JP4343616B2 - Nanostructure manufacturing method and nanostructure - Google Patents

Description

    The present invention relates to a method for producing a nanostructure by electroless plating and the nanostructure.

  Metal and semiconductor thin films, thin wires, dots, and the like may exhibit unique electrical, optical, and chemical properties by confining the movement of electrons in a size smaller than a certain characteristic length. From such a viewpoint, as a functional material, there is an increasing interest in a material (hereinafter, “nanostructure”) having a structure having a size (width, thickness, etc.) smaller than several tens of nm.

  As a method for producing such a nanostructure, for example, a method for directly producing a nanostructure by a semiconductor processing technique including a fine pattern forming technique such as photolithography, electron beam exposure, and X-ray exposure is given. It is done.

  In addition to the method for producing the nanostructure, there is also a regular structure that is naturally formed, that is, a self-regularly formed structure or a self-formed method. Many of these techniques are being studied because there is a possibility that a fine and special structure can be produced over the conventional method depending on the fine structure used as a base. As such a self-regular or self-forming method, anodization capable of forming a nanostructure having nano-sized pores in a large area with good control can be mentioned (see Patent Document 1). For example, anodized alumina prepared by anodizing aluminum in an acidic bath is known.

In addition, the electroless plating method is characterized by the ability to obtain a uniform thin film with a uniform thickness regardless of the material of the substrate and its shape. Widely used in As metals used for electroless plating, Cu, Ni, and Co are relatively used, and noble metals such as Au, Pd, Pt, and Ag have recently been frequently used. For example, copper plating is used as a surface treatment technology for the purpose of decoration, corrosion resistance, and abrasion resistance in the electronic industry. Recently, resistors, electrodes, wiring, magnetic recording media, etc. have been put to practical use as functional plating utilizing the characteristics of electroless plating films mainly composed of Ni, Co, etc. (Patent Document 2). reference).
JP 07-0178080 A Japanese Patent Laid-Open No. 08-173810

  In the electroless plating as described above, a thin film can be formed by a simple method of immersing in a plating solution, and high functionality of a fine structure such as an electrode or a wiring has been advanced. In particular, a structure having a size of several tens of nanometers to several μm or less is increasing in functionality or density, but it is difficult to form a fine structure having a size of several tens of nanometers or less.

  The present invention has been made in view of such conventional circumstances, and is intended to increase the functionality by electroless plating and to form a nanostructure capable of forming a fine structure having a size of several tens of nanometers or less. A manufacturing method is provided.

  The present invention relates to a substrate, a base film, a thin film mainly composed of Si or Ge, and a nanostructure manufacturing method including a columnar structure formed in the pores of the thin film. A columnar member mainly composed of Al formed on the surface of the substrate and a matrix mainly composed of any one of Si, Ge, and SiGe disposed so as to surround the side surface of the columnar member mainly composed of Al. A step of forming pores in the substrate by removing the columnar member mainly composed of Al in the substrate on which the Al (Si, Ge) mixed thin film having the structure is formed, and an electroless plating bath Forming a columnar structure in the pores by immersing the substrate on which the pores are formed.

  The columnar member is preferably formed in a direction perpendicular or substantially perpendicular to the substrate.

  In the method for producing a nanostructure, the step of forming pores in the substrate may be performed by immersing the substrate in an electroless plating bath to simultaneously remove the columnar member mainly composed of Al in the substrate. Those that form holes are preferred.

  In the method for manufacturing a nanostructure, the base film may have catalytic activity. The base film having catalytic activity may be Pd or a Pd alloy.

Further, in the method for producing a nanostructure, the matrix includes (Si, Al) O _x mixed thin film (0 ≦ X ≦ 2), (Ge, Al) O _x mixed thin film (0 ≦ X ≦ 2), ( Any of Si, Ge, Al) O _x mixed thin films (0 ≦ X ≦ 2) may be used.

  In the method for manufacturing a nanostructure, the columnar structure may be a metal or an oxide. The metal may be at least one of Co, Ni, Pt, and Pd. A small amount of either B or P may be included as the metal material of the columnar structure. The oxide may be ZnO.

  In the method for producing a nanostructure in the present invention, a columnar structure can be formed in the pores of the substrate by immersing the substrate in an electroless plating bath.

  According to the present invention, it is possible to provide a method for producing a nanostructure in which a columnar structure that is either a metal or an oxide is formed in pores in the substrate by immersing the substrate in an electroless plating bath. it can.

  In addition, according to the present invention, it is possible to provide a method for manufacturing a nanostructure that can easily form a columnar structure in a large area at low cost. Furthermore, according to the present invention, it is possible to provide a highly functional nanodevice such as an electrode or a wiring by using a nanostructure formed with a columnar structure that is a metal. Moreover, the magnetic device using the nanostructure which formed the columnar structure which is a magnetic body by this invention can be provided. Furthermore, the present invention can provide an optical device using a nanostructure formed with a ZnO columnar structure such as a light emitting element, a photoelectric conversion element, and a photocatalytic element.

Hereinafter, the best mode for carrying out the nanostructure according to the present invention will be described in detail with reference to the accompanying drawings.
(Nanostructure in the present invention)
FIG. 1 is a schematic view showing an example of the configuration of a nanostructure in the present invention. In FIGS. 1A and 1B, 11 is a columnar structure, 12 is a matrix (matrix portion) containing Si, Ge, or SiGe as a main component, 13 is a base film (base layer), and 14 is a substrate. , 15 are nanostructures.

  As shown in FIGS. 1A and 1B, the nanostructure 15 is formed on the surface of the base film 13 formed on the substrate 14 in a direction perpendicular or substantially perpendicular to the surface of the substrate 14. A plurality of columnar structures 11 and a matrix 12 which is arranged so as to surround the side surface of the columnar structures 11 and mainly contains any one of Si, Ge and SiGe. The columnar structures 11 are dispersed.

  The columnar structure 11 is made of any one of metals such as Pt, Pd, CoP, CoB, CoNiP, NiP, and NiB, and oxides such as ZnO. The diameter of the columnar structure 11 (diameter when the planar shape is a circle) 2r (see FIG. 1B) can be controlled mainly by the manufacturing conditions of the nanostructure 15, but the average diameter is 20 nm. Hereinafter, it is preferably 1 nm or more and 15 nm or less. In the case of an ellipse or the like, it may be within the range of the longest outer diameter portion. Here, the average diameter is a value derived from, for example, a columnar portion observed in an actual SEM photograph, either directly from the photograph or by image processing with a computer. Although it depends on what device the thin film is used for and what kind of treatment is performed, the practical lower limit is that the lower limit of the average diameter is 1 nm or more, or several nm or more. The center distance 2R between the columnar structures 11 (see FIG. 1B) is 30 nm or less, preferably 5 nm or more and 20 nm or less.

The nanostructure 15 is preferably a film-like structure, and the columnar structures 11 are dispersed in the matrix 12 so as to be perpendicular or substantially perpendicular to the base film 13 and the substrate 14. preferable. Although it does not specifically limit as a film thickness of the film-form structure which comprises the nanostructure 15, It is applicable in the range of 1 nm-100 micrometers. A more realistic film thickness in consideration of process time and the like is about 1 nm to 1 μm.
(Al (Si, Ge) mixed thin film structure)
FIG. 2 is a schematic view of an Al (Si, Ge) mixed thin film on which the nanostructure 15 is based. 2 (a) and 2 (b), 21 is a columnar member, 22 is a matrix (matrix portion) containing Si, Ge, or SiGe as a main component, 23 is a substrate, and 24 is Al (Si, Ge) mixed. It is a thin film. The Al (Si, Ge) mixed thin film 24 has a structure in which a number of columnar members 21 containing Al as a component in a material made of Si or Ge are formed in a direction perpendicular or substantially perpendicular to a substrate 23 with a base film. A thin film having a body. Hereinafter, the structure will be described in detail.

