JP2000107594A - Three-dimensional arrangement method for minute substance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the manufacture of optical devices, sensors, and others by forming a projection in an electrode, filling the space between the electrodes with a solvent in which minute substances are dispersed, and forming a chain-shaped body comprising the substances only at the position of the projection by applying an electric field so that the longitudinal direction of the chain-shaped body coincides with the direction of the electric field. SOLUTION: When applied to the manufacture of an optical device, a magnetic device, and others, a conductive projection 1 is formed at an optional position of an electrode 2, a counter electrode 3 is disposed, and the space between the electrodes 2, 3 is filled with a solution in which granular or fibrous minute substances 4 comprising an oxide such as glass, a nitride, ceramic, and others are dispersed in a solvent such as a liquid polymer and others. By applying an electric field between the electrodes 2, 3, a chain-shaped body 7 comprising the substances 4 is disposed only at the position of the projection so that the longitudinal direction of the body 7 coincides with the direction of the electric field. After the arrangement of the body 7, the liquid polymer 5 is cured by heating or light irradiation to fix the arrangement of the chain-shaped body 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for precisely arranging three-dimensional objects, which is useful for manufacturing optical devices, magnetic devices, semiconductor devices, micromachines, sensors, and the like.

[0002]

2. Description of the Related Art In the manufacturing technology of an integrated circuit or the like which can process the finest of the technologies used in the industry, a large-scale device such as a strong light source or an electron beam source is required. Therefore, there is a problem that the fabrication must be performed under a high vacuum and the number of fabrication steps is large. There is also a problem that a large amount of waste such as a resist material after use is generated. And there is a problem that it costs and time naturally from these things. In addition, the target material is also substantially limited to a specific material such as silicon,
It is difficult to produce a structure having a high aspect ratio, and there is a problem that a protective layer must be formed after the production.

Accordingly, the invention of the present application is to provide a new three-dimensional precision arrangement method of minute objects, which can solve the problems of the above-described conventional fabrication techniques of integrated circuits and the like and enables fine processing. With the goal.

[0004]

Means for Solving the Problems In order to solve the above problems, the invention of this application firstly forms a projection made of a conductor at an arbitrary position of an electrode, arranges a counter electrode, and arranges a space between the electrodes. Is filled with a solution in which particulate matter or fibrous fine particles are dispersed in a solvent, and an electric field is applied. A method for three-dimensionally arranging minute objects, characterized in that the long axis direction is formed so as to coincide with the electric field direction.

Secondly, the invention of this application is to fix the arrangement by using a liquid polymer as a solvent, forming and arranging the chain, and then raising the temperature or irradiating light to cure the liquid polymer. The present invention provides a three-dimensional precise arrangement method of minute objects to be arranged.
According to the first and second methods, fine processing is possible. For example, if the cured polymer is removed, the electrode can be used any number of times. There is an advantage that a large-scale apparatus is not required, manufacturing can be performed under atmospheric pressure, the number of manufacturing steps is small, and cost and time can be reduced because little waste is generated. In addition, most target materials can be finely processed, and the types of materials are not limited to specific ones. In addition, since the chains composed of minute objects are arranged, a structure having a high aspect ratio can be easily formed. When the chain arrangement is solidified with a polymer, there is an advantage that a protective layer is formed at the same time.

The invention of the present application is, in the third aspect, in the above-mentioned three-dimensional precise arrangement method of minute objects, in which a part of an electrode is cut using light, an ion beam or an electron beam,
The fourth method is to form an electric field concentrated portion by using a raised portion formed at the edge of the shaved portion as a projection to form an electric field concentrated portion. Fourth, a portion of the electrode is cut by laser beam irradiation, and the remaining portion is formed as a projected portion by forming an electric field concentrated portion. Fifth, an electrode manufacturing method is performed by a vapor deposition method or by using a conductive probe.
A method of manufacturing an electrode in which a conductor is attached to a part of an electrode and an electric field concentrating portion is formed using the conductor as a protrusion. Sixth, a liquid metal is poured into a mold or the metal is plated, and then the solid is formed. Provided is an electrode manufacturing method for removing a converted metal from a mold and forming a projection serving as an electric field concentration portion.

