portions in the resin film, the above-mentioned mold is provided with a ridge-like protrusion provided in the Y direction corresponding to the shape of the groove portion on the transfer surface ( (Bottom surface). The mold is made of a material that has sufficient strength so as not to be deformed at the time of transfer or the like and is easy to be finely processed. Quartz or the like that transmits ultraviolet rays is used. The mold is processed by a known method such as direct drawing with an electron beam.

  According to the nanoimprint method, depending on the shape of the mold, it can be processed into a complicated shape such as not only being fine but also having two or more steps (suitable for forming the stepped surface 1e), for example, The magnetic wire 1 or 1D with the recess 1c can be formed integrally. However, in the manufacturing method according to the present invention, the magnetic wire 1 or 1D is processed separately into a thin wire shape (magnetic wire processing step S20), and the nanoimprint method is relatively shallow with respect to the thickness of the magnetic wire 1 or 1D. This is applied to the formation of only the recess 1c which is a groove. As a result, only a relatively small (shallow) shape groove (groove portion) corresponding to the recess 1 c needs to be formed in the resin film 9. Further, in the spatial light modulator 10, since the concave portions 1c are provided in a straight line in the thin wire width direction (Y direction) in all eight magnetic fine wires 1 (see FIG. 1), all the magnetic fine wires 1 of the resin film are provided. A recess 1c can be formed in each of the magnetic wires 1 or 1D by one groove extending in the Y direction (that is, one groove portion. That is, the resin film as a whole is one magnetic wire. It is only necessary to form the same number of grooves as the concave portions 1c formed in 1. Since the resin film has such a simple and small difference in unevenness, the transfer surface of the mold, that is, the contact area between the mold and the resin film is small. As a result, the groove portion is easily formed with high dimensional accuracy by being faithfully transferred from the mold.

  Thus, by forming only the groove portion for forming the recess 1c in the magnetic thin wire 1 or 1D in the resin film, the groove portion can be easily formed with high dimensional accuracy, whereby the fine recess 1c is formed in the magnetic thin wire. 1 or 1D can be formed. Further, by forming a groove portion having a V-shaped cross-sectional view in which the deepest portion (bottom portion) is narrowed (see FIGS. 4 and 5), it is possible to form the concave portion 1c having a narrower groove width (length in the thin line direction) than the groove portion. it can. In the magnetic wire processing step S20, a resist mask is used. However, a nanoimprint method may be applied, that is, the shape of the magnetic wire 1 or 1D (the recess 1c is formed separately from the mold for forming the recess 1c). Use a mold matched to the above.

The specific example described above is merely an example, and the present invention can be implemented in various steps. For example, each manufacturing method described in JP2013-242940A can be applied to the present invention.
According to the method for manufacturing a magnetic wire mounting substrate described above, since the concave portion 1c can be formed in the magnetic wire 1 or 1D of the magnetic wire device described above, the magnetic wire device (spatial light) that can exhibit the above-described effects. Modulator, magnetic recording medium).
Further, by using the nanoimprint method to manufacture a magnetic wire mounting substrate applied to the magnetic wire device of the present invention, the device can be further miniaturized.

DESCRIPTION OF SYMBOLS 1 Magnetic wire 1c Concave part 1D Magnetic wire 10 Spatial light modulator (magnetic wire apparatus)
10B Magnetic recording medium (magnetic wire device)
31 Positive electrode (electrode)
32 Negative electrode (electrode)

Claims (4)

A magnetic thin film in which a magnetic film is formed in a thin line shape, a plurality of magnetic films are arranged in parallel, and a magnetic domain having a different magnetization direction from the other part is formed in a part in the longitudinal direction;
An electrode that shifts the magnetic domain by supplying electrons only from one to the other in the longitudinal direction of each magnetic wire;
A plurality of concave portions for trapping the magnetic domains that are provided at a plurality of locations of the magnetic fine wires and shift in the magnetic fine wires by the movement of the electrons;
The recess is formed on the upper surface of the magnetic wire, and has an inclined surface from the opening of the recess to the bottom so that the inclination on the downstream side is gentler than the upstream side of the electron movement ,
The magnetic thin wire device characterized in that the concave portion has an asymmetric inclination in the longitudinal direction of the magnetic thin wire when viewed from above .   2. The magnetic wire device according to claim 1, wherein the concave portion is formed with a plurality of steps in the inclined surface on the downstream side of the electron flow.   3. The magnetic wire device according to claim 1, wherein the concave portion has an inclination in which the inclined surface on the upstream side of the electron flow is substantially in the thickness direction of the magnetic wire. 4. A magnetic film is formed in a thin line shape on a substrate, and a plurality of the magnetic films are arranged in parallel to form a magnetic thin line in which a magnetic domain having a magnetization direction different from the other part is formed in a part of the longitudinal direction. Process,
Wherein provided in each plurality of locations each magnetic thin wire, a recess for trapping the magnetic domains of the shifting movement the in magnetic wire by the movement of the conductive element, and a second step of forming by using a nanoimprinting method,
In the second step, the concave portion is formed on the upper surface of the magnetic wire, and has an inclined surface from the opening of the concave portion to the bottom so that the inclination on the downstream side is gentler than the upstream side of the electron movement. A method for manufacturing a magnetic wire mounting substrate, characterized by being formed as described above.

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