JP2009295212A - Manufacturing method of perpendicular magnetic recording medium, perpendicular magnetic recording medium, magnetic recording and playback device, manufacturing method of magnetic recording medium, manufacturing method of magnetic element, manufacturing method of porous material, manufacturing method of functional element, and manufacturing method of semiconductor element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a perpendicular magnetic recording medium by which magnetic separation between magnetic particles is satisfactorily performed, and the perpendicular magnetic recording medium is easily manufactured. <P>SOLUTION: A granular film 15 including the magnetic particles 15a and MoCuO 15b enclosing the magnetic particles 15a is formed on a substrate 11. The MoCuO 15b is removed by wet etching the granular film 15 by using an alkali solution or water to form gaps. The film from which the MoCuO 15b is thus removed is used as a magnetic recording layer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a perpendicular magnetic recording medium, a perpendicular magnetic recording medium, a magnetic recording / reproducing apparatus, a method of manufacturing a magnetic recording medium, a method of manufacturing a magnetic element, a method of manufacturing a porous body, a method of manufacturing a functional element, and a semiconductor device The manufacturing method is suitable for use in manufacturing a perpendicular magnetic recording medium suitable for use in, for example, ultra-high density recording.

A perpendicular magnetic recording medium mainly comprises a protective layer, a magnetic recording layer, an underlayer, a seed layer, and a soft magnetic backing layer. Among these layers, the magnetic recording layer is mainly a granular film composed of fine magnetic particles and a nonmagnetic grain boundary material surrounding the magnetic particles (see, for example, Patent Documents 1 to 3). As this granular film, a CoCrPt—SiO ₂ film, a CoCrPt—TiO ₂ film, and the like are well known. In these CoCrPt—SiO ₂ film and CoCrPt—TiO ₂ film, SiO ₂ or TiO ₂ precipitates to surround the CoCrPt crystal grain at the grain boundary of the CoCrPt crystal grain having a grain size of about 7 nm, and the grain boundary width is It is about 1-2 nm.

In such a granular film, the exchange coupling between magnetic particles is broken to promote magnetic separation so that each magnetic particle behaves magnetically independently of each other. Is important.
JP 2006-190487 A JP 2007-270248 A JP 2007-35139 A JP 2007-95370 A JP 2007-35437 A JP 2007-116097 A IEEE TRANSACTIONS ON MAGNETICS, VOL.43, NO.6,2007

However, in the above-described conventional granular film using SiO ₂ or TiO ₂ as a grain boundary material, magnetic separation between magnetic particles is not always sufficient.
Therefore, a problem to be solved by the present invention is a method of manufacturing a perpendicular magnetic recording medium, which can sufficiently separate magnetic particles and can easily manufacture a perpendicular magnetic recording medium, Another object of the present invention is to provide a perpendicular magnetic recording medium manufactured by such a manufacturing method and a magnetic recording / reproducing apparatus using the perpendicular magnetic recording medium.

Another problem to be solved by the present invention is to provide a method of manufacturing a magnetic recording medium that can sufficiently perform magnetic separation between magnetic particles and that can easily manufacture a magnetic recording medium. It is.
Another problem to be solved by the present invention is to provide a method of manufacturing a magnetic element that can sufficiently perform magnetic separation between magnetic particles and can easily manufacture a magnetic element. .

Still another problem to be solved by the present invention is to provide a method for producing a porous body that can easily produce a porous body made of various materials.
Still another problem to be solved by the present invention is that, after an element layer is formed on a substrate, the substrate can be easily peeled off at a low cost with almost no physical damage to the element layer. It is an object of the present invention to provide a method of manufacturing a functional element that can easily manufacture the element.

  Still another problem to be solved by the present invention is that, after an element layer is formed on a substrate, the substrate can be easily peeled off at low cost with almost no physical damage to the element layer. An object of the present invention is to provide a method of manufacturing a semiconductor device that can easily manufacture the device.

In order to solve the above problem, the first invention is:
Forming a granular film made of magnetic particles and MoCuO surrounding the magnetic particles on a substrate;
And a step of removing at least a part of the MoCuO in the granular film by wet etching.

The second invention is
Forming a granular film made of magnetic particles and MoCuO surrounding the magnetic particles on a substrate;
The perpendicular magnetic recording medium is manufactured by performing a step of removing at least a part of the MoCuO of the granular film by wet etching.

  In the first and second inventions, a magnetic recording layer is obtained by removing at least a part of MoCuO from the granular film by wet etching. From the viewpoint of more reliably magnetically separating the magnetic particles in the magnetic recording layer, preferably, all of the MoCuO in the granular film is removed by wet etching. This wet etching can be easily performed using, for example, an alkaline solution or water (pure water or the like). As the alkali solution, for example, an aqueous tetramethylammonium hydroxide solution can be used. The magnetic particles can be formed of various magnetic materials and are selected as necessary. Specifically, the magnetic particles are made of, for example, CoPt, CoCrPt, FePt, or the like. The form of the magnetic particles is not particularly limited, and may be any form such as a columnar shape, a spherical shape, and an ellipsoidal shape. Typically, a seed layer and an underlayer are sequentially formed on a substrate before forming a granular film, but the present invention is not limited to this. As materials for the substrate, the seed layer, and the underlayer, conventionally known materials can be used. Various methods can be used as a method for forming the granular film, and the method is selected as necessary. Specifically, for example, a sputtering method, a vacuum deposition method, or the like can be used.

The perpendicular magnetic recording medium can be used as a perpendicular magnetic recording medium for heat-assisted magnetic recording, for example. Here, heat-assisted magnetic recording (HAMR) (see, for example, Non-Patent Document 1) is narrowed down to, for example, a minute spot only when recording on a recording medium having a large anisotropy constant Ku. In this method, the temperature of the recording medium is increased by applying a laser beam, the coercive force _Hc is decreased and recording is performed, and the temperature is decreased immediately after recording to suppress thermal demagnetization. In order to achieve ultra-high density recording that greatly exceeds 1 Tbit / inch ² , the recording capability of the magnetic head and the thermal fluctuation resistance of the recording medium must be compatible. That is, as the recording medium, it is necessary to enable minute recording to withstand thermal fluctuations, and thus it is necessary to increase the anisotropy constant Ku. This means that the coercive force H _c of the recording medium is increased, but the magnetic head exists actually has the ability to write to a recording medium having a large H _c as such. Thermally assisted magnetic recording is one means to overcome this problem. When this perpendicular magnetic recording medium for heat-assisted magnetic recording is considered, in order to produce a clear recording mark, control of heat becomes very important. In the perpendicular magnetic recording medium according to the first and second inventions, at least a part of the MoCuO in the granular film is removed by wet etching, so that the removed portion becomes a void. Therefore, SiO ₂ or Compared to a conventional perpendicular magnetic recording medium using a granular film containing TiO ₂ or the like as a magnetic recording layer, heat diffusion can be suppressed. Therefore, the perpendicular magnetic recording medium according to the first and second inventions is suitable as a perpendicular magnetic recording medium for heat-assisted magnetic recording.

The third invention is
Forming a granular film made of magnetic particles and MoCuO surrounding the magnetic particles on a substrate;
A magnetic recording / reproducing apparatus having a perpendicular magnetic recording medium manufactured by performing a step of removing at least a part of the MoCuO of the granular film by wet etching.

  This magnetic recording / reproducing apparatus includes a device capable of both recording and reproduction and a device capable of only one of recording and reproduction. The perpendicular magnetic recording medium is suitable for use in the hard disk of this magnetic recording / reproducing apparatus.

The fourth invention is:
Forming a granular film made of magnetic particles and MoCuO surrounding the magnetic particles on a substrate;
And a step of removing at least a part of the MoCuO of the granular film by wet etching.
This magnetic recording medium includes a horizontal magnetic recording medium in addition to a perpendicular magnetic recording medium.

The fifth invention is:
Forming a granular film made of magnetic particles and MoCuO surrounding the magnetic particles on a substrate;
And a step of removing at least a part of the MoCuO in the granular film by wet etching.
Examples of the magnetic element include various elements such as a magnetic memory such as a magnetic random access memory (MRAM) and a magnetoresistive effect element.

The sixth invention is:
Forming a film made of particles and MoCuO surrounding the particles on a substrate;
And a step of removing at least a part of the MoCuO of the film by wet etching.