The Al (Si, Ge) mixed thin film 24 includes (Si, Al) O _x mixed thin film (0 ≦ X ≦ 2), (Ge, Al) O _x mixed thin film (0 ≦ X ≦ 2), and (Si, Ge). , Al) O _x mixed thin film (0 ≦ X ≦ 2).

Here, an (Si, Al) O _x mixed thin film (0 ≦ X ≦ 2) will be described as the Al (Si, Ge) mixed thin film 24, and among these, the (Al, Si) mixed thin film 24 with X = 0. Is used.

  In this mixed thin film 24, the columnar member 21 mainly composed of Al is surrounded by a region constituted mainly by Si, that is, a matrix 22. The mixed thin film 24 contains Si at a ratio of 20 at% to 70 at% with respect to the total amount of Al and Si. This ratio is the ratio of Si to the total amount of Al and Si constituting the mixed thin film 24, and is preferably 25 at% or more and 65 at% or less, more preferably 30 at% or more and 60 at% or less. The at% indicating the ratio of Al to Si indicates the ratio of the number of Si and Al atoms, and is also described as atom% or at%. For example, the inductively coupled plasma emission analysis method (ICP method) uses (Al , Si) is a value when the amount of Si and Al in the mixed thin film 24 is quantitatively analyzed.

  The columnar shape may be substantially realized. For example, the columnar member 21 may contain Si as a component of the member, or the region other than the columnar member 21, that is, the matrix 22 may contain Al. Also good. In addition, the columnar member 21 and its surrounding region may contain oxygen, argon, nitrogen, hydrogen, or the like.

  Similarly, in the case of the (Al, Ge) mixed thin film and the (Al, Si, Ge) mixed thin film, Ge and SiGe are used instead of Si as described above in the case of the (Al, Si) mixed thin film. it can.

Further, the mixed thin film 24 has eutectic points in the component phase equilibrium diagram of both the A and B materials, where Al is “A material” and any of Si, Ge, and SiGe is “B material”. Material (so-called eutectic material) is used. In particular, the eutectic point is 300 ° C. or higher, preferably 400 ° C. or higher. As a preferable combination of the A material and the B material, Al is used as the A material, Si is used as the B material, Al is used as the A material, Ge is used as the B material, or Al is used as the A material. It is preferable to use Si _y Ge _1-y (0 <y <1) as the B material.

  The matrix 22 surrounding the columnar member 21 is preferably amorphous. The planar shape of the columnar member 21 is circular or elliptical.

  In the mixed thin film 24, a plurality of the columnar members 21 are dispersed in a matrix 22 including the B material. The diameter of the columnar member 21 (in the case where the planar shape is a circle) can be controlled mainly depending on the composition of the mixed thin film 24 (that is, the ratio of the B material), but the average diameter is preferably 20 nm or less. Is 1 nm or more and 15 nm or less. In the case of an ellipse or the like, it may be within the range of the longest outer diameter portion. Here, the average diameter is a value derived from, for example, a columnar portion observed in an actual SEM photograph, either directly from the photograph or by image processing with a computer. The lower limit of the average diameter is 1 nm or more, or several nm or more is a practical lower limit depending on what device the mixed thin film 24 is used for and what kind of processing is performed. is there.

  The center distance 2R (FIG. 2) between the plurality of columnar members 21 is 30 nm or less, preferably 5 nm or more and 20 nm or less.

The mixed thin film 24 is preferably a film-like structure, and the columnar members 21 are preferably dispersed in a matrix 22 including the B material so as to be perpendicular to the substrate 23. Although it does not specifically limit as a film thickness of the mixed thin film 24, It can apply in the range of 1 nm-100 micrometers. Considering the process time and the like, the practical film thickness is preferably about 1 nm to 1 μm.
(About the manufacturing method of the nanostructure in this invention)
Next, the manufacturing method of the nanostructure in this invention is demonstrated in detail.

FIG. 3 is a process chart showing one embodiment of a method for producing a nanostructure in the present invention. In the manufacturing method according to the present invention, a mixed thin film 24 (an (Si, Al) O _x mixed thin film (0 ≦ X ≦ 2) is adopted as an example) is formed on a substrate 14 on which a base film 13 is formed, and this mixing is performed. A columnar structure 33 is formed in the vertical direction on the substrate 14 in the pores 31 of the thin film 24, and includes the following steps (a) to (d).

(A) Process (refer FIG. 3 (a))
First, the base film 13 is formed on the substrate 14. In this step, a substrate 14 having catalytic activity may be used.

(B) Process (refer FIG.3 (b))
Next, an (Al, Si) mixed thin film 24 is formed on the substrate 14 produced in the step (a) by using a film forming method in which a material is formed in a non-equilibrium state between Al and Si (here, (Si , Al) O _x mixed thin film 24 (X = 0)).

  The formed (Al, Si) mixed thin film 24 includes a columnar member 21 containing Al as a main component and a matrix 22 containing Si as a main component surrounding the columnar member 21, with respect to the total amount of Al and Si. And a structure containing Si at a ratio of 20 at% to 70 at%.

(C) Process ((refer FIG.3 (c)))
Next, only the Al of the (Al, Si) mixed thin film 24 is selectively etched to form the pores 31. When this (Al, Si) mixed thin film 24 is subjected to wet etching using an acid or alkali that dissolves Al more easily than Si, Al is etched from the columnar member 21 containing Al as a main component, thereby forming pores 31. And (Si, Al) O _x porous body 32 (0 <X ≦ 2) is formed.

(D) Process (refer FIG.3 (d))
Next, the (Al, Si) mixed thin film 24 produced in the step (b) or the pores 31 of the (Si, Al) O _x porous body 32 (0 <X ≦ 2) produced in the step (c). The columnar structure 33 is filled therein by electroless plating to form the nanostructure 34 of the present invention.

In the above as a mixed film 24 (Si, Al) O _X mixed film describes a manufacturing method of (0 ≦ X ≦ 2) when adopted, but other, (Ge, Al) O _X mixed thin film ( 0 ≦ X ≦ 2), (Si, Ge, Al) O _x mixed thin film (0 ≦ X ≦ 2) is manufactured as described above (Si, Al) except that Ge and SiGe are used instead of Si. Similar to the case of the O _x mixed thin film (0 ≦ X ≦ 2), the above-described steps (a) to (d) are included.

  The nanostructure 34 can be manufactured using a method of forming a film in a non-equilibrium state. As a film forming method in the present invention, a sputtering method is preferable, but a film forming method for forming a material in any non-equilibrium state such as resistance heating evaporation, electron beam evaporation (EB evaporation), or ion plating method is applied. Is possible. When the sputtering method is used, magnetron sputtering, RF sputtering, ECR sputtering, or DC sputtering can be used.

Next, as an example, the manufacturing method of the nanostructure in the case of using the (Si, Al) O _x mixed thin film (0 ≦ X ≦ 2) 24 of the present invention is followed in the order of the following (a) to (d). explain.

(A) Process: Formation process of base film In order to perform electroless plating, it is necessary to form the base film 13 having catalytic activity on the substrate 14. The catalyst is preferably a noble metal element such as Pd, Pt, Cu, Ag, Au, Rh, or Ir. Further, not only a simple substance but also an alloy film in which two or more kinds of metals are mixed may be used, and the composition ratio of the alloy film may be controlled as desired. In the present invention, since Pd has a very excellent catalytic activity, it is particularly preferable to use Pd alone or a Pd alloy. An electroless plating film can be selectively formed by selectively forming a film having catalytic activity, but a continuous film having flatness is particularly preferable. One or more fine particle films may be used. The film thickness may also be controlled as desired, but is preferably 100 nm or less. In particular, 20 nm or less is preferable. Examples of the method for forming the base film 13 having catalytic activity include a sol-gel method, a vapor deposition method, and a sputtering method. In the present invention, a sputtering method is employed to form a continuous film having a catalytic activity of 20 nm or less. To do.