With the above-described third to sixth invention methods, an electric field concentrating portion of any size can be formed at any position of the electrode. Using the electrode created in this way,
A three-dimensional precise arrangement of minute objects becomes possible.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The invention of this application has the features as described above, and the embodiment will be further described. First, in the three-dimensional precision arrangement method of the present invention, a conductor-made projection is formed at an arbitrary position on an electrode. The size of the protrusion is equal to or smaller than the size of the particle as a minute substance or the diameter of the fiber. After disposing the counter electrode, the space between the electrodes is filled with a solution in which fine particles are dispersed in a solvent, and an electric field is applied. Then, an electric dipole is induced in the minute object by the electric field.
Electric field concentration occurs at the position of the protrusion and the electric field becomes stronger,
The minute objects gather at the positions of the protrusions due to electrostatic force such as dielectrophoretic force. Moreover, due to the interaction between the electric dipoles, the minute objects aggregate in a chain (one-dimensionally), and the major axis direction of the chain coincides with the direction of the electric field. That is, the chain of minute objects is arranged at the position of the protrusion in the direction of the electric field.
At this time, by adjusting the volume fraction of the minute substance in the solution,
A chain body can be prevented from being formed except for the position of the projection. As a result, by determining the positions of the plurality of protrusions, various three-dimensional precise arrangements of minute objects are performed. At this time, the liquid polymer is used as a solvent, and after the target sequence is formed, the sequence can be fixed by curing the liquid polymer by increasing the temperature or irradiating light.

Examples will be shown below, and embodiments of the present invention will be described in more detail.

[0010]

(Embodiment 1) FIGS. 1 (a) and 1 (b) show minute 3
It shows an example of the dimensional precision array method. In the figure, reference numeral 1 denotes a protrusion, 2 denotes an electrode having a protrusion 1, 3 denotes a counter electrode, and 4 denotes a minute substance. The minute substance 4 is assumed to be dispersed in a liquid polymer 5. 6 is a power supply, 7 is a minute object 4
It is a chain consisting of FIG. 1A illustrates a state where no electric field is applied, and FIG. 1B illustrates a state where an electric field is applied. As shown in FIG. 1B, when an electric field is applied, the long axis of the chain 7 composed of the minute objects 4 coincides with the direction of the electric field only at the position of the protrusion 1. As a result, a three-dimensional precise arrangement of the minute objects 4 becomes possible. After the arrangement, the liquid polymer 5 can be cured by increasing the temperature to fix the arrangement.

The height of the projections 1 on the surface of the electrode 2 is not particularly limited. However, as described above, the size of the minute object 4 is determined according to the purpose, application, and function of the three-dimensional chain arrangement of the minute objects. May be determined in consideration of the above. From the viewpoint of enabling microfabrication, the protrusion 1 is, for example, 100 μm or less,
Furthermore, it can be 60 μm or less. When a plurality of projections 1 are provided, their mutual intervals are also determined appropriately.

When a liquid polymer is used, the polymer is preferably a thermosetting or photocurable polymer.
For example, it is a polymer of acrylic type, unsaturated polyester type, silicone type, epoxy type and the like. The minute substance may be, for example, glass, oxides or nitrides such as SiO ₂ , ceramics, resins, polypeptide proteins, minerals, and other various kinds. The size of these minute objects is generally 1 mm or less, more suitably 100 μm or less.

FIG. 2A is an optical microscope photograph showing an example of an electrode having an electric field concentration portion. The copper electrode surface is YAG
It is formed as a circularly cut state using a harmonic of a laser (having a wavelength of 266 nm). The diameter of the circle is 28 μm, and the height of the raised portion at the edge is 40 μm from the electrode surface. The distance between the nearest circles is 200 μm
It is. Fabrication was carried out under atmospheric pressure, and a thin copper oxide film formed on the surface of the copper irradiated with the laser was removed by washing with sulfuric acid. As described above, a part of the electrode can be shaved by using a laser, and an electrode can be manufactured in which a raised portion formed at the edge of the shaved portion is used as an electric field concentration portion. FIG. 2 (b)
A schematic view of a cross section of an electric field concentration portion when cut perpendicular to an electrode is shown, where 8 denotes a projection and 9 denotes an electrode having a projection 8.
FIG. 2C is a schematic view showing the formation of a chain of minute objects in the electric field concentration portion of FIG. 2B, and reference numeral 10 denotes a chain of minute objects. Also, an electrode having an electric field concentration portion can be formed by using light other than a laser, an ion beam, or an electron beam.