  The material of the particles may be various, and may be either conductive or nonconductive. For example, when particles made of a conductive material are used, a conductive porous body can be manufactured. This conductive porous body can be used as an electrode. For example, when particles made of a semiconductor are used, a semiconductor porous body electrode can be manufactured. This semiconductor porous body electrode is suitable for use as a semiconductor electrode of a dye-sensitized photoelectric conversion element, for example. When carbon particles are used, a carbon porous electrode can be produced. This carbon porous body electrode is suitable for use as an electrode of a fuel cell, for example. The form and size of the particles are not particularly limited and are selected as necessary.

The seventh invention
Forming a MoCuO layer on the substrate;
Forming an element layer on the MoCuO layer;
And a step of removing the MoCuO layer by wet etching.

  Functional elements include, for example, semiconductor elements, piezoelectric elements, pyroelectric elements, optical elements (second harmonic generation elements using nonlinear optical crystals, etc.), dielectric elements (including ferroelectric elements), superconducting elements, etc. It is. The semiconductor element is, for example, a light emitting element, a light receiving element, an electron traveling element, or the like. The light emitting element is, for example, a semiconductor laser or a light emitting diode. The light receiving element is a photodiode or the like. The electron transit element is represented by a transistor such as a field effect transistor (FET) such as a high electron mobility transistor or a bipolar transistor such as a heterojunction bipolar transistor (HBT). The configuration and material of the element layer are appropriately selected according to the type of the functional element, the function of the functional element, and the like. The material of the element layer of the semiconductor element may be, for example, a nitride-based III-V group compound semiconductor, other wurtzit structures, more generally other semiconductors having a hexagonal crystal structure, For example, it may be made of various semiconductors having other crystal structures such as ZnO, α-ZnS, α-CdS, α-CdSe, and CrN (111). Various materials such as oxides having a hexagonal crystal structure can be used for piezoelectric elements, pyroelectric elements, optical elements, dielectric elements, superconducting elements, and the like.

The eighth invention
Forming a MoCuO layer on the substrate;
Forming a plurality of protrusions on the MoCuO layer;
Growing a first nitride-based III-V group compound semiconductor layer in a concave portion between the convex portions through a triangular cross-sectional shape with the bottom surface as a base; and
Laterally growing a second nitride III-V compound semiconductor layer from the first nitride III-V compound semiconductor layer;
Growing a nitride III-V compound semiconductor layer constituting an element layer on the second nitride III-V compound semiconductor layer;
A step of removing the MoCuO layer by wet etching.

The semiconductor element is, for example, a light emitting element, a light receiving element, an electron traveling element, or the like.
The thickness of the MoCuO layer can be selected as appropriate, but is generally 10 nm to 10 μm.

  The conductivity type of the first nitride III-V compound semiconductor layer and the second nitride III-V compound semiconductor layer may be any of p-type, n-type, and i-type, It may or may not be the same conductivity type. Typically, when the first nitride-based III-V compound semiconductor layer is grown, dislocations occur in a direction perpendicular to the principal surface of the substrate from the interface with the bottom surface of the recess, and the dislocations are When the slope of the first nitride-based III-V compound semiconductor layer in the state of the triangular cross section or the vicinity thereof is reached, it moves away from the triangular portion in a direction parallel to the one main surface. Bend like so. Preferably, in the initial growth stage of the first nitride-based III-V compound semiconductor layer, a plurality of micronuclei are formed on the bottom surface of the recess, and the substrate grows and coalesces. Dislocations that occur in a direction perpendicular to the one principal surface of the substrate from the interface with the bottom surface of the recess are repeatedly bent in a direction parallel to the one principal surface. By doing so, dislocations that escape to the top during the growth of the first nitride-based III-V compound semiconductor layer can be reduced.

Typically, convex portions and concave portions are alternately and periodically formed on the MoCuO layer. In this case, the period of a convex part and a recessed part is 3-5 micrometers, for example. The ratio of the length of the bottom of the convex portion to the length of the bottom of the concave portion is preferably 0.5 to 3, and most preferably around 0.5. The height of the convex portion viewed from one main surface of the MoCuO layer is preferably 0.3 μm or more, and more preferably 1 μm or more. The convex portion preferably has a side surface inclined with respect to one main surface of the substrate. The cross-sectional shape of the convex portion may be various shapes, and the side surface thereof may be a curved surface as well as a flat surface. The cross-sectional shape of the recess may be various shapes. From the viewpoint of minimizing the dislocation density of the second nitride-based III-V compound semiconductor layer, it is preferable that the depth of the concave portion (same as the height of the convex portion) be d and the width of the bottom surface of the concave portion be W _g. When the angle formed between the slope of the first nitride-based III-V compound semiconductor layer in the triangular cross-sectional shape and one principal surface of the substrate is α, 2d ≧ W _g tanα is established. D, W _g , and α are determined. Since α is normally constant, d and W _g are determined so that this equation is satisfied. If d is too large, the source gas is not sufficiently supplied to the inside of the recess, which hinders the growth of the first nitride III-V compound semiconductor layer from the bottom of the recess, and conversely, if d is too small. Since the first nitride-based III-V compound semiconductor layer grows not only on the concave portion of the substrate but also on the convex portions on both sides thereof, in general, from the viewpoint of preventing these, 0.5 μm <d It is selected within the range of <5 μm, and typically selected within the range of 1.0 ± 0.2 μm. W _g is generally 0.5 to 5 μm, and is typically selected within a range of 2 ± 0.5 μm. Further, the width of the upper surface of the convex portion is 0 when the cross-sectional shape of the convex portion is triangular, but when the cross-sectional shape of the convex portion is trapezoidal, the convex portion is the second nitride III- Since this is a region used for lateral growth of the group V compound semiconductor layer, the longer the area, the larger the area of the portion with less dislocation density. When the cross-sectional shape of the convex portion is trapezoidal, the width of the upper surface of the convex portion is generally in the range of 1 to 1000 μm, for example, 4 ± 2 μm, but is not limited thereto.

  For example, the convex portion or the concave portion may extend in a stripe shape in one direction on the substrate, or may extend in a stripe shape in at least a first direction and a second direction intersecting each other. As a result, the convex portion is an n-gon (where n is an integer of 3 or more), specifically, a triangle, a quadrangle, a pentagon, a hexagon, or the like, or those with the corners cut off, rounded, or circular Alternatively, it may be a two-dimensional pattern such as an ellipse or a dot. In a preferred example, the convex portions have a hexagonal planar shape, the convex portions are two-dimensionally arranged in a honeycomb shape, and concave portions are formed so as to surround the convex portions. When the semiconductor element is a light emitting diode, light emitted from the active layer can be efficiently extracted in all directions of 360 °.

The material of the convex portion may be various, and may or may not be conductive. For example, a dielectric such as an oxide, nitride, or carbide, or a conductor such as a metal or alloy (including a transparent conductor) ) Etc. As the oxide, for example, silicon oxide (SiO _x ), titanium oxide (TiO _x ), tantalum oxide (TaO _x ), or the like can be used. A mixture of two or more of these or in the form of a laminated film It can also be used. As the nitride, for example, silicon nitride (SiN _x ), TiN, WN, CN, BN, LiN, TiON, SiON, CrN, CrNO, or the like can be used. It can also be used in the form of a membrane. As the carbide, SiC, HfC, ZrC, WC, TiC, CrC or the like can be used, and two or more of these can be mixed or used in the form of a laminated film. Examples of metals or alloys include B, Al, Ga, In, W, Ni, Co, Pd, Pt, Ag, Hf, Zr, Au, Cu, Ru, Ir, AgNi, AgPd, AuNi, AuPd, AlCu, AlSi, AlSiCu or the like can be used, and two or more of these can be mixed or used in the form of a laminated film. As the transparent conductor, ITO (indium-tin composite oxide), IZO (indium-zinc composite oxide), ZO (zinc oxide), FTO (fluorine-doped tin oxide), tin oxide, and the like can be used. Two or more of these may be mixed or used in the form of a laminated film. Further, two or more of the various materials described above can be mixed or used in the form of a laminated film.

  For example, when the semiconductor element is a light emitting diode, the third nitride III-V compound of the first conductivity type is used as the element layer on the second nitride III-V compound semiconductor layer. A semiconductor layer, an active layer, and a fourth conductivity type fourth nitride III-V compound semiconductor layer are sequentially grown.

