JP3341387B2 - Method for manufacturing microstructured material, apparatus for manufacturing the same, and light emitting device having microstructure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a cluster having a uniform particle diameter (typically, a cluster whose diameter is about several tens nm or less in diameter, the same applies hereinafter), in other words, a quantum box (electron , A zero-dimensional electron system in which charged substances such as excitons are three-dimensionally confined within a small region of several tens of nanometers or less), a one-dimensional polymer having a uniform arrangement direction, a one-dimensional electric conductor or a fine wire cluster, A quantum wire (a charged body such as an electron or an exciton is two-dimensionally confined in a minute area
Manufacturing method, manufacturing apparatus, etc.
Further, the present invention relates to a light emitting element using these.

[0002]

2. Description of the Related Art In recent years, optoelectronic devices using a quantum well structure, such as a quantum well laser, an optical modulator, a bistable optical device, and the like, have been actively developed.

[0003] By using a quantum well structure (two-dimensional electron system), for example, in a quantum well laser, (1) an increase in differential gain and (2) a relaxation oscillation frequency as compared with an ordinary double heterojunction laser. Improvements in characteristics such as increase and (3) reduction in spectral line width have been made.

Further, a two-dimensional electron system is further reduced in dimension, that is, a quantum wire (one-dimensional electron system) or a quantum box (0
Attempts to further improve the characteristics of the optoelectronic device or to construct a device based on a new physical phenomenon have been made by realizing a three-dimensional electronic system.

For example, if a quantum box laser is realized,
(1) Reduction of threshold current, (2) Relaxation of temperature dependence of threshold current, (3) Further improvement of characteristics of items (1) to (3) described in the quantum well laser, and the like. Be expected.

[0006] These situations are described, for example, in "Solid State Physics".
(Yasuhiko Arakawa, Vol. 22, No. 2, p. 71 (1987))
It is described in.

On the other hand, quantum wires and quantum boxes are attracting attention from the viewpoint of optical nonlinearity.

The optical nonlinearity is generally classified by the nonlinear susceptibility, and a material having a high second-order nonlinear susceptibility (proportional constant of a nonlinear polarization component proportional to the square of the applied electric field) is the second material.
Materials with high harmonic generation (SHG), optical mixing or optical parametric oscillation, etc., and a material with a high third-order nonlinear susceptibility (proportional constant of nonlinear polarization component proportional to the cube of the applied electric field) can be used as a third harmonic generator. (THG), a nonlinear refractive index change, a stimulated Raman effect, etc., are utilized, respectively, and bring great effects to application to optoelectronic devices.

Such optical nonlinearity is increased by using a quantum well structure (two-dimensional electronic system), a quantum wire (one-dimensional electronic system) or a quantum box (zero-dimensional electronic system), as compared with a bulk crystal. I do.

For example, the third-order nonlinear susceptibility of a quantum box is
Although it depends on the constituent materials and dimensions, it is expected to be 200 to 8000 times that of the bulk crystal.

Even if only about 1% of the quantum box is contained in the substance, the third-order nonlinear susceptibility becomes 2-80 times.

Further, in a quantum box, a change in energy state due to a quantum confinement (quantum size) effect is remarkable. In the case of a light emitting element, for example, the emission spectrum width is reduced (monochromaticity is increased) and the photon energy is increased. This has a great effect on the increase (shortening of the emission wavelength).

These situations are described, for example, in "Nonlinear Optoelectronics in Latest Patents-From Materials to Devices-" (Takao Fushimi, published by the Industrial Research Institute, Inc. (199).
2)) or “Physical Society of Japan” (Toshihiro Arai, Vol. 44, No. 4, page 252 (1989)).

By the way, many optoelectronic devices including the above-mentioned quantum wire or quantum box application use a semiconductor material.
It is composed of a III-V or II-VI direct transition semiconductor, and indirect transition semiconductors such as silicon crystals are rarely used except for solar cells.

It is difficult to manufacture an efficient optoelectronic device (especially a light emitting device) because an indirect transition type semiconductor requires the intervention of lattice vibration (phonon) for absorption and emission of light. It is because.

However, in recent years, there has been shown a possibility that an efficient light-emitting element can be obtained by using a quantum wire or a quantum box exhibiting a quantum confinement effect even if an indirect transition type semiconductor is used.

These situations are described, for example, in “Applied
Physics Letters "(LTCanham, Applied Physi
cs Letters Vol. 57, No. 10, 1046 (1990)).