(B) Process: (Al, Si) mixed thin film (here, (Si, Al) O _x mixed thin film (X = 0)) forming process Next, (Al, Si) is formed on the substrate 14 prepared in the (a) process. A Si) mixed thin film 24 is formed. Here, an example in which a sputtering method is used as a film formation method for forming a substance in a non-equilibrium state will be described.

  An (Al, Si) mixed thin film 24 is formed on the substrate by magnetron sputtering, which is a film forming method for forming a material in a non-equilibrium state. The (Al, Si) mixed thin film 24 is composed of a columnar member 21 whose main component is Al and a matrix 22 whose main component is Si around it.

  In FIG. 4, 41 is a substrate, 42 is Ar plasma, 43 is a Si chip (Si or Ge chip), and 44 is a sputtering target of Al. When the sputtering method is used, the ratio of Al and Si can be easily changed.

  As shown in FIG. 4, Ar gas introduced as a discharge gas onto an Al target 44 in which a Si chip 43 is arranged in a reactor by magnetron sputtering, which is a film forming method for forming a substance in a non-equilibrium state. A high-density Ar plasma 42 is generated, and Ar ions in the plasma 62 are made to collide with an Al target 44 on which an Si chip 43 is disposed, and Si and Al are ejected by the ion bombardment. A (Al, Si) mixed thin film 24 made of a mixture of Al is formed.

  As shown in FIG. 4, Si and Al as raw materials can be achieved by arranging a Si chip 43 on an Al target 44. Further, as shown in FIG. 4, the Si chip 43 is divided into a plurality of parts, but of course, the present invention is not limited to this, and may be one if the desired film formation is possible. . However, in order to uniformly disperse the columnar member 21 containing uniform Al in the region of the matrix 22 containing Si as a main component, it is preferable to arrange the Si chips 43 symmetrically on the Al target 44. Also, an AlSi fired product produced by firing a predetermined amount of Al and Si powder can be used as a film forming target material. Alternatively, a method may be used in which an Al target and a Si target are prepared separately and both targets are sputtered simultaneously.

  The amount of silicon in the film to be formed is 20 to 70 at%, preferably 25 to 65 at%, more preferably 30 to 60 at%, based on the total amount of Al and Si. If the amount of Si is within such a range, the (Al, Si) mixed thin film 24 in which the columnar members 21 whose main component is Al is dispersed in the matrix 22 region whose main component is Si is obtained.

  The (Al, Si) mixed thin film 24 formed as described above includes a columnar member 21 having Al as a main component and a matrix 22 region having Si as a main component around it.

  The composition of the columnar member 21 containing Al as a main component may contain other elements such as silicon, hydrogen, oxygen, argon, and nitrogen as long as a microstructure having a columnar structure is obtained.

  Further, the composition of the matrix 22 region surrounding the columnar member 21 containing Al as a main component is mainly Si, but if a microstructure having a columnar structure is obtained, aluminum, oxygen, argon Various elements such as nitrogen and hydrogen may be contained.

  In addition, the temperature of the substrate 41 is 300 ° C. or lower, preferably 200 ° C. or lower.

  When the (Al, Si) mixed thin film 24 is formed by such a method, Al and Si become a metastable eutectic structure, and a nanostructure (columnar member) having a level of several nanometers in the Si matrix 22 is obtained. 21) and separate in a self-organizing manner. At that time, Al has a substantially cylindrical shape, its pore diameter is 1 to 15 nm, and the center-to-center distance is 2 nm or more and 30 nm or less.

  The amount of Si in the (Al, Si) mixed thin film 24 can be controlled by changing the amount of the Si chip 43 placed on the Al target 44, for example. Further, when film formation is performed in a non-equilibrium state, particularly in the case of sputtering, the pressure in the reaction apparatus when Ar gas is flowed is preferably about 0.2 to 1 Pa. The output for forming plasma is preferably about 150 to 1000 W for a 4-inch target. However, the present invention is not particularly limited to this, and the film formation may be performed at a pressure and output at which the Ar plasma 42 is stably formed.

  As the substrate 14, for example, an insulator substrate such as quartz glass or plastic, a semiconductor substrate such as silicon or gallium arsenide, a metal substrate, or one or more layers of insulator, semiconductor, metal on these substrates A film in which any one of the above films is formed. If there is no problem in forming the (Al, Si) mixed thin film 24, the material, thickness, mechanical strength, etc. of the substrate are not particularly limited. Further, the shape of the substrate is not limited to a flat plate shape, but may include a curved surface and a surface having a certain degree of unevenness or steps, but there is no problem with the (Al, Si) mixed thin film 24. For example, there is no particular limitation.

  Similarly, the (Al, Ge) mixed thin film and the (Al, Si, Ge) mixed thin film can be similarly applied if Ge and SiGe are used instead of Si used in the case of the (Al, Si) mixed thin film described above. it can.

(C) Process: Pore forming process Only the Al region (the columnar member 21 region containing Al as a main component) in the (Al, Si) mixed thin film 24 is selectively etched. As a result, in the (Al, Si) mixed thin film 24, only the matrix 22 region having Si as a main component having the pores 31 remains, but the (Al, Si) mixed thin film 24 is oxidized each time etching is performed. In some cases, the (Si, Al) O _x porous body 32 (0 ≦ X ≦ 2) is formed. The pores 31 of the (Si, Al) O _x porous body 32 (0 ≦ X ≦ 2) have a center-to-center distance 2R of 30 nm or less and an average diameter 2r of 20 nm or less. The average diameter 2r is 1 nm to 15 nm, and the center distance 2R is 5 nm to 20 nm. The length is in the range of 0.5 nm to several μm, preferably 1 nm to 1000 nm.

Examples of the solution used for etching include acids such as phosphoric acid, sulfuric acid, hydrochloric acid, and chromic acid solution in which Al is dissolved and Si is hardly dissolved. However, if there is no problem in forming pores by etching, sodium hydroxide or aqueous ammonia is used. An alkali such as, for example, can be used, and is not particularly limited to the type of acid or the type of alkali. Also, a mixture of several types of acid solutions or several types of alkali solutions may be used. Etching conditions can be set as appropriate according to the (Si, Al) O _x porous body 32 (0 ≦ X ≦ 2) to be produced, for example, the solution temperature, concentration, and time. Similarly, the (Al, Ge) mixed thin film 24 and the (Al, Si, Ge) mixed thin film 24 are replaced with Si and GeGe, respectively, instead of Si used in the case of the (Al, Si) mixed thin film 24 described above. Applicable if used.

Step (d): (Al, Si) mixed thin film 24 prepared in step (b) or pore 31 of (Si, Al) O _x porous body 32 (0 ≦ X ≦ 2) prepared in step (c). Step of filling the columnar structure 33 by electroless plating to form the nanostructure 34 of the present invention The material of the columnar structure 33 produced by electroless plating in the present invention is an iron group metal of Ni or Co It is preferable to use noble metals such as Au, Pd, Pt, and Ag, and oxides such as ZnO, but V, Mo, W, Mn, Re, Fe, Zn, Tl, B, C, N, P, etc. A small amount of impurities may be contained. For example, CoP, CoB, CoNiP, CoFeP, CoZnP, CoNiMnP, etc. Further, the pores 31 of the (Al, Si) O _x porous body 32 (0 ≦ X ≦ 2) in the present invention, such as miniaturization and higher density of the resistor, electrode, wiring, magnetic recording medium, etc. By filling the columnar structure 33 therein, the high functionality of the columnar structure 33 is exhibited. Any material as described above may be used depending on the purpose.