The first to fifth nitride-based III-V compound semiconductor layer and the nitride-based III-V constituting the active layer compound semiconductor layer, the most _{common, Al X B y Ga 1-} xyz In z As _u N _1-uv P _v (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ z ≦ 1, 0 ≦ u ≦ 1, 0 ≦ v ≦ 1, 0 ≦ x + y + z <1, 0 ≦ u + v <consists 1), more _{specifically, Al X B y Ga 1-} xyz in z N ( However, 0 ≦ x ≦ 1,0 ≦ y ≦ 1,0 ≦ z ≦ 1,0 ≦ x + y + z <1) Typically, it consists of Al _x Ga _{1 -xz} In _z N (where 0 ≦ x ≦ 1, 0 ≦ z ≦ 1). Specific examples are GaN, InN, AlN, AlGaN, InGaN. And AlGaInN. The nitride III-V compound semiconductor layer constituting the first to fifth nitride III-V compound semiconductor layers and the active layer promotes the bending of dislocations when, for example, B or Cr is contained in GaN. Therefore, it may be made of BGaN, GaN: B doped GaN: B, GaN: Cr doped GaN: Cr, or the like. Particularly first first nitride III-V compound semiconductor layer grown on the recessed portions of the substrate, _{preferably, GaN, In X Ga 1-} x N (0 <x <0.5), Al X A material consisting of Ga _1-x N (0 <x <0.5) and Al _x In _y Ga _1-xy N (0 <x <0.5, 0 <y <0.2) is used. The first conductivity type may be n-type or p-type, and the second conductivity type is p-type or n-type accordingly. In addition, as a so-called low-temperature buffer layer that is first grown on the substrate, a GaN buffer layer, an AlN buffer layer, an AlGaN buffer layer, etc. are generally used, and those doped with Cr or CrN buffer layers are used. Also good.

The thickness of the second nitride-based III-V compound semiconductor layer is selected as necessary, and is typically about several μm or less, but is thicker depending on the application, for example, about several tens to 300 μm. It may be.
Examples of the growth method of the nitride III-V compound semiconductor layers constituting the first to fifth nitride III-V compound semiconductor layers and the active layer include, for example, metal organic chemical vapor deposition (MOCVD), Various epitaxial growth methods such as hydride vapor phase epitaxial growth, halide vapor phase epitaxial growth (HVPE), and molecular beam epitaxy (MBE) can be used.
In the eighth aspect of the invention, what has been described in relation to the first and second aspects of the invention is valid as long as not against its nature.

  In the present invention configured as described above, since MoCuO can be removed very easily by wet etching, after forming a film such as a granular film composed of particles such as magnetic particles and MoCuO surrounding the particles. Further, at least a part of the MoCuO can be easily removed by wet etching, and a void can be formed in the removed portion. Or after forming an element layer through a MoCuO layer on a board | substrate, this board | substrate can be easily peeled from an element layer by removing this MoCuO layer by wet etching.

According to the present invention, magnetic separation between magnetic particles can be sufficiently performed, and a perpendicular magnetic recording medium can be easily manufactured. A high-performance magnetic recording / reproducing apparatus can be realized using this perpendicular magnetic recording medium.
In addition, magnetic separation between magnetic particles can be sufficiently performed, and a magnetic recording medium can be easily manufactured.
In addition, magnetic separation between magnetic particles can be sufficiently performed, and a magnetic element can be easily manufactured.
Moreover, the porous body which consists of various materials can be manufactured easily.
In addition, after the element layer is formed on the substrate, the substrate can be easily peeled at a low cost with almost no physical damage to the element layer, and the functional element can be easily manufactured.
Further, after the element layer is formed on the substrate, the substrate can be easily peeled at a low cost with almost no physical damage to the element layer, and the semiconductor element can be easily manufactured.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 3 show a method of manufacturing a perpendicular magnetic recording medium according to the first embodiment of the present invention.
In the first embodiment, first, as shown in FIG. 1A, a soft magnetic backing layer 12, a seed layer 13, and an underlayer 14 are sequentially formed on a substrate 11 made of a nonmagnetic material.

  Here, as the substrate 11, it is desirable to use a nonmagnetic substrate having a smooth surface. Generally, a conventionally known substrate used for a magnetic recording medium can be used. A glass substrate (particularly a tempered glass substrate), a Si substrate, an Al alloy substrate plated with NiP, or the like can be used. As the substrate 11, a plastic substrate such as polycarbonate used for an optical disk can also be used. The thickness of the substrate 11 is not particularly limited and is selected as necessary.

  The soft magnetic underlayer 12 is for concentrating the magnetic flux generated by the magnetic head used for recording / reproducing on the perpendicular magnetic recording medium on the magnetic recording layer 16 described later. As the material of the soft magnetic underlayer 12, conventionally known materials generally used for magnetic recording media can be used. Specifically, for example, a microcrystalline structure such as FeTaC, FeSiAl, etc. CoNbZr, CoTaZr, and the like, which are Co alloys having an amorphous structure, can be used. The soft magnetic backing layer 12 may have a single layer structure or a multilayer structure. The thickness of the soft magnetic backing layer 12 is not particularly limited and is selected as necessary, and is, for example, about 50 nm to 2 μm.

  The seed layer 13 is for controlling the growth of a base layer 14 to be described later formed thereon. As the material of the seed layer 13, conventionally known materials can be used. Specifically, for example, an amorphous material such as Ta, NiTa, NiTaZr, or the like can be used. The thickness of the seed layer 13 is not particularly limited and is selected as necessary, but is about 1 to 10 nm, for example.

  The underlayer 14 is for controlling the crystal orientation of a granular film 15 to be described later formed thereon. As the material of the underlayer 14, conventionally known materials can be used, but it is desirable to use a hexagonal close-packed structure (HCP) or face-centered cubic structure (FCC) metal or alloy, for example, Ru. Etc. can be used. The thickness of the underlayer 14 is not particularly limited and is selected as necessary, but is, for example, about 1 to 20 nm.

  Next, as shown in FIG. 1B, a granular film 15 made of magnetic particles 15a and MoCuO 15b surrounding the magnetic particles 15a is formed on the underlayer 14 by, for example, sputtering or vacuum deposition. Specifically, for example, a magnetic material for forming the magnetic particles 15 a and MoCuO are simultaneously deposited from a direction substantially perpendicular to the surface of the underlayer 14. In this case, the magnetic particles 15 a grow as columnar crystals perpendicular to the surface of the underlayer 14, and the easy axis of magnetization is perpendicular to the surface of the underlayer 14. A plan view of the granular film 15 is shown in FIG. The cross-sectional dimensions of the magnetic particles 15a and the intervals between the magnetic particles 15a of the granular film 15 are generally different from each other, but in FIG. 1B, the cross-sectional dimensions and intervals of the magnetic particles 15a are the same for simplicity. As shown.

  Next, as shown in FIG. 3, the granular film 15 is wet-etched using an alkali solution or water (pure water or the like) as an etchant, whereby all of the MoCuO 15b as the grain boundary material is removed by etching. Thus, a gap is formed in the portion where MoCuO15b is removed. Thus, the magnetic recording layer 16 is formed which is composed of the magnetic particles 15a and is separated from each other by the air gaps. A plan view of the magnetic recording layer 16 is shown in FIG. The magnetic recording layer 16 is composed of a perpendicular magnetic recording film.

Next, as shown in FIG. 5, a protective layer 17 is formed on the magnetic recording layer 16. As the material of the protective layer 17, conventionally known materials can be used. Specifically, for example, amorphous carbon, aluminum oxide, or the like can be used. The thickness of the protective layer 17 is not particularly limited and is selected as necessary, and is, for example, 1 to 15 nm.
As described above, the intended perpendicular magnetic recording medium can be manufactured.

Examples will be described.
A glass substrate having a smooth surface was used as the substrate 11. On this glass substrate, a DC film is first formed to form a Ta film as a seed layer 13 with a thickness of 2 nm, a Ru film as a base layer 14 with a thickness of 18 nm thereon, and a granular film 15 as a CoPt− A MoCuO granular film was formed to a thickness of 10 nm. In this CoPt—MoCuO granular film, the composition (atomic%) of CoPt is Co ₈₀ Pt ₂₀ , and the composition (atomic%) of MoCuO is (Mo ₇₀ Cu ₃₀ ) ₄₀ O ₆₀ .