Advantages in realizing an optoelectronic device (especially a light emitting device) using an indirect transition semiconductor will be described below.

For example, silicon constituting a typical indirect transition type semiconductor is different from III-V or II-VI semiconductor constituent materials in that it exists in a large amount on the earth (that is, is inexpensive) and has high safety. Is high (that is, non-toxic), and furthermore, it is a central substance constituting an electronic element such as an IC or an VLSI.

That is, if a light-emitting element having characteristics not inferior to conventional ones can be realized using silicon,
A great effect is brought about in terms of price, environmental friendliness, and consistency when considering integration with electronic elements.

As described above, the range and expectation of the application of quantum wires or quantum boxes to optoelectronic devices, including the use of silicon materials, are great.

In particular, by obtaining quantum wires or quantum boxes with uniform shapes and dimensions at high density, it is possible to obtain a light-emitting element having high monochromaticity and high luminous efficiency, a nonlinear optical element having high optical nonlinearity, and the like.

Techniques that have been tried in the past to achieve these include lithography techniques (that is, fabrication of quantum wires and quantum boxes), heat treatment of mixed crystal substances or glass in which metal (or semiconductor) particles are dispersed. Deposits clusters (that is, manufacture of quantum boxes), directly forms clusters by dry process (that is, manufactures quantum boxes), or one-dimensional polymer (that is, manufactures quantum wires). Use of matter (that is, use of quantum wire and / or quantum box effect) and the like can be mentioned.

A first conventional technique using the lithography technique will be described below. Normal quantum well structure (two-dimensional electron system)
Is epitaxially grown on a substrate, and then a mask pattern is transferred by a normal photolithography technique. The minimum horizontal size obtained at this time is 0.3 to 1 μm.
It is about.

Thereafter, the quantum well layer is etched by wet etching to perform horizontal separation (quantum thinning or quantum boxing) on the substrate and to reduce the horizontal dimension by utilizing the side etching effect. , To control the dimensions of the horizontal quantum wires or quantum boxes.

A similar second prior art is that a normal quantum well structure (two-dimensional electron system) is epitaxially grown on a substrate, and then (1) a mask by X-ray lithography and focused electron (or ion) beam lithography. Quantum thinning or quantum boxing is performed by pattern transfer and dry etching, or (2) Quantum thinning or quantum boxing is performed by simultaneously performing lithography and etching using a focused ion beam. is there.

A third conventional technique by heat treatment of a mixed crystal material includes, for example, “Applied Physics Letters” (Y. Maeda et al., Applied Physics Letters Vol.
59, No. 24, 3168 (1991)).

First, Ge, Ge is deposited by a radio frequency (RF) magnetron sputtering method using a silicon oxide (SiO ₂ ) target on which a germanium (Ge) chip is arranged.
A mixed crystal material composed of Si and O is deposited on a Si substrate.

Next, heat treatment (800 ° C., 30 minutes) is performed to obtain Ge clusters (fine crystals, average particle size: 6 nm) embedded in the SiO ₂ glass.

As a result, when the peak wavelength is
Room temperature visible light emission having a spectrum extending from 00 to 700 nm is obtained.

In the fourth prior art in which the metal (or semiconductor) particle-dispersed glass is heat-treated, diffusion, ion exchange, ion implantation, or the like is usually used for particle dispersion.
This technique has been widely used as a method for manufacturing a nonlinear optical material.

A fifth prior art relating to direct generation of clusters by a dry process is disclosed in, for example,
There is a method described in JP-A-65930.

The conventional example will be described below with reference to a schematic view of a conventional manufacturing apparatus shown in FIG.

Microwave of gaseous gas (2.45 GHz)
From a nozzle 502 of a cluster (ultrafine particle) source 501 using excitation, a semiconductor (S
i) Generate a cluster (ultra-fine particle) beam 503.

On the other hand, from a nozzle 505 of the similar cluster source 504, an insulator (SiO ₂ ) cluster (ultrafine particle) beam 506 having a particle size equal to or larger than that of the Si cluster is generated.

By irradiating the substrate 507 with both of the cluster beams 503 and 506, a cluster formed by mixing and depositing a semiconductor cluster (ultrafine particle) 508 and an insulator cluster (ultrafine particle) 509 as shown in FIG. (Ultra fine particles) film 510 is manufactured.

In the cluster film 510, an optical absorption spectrum indicating the quantum confinement effect is obtained.