As a manufacturing method of the columnar structure 33 in the present invention, the (Si, Al) O _x porous body (0 ≦ X ≦ 2) 32 and the substrate 14 with the base film 13 prepared in the step (c) in the electroless plating solution. It is possible to form a columnar structure 33 in the pores 31 of the (Si, Al) O _x porous body 32 (0 ≦ X ≦ 2).

The main component of the plating solution used for electroless plating is a reducing agent that gives electrons to deposit metal ions such as salts containing metal to be deposited, that is, metal salts, hydrazine, sodium hypophosphite, dimethylamine borane, etc. There is. There are also additives, i.e. complexing agents, necessary to prevent metal precipitation in the plating bath. The addition of a complexing agent such as sodium citrate or sodium tartrate makes it possible to convert the metal ion into a metal complex and leave it as it is, so it is also preferable to add a complexing agent. In addition, pH adjusters such as basic compounds such as sodium hydroxide and aqueous ammonia greatly affect the plating rate, reduction efficiency, and the state of the plating film, but in order to stabilize the pH of the electroless plating solution, a pH adjuster is used. It is preferable to add. The pH of the electroless plating solution varies depending on the type of electroless plating, but the pH of the electroless plating solution is such that (Si, Al) O _x porous body 32 (0 ≦ X ≦ 2) does not dissolve at high speed. If it is in the range, an electroless plating solution having acidity or alkalinity may be used.

  As the preparation conditions of the columnar structure 33 by electroless plating, combinations of the types of components in the plating bath such as metal salt, reducing agent, complexing agent, pH adjusting agent, each concentration, plating solution temperature, stirring speed, pH The adjustment and the time for immersing the substrate in the electroless plating solution can be mentioned. By controlling these, the columnar structure 33 having a desired size can be produced.

Further, the (Si, Al) O _x porous body 32 (0 ≦ X ≦ 2) formed by oxidation by immersing the (Al, Si) mixed thin film 24 produced in the step (b) in an electroless plating solution. As for the method of forming the columnar structures 33 in the pores 31 of the present invention, while the (Al, Si) mixed thin film 24 is immersed in the electroless plating solution, Al is dissolved without dissolving the matrix 22 mainly composed of Si. By dissolving the columnar member 21 as a main component to the position of the surface of the base film 13 and opening the pores 31 in the (Al, Si) mixed thin film 24, the (Si, Al) O _x porous body 32 (0 ≦ X ≦ 2) needs to be formed. That is, the plating solution used for electroless plating has a pH range in which the matrix 22 containing Si as a main component does not change or oxidizes, or dissolves slightly, and the columnar member 21 containing Al as a main component dissolves. It is preferable to have. In particular, the acidity is preferably pH 3 or more and pH 6 or less, or alkaline pH 10 or more and pH 12 or less. Combination of component types in plating baths such as metal salts, reducing agents, complexing agents, pH adjusters, etc., adjustment of each concentration, plating solution temperature, stirring speed, pH, control of time for dipping the substrate in electroless plating solution Thus, it is possible to control the degree of melting of the columnar member 21 mainly composed of Al. By adjusting the stirring speed, the time for immersing the substrate in the electroless plating solution, etc., the pores 31 are formed by dissolving all the columnar members 21 mainly composed of Al. Subsequently, the columnar structures 33 may be formed in the pores 31 while the substrate is immersed in the electroless plating solution. Similarly, the (Al, Ge) mixed thin film and the (Al, Si, Ge) mixed thin film can be similarly applied if Ge and SiGe are used instead of Si used in the case of the (Al, Si) mixed thin film described above. it can.

  The present invention will be further described below using examples.

  In this embodiment, as an example, after the Si substrate 14 with the base Pd film 13 on which the (Al, Si) mixed thin film 24 is formed is etched, the substrate 14 is immersed in a platinum electroless plating solution to thereby form the nanostructure 34. An example of manufacturing the above will be described (see FIG. 3).

  First, as the base film 13 having catalytic activity, a Pd thin film having a thickness of 20 nm was formed on the Si substrate 14 by a sputtering method (see FIG. 3A). Further, an (Al, Si) mixed thin film 24 having an Al: Si composition ratio of 3: 2 having a thickness of 100 nm was formed on the Si substrate 14 with the base Pd film 13 by sputtering (FIG. 3 ( b)).

  As a result of observing the surface of the substrate with a FE-SEM (Field Emission Scanning Electron Microscope), the columnar member 21 mainly composed of Al having a diameter of about 5 nm and a center-to-center distance of about 10 nm is composed mainly of Si. Many were formed on the surface of the matrix 22 (see FIG. 2A). As a result of observing the cross section, the columnar member 21 containing Al as a main component was formed in a direction perpendicular to the Si substrate 23 with the base film 13 (see FIG. 2B). Hereinafter, this is referred to as “substrate”.

  Next, etching was performed by immersing the substrate in 5 wt% phosphoric acid set at 25 ° C. for 6 hours. As a result of cross-sectional observation of this sample by FE-SEM, all the columnar members 21 containing Al as a main component were dissolved to form pores 31 having a diameter of about 5 nm and a center-to-center distance of about 10 nm (FIG. 3). (See (c)).

  Next, as a method for preparing a platinum electroless plating solution, 100 mL of Rectoless Pt100 basic solution (Nippon Electroplating Engineers Co., Ltd.), 10 mL of ammonia water 28%, 2 mL of Rectoles Pt100 reducing agent (Nippon Electroplating) -Engineers Co., Ltd.) and 88 mL of pure water were mixed to prepare a platinum electroless plating solution. The pH of the plating solution was 12.

  Subsequently, the platinum electroless plating solution was heated to 60 ° C. In this state, the substrate was immersed in the plating solution for 30 minutes. As a result of observing this sample with an FE-SEM, a platinum columnar structure 33 was formed in the pore 31 formed by dissolving the columnar member 21 mainly composed of Al in the previous substrate (FIG. 3D )reference). The platinum columnar structure 33 had a diameter of about 5 nm and a height of about 100 nm. The center-to-center distance was about 10 nm.

  As described above, after etching the columnar member 21 containing Al as a main component in the (Al, Si) mixed thin film 24 formed by controlling the composition ratio and film thickness of Al and Si, the platinum electroless plating solution It is possible to form a platinum columnar structure 33 in the pores 31 formed by the etching. In addition, by controlling the selection of the type of etchant, the etching time, the temperature of the etchant, the stirring speed, and the pH of the etchant, it is possible to control the degree of melting of the columnar member 21 containing Al as a main component as desired. It is.

  In the present embodiment, as an example, after the Si substrate 14 with the base Pd film 13 on which the (Al, Si) mixed thin film 24 is formed is etched, the substrate 14 is immersed in a palladium electroless plating solution to thereby form the nanostructure 34. An example of manufacturing the above will be described (see FIG. 3).

  First, as the base film 13 having catalytic activity, a Pd thin film having a thickness of 20 nm was formed on the Si substrate 14 by a sputtering method (see FIG. 3A). Further, an (Al, Si) mixed thin film 24 having an Al: Si composition ratio of 3: 2 having a thickness of 100 nm was formed on the Si substrate 14 with the base Pd film 13 by sputtering (FIG. 3 ( b)).

  As a result of observing the surface of the substrate with FE-SEM, a large number of columnar members 21 whose main component is Al having a diameter of 5 nm and a center-to-center distance of 10 nm are formed on the surface of the matrix 22 whose main component is Si. (See FIG. 2 (a)). As a result of observing the cross section, the columnar member 21 containing Al as a main component was formed in a direction perpendicular to the Si substrate 23 with the base film 13 (see FIG. 2B). Hereinafter, this is referred to as “substrate”.