FIG. 3 shows an example of an arrangement in the state of FIG. 2 (c) prepared using the electrodes of FIGS. 2 (a) and 2 (b). The cured polymer is removed from the electrode and cut perpendicular to the electrode. It is an optical microscope photograph of the cross section. The minute object is a glass sphere having a diameter of 30 μm, and the polymer is a transparent silicone rubber. It was confirmed that chain-like bodies composed of glass spheres were formed only in the electric field concentrated portions formed at intervals of 200 μm. It can be seen that three-dimensional precise arrangement of minute objects is possible. The experimental conditions in this example are as follows. That is, the electrodes are made of copper, the size is 40 mm × 40 mm, the thickness is 1 mm, and the distance between the electrodes is 1.
4 mm, the volume fraction of glass spheres in the polymer solution is 1.3
%, The direction of the AC electric field is parallel to the direction of gravity, the magnitude (maximum value) is 7.1 kV / mm, and the frequency is 10 Hz. The curing of the polymer was performed at 100 ° C. for 1 hour. (Example 2) FIG. 4 shows an example of the formation of a chain, and is an optical microscope photograph of a cross section taken perpendicular to the electrode by removing the cured polymer from the electrode. The minute object is a silicon dioxide sphere having a diameter of 5 μm, and the polymer is a transparent silicone rubber. It is confirmed that a chain of silicon dioxide spheres is formed in the direction of the electric field (almost in the vertical direction in the photograph). Thus, it can be understood that a minute object having a size of about 5 μm can be three-dimensionally precisely arranged. The experimental conditions in this example are as follows. That is, the electrode is copper and the size is 40 mm × 4
0 mm, thickness 1 mm (there is no electric field concentrated part of the electrode), distance between the electrodes is 1.4 mm, volume fraction of silicon dioxide sphere in the solution is 6.8%, and the direction of the alternating electric field is parallel to the direction of gravity. , The magnitude (maximum value) is 1.4 kV / mm, and the frequency is 10 Hz. In addition, curing of the polymer is performed at 100 ° C., 1
Went on time. (Embodiment 3) FIG. 5 is an optical microscope photograph showing an example of an electrode having an electric field concentration portion. The copper electrode surface is shaved in a lattice pattern at intervals of 80 μm using a harmonic (wavelength: 266 nm) of a YAG laser. The width of the shaved portion (groove) is 28 μm and the depth measured from the surface is 8 μm
It is. Fabrication was performed under atmospheric pressure, and a swelling portion formed on an edge of a laser irradiation portion and a thin copper oxide film formed on a copper surface of the laser irradiation portion were removed by nitric acid cleaning. In this manner, an electrode can be manufactured by shaving a part of an electrode and making the remaining part an electric field concentration part by using laser processing. Also, an electrode having an electric field concentration portion can be manufactured by using an etching technique. (Embodiment 4) FIG. 6 shows an example of a method for producing an electrode having an electric field concentration portion. The electrode 11 is disposed in an atmosphere of a gas 12 of a metal compound such as tungsten hexacarbonyl,
The focused ion beam 13 is applied to a place where the projection 14 is to be formed. The metal is liberated from the gas 12 by the ion beam 13, and the metal is selectively deposited on the electrode 11 at a position irradiated with the focused ion beam 13, thereby forming a projection 14 serving as an electric field concentration portion. Therefore, an electrode having an electric field concentration portion can be manufactured. Alternatively, an electrode having an electric field concentration portion can be manufactured by depositing a conductor on a part of the electrode by using another evaporation method, or by carrying and attaching the conductor onto the electrode using a conductive probe. . (Embodiment 5) FIG. 7 shows an example of a method for manufacturing an electrode having an electric field concentration portion. FIG. 7A is a schematic diagram showing a cross section in a state where the liquid metal 16 is poured into the mold 15. FIG.
(B) is a schematic view showing a cross section of an electrode 18 having a projection 17 taken out of the mold 15 after cooling and solidifying the metal. By this method, an electrode having a projection serving as an electric field concentration portion can be manufactured. In addition, liquid metal 1
Alternatively, an electrode having a projection serving as an electric field concentration portion can be manufactured by plating the mold 15 with metal instead of pouring 6.