The conditions for DC sputtering are as follows.
Degree of vacuum: 1.0 × 10 ⁻⁸ Torr
Ta film: 150 W, Ar gas pressure 4.0 mTorr
Ru film: 150 W, Ar gas pressure 5.0 mTorr / 11.0 mTorr
(The Ru film consists of two Ru films formed using different Ar gas pressures.)
CoPt-MoCuO granular film: CoPt100W, MoCuO30W, Ar gas pressure 13.0 mTorr

  Next, the glass substrate thus formed with the CoPt-MoCuO granular film is dipped in NMD-3 solution (tetramethylammonium hydroxide (TMAH) 2.38% aqueous solution) manufactured by Tokyo Ohka Co., Ltd. for 3 minutes to perform wet etching. -MoCuO in the MoCuO granular film was removed. Thereafter, it was thoroughly washed with pure water. Thus, the magnetic recording layer 16 in which the CoPt magnetic particles were separated by the gap was formed.

  The surface of the sample before the wet etching and after the wet etching was observed with a scanning electron microscope (SEM). FIG. 6 shows an SEM image (10,000 magnifications) of the surface of the sample before wet etching. Further, FIG. 7 shows an SEM image (10,000 magnifications) of the surface of the sample after wet etching. From FIG. 7, it can be seen that columnar CoPt magnetic particles having a height of 10 nm are dispersed with voids having a width of about 1 nm.

The M (magnetization) -H (magnetic field) loop was measured using the Kerr effect measuring device for the sample before the wet etching and after the wet etching. The measurement result of the MH loop of the sample before performing wet etching is shown in FIG. Moreover, the measurement result of the MH loop of the sample after performing wet etching is shown in FIG. Comparing FIGS. 8 and 9, since the direction of FIG. 9 has a higher coercive force H _c, the sample after the wet etching, it was confirmed that the physical separation of the CoPt magnetic particles is performed It was.

As described above, according to the first embodiment, the magnetic recording layer 16 has a structure in which the magnetic particles 15a are arranged with gaps therebetween, so that the magnetic particles can be made of SiO ₂ , TiO ₂ or the like as in the prior art. Compared to a magnetic recording layer made of a granulated film surrounded by a grain boundary material made of, magnetic separation between the magnetic particles 15a can be sufficiently performed, and the magnetic particles 15a behave magnetically independently of each other. Can do. Therefore, ultra-high density recording can be easily realized with this perpendicular magnetic recording medium. Further, the magnetic recording layer 16 can be formed very easily by only wet-etching the granular film 15 made of the magnetic particles 15a and the MoCuO 15b surrounding the magnetic particles 15a and removing the MoCuO 15b. The manufacturing cost can be kept low. Furthermore, since an innocuous alkaline solution or water can be used as the etchant for this wet etching, the load on the environment is small and safety is high.

This perpendicular magnetic recording medium is suitable for use in heat-assisted magnetic recording. That is, in the magnetic recording layer 16, since the grain boundaries of the magnetic particles 15 a are voids, when heat-assisted magnetic recording is performed, heat does not diffuse in the in-plane direction of the magnetic recording layer 16 and is mainly perpendicular. Spread in the direction. For this reason, a minute and clear recording mark can be produced, and ultrahigh density recording can be realized.
This perpendicular magnetic recording medium capable of ultra-high density recording is suitable for application to a hard disk of a magnetic recording / reproducing apparatus.

Next explained is the second embodiment of the invention. In the second embodiment, a method for producing a dye-sensitized semiconductor electrode used for a dye-sensitized photoelectric conversion element such as a dye-sensitized solar cell (for example, see Patent Document 4) will be described.
In the second embodiment, first, as shown in FIG. 10A, a granular film 22 composed of semiconductor fine particles 22a and MoCuO 22b surrounding the semiconductor fine particles 22a is formed on a transparent conductive substrate 21.

  The transparent conductive substrate 21 may be formed by forming a transparent conductive film on a conductive or non-conductive transparent support substrate, or the whole may be a conductive transparent substrate. The material in particular of this transparent support substrate is not restrict | limited, A various base material can be used if it is transparent. This transparent support substrate is preferably one that is excellent in moisture and gas barrier properties, solvent resistance, weather resistance, and the like that enter from the outside of the dye-sensitized photoelectric conversion element, and specifically, quartz, sapphire, glass, etc. Examples include transparent inorganic substrates, transparent plastic substrates such as polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polystyrene, polyethylene, etc. Among these, it is preferable to use a substrate having a high transmittance in the visible light region, but it is not limited thereto. It is not a thing. The thickness of the transparent support substrate is not particularly limited, and can be freely selected depending on the light transmittance, the shielding property between the inside and the outside of the dye-sensitized photoelectric conversion element, and the like.

As a material of the semiconductor fine particles 22a, various compound semiconductors, compounds having a perovskite structure, and the like can be used in addition to an elemental semiconductor represented by silicon. These semiconductors are preferably n-type semiconductors in which conduction band electrons become carriers under photoexcitation and give an anode current. Specifically, these semiconductors are TiO ₂ , ZnO, WO ₃ , Nb ₂ O ₅ , TiSrO ₃ , SnO _2, etc. Among these, anatase type TiO ₂ is particularly preferable. The types of semiconductors are not limited to these, and two or more of these can be mixed and used. Furthermore, the semiconductor fine particles can take various forms such as particles, tubes, and rods as required. Although there is no restriction | limiting in particular in the particle size of the semiconductor fine particle 22a, For example, 1-200 nm is preferable at an average particle diameter, Especially preferably, it is 5-100 nm.

  Next, as shown in FIG. 10B, the granular film 22 is wet-etched using an alkaline solution or water (pure water or the like) as an etchant, whereby all of the MoCuO 22b as the grain boundary material is removed by etching. Thus, a gap is formed in the portion where MoCuO22b is removed. Thus, the semiconductor electrode 23 is formed which is composed of the semiconductor fine particles 22a and the semiconductor fine particles 22a are separated from each other by the gap.

  Next, the semiconductor electrode 23 is baked to bring the semiconductor fine particles 22a into electrical contact with each other and to improve the film strength and the adhesion to the transparent conductive substrate 21. Although there is no restriction | limiting in particular in the range of baking temperature, Since the resistance of the transparent conductive substrate 21 will become high if it raises temperature too much and may melt | fuse, it is 450-700 degreeC normally, Preferably 450- 650 ° C. The firing time is not particularly limited, but is usually about 10 minutes to 10 hours. Baking may be performed before the above-described wet etching, if necessary.

  Next, a sensitizing dye is supported on the semiconductor electrode 23. The dye is not particularly limited as long as it exhibits a sensitizing action, but preferably has an acid functional group that adsorbs to the semiconductor electrode 23, and specifically has a carboxy group or a phosphate group. Of these, those having a carboxy group are particularly preferred. Specific examples of the dye include, for example, xanthene dyes such as rhodamine B, rose bengal, eosin, and erythrosine; cyanine dyes such as merocyanine, quinocyanine, and cryptocyanine; Examples include dyes, chlorophyll, zinc porphyrin, and porphyrin compounds such as magnesium porphyrin, and others include azo dyes, phthalocyanine compounds, coumarin compounds, bipyridine complex compounds, anthraquinone dyes, and polycyclic quinone dyes. . Among these, the dye of the complex of at least one metal selected from the group consisting of Ru, Os, Ir, Pt, Co, Fe, and Cu includes a pyridine ring or an imidazolium ring. High yield is preferred. In particular, cis-bis (isothiocyanato) -N, N-bis (2,2′-dipyridyl-4,4′-dicarboxylic acid) -ruthenium (II) or tris (isothiocyanato) -ruthenium (II) — A dye molecule having 2,2 ': 6', 2 "-terpyridine-4,4 ', 4" -tricarboxylic acid as a basic skeleton has a wide absorption wavelength range and is preferable. However, the dyes are not limited to these, and two or more of these dyes may be mixed and used.