  Etching was performed by immersing the substrate in 5 wt% phosphoric acid set at 25 ° C. for 6 hours. As a result of cross-sectional observation of this sample by FE-SEM, all the columnar members 21 containing Al as a main component were dissolved to form pores 31 having a diameter of about 5 nm and a center-to-center distance of about 10 nm (FIG. 3). (See (c)).

  Next, as a method for preparing a palladium electroless plating solution, 0.01 mol / l palladium chloride, 0.08 mol / l ethylenediamine, 0.02 mol / l sodium phosphite, 30 mg / l thiodiglycolic acid were used. A palladium electroless plating solution was prepared by mixing. The pH of the plating solution was 7. Subsequently, the palladium electroless plating solution was heated and set to 50 ° C. In this state, the substrate was immersed in the plating solution for 30 minutes.

  As a result of observing this sample with an FE-SEM, a PdP columnar structure 33 containing a small amount of P was formed in the pores 31 formed by dissolving the columnar member 21 mainly composed of Al in the previous substrate. (See FIG. 3 (d)). This columnar structure 33 had a diameter of about 5 nm and a height of about 80 nm. The center-to-center distance was about 10 nm.

  As described above, after etching the columnar member 21 containing Al as a main component of the (Al, Si) mixed thin film 24 formed by controlling the composition ratio and film thickness of Al and Si, the palladium electroless plating solution It is possible to form PdP columnar structures 33 in the pores 31 formed by the etching. Further, by controlling the selection of the type of etchant, the etching time, the temperature of the etchant, the stirring speed, and the pH of the etchant, it is possible to control the degree of dissolution of the Al columnar member 21 as desired.

  In this embodiment, as an example, an example in which the nanostructure 34 is produced by immersing the Si substrate 14 with the base Pd film 13 on which the (Al, Si) mixed thin film 24 is formed in a platinum electroless plating solution will be described. (See FIGS. 3A, 3B, and 3D).

  First, as the base film 13 having catalytic activity, a Pd thin film having a thickness of 20 nm was formed on the Si substrate 14 by a sputtering method (see FIG. 3A). Further, an (Al, Si) mixed thin film 24 having an Al: Si composition ratio of 3: 2 having a thickness of 100 nm is formed on the Si substrate 14 with the base Pd film 13 by sputtering (FIG. 3 ( b)). Hereinafter, this is referred to as “substrate”.

  As a result of observing the surface of the substrate by FE-SEM, the columnar member 21 mainly composed of Al having a diameter of about 5 nm and a center-to-center distance of about 10 nm is present in the surface of the matrix 22 composed mainly of Si. Many were made (see FIG. 2A). Further, as a result of observing the cross section, the columnar member 21 containing Al as a main component was formed in a direction perpendicular to the Si substrate 14 from the base Pd film 13 (see FIG. 2B).

  Next, as a method for preparing a platinum electroless plating solution, 100 mL of Rectoless Pt100 basic solution (Nippon Electroplating Engineers Co., Ltd.), 10 mL of ammonia water 28%, 2 mL of Rectoles Pt100 reducing agent (Nippon Electroplating) -Engineers Co., Ltd.) and 88 mL of pure water were mixed to prepare a platinum electroless plating solution. The pH of the plating solution was 12.

  Subsequently, the platinum electroless plating solution was heated to 60 ° C. In this state, the substrate was immersed in the plating solution for 1 hour. As a result of observing this sample with an FE-SEM, a platinum columnar structure 33 was formed in the pores 31 formed by dissolving the portion of the needle-like member 21 mainly composed of Al in the front substrate. The platinum columnar structure 33 had a diameter of about 5 nm and a height of about 100 nm. The center-to-center distance was about 10 nm (see FIG. 3 (d)).

  Further, as described above, according to the film thickness of the (Al, Si) mixed thin film 24 formed by controlling the composition ratio of Al and Si and the film thickness, the time for dipping in the platinum electroless plating solution, The platinum columnar structure 33 having a desired size can be formed by controlling the pH, the temperature of the plating solution, and the stirring speed. In addition, even when electroless plating of a metal other than platinum is performed, it is also possible to form the nanostructure 34 having a desired size.

  In this embodiment, as an example, an example in which the nanostructure 34 is produced by immersing the Si substrate 14 with the base Pd alloy film 13 formed with the (Al, Si) mixed thin film in a platinum electroless plating solution ( (See FIG. 3).

  First, a Pd alloy film was used for the base film 13 having catalytic activity, Pt was selected as a metal other than Pd, and a base Pd alloy film having a thickness of 20 nm was formed on the Si substrate 14 by sputtering. Three types of base Pd alloy thin films containing composition ratios of Pd: Pt of 2: 1, 1: 1, and 1: 2 were formed (see FIG. 3A). Further, the (Al, Si) mixed thin film 24 having a composition ratio of Al: Si of 100 nm thickness is 3: 2 on the Si substrate 14 with the three types of base Pd alloy thin films by sputtering. It formed (refer FIG.3 (b)). These are hereinafter referred to as “substrates”.

  As a result of observing the surface of the substrate with an FE-SEM, all the substrates have a columnar member 21 mainly composed of Al having a diameter of about 5 nm and a center-to-center distance of about 10 nm. Many were formed in the surface of the matrix 22 (see FIG. 2A). Further, as a result of observing the cross section of the substrate, the columnar member 21 containing Al as a main component was formed in a direction perpendicular to the Si substrate 14 from the base Pd alloy film (see FIG. 2B).

  Next, as a method for preparing a platinum electroless plating solution, 100 mL of Rectoless Pt100 basic solution (Nippon Electroplating Engineers Co., Ltd.), 10 mL of ammonia water 28%, 2 mL of Rectoles Pt100 reducing agent (Nippon Electroplating) -Engineers Co., Ltd.) and 88 mL of pure water were mixed to prepare a platinum electroless plating solution. The pH of the plating solution was 12.

  Subsequently, the platinum electroless plating solution was heated to 60 ° C. In this state, the substrate was immersed in the plating solution for 1 hour. As a result of observing this sample with an FE-SEM, as for all the substrates, platinum columnar structures 33 are formed in the pores 31 formed by dissolving the portion of the columnar member 21 mainly composed of Al in the substrate. It was.

  Platinum columnar structures 33 were obtained on the three types of underlying Pd alloy thin films having Pd: Pt composition ratios of 2: 1, 1: 1, and 1: 2, and their respective diameters were all about 5 nm. . The center-to-center distance was about 10 nm (see FIG. 3 (d)).

  As described above, the platinum columnar structure 33 can be formed even if the composition ratio of Pd: Pt in the underlying Pd alloy thin film is changed.

  In this embodiment, as an example, an example in which the nanostructure 33 is produced by immersing the Si substrate 14 with the base Pd film 13 on which the (Al, Ge) mixed thin film 24 is formed in a platinum electroless plating solution will be described. (See FIG. 3).

  For example, an (Al, Ge) mixed thin film 32 having an Al: Ge composition ratio of 3: 2 is formed by sputtering on a Si substrate 33 with a base Pd thin film (film thickness 20 nm) by sputtering. (See FIG. 3B). Hereinafter, this is referred to as “substrate”.

  As a result of observing the surface of the substrate with FE-SEM, as in Example 1, the columnar member 21 mainly composed of Al having a diameter of about 10 nm and a center-to-center distance of about 15 nm is composed mainly of Ge. Many were formed on the surface of the matrix 22 (see FIG. 2A). Further, as a result of observing the cross section of the substrate, the columnar member 21 containing Al as a main component was formed in a direction perpendicular to the Si substrate 14 from the base Pd film 13 (see FIG. 2B).