As a sixth prior art relating to one-dimensional polymers as quantum wires, for example, those described in “Surface Science” (Nobuo Matsumoto, Vol. 13, No. 4, pp. 219 (1992)) There is.

Among them, the one-dimensional polymer obtained by the chemical synthesis is a one-dimensional linear array polysilane: (R ¹ R ² Si) _n
Wherein R ¹ and R ² are an organic group such as an alkyl group such as a methyl group or an ethyl group. Specifically, a dichlorosilane derivative having two organic groups and two chlorine groups:
R ¹ R ² SiCl ₂ is used as a source molecule.

First, an organic solvent such as toluene is put in a flask, and metallic sodium (Na) is melted by heating under reflux in an argon (Ar) atmosphere, and the above-mentioned raw material molecules are added dropwise with stirring. In this state, if the reaction is carried out for several hours, white one-dimensional linearly arranged polysilane is deposited.

FIG. 20 is a schematic view of the chemical synthesis of the present polysilane.
Shown in The seventh prior art use of porous silicon materials has been widely studied in recent years.

This is basically made of single crystal silicon (Si)
It is obtained by anodizing the surface of a substrate in a hydrogen fluoride-based solution.
Many luminescence in the visible region of 0 nm (blue) has been confirmed.

In addition to photoluminescence, light emission characteristics have been confirmed by current injection, and attempts have been made to manufacture current injection type light emitting elements (eg, LEDs).

The structure and light emitting mechanism of the light emitting layer in porous Si
Although the details are not clear, the quantum layer
A microcrystal corresponding to a wire or a quantum box, for example, an oxide layer (S
iO _Two) Covered with Si (semiconductor) region or its boundaries
Planes, or quantum confined regions, exist at high density
Charged body constrained by k-conserving transition selection rule
Light emission mechanism that emits light because it is not
Is considered as one theory.

These situations are described in, for example, “Research Reports of the Subcommittee of Applied Electronic Properties” (published by the Japan Society of Applied Physics, No. 446 (1992)), or “Nikkei Microdevices”.
(May issue, Nikkei BP, p. 15, p. 1993).

[0046]

In the case of the first and second prior arts, the minimum horizontal dimension obtained is at most 10n.
m. In addition, the first conventional technique is simple in that normal process technology is used, but it is almost impossible to obtain a dimension as designed stably due to the use of wet etching. One quantum wire or quantum box can be obtained in the range of several hundred nm, and there is a limit in increasing the density.

In the case of the third and fourth prior arts, since a thermal equilibrium process is used, it is expected to manufacture a dense cluster buried structure with stable optoelectronic characteristics, but control beyond the natural law of thermodynamics. Is impossible in principle.
That is, there is a limit to the high-density embedding of clusters, the control of the particle size and the particle size distribution, and the like. For example, the embedding density is generally said to be up to several percent. Also, the fact that the particle size distribution width cannot be narrowed, taking a light emitting element as an example,
This leads to an increase in the emission spectrum width (a decrease in monochromaticity).

In the cluster (ultra-fine particle) film manufactured according to one example of the fifth prior art, since the ultra-fine particles of the semiconductor and the ultra-fine particles of the insulator are mixed and deposited, the gap as shown in FIG. 511 are likely to occur, and problems remain in terms of stability of optoelectronic characteristics or life. No consideration is given to particle size control or the like.

The method for producing a one-dimensional polymer (quantum wire) according to an example of the sixth prior art is simple, but the arrangement direction of the one-dimensional polymer, the length of each polymer and the like are completely random. There remains a problem in using it as the quantum wire for an optoelectronic device.

The seventh prior art has a feature that a visible light emitting material can be easily manufactured using a silicon crystal, but at present, the characteristics are sensitively changed depending on manufacturing conditions and the like.
Further, there is a problem that the change with time (deterioration) is remarkable.

When a current injection type light emitting device is manufactured, in order to obtain a device having high luminous efficiency and stable characteristics, one of the two surfaces of the light emitting layer has a P type (a charged body is a hole),
On the other hand, it is necessary to form an N-type (electron is a charged body) semiconductor electrically conductive layer. However, in the application of the seventh prior art, the light emitting layer is a porous layer, so that the electrical conduction layer having good interface characteristics is formed. It is difficult to form a layer.

The present invention solves the various problems of the prior art described above, and includes clusters (quantum boxes) having a uniform particle size and particle size distribution, and dense and high-density embedding of the clusters. It is possible to produce a one-dimensional polymer having a high orientation, a one-dimensional polymer having