[0015]

As described above, according to the method of the present invention, a chain of small objects can be arranged at a target position (projection position), and various three-dimensional precision arrangements of small objects can be achieved. It is possible. The method of the present invention includes an optical device, a magnetic device, a semiconductor device, a micromachine,
It can be used to make sensors. For example, as for an optical device, a mirror that reflects only light of a specific wavelength, a light filter that transmits light, and a monochromator that can be applied to light in a wide wavelength range can be manufactured by periodically arranging the chains. In addition, by periodically arranging the chain-like body and introducing an arbitrary line defect (not arranging the chain-like body in a specific part), only light of a specific wavelength can remove the line defect part. An optical waveguide that can transmit light can be manufactured. As for the magnetic device, a perpendicular magnetic recording medium can be manufactured by using a ferromagnetic fine substance. Furthermore, if a non-curable solvent is used, it is possible to produce an optical device whose characteristics are reversibly changed when an electric field is turned on and off.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a three-dimensional precise arrangement method of minute objects.

FIG. 2 is a diagram showing an example of an electrode having an electric field concentration portion manufactured using a laser. (A) Optical microscope photograph (b) Schematic drawing of the cross section of the electric field concentration part when cut | disconnected perpendicularly to an electrode. (C) Schematic view showing the formation of a chain in the electric field concentration portion.

FIG. 3 is an optical micrograph showing an arrangement of glass spheres having a diameter of 30 μm.

FIG. 4 is an optical micrograph showing the formation of a chain of silicon dioxide spheres having a diameter of 5 μm.

FIG. 5 is an optical microscope photograph of an electrode having an electric field concentration portion manufactured using laser processing.

FIG. 6 is a conceptual diagram of a method for manufacturing an electrode having an electric field concentration portion using a vapor deposition method.

FIG. 7 is a conceptual diagram of a method for manufacturing an electrode having an electric field concentration portion using a mold.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Protrusion 2 Electrode 3 Counter electrode 4 Micro object 5 Liquid polymer 6 Power supply 7 Micro object chain 8 Projection 9 Electrode 10 Micro object chain

Claims (6)

[Claims] A projection made of a conductor is formed at an arbitrary position on an electrode, an opposing electrode is arranged, and a space between the electrodes is filled with a solution in which particulate matter or fibrous fine particles are dispersed in a solvent. Wherein the long axis direction of the chain body is formed so that the long axis direction of the chain body coincides with the direction of the electric field only at the position of the projection serving as the electric field concentration portion. Dimensional precision array method. 2. The method according to claim 1, wherein a liquid polymer is used as a solvent, and after the formation of the chain, the liquid polymer is cured by increasing the temperature or irradiating light to fix the arrangement. Precise array method. 3. The method according to claim 1, wherein at least one of light, an ion beam and an electron beam is used to cut off a part of the electrode, and a bulge is formed at an edge of the cut-off part. An electrode manufacturing method in which an electric field concentration portion is formed using a portion as a protrusion. 4. The electrode manufacturing method according to claim 3, wherein a part of the electrode is shaved by irradiating a laser beam, and the remaining part is formed as a projection to form an electric field concentration part. 5. The method of claim 1, wherein a conductor is attached to a part of the electrode by vapor deposition or by using a conductive probe, and the electric field concentrating portion is formed by using the conductor as a protrusion. The method of manufacturing the electrode to be formed. 6. The method according to claim 1, wherein a liquid metal is poured into the mold.
Alternatively, an electrode manufacturing method in which a metal is plated, and then the solidified metal is removed from the mold to form a projection serving as an electric field concentration portion.