  Next, as a method for preparing a platinum electroless plating solution, 100 mL of Rectoless Pt100 basic solution (Nippon Electroplating Engineers Co., Ltd.), 10 mL of ammonia water 28%, 2 mL of Rectoles Pt100 reducing agent (Nippon Electroplating) -Engineers Co., Ltd.) and 88 mL of pure water were mixed to prepare a platinum electroless plating solution. The pH of the plating solution was 12.

  Subsequently, the platinum electroless plating solution was heated to 60 ° C. In this state, the substrate was immersed in the plating solution for 1 hour. As a result of observing this sample with an FE-SEM, a platinum columnar structure 33 was formed in the pore 31 formed by dissolving the portion of the columnar member 21 mainly composed of Al in the previous substrate. The platinum columnar structure 33 had a diameter of about 10 nm and a height of about 70 nm. The center-to-center distance was about 15 nm (see FIG. 3D).

  Further, as described above, according to the film thickness of the (Al, Ge) mixed thin film 24 formed by controlling the composition ratio of Al and Ge and the film thickness, the time for dipping in the platinum electroless plating solution, By controlling the pH, the plating solution temperature, and the stirring speed, it is possible to form the nanostructure 34 in which the platinum columnar structure 33 having the desired size is formed. In addition, even when electroless plating of a metal other than platinum is performed, it is also possible to form the nanostructure 34 having a desired size.

  Similarly, in the case of the (Al, Si, Ge) mixed thin film, the thickness is adjusted to the thickness of the (Al, Si, Ge) mixed thin film 24 formed by controlling the composition ratio and film thickness with Al, Si, Ge. Then, by controlling the time of immersion in the platinum electroless plating solution, the pH of the plating solution, the temperature of the plating solution, and the stirring speed, the nanostructure 34 in which the platinum columnar structure 33 having the desired size is formed is formed. Is possible. Further, even when electroless plating of metals other than platinum and oxides is performed, it is also possible to form the nanostructure 34 having a desired size.

  In this embodiment, as an example, after etching the Si substrate 14 with the base Pd film 13 on which the (Al, Si) mixed thin film 24 is formed, the substrate 14 is immersed in a CoNiB electroless plating solution to thereby form the nanostructure 34. An example of manufacturing the above will be described (see FIG. 3).

  For example, a (Al, Si) mixed thin film 24 having a film thickness of 100 nm and an Al: Si atomic weight ratio of 3: 2 is formed on a Si substrate 14 with a base Pd film 13 (film thickness 20 nm) by sputtering. (See FIG. 3B). Hereinafter, this is referred to as “substrate”.

  As a result of observing the surface of the substrate by FE-SEM, the columnar member 21 mainly composed of Al having a diameter of about 5 nm and a center-to-center distance of about 10 nm is present in the surface of the matrix 22 composed mainly of Si. Many were made (see FIG. 2A). Further, as a result of observing the cross section of the substrate, the columnar member 21 containing Al as a main component was formed in a direction perpendicular to the Si substrate 14 from the base Pd film 13 (see FIG. 2B).

  Next, etching was performed by immersing the substrate in 5 wt% phosphoric acid set at 25 ° C. for 6 hours. As a result of cross-sectional observation with this FE-SEM, all the columnar members 21 mainly composed of Al were dissolved to form pores 31 having a diameter of about 5 nm and a center-to-center distance of about 10 nm (FIG. 3 (c). )reference).

  Next, a CoNiB electroless plating solution was prepared by using 0.03 mol / l cobalt sulfate, 0.07 mol / l nickel sulfate, 0.2 mol / l sodium hypophosphite, 0.2 mol / l quencher. Sodium niobate and 0.5 mol / l borax were mixed to prepare a CoNiB electroless plating solution. Furthermore, the pH of the electroless plating solution was set to 7 by adding sodium hydroxide. The electroless plating solution was heated to 90 ° C. In this state, the substrate was immersed in the plating solution for 30 minutes.

  As a result of observing this sample with an FE-SEM, CoNiB columnar structures 33 were formed in the pores 31 formed by dissolving the columnar member 21 portion mainly composed of Al in the previous substrate (FIG. 3 ( d)). The columnar structure 33 had a diameter of about 5 nm and a height of about 100 nm. The center-to-center distance was about 10 nm.

  Further, as a result of applying and measuring a magnetic field to the CoNiB columnar structure 33, the ferromagnetic characteristics having perpendicular magnetic anisotropy were shown. Therefore, a magnetic device used as a high-density perpendicular magnetic recording medium is provided. It is possible.

  As described above, the columnar structure 33 in which two or more kinds of metals such as CoNiB and CoNiP are mixed may be formed by electroless plating in the pores 31 in which the Al (Si, Ge) mixed thin film 24 is formed. As possible, the nanostructure 34 as described above can provide a magnetic device.

  In this embodiment, as an example, after etching the glass substrate 14 with the base Pd film 13 on which the (Al, Si) mixed thin film 24 is formed, the substrate 14 is immersed in a ZnO electroless plating solution to thereby form the nanostructure 34. An example of manufacturing the above will be described (see FIG. 3).

  For example, an (Al, Si) mixed thin film 24 having an Al: Si atomic weight ratio of 3: 2 is formed by sputtering on a Si substrate 14 with a base Pd film 13 (film thickness 5 nm) by sputtering. It forms (refer FIG.3 (b)). Hereinafter, this is referred to as “substrate”.

  As a result of observing the surface of the substrate by FE-SEM, the columnar member 21 mainly composed of Al having a diameter of about 5 nm and a center-to-center distance of about 10 nm is present in the surface of the matrix 22 composed mainly of Si. Many were made (see FIG. 2A). Further, as a result of observing the cross section of the substrate, the columnar member 21 containing Al as a main component was formed in a direction perpendicular to the glass substrate 14 from the base Pd film 13 (see FIG. 2B).

  Next, etching was performed by immersing the substrate in 5 wt% phosphoric acid set at 25 ° C. for 6 hours. As a result of cross-sectional observation of this sample by FE-SEM, all the columnar members 21 containing Al as a main component were dissolved to form pores 31 having a diameter of about 5 nm and a center-to-center distance of about 10 nm (FIG. 3). (See (c)).

  Next, as a method for producing a ZnO electroless plating solution, 0.05 mol / l zinc nitrate and 0.05 mol / l dimethylenylborane were mixed to produce a ZnO electroless plating solution. The electroless plating solution was heated and set to 65 ° C. In this state, the substrate was immersed in the plating solution for 40 minutes.

  As a result of observing this sample with an FE-SEM, ZnO columnar structures 33 were formed in the pores 31 formed by dissolving the columnar member 21 portion mainly composed of Al in the previous substrate (FIG. 3 ( d)). This columnar structure 33 had a diameter of about 5 nm and a height of about 90 nm. The center-to-center distance was about 10 nm.

  Further, as a result of measuring the photoluminescence using the He—Cd laser as an excitation source for the substrate, it was confirmed that interband emission near a wavelength of 385 nm and green emission near a wavelength of 500 nm to 550 nm were confirmed from the substrate. Can be used as a light-emitting element.

  As described above, since the ZnO columnar structure 33 can be formed by electroless plating in the pores 31 of the Al (Si, Ge) mixed thin film 24, light emission is obtained by using the nanostructure 34 as described above. It is possible to provide an optical device that can exhibit functionality such as an element, a photoelectric conversion element, and a photocatalytic element.