  The method for adsorbing the dye to the semiconductor electrode 23 is not particularly limited, but the above dyes may be used, for example, alcohols, nitriles, nitromethane, halogenated hydrocarbons, ethers, dimethyl sulfoxide, amides, N-methylpyrrolidone, 1, It is dissolved in a solvent such as 3-dimethylimidazolidinone, 3-methyloxazolidinone, esters, carbonates, ketones, hydrocarbons and water, and the semiconductor electrode 23 is immersed in the dye solution, or the dye solution is used as a semiconductor. It can apply | coat on the electrode 23. FIG.

  In order to manufacture the dye-sensitized photoelectric conversion element, although not shown, the transparent conductive substrate 1 and the counter electrode substrate are separated from each other by a predetermined distance between the dye-sensitized semiconductor layer 23 and the counter electrode substrate, for example, 1 to 100 μm, preferably Are arranged so as to be opposed to each other with an interval of 1 to 50 μm, and a space in which the electrolyte layer is enclosed by a sealing material is formed, and the electrolyte layer is injected from a liquid injection port formed in advance in this space. Thereafter, the liquid injection port is closed. Thus, a dye-sensitized photoelectric conversion element is manufactured.

  The counter electrode substrate is obtained by forming a counter electrode on a transparent or opaque substrate. Any material can be used as the counter electrode as long as it is a conductive material, but even an insulating material can be used if a conductive catalyst layer is installed on the side facing the dye-sensitized semiconductor layer. Is possible. However, as the counter electrode material, an electrochemically stable material is preferably used, and specifically, platinum, gold, carbon, a conductive polymer, or the like is preferably used. For the purpose of improving the catalytic effect of redox, it is preferable that the side facing the dye-sensitized semiconductor layer 23 has a fine structure and an increased surface area. If it is carbon, it is desired to be in a porous state. The platinum black state can be formed by a method of anodizing platinum, a reduction treatment of a platinum compound, or the like, and the porous carbon can be formed by a method such as sintering of carbon fine particles or firing of an organic polymer.

Electrolytes include combinations of iodine (I ₂ ) and metal iodide or organic iodide, bromine (Br ₂ ) and metal bromide or organic bromide, ferrocyanate / ferricyanate, ferrocene / ferri Metal complexes such as sinium ion, sodium polysulfide, sulfur compounds such as alkyl thiol / alkyl disulfide, viologen dye, hydroquinone / quinone, and the like can be used. As the cation of the metal compound, Li, Na, K, Mg, Ca, Cs and the like, and as the cation of the organic compound, a quaternary ammonium compound such as tetraalkylammonium, pyridinium, and imidazolium is preferable. It is not limited, and two or more of these can be mixed and used. Among these, an electrolyte obtained by combining I ₂ and a quaternary ammonium compound such as LiI, NaI or imidazolium iodide is preferable. The concentration of the electrolyte salt is preferably 0.05 to 10M, more preferably 0.05 to 5M, and still more preferably 0.2 to 3M with respect to the solvent. The concentration of I ₂ or Br ₂ is preferably 0.0005 to 1M, more preferably 0.001 to 0.5M, and still more preferably 0.001 to 0.3M. Various additives such as 4-tert-butylpyridine and benzimidazoliums may be added for the purpose of improving the open circuit voltage of the dye-sensitized photoelectric conversion element.

Water, alcohols, ethers, esters, carbonate esters, lactones, carboxylic acid esters, phosphoric acid triesters, heterocyclic compounds, nitriles, ketones, amides as a solvent constituting the electrolyte composition Nitromethane, halogenated hydrocarbons, dimethyl sulfoxide, sulfolane, N-methylpyrrolidone, 1,3-dimethylimidazolidinone, 3-methyloxazolidinone, hydrocarbons and the like, but are not limited thereto, Moreover, these can also be used in mixture of 2 or more types. Furthermore, an ionic liquid of a tetraalkyl, pyridinium, or imidazolium quaternary ammonium salt can be used as the solvent.
According to the second embodiment, the dye-sensitized semiconductor electrode 23 used in the dye-sensitized photoelectric conversion element can be manufactured very easily.

Next explained is the third embodiment of the invention. In the third embodiment, a method for manufacturing a porous electrode will be described.
In the third embodiment, first, as shown in FIG. 11A, a MoCuO layer 32 is formed on a substrate 31, and then columnar conductive fine particles 33a and conductive fine particles 33a are formed on the MoCuO layer 32. A film 33 made of surrounding MoCuO 33b is formed. Various materials can be used as the material of the conductive fine particles 33a. For example, carbon, metal, alloy, or the like can be used.

  Next, as shown in FIG. 11B, the substrate 31 on which the film 33 is formed is wet-etched using an alkaline solution or water (pure water or the like) as an etchant, so that MoCuO 33b as the grain boundary material and the substrate 31 are formed. All of the MoCuO layer 32 between the film 33 and the film 33 is removed by etching. Thus, a gap is formed in the portion where MoCuO33b is removed. In this way, the porous electrode 34 is formed which is made of the conductive fine particles 33a and in which the conductive fine particles 33a are separated by the gaps. At the same time, the substrate 31 is peeled from the porous electrode 34 by removing the MoCuO layer 32.

Thereafter, the conductive fine particles 33a are electrically contacted, and the porous electrode 34 is baked in order to improve the film strength and the adhesion to the substrate 21. Baking may be performed before the above-described wet etching, if necessary.
The porous electrode 34 is suitable for use as, for example, a negative electrode or a positive electrode of a biofuel cell. In this case, an enzyme, a coenzyme, an electron mediator, and the like necessary for fuel decomposition can be immobilized on the porous electrode 34 (see, for example, Patent Document 5).

  According to the third embodiment, the porous electrode 34 can be manufactured very easily. For example, an enzyme or the like is supported in the voids of the porous electrode 34 and used as a negative electrode or a positive electrode of a biofuel cell. Can do.

Next explained is the fourth embodiment of the invention. In the fourth embodiment, a method for manufacturing a porous electrode will be described.
In this fourth embodiment, first, as shown in FIG. 12A, after a MoCuO layer 32 is formed on a substrate 31, substantially spherical conductive fine particles 33a and conductive fine particles 33a are formed on the MoCuO layer 32. A film 33 made of MoCuO 33b is formed.

  Next, as shown in FIG. 12B, wet etching is performed on the substrate 31 on which the film 33 is formed using an alkaline solution or water (pure water or the like) as an etchant, whereby MoCuO 33b as the grain boundary material and the substrate 31 are formed. All of the MoCuO layer 32 between the film 33 and the film 33 is removed by etching. Thus, a gap is formed in the portion where MoCuO33b is removed. In this way, a porous electrode 34 is formed which is composed of substantially spherical conductive fine particles 33a, and the conductive fine particles 33a are separated by the gaps. At the same time, the substrate 31 is peeled from the porous electrode 34 by removing the MoCuO layer 32.

Thereafter, the conductive fine particles 33a are brought into electronic contact with each other, and the porous electrode 34 is baked in order to improve the film strength and the adhesion to the substrate 21.
The porous electrode 34 is suitable for use as, for example, a negative electrode or a positive electrode of a biofuel cell. In this case, an enzyme, a coenzyme, an electron mediator, and the like necessary for fuel decomposition can be immobilized on the porous electrode 34 (see, for example, Patent Document 5).
According to the fourth embodiment, the same advantages as those of the third embodiment can be obtained.

Next explained is the fifth embodiment of the invention. In the fifth embodiment, a method for manufacturing a light emitting diode using a nitride III-V compound semiconductor such as GaN will be described (for example, see Patent Document 6).
13A to 13C, 14A to 14C, and FIGS. 15 to 18 show a manufacturing method of this light emitting diode in the order of steps.

In the fifth embodiment, as shown in FIG. 13A, first, a substrate 41 having a flat main surface is prepared, and a MoCuO layer 42 is formed on the substrate 41 as a layer that can be wet etched. The MoCuO layer 42 is typically formed with c-axis orientation, but is not limited to this. The thickness of the MoCuO layer 42 is selected as necessary, but is 100 nm, for example. A method for forming the MoCuO layer 42 is also appropriately selected. For example, a DC sputtering method, a vacuum evaporation method, or the like is used. Various substrates can be used as the substrate 41 and are selected as necessary. For example, as a substrate made of a material different from a nitride III-V compound semiconductor, sapphire (including c-plane, a-plane, r-plane, etc., including planes off from these planes), SiC (6H 4H, 3C), Si, ZnS, ZnO, LiMgO, GaAs, spinel (MgAl ₂ O ₄ , ScAlMgO ₄ ), garnet, CrN (eg, CrN (111)), or the like can be used. As the substrate 41, a substrate made of a nitride III-V group compound semiconductor (GaN, AlGaInN, AlN, GaInN, etc.), particularly a GaN substrate may be used. Alternatively, as the substrate 41, a substrate made of a material different from the nitride-based III-V compound semiconductor, for example, a nitride-based III-V compound semiconductor layer grown on a sapphire substrate may be used.