Next, a preliminary experiment on an Al (Si, Ge) mixed thin film structure (see the mixed thin film 24 in FIGS. 2 and 3B) used in the nanostructure manufacturing method according to the present invention will be described. This structure includes a matrix portion mainly composed of at least one element of Al as the first material, Si as the second material, and Ge. Here, Si is used as the second material. .
(Experimental example 1: first material Al, second material Si)
The Al structure part surrounded by Si is a columnar structure, the diameter 2r is 3 nm, the interval 2R is 7 nm, and the length L is 200 nm (the columnar shape of FIGS. 2 and 3B). The member 21) will be described.

  First, a method for producing an Al thin wire will be described.

  An AlSi mixed film containing Si at 55 atomic% with respect to the total amount of Al and Si is formed on a glass substrate by using an RF magnetron sputtering method. The target used was 8 pieces of 15 mm square Si chips 13 on a 4-inch Al target. Sputtering conditions were as follows: using an RF power source, Ar flow rate: 50 sccm, discharge pressure: 0.7 Pa, and input power: 1 kW. The substrate temperature was room temperature.

  In this case, the target used was eight Si chips placed on an Al target. However, the number of Si chips is not limited to this, and changes depending on sputtering conditions, and the composition of the AlSi mixed film is not limited to this. It should be around 55 atomic%. Further, the target is not limited to the one in which the Si chip is placed on the Al target, but the target in which the Al chip is placed on the Si target may be used, or a target obtained by sintering powder of Si and Al may be used. .

  Next, the amount (atomic%) of Si with respect to the total amount of Al and Si was analyzed by ICP (inductively coupled plasma emission analysis) for the AlSi mixed film thus obtained. As a result, the amount of Si relative to the total amount of Al and Si was about 55 atomic%. Here, for convenience of measurement, an AlSi mixed film deposited on a carbon substrate was used as the substrate.

  The AlSi mixed film was observed with FE-SEM. The shape of the surface seen from right above the substrate was a two-dimensional array of circular Al nanostructures surrounded by Si. The pore diameter of the Al nanostructure part was 3 nm, and the average center-to-center spacing was 7 nm. Moreover, when the cross section was observed with FE-SEM, the height was 200 nm, and each Al nanostructure part was mutually independent.

  Further, when this sample was observed by an X-ray diffraction method, a Si peak showing crystallinity could not be confirmed, and Si was amorphous.

  Therefore, an AlSi nanostructure including an Al thin wire surrounded by Si and having an interval 2R of 7 nm, a diameter 2r of 3 nm, and a height L of 200 nm could be produced.

(Comparative example)
Further, as a comparative sample A, an AlSi mixed film containing 15 atomic% of Si with respect to the total amount of Al and Si was formed on a glass substrate by a sputtering method with a thickness of about 200 nm. The target used was two 15 mm square Si chips 13 on a 4-inch Al target. Sputtering conditions were as follows: using an RF power source, Ar flow rate: 50 sccm, discharge pressure: 0.7 Pa, and input power: 1 kW. The substrate temperature was room temperature.

  Comparative sample A was observed with FE-SEM. As for the shape of the surface viewed from directly above the substrate, the Al portion was not circular but was rope-shaped. That is, the Al columnar structure was not a fine structure uniformly dispersed in the Si region. Furthermore, its size was far over 10 nm. Moreover, when the cross section was observed by FE-SEM, the width of the Al portion exceeded 15 nm. The AlSi mixed film thus obtained was analyzed by ICP (inductively coupled plasma emission analysis) for the amount (atomic%) of Si with respect to the total amount of Al and Si. As a result, the amount of Si with respect to the total amount of Al and Si was about 15 atomic%.

  Further, as a comparative sample B, an AlSi mixed film containing Si at 75 atomic% with respect to the total amount of Al and Si was formed on a glass substrate by sputtering using a sputtering method. The target was a 14-inch Al target with 14 pieces of 15 mm square Si chips 13 placed thereon. Sputtering conditions were as follows: using an RF power source, Ar flow rate: 50 sccm, discharge pressure: 0.7 Pa, and input power: 1 kW. The substrate temperature was room temperature.

  Comparative sample B was observed with FE-SEM. The Al portion could not be observed on the sample surface viewed from directly above the substrate. Further, even when the cross section was observed with FE-SEM, the Al portion could not be clearly observed. The AlSi mixed film thus obtained was analyzed by ICP (inductively coupled plasma emission analysis) for the amount (atomic%) of Si with respect to the total amount of Al and Si. As a result, the amount of Si with respect to the total amount of Al and Si was about 75 atomic%.

  Moreover, the sample in which the ratio of Si to the total amount of the AlSi mixture is 20 atomic%, 35 atomic%, 50 atomic%, 60 atomic%, and 70 atomic% is different from that in the case where the comparative sample A is manufactured. Produced. The case where the columnar structure of Al is a fine structure uniformly dispersed in the Si region is indicated by ◯, and the case where it is not indicated by × is shown below.

このように、ＡｌとＳｉの全量に対するＳｉ含有量を、２０atomic％以上７０atomic％以下に調整することで、作製されたＡｌナノ構造体の孔径の制御が可能であり、また、直線性に優れたＡｌ細線の作製が可能になる。なお、構造の確認には、ＳＥＭの他にもＴＥＭ（透過型電子顕微鏡）等を利用するのがよい。なお、上記含有量に関しては上記Ｓｉに代えてゲルマニウム、あるいはＳｉとゲルマニウムの混合物を用いても同様であった。

Thus, by adjusting the Si content with respect to the total amount of Al and Si to 20 atomic% or more and 70 atomic% or less, it is possible to control the pore diameter of the manufactured Al nanostructure, and it has excellent linearity. Al wires can be produced. For confirmation of the structure, a TEM (transmission electron microscope) or the like may be used in addition to the SEM. The content was the same when germanium or a mixture of Si and germanium was used instead of Si.

  Furthermore, as a comparative sample C, an AlSi mixed film containing Si at 55 atomic% with respect to the total amount of Al and Si was formed on a glass substrate by a sputtering method with a thickness of about 200 nm. The target used was 8 pieces of 15 mm square Si chips 13 on a 4-inch Al target. Sputtering conditions were as follows: using an RF power source, Ar flow rate: 50 sccm, discharge pressure: 0.7 Pa, and input power: 1 kW. The substrate temperature was 250 ° C.

  Comparative sample C was observed with an FE-SEM (field emission scanning electron microscope). A clear boundary between Al and Si could not be confirmed on the sample surface viewed from directly above the substrate. That is, the Al nanostructure could not be confirmed. That is, if the substrate temperature is too high, the state changes to a more stable state, so that it is considered that film growth for forming such an Al nanostructure cannot be performed.

  In order to obtain a structure in which columnar members are dispersed, it is also preferable to set the target composition to Al: Si = 55: 45 or the like.

As mentioned above, although embodiment of this invention was described, the suitable aspect of this invention is enumerated as follows.
[Embodiment 1] In the method of manufacturing a nanostructure comprising a substrate, a base film, a thin film mainly composed of Si or Ge, and a columnar structure formed in the pores of the thin film, the substrate with the base film And a columnar member mainly composed of Al formed in a direction perpendicular or substantially perpendicular to the substrate and any one of Si, Ge, and SiGe disposed so as to surround the side surface of the columnar member. A step of forming pores in the substrate by removing the columnar member from the substrate having an Al (Si, Ge) mixed thin film forming a matrix structure, and the formation of the pores in an electroless plating bath And a step of forming a columnar structure in the pores by immersing the formed substrate.
[Embodiment 2] In the method for producing a nanostructure according to Embodiment 1, in the step of forming pores in the substrate, the Al in the substrate is mainly contained by dipping in an electroless plating bath. A method for producing a nanostructure, comprising removing a columnar member to be formed and simultaneously forming pores.
[Embodiment 3] The method for producing a nanostructure according to Embodiment 1 or 2, wherein the base film has catalytic activity.
[Embodiment 4] In the method of manufacturing a nanostructure according to any one of Embodiments 1 to 3, the matrix includes (Si, Al) O _x mixed thin film (0 ≦ X ≦ 2), (Ge, A method for producing a nanostructure, which is one of an Al) O _x mixed thin film (0 ≦ X ≦ 2) and a (Si, Ge, Al) O _x mixed thin film (0 ≦ X ≦ 2).
[Embodiment 5] In the method for manufacturing a nanostructure according to any one of Embodiments 1 to 4, the columnar structure is any one of a metal and an oxide. Production method.
[Embodiment 6] In the method for manufacturing a nanostructure according to Embodiment 5, the metal that is a material of the columnar structure is at least one of Co, Ni, Pt, and Pd. Manufacturing method of structure.
[Embodiment 7] The method for manufacturing a nanostructure according to Embodiment 6, wherein the columnar structure includes a small amount of either B or P as a material for the columnar structure.
[Embodiment 8] The method for manufacturing a nanostructure according to Embodiment 5, wherein the oxide that is a material of the columnar structure is ZnO.
[Embodiment 9] The method for producing a nanostructure according to any one of Embodiments 1 to 8, wherein the base film having catalytic activity is Pd or a Pd alloy. Method.
[Embodiment 10] The nanostructure manufacturing method according to any one of Embodiments 1 to 9, wherein the Al (Si, Ge) mixed thin film has a thickness of 1 μm or less. Body manufacturing method.
[Embodiment 11] In the method for producing a nanostructure according to any one of Embodiments 1 to 10, an average diameter of the columnar structure formed by electroless plating is 20 nm or less, and a center-to-center distance is The manufacturing method of the nanostructure characterized by being 30 nm or less.
[Embodiment 12] In the method for producing a nanostructure according to any one of Embodiments 1 to 11, an average diameter of the columnar structure formed by electroless plating is 1 nm or more and 15 nm or less, A method for producing a nanostructure, wherein the distance is 5 nm or more and 20 nm or less.
[Embodiment 13] The method for producing a nanostructure according to any one of Embodiments 1 to 12, wherein the columnar structure formed by electroless plating has a height of 1 nm to 1 μm. A method for producing a nanostructure.
[Embodiment 14] A substrate, a base film formed on the substrate, a thin film having Si or Ge as a main material and having pores formed on the base film, and formed in the pores of the thin film In the nanostructure having a columnar structure formed, the thin film surrounds a columnar member mainly composed of Al formed in a direction perpendicular or substantially perpendicular to the substrate surface and a side surface of the columnar member. The columnar structure is formed of an Al (Si, Ge) mixed thin film that forms a structure composed of a matrix composed mainly of any one of Si, Ge, and SiGe. A nanostructure formed by an electroless plating bath in pores formed by removing the columnar member from a mixed thin film.
[Embodiment 15] The nanostructure according to Embodiment 14, wherein the underlayer has catalytic activity.
[Embodiment 16] In the nanostructure according to any one of Embodiments 14 and 15, the matrix is a (Si, Al) O _x mixed thin film (0 ≦ X ≦ 2), (Ge, Al) O. A nanostructure characterized by being one of an _X mixed thin film (0 ≦ X ≦ 2) and a (Si, Ge, Al) O _x mixed thin film (0 ≦ X ≦ 2).
[Embodiment 17] The nanostructure according to any one of Embodiments 14 to 16, wherein the columnar structure is any one of a metal and an oxide.
[Embodiment 18] The nanostructure according to Embodiment 17, wherein the metal that is a material of the columnar structure is at least one of Co, Ni, Pt, and Pd.
[Embodiment 19] The nanostructure according to embodiment 18, wherein the columnar structure includes a small amount of either B or P as a material for the columnar structure.
[Embodiment 20] The nanostructure according to Embodiment 17, wherein the oxide that is a material of the columnar structure is ZnO.
[Embodiment 21] The nanostructure according to any one of Embodiments 14 to 20, wherein the base film having catalytic activity is Pd or a Pd alloy.
[Embodiment 22] The nanostructure according to any one of Embodiments 14 to 21, wherein the Al (Si, Ge) mixed thin film has a thickness of 1 μm or less.
[Embodiment 23] In the nanostructure according to any one of Embodiments 14 to 22, the columnar structure formed by electroless plating has an average diameter of 20 nm or less and a center-to-center distance of 30 nm or less. Nanostructure characterized by being.
[Embodiment 24] In the nanostructure according to any one of Embodiments 14 to 23, the columnar structure formed by electroless plating has an average diameter of 1 nm to 15 nm and a center-to-center distance of 5 nm. A nanostructure having a thickness of 20 nm or less.
[Embodiment 25] The nanostructure according to any one of Embodiments 14 to 24, wherein the columnar structure formed by electroless plating has a height of 1 nm to 1 μm. body.
[Embodiment 26] A magnetic device using the nanostructure according to Embodiment 18 or 19, wherein the columnar structure is a magnetic body, and uses the nanostructure. .
[Embodiment 27] An optical device using the nanostructure according to Embodiment 20.

  As described above, the present invention provides a nanostructure manufacturing method for forming a columnar structure that is either a metal or an oxide in pores in a substrate, and easily forms a columnar structure in a large area at low cost. It is applicable to the manufacturing method of the nanostructure. In particular, by using a nanostructure formed with a metal columnar structure, a highly functional nanodevice such as an electrode or wiring, a magnetic device using a nanostructure formed with a magnetic columnar structure, The present invention can be applied to applications such as an optical device using a nanostructure formed with a ZnO columnar structure such as a light emitting element, a photoelectric conversion element, and a photocatalytic element.

BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic which shows the nanostructure by embodiment of this invention, (a) is a top view, (b) is sectional drawing along the AA in (a). It is the schematic of the mixed thin film which made Si or Ge the main material, (a) is a top view, (b) is sectional drawing along the BB line in (a). It is process drawing explaining the manufacturing method of the nanostructure by embodiment of this invention. It is the schematic explaining an example of the film-forming method in the manufacturing method of the nanostructure by embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Columnar structure 12 Matrix 13 Base film 14 Substrate 15 Nanostructure 21 Columnar member 22 Matrix 23 Substrate 24 Mixed thin film 31 Pore 32 Porous body 33 Columnar structure 34 Nanostructure 41 Base 42 Ar plasma 43 Si or Ge chip 44 Al target

Claims (5)

In a method for producing a nanostructure comprising a substrate, a base film, a thin film mainly composed of Si or Ge, and a columnar structure formed in the pores of the thin film,
The substrate with the base film, the columnar member mainly composed of Al formed on the surface of the substrate, and the matrix mainly composed of any one of Si, Ge, and SiGe disposed so as to surround the side surface of the columnar member A step of forming pores in the substrate by removing the columnar member from the substrate having an Al (Si, Ge) mixed thin film that forms a structure comprising: the pores are formed in the electroless plating bath. And a step of forming a columnar structure in the pores by dipping the substrate. In the manufacturing method of the nanostructure according to claim 1,
The step of forming pores in the base is to remove the columnar member mainly composed of Al in the base by immersing in an electroless plating bath, and simultaneously form the pores. A method for producing a nanostructure. In the manufacturing method of the nanostructure according to claim 1 or 2,
The said base film has a catalytic activity, The manufacturing method of the nanostructure characterized by the above-mentioned. In the manufacturing method of the nanostructure of any one of Claims 1 thru | or 3,
The method for producing a nanostructure according to claim 1, wherein the columnar structure is one of a metal and an oxide. In the manufacturing method of the nanostructure according to any one of claims 1 to 4,
A method for producing a nanostructure, wherein the material of the columnar structure includes any one of B and P.

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