Next, on the MoCuO layer 42, convex portions 43 having an isosceles triangular cross section are periodically formed in a predetermined plane shape. A concave portion 44 having an inverted trapezoidal cross-sectional shape is formed between the convex portions 43. The planar shape of the convex portion 43 and the concave portion 44 can be various planar shapes.For example, as shown in FIG. 19, when the convex portion 43 and the concave portion 44 have a stripe shape extending in one direction, As shown in FIG. 20, the convex part 43 has a hexagonal planar shape, and this is two-dimensionally arranged in a honeycomb shape. Typically, the direction of the dotted line in FIG. 19 (direction perpendicular to the stripe) is parallel to the a-axis of the nitride III-V compound semiconductor layer 46 described later, and the direction of the dotted line in FIG. The direction connecting the portions 43 is made parallel to the m-axis of the nitride III-V compound semiconductor layer 46 described later. The materials described above can be used as the material of the convex portion 43, but a dielectric having a refractive index of 1.0 to 2.3 is preferably used, and particularly from the viewpoint of ease of processing, etc. For example, SiO ₂ , SiN, SiON or the like is used.

In order to form the convex part 43 having an isosceles triangular cross section on the MoCuO layer 42, a conventionally known method can be used. For example, a film (for example, a SiO ₂ film or a SiN film) that forms the material of the convex portion 43 is formed on the entire surface of the MoCuO layer 42 by a CVD method, a vacuum evaporation method, a sputtering method, or the like. Next, a resist pattern having a predetermined shape is formed on the film by lithography. Next, this film is etched using the resist pattern as a mask under conditions where taper etching is performed by a reactive ion etching (RIE) method or the like, thereby forming a convex portion 43 having an isosceles triangular cross section. The As an example, a SiO ₂ film having a thickness of about 1.5 μm is formed, and this is patterned to form convex portions 43 having an interval of about 1.5 μm.

  Next, after cleaning the surfaces of the MoCuO layer 42 and the convex portion 43 by performing thermal cleaning or the like, for example, a GaN buffer layer, an AlN buffer layer, etc. at a growth temperature of, for example, about 550 ° C. by a conventionally known method. A CrN buffer layer, a Cr-doped GaN buffer layer, or a Cr-doped AlN buffer layer (not shown) is grown. Next, epitaxial growth of a nitride III-V compound semiconductor is performed by, for example, MOCVD. This nitride-based III-V group compound semiconductor is, for example, GaN. At this time, as shown in FIG. 13B, first, growth is started from the bottom surface of the recess 44 to generate a plurality of micronuclei 45 made of a nitride III-V compound semiconductor. Next, as shown in FIG. 13C, an isosceles triangular shape having a bottom face of the recess 44 and a facet inclined with respect to the main surface of the substrate 41 on the slope through the process of growth and coalescence of the micronuclei 45. The nitride III-V compound semiconductor layer 46 is grown so as to have a cross-sectional shape. In this example, the height of the nitride-based III-V group compound semiconductor layer 46 having an isosceles triangular cross-sectional shape is larger than the height of the protrusion 43. For example, the extending direction of the nitride III-V compound semiconductor layer 46 is the <1-100> direction, and the facet of the inclined surface is the (1-101) plane. The nitride III-V compound semiconductor layer 46 may be undoped or doped with n-type impurities or p-type impurities. The growth conditions for the nitride III-V compound semiconductor layer 46 will be described later. The extending direction of the nitride-based III-V compound semiconductor layer 46 may be the <11-20> direction.

Subsequently, by performing the growth of the nitride-based III-V compound semiconductor layer 46 while maintaining the facet plane orientation of the inclined surface, as shown in FIG. Both end portions are grown to the lower portion of the side surface of the convex portion 43 so that the cross-sectional shape becomes a pentagonal shape.
Next, when the growth condition is set to a condition in which the lateral growth is dominant and the growth is continued, as shown in FIG. 14B, the nitride-based III-V group compound semiconductor layer 46 has a lateral shape as indicated by an arrow. It grows in the direction and spreads on the convex portion 43 in a state where the cross-sectional shape becomes a hexagonal shape. In FIG. 14B, a dotted line indicates a growth interface in the middle of growth (the same applies hereinafter).

When the lateral growth is further continued, as shown in FIG. 14C, the nitride-based III-V compound semiconductor layer 46 grows while increasing its thickness, and finally the nitride-based III-III grown from the adjacent recess 44. The group V compound semiconductor layers 46 come into contact with each other on the convex portion 43 and are associated with each other.
Subsequently, as shown in FIG. 14C, the nitride-based III-V compound semiconductor layer 46 is laterally grown until the surface thereof becomes a flat surface parallel to the main surface of the substrate 41. The nitride-based III-V group compound semiconductor layer 46 thus grown has a very low dislocation density in the portion above the recess 44.

  Next, as shown in FIG. 15, the n-type nitride III-V compound semiconductor layer 47, the nitride III-V group are formed on the nitride III-V compound semiconductor layer 46 by, eg, MOCVD. An active layer 48 using a compound semiconductor and a p-type nitride-based III-V group compound semiconductor layer 49 are sequentially epitaxially grown. In this case, the nitride III-V compound semiconductor layer 46 is assumed to be n-type.

The growth source of the above-mentioned nitride III-V compound semiconductor layer is, for example, triethylgallium ((C ₂ H ₅ ) ₃ Ga, TEG) or trimethyl gallium ((CH ₃ ) ₃ Ga, TMG as a Ga source. ), Trimethylaluminum ((CH ₃ ) ₃ Al, TMA) as a raw material of Al, triethylindium ((C ₂ H ₅ ) ₃ In, TEI) or trimethylindium ((CH ₃ ) ₃ In, TMI), and ammonia (NH ₃ ) is used as a raw material for N. As for the dopant, for example, silane (SiH ₄ ) or disilane (Si ₂ H ₆ ) is used as the n-type dopant, and bis (methylcyclopentadienyl) magnesium ((CH ₃ C ₅ H ₄ ) ₂ is used as the p-type dopant. Mg), bis (ethylcyclopentadienyl) magnesium ((C ₂ H ₅ C ₅ H ₄ ) ₂ Mg) or bis (cyclopentadienyl) magnesium ((C ₅ H ₅ ) ₂ Mg) is used. For the carrier gas atmosphere during the growth of the nitride-based III-V compound semiconductor layer, eg, H ₂ gas is used.

Next, the substrate 41 on which the nitride-based III-V compound semiconductor layer is grown in this way is taken out from the MOCVD apparatus.
Next, the p-side electrode 50 is formed on the p-type nitride III-V compound semiconductor layer 49. As a material of the p-side electrode 50, for example, an ohmic metal having a high reflectance is preferably used.

Thereafter, in order to activate the p-type impurity of the p-type nitride III-V compound semiconductor layer 49, for example, a mixed gas of N ₂ and O ₂ (composition is, for example, 99% N ₂ and O ₂ In a 1% atmosphere, heat treatment is performed at a temperature of 550 to 750 ° C. (for example, 650 ° C.) or 580 to 620 ° C. (for example, 600 ° C.). Here, for example, activation is easily caused by mixing O ₂ with N ₂ . Further, for example, nitrogen halide (NF ₃ , NCl _3, etc.) is mixed in a mixed gas atmosphere of N ₂ or N ₂ and O ₂ as a raw material such as F and Cl having high electronegativity as in O and N. You may do it. The time for this heat treatment is, for example, 5 minutes to 2 hours or 40 minutes to 2 hours, generally about 10 to 60 minutes. The reason for making the temperature of the heat treatment relatively low is to prevent deterioration of the active layer 48 and the like during the heat treatment. This heat treatment may be performed after the p-type nitride III-V compound semiconductor layer 49 is epitaxially grown and before the p-side electrode 50 is formed.

Next, a metal film 51 for bonding substrates is formed on the p-side electrode 50. The metal film 51 can be formed by, for example, a sputtering method or a vacuum evaporation method. The metal film 51 is made of, for example, Au, but is not limited thereto.
On the other hand, as shown in FIG. 16, a substrate in which a metal film 53 for bonding the substrate is formed on one main surface of the support substrate 52 is prepared, and the metal film 53 side of the support substrate 52 is placed on the substrate 41. The metal film 51 is attached. The metal film 51 is made of, for example, Au, but is not limited thereto. The support substrate 52 may be either conductive or non-conductive. When the support substrate 52 is non-conductive, a structure that allows a current to flow to the light emitting diode through the metal films 51 and 53 is used. 52 may be provided.

  Next, the MoCuO layer 42, the protrusion 43, the nitride III-V compound semiconductor layer 46, the n-type nitride III-V compound semiconductor layer 47, the active layer 48, and the p-type nitride are formed on the substrate 41. A solution in which the group III-V compound semiconductor layer 49, the p-side electrode 50, and the metal film 51 are formed and a structure in which the metal film 53 is formed on the support substrate 52 is bonded to an alkali solution or Wet etching is performed using water (such as pure water). Thus, the MoCuO layer 42 is removed as shown in FIG. Then, by removing the MoCuO layer 42 in this way, the substrate 41 is peeled from the nitride-based III-V compound semiconductor layer 46.

Next, the n-side electrode 54 is formed on the n-type nitride III-V compound semiconductor layer 46 exposed by removing the MoCuO layer 42. The n-side electrode 54 is made of a transparent electrode material.
Next, a bar is formed by scribing the nitride-based III-V compound semiconductor layer forming the light emitting diode structure on the support substrate 52, and the bar is scribed to form a chip.
Thus, the target light emitting diode is manufactured. This light emitting diode is a vertical current injection type.

  A specific structural example of the light emitting diode will be described. That is, for example, the nitride-based III-V compound semiconductor layer 46 is an n-type GaN layer, the n-type nitride-based III-V compound semiconductor layer 47 is in order from the bottom, an n-type GaN layer and an n-type GaInN layer, p The type nitride III-V compound semiconductor layer 49 is a p-type AlInN layer, a p-type GaN layer, and a p-type GaInN layer in order from the bottom. The active layer 48 has, for example, a GaInN-based multiple quantum well (MQW) structure (for example, one in which GaInN quantum well layers and GaN barrier layers are alternately stacked), and the In composition of the active layer 48 is the light emission of the light emitting diode. It is selected according to the wavelength. For example, it is ˜11% at an emission wavelength of 405 nm, ˜18% at 450 nm, and ˜24% at 520 nm. As a material of the p-side electrode 51, for example, Ag, Pd / Ag, or the like is used, or a barrier metal made of Ti, W, Cr, WN, CrN, or the like is used in addition to this, if necessary. As the n-side electrode 54, for example, an electrode made of ITO is used.

  In the light-emitting diode shown in FIG. 18 thus obtained, light is emitted by applying a forward voltage between the p-side electrode 50 and the n-side electrode 54 to flow current, and the light is emitted from the n-side electrode 54 side to the outside. Take out the light. Depending on the selection of the In composition of the active layer 48, red to ultraviolet light emission, particularly blue light emission, green light emission or red light emission can be obtained. In this case, of the light generated from the active layer 48, the light directed toward the n-side electrode 54 is refracted at the interface between the convex portion 43 and the nitride-based III-V compound semiconductor layer 46, and then the n-side electrode 54. Out of the light emitted from the active layer 48 through the active layer 48, the light directed to the p-side electrode 50 is reflected by the p-side electrode 50 and travels toward the n-side electrode 54. Go out and go outside.

In the fifth embodiment, in order to minimize the threading dislocation density of the nitride-based III-V compound semiconductor layer 46, the width W _g of the bottom surface of the recess 44, the depth of the recess 44, that is, the protrusion 43 And the angle α formed by the slope of the nitride III-V compound semiconductor layer 46 in the state shown in FIG. 13C and the principal surface of the substrate 41 are determined so as to satisfy the following formula ( (See FIG. 21).
2d ≧ W _g tan α
For example, when W _g = 2.1 μm and α = 59 °, d ≧ 1.75 μm, W _g = 2 μm, and when α = 59 °, d ≧ 1.66 μm, W _g = 1.5 μm, α When d = 59 °, d ≧ 1.245 μm, W _g = 1.2 μm, and when α = 59 °, d ≧ 0.966 μm. However, in any case, it is desirable that d <5 μm.

During the growth of the nitride-based III-V compound semiconductor layer 46 in the steps shown in FIGS. 13B and 13A and FIG. 14A, it is preferable to set the growth temperature to a low value in order to increase the V / III ratio of the growth material. Specifically, when the growth of the nitride-based III-V compound semiconductor layer 46 is performed under a pressure condition of 1 atm, the V / III ratio of the growth material is in the range of, for example, 13000 ± 2000, and the growth temperature is, for example, 1100. It is preferable to set in the range of ± 50 ° C. Regarding the V / III ratio of the growth raw material, when the growth of the nitride-based III-V compound semiconductor layer 46 is performed under a pressure condition of x atmospheric pressure, the pressure is determined from Bernoulli's law that defines the relationship between the flow velocity and the pressure. It is preferable to set the V / III ratio corresponding to the square of the amount of change, specifically (13000 ± 2000) × x ² . For example, when the growth is performed at 0.92 atmospheres (700 Torr), the V / III ratio of the growth raw material is preferably set to a range of 11000 ± 1700 (for example, 10530). x is generally from 0.01 to 2 atmospheres. When the growth is performed under a pressure condition of 1 atm or less, the lateral growth of the nitride-based III-V compound semiconductor layer 46 is suppressed, and the nitride-based III-V compound semiconductor in the recess 44 is suppressed. In order to facilitate selective growth of the layer 46, it is preferable to set a lower growth temperature. For example, when growth is performed at 0.92 atmospheres (700 Torr), the growth temperature is preferably set in a range of 1050 ± 50 ° C. (for example, 1050 ° C.). As described above, the nitride III-V compound semiconductor layer 46 grows as shown in FIGS. 13B and 13C and FIG. 14A. At this time, the nitride-based III-V compound semiconductor layer 46 does not start growing on the convex portion 43. The growth rate is generally 0.5 to 5.0 μm / h, preferably about 3.0 μm / h. When the nitride III-V compound semiconductor layer 46 is, for example, a GaN layer, the flow rate of the source gas is, for example, 20 SCCM for TMG and 20 SLM for NH ₃ . On the other hand, the growth (lateral growth) of the nitride-based III-V compound semiconductor layer 46 in the steps shown in FIGS. 14B and 14C is set to a high growth temperature with a low V / III ratio of the growth material. Specifically, when the growth of the nitride-based III-V compound semiconductor layer 46 is performed under a pressure condition of 1 atm, the V / III ratio of the growth material is in the range of, for example, 5000 ± 2000, and the growth temperature is, for example, 1200. Set in the range of ± 50 ° C. Regarding the V / III ratio of the growth raw material, when the growth of the nitride-based III-V compound semiconductor layer 46 is performed under a pressure condition of x atmospheric pressure, the pressure is determined from Bernoulli's law that defines the relationship between the flow velocity and the pressure. It is preferable to set the V / III ratio corresponding to the square of the amount of change, specifically (5000 ± 2000) × x ² . For example, when the growth is performed at 0.92 atmospheres (700 Torr), the V / III ratio of the growth material is preferably set in the range of 4200 ± 1700 (for example, 4232). As for the growth temperature, when growth is performed under a pressure condition of 1 atm or less, the surface of the nitride III-V compound semiconductor layer 46 is prevented from being roughened, and the lateral growth is favorably performed. It is preferable to set the temperature. For example, when growth is performed at 0.92 atmospheres (700 Torr), the growth temperature is preferably set in the range of 1150 ± 50 ° C. (eg, 1110 ° C.). When the nitride III-V compound semiconductor layer 46 is, for example, a GaN layer, the flow rate of the source gas is, for example, 40 SCCM for TMG and 20 SLM for NH ₃ . By doing so, as shown in FIGS. 14B and 14C, the nitride-based III-V compound semiconductor layer 46 grows in the lateral direction.

According to the fifth embodiment, the threading dislocations in the nitride III-V compound semiconductor layer 46 are concentrated near the center of the convex portion 43 on the substrate 41, and the dislocation density in other portions is, for example, 6 ×. This is greatly reduced to about 10 ⁷ / cm ² . Therefore, the crystallinity of the nitride III-V compound semiconductor layer 46 and the nitride III-V compound semiconductor layer such as the active layer 48 grown on the nitride III-V compound semiconductor layer 46 is greatly improved, and the non-luminescent center is also improved. Decrease significantly. As a result, a nitride-based III-V compound semiconductor light-emitting diode with extremely high luminous efficiency can be obtained.

In addition, the epitaxial growth required for the production of the nitride III-V compound semiconductor light emitting diode is only required once, and no growth mask is required. Further, the convex portion 43 is formed by forming a film as a material of the convex portion 43 on the MoCuO layer 42, for example, a SiO ₂ film, a SiON film, a SiN film, a CrN film, a CrON film, etc., and etching or powder blasting. It can be formed only by processing by a sandblasting method or the like. For this reason, since it is not necessary to process the substrate 41 such as a sapphire substrate, which is difficult to process unevenness, a manufacturing process is simple, and a low-cost vertical current injection type nitride III-V compound semiconductor light emitting diode is manufactured. Can be manufactured. Further, since the substrate 41 can be easily peeled by removing the MoCuO layer 42 by wet etching, the substrate 41 can be reused repeatedly by performing mirror polishing if necessary. Effective use can be achieved, and the manufacturing cost of the light emitting diode can be reduced.

Although the embodiments and examples of the present invention have been specifically described above, the present invention is not limited to the above-described embodiments and examples, and various modifications based on the technical idea of the present invention are possible. It is.
For example, the numerical values, structures, shapes, materials, raw materials, processes, and the like given in the above-described embodiments and examples are merely examples, and numerical values, structures, shapes, materials, raw materials, processes, and the like that are different from these as necessary. May be used.

It is sectional drawing for demonstrating the manufacturing method of the perpendicular magnetic recording medium by 1st Embodiment of this invention. It is a top view for demonstrating the manufacturing method of the perpendicular magnetic recording medium by 1st Embodiment of this invention. It is sectional drawing for demonstrating the manufacturing method of the perpendicular magnetic recording medium by 1st Embodiment of this invention. It is a top view for demonstrating the manufacturing method of the perpendicular magnetic recording medium by 1st Embodiment of this invention. It is sectional drawing for demonstrating the manufacturing method of the perpendicular magnetic recording medium by 1st Embodiment of this invention. It is a drawing substitute photograph which shows the SEM image of the surface of the sample before performing wet etching in the Example of this invention. It is a drawing substitute photograph which shows the SEM image of the surface of the sample after performing wet etching in the Example of this invention. It is a basic diagram which shows the MH loop measured about the sample before performing wet etching in the Example of this invention. It is a basic diagram which shows the MH loop measured about the sample after performing wet etching in the Example of this invention. It is sectional drawing for demonstrating the manufacturing method of the semiconductor electrode by 2nd Embodiment of this invention. It is sectional drawing for demonstrating the manufacturing method of the porous body electrode by 3rd Embodiment of this invention. It is sectional drawing for demonstrating the manufacturing method of the porous body electrode by 4th Embodiment of this invention. It is sectional drawing for demonstrating the manufacturing method of the light emitting diode by 5th Embodiment of this invention. It is sectional drawing for demonstrating the manufacturing method of the light emitting diode by 5th Embodiment of this invention. It is sectional drawing for demonstrating the manufacturing method of the light emitting diode by 5th Embodiment of this invention. It is sectional drawing for demonstrating the manufacturing method of the light emitting diode by 5th Embodiment of this invention. It is sectional drawing for demonstrating the manufacturing method of the light emitting diode by 5th Embodiment of this invention. It is sectional drawing for demonstrating the manufacturing method of the light emitting diode by 5th Embodiment of this invention. It is a top view which shows the example of the planar shape of the convex part formed on a board | substrate in the manufacturing method of the light emitting diode by 5th Embodiment of this invention. It is a top view which shows the example of the planar shape of the convex part formed on a board | substrate in the manufacturing method of the light emitting diode by 5th Embodiment of this invention. It is a basic diagram which shows the board | substrate used in the manufacturing method of the light emitting diode by 5th Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Substrate, 12 ... Soft magnetic backing layer, 13 ... Seed layer, 14 ... Underlayer, 15 ... Granular film, 15a ... Magnetic particle, 15b ... MoCuO, 16 ... Magnetic recording layer, 17 ... Protective layer, 21 ... Transparent conductive Conductive substrate, 22a ... semiconductor fine particle, 22b ... MoCuO, 23 ... semiconductor electrode, 31 ... substrate, 32 ... MoCuO layer, 33a ... conductive fine particle, 33b ... MoCuO, 34 ... porous electrode, 41 ... substrate, 42 ... MoCuO layer , 43 ... convex part, 44 ... concave part, 45 ... micronucleus, 46 ... nitride-based III-V compound semiconductor layer, 47 ... n-type nitride III-V compound semiconductor layer, 48 ... active layer, 49 ... p-type nitride III-V compound semiconductor layer, 50... p-side electrode, 51, 53... metal film, 52 .. support substrate, 54.

Claims (15)

Forming a granular film made of magnetic particles and MoCuO surrounding the magnetic particles on a substrate;
And a step of removing at least a part of the MoCuO in the granular film by wet etching.   2. The method of manufacturing a perpendicular magnetic recording medium according to claim 1, wherein all of the MoCuO in the granular film is removed by wet etching.   3. The method of manufacturing a perpendicular magnetic recording medium according to claim 2, wherein the wet etching is performed with an alkaline solution or water.   4. The method for producing a perpendicular magnetic recording medium according to claim 3, wherein an aqueous tetramethylammonium hydroxide solution is used as the alkaline solution.   2. The method of manufacturing a perpendicular magnetic recording medium according to claim 1, wherein the magnetic particles are made of CoPt, CoCrPt, or FePt.   2. The method of manufacturing a perpendicular magnetic recording medium according to claim 1, wherein a seed layer and an underlayer are sequentially formed on the substrate before forming the granular film.   2. The method for manufacturing a perpendicular magnetic recording medium according to claim 1, wherein the granular film is formed by a sputtering method or a vacuum evaporation method.   2. The method of manufacturing a perpendicular magnetic recording medium according to claim 1, wherein the perpendicular magnetic recording medium is a perpendicular magnetic recording medium for heat-assisted magnetic recording. Forming a granular film made of magnetic particles and MoCuO surrounding the magnetic particles on a substrate;
A perpendicular magnetic recording medium manufactured by performing a step of removing at least a part of the MoCuO of the granular film by wet etching. Forming a granular film made of magnetic particles and MoCuO surrounding the magnetic particles on a substrate;
A magnetic recording / reproducing apparatus having a perpendicular magnetic recording medium manufactured by performing a step of removing at least a part of the MoCuO of the granular film by wet etching. Forming a granular film made of magnetic particles and MoCuO surrounding the magnetic particles on a substrate;
And a step of removing at least a part of the MoCuO in the granular film by wet etching. Forming a granular film made of magnetic particles and MoCuO surrounding the magnetic particles on a substrate;
Removing at least a part of the MoCuO of the granular film by wet etching. Forming a film made of particles and MoCuO surrounding the particles on a substrate;
And a step of removing at least a part of the MoCuO of the film by wet etching. Forming a MoCuO layer on the substrate;
Forming an element layer on the MoCuO layer;
And a step of removing the MoCuO layer by wet etching. Forming a MoCuO layer on the substrate;
Forming a plurality of protrusions on the MoCuO layer;
Growing a first nitride-based III-V group compound semiconductor layer in a concave portion between the convex portions through a triangular cross-sectional shape with the bottom surface as a base; and
Laterally growing a second nitride III-V compound semiconductor layer from the first nitride III-V compound semiconductor layer;
Growing a nitride III-V compound semiconductor layer constituting an element layer on the second nitride III-V compound semiconductor layer;
And a step of removing the MoCuO layer by wet etching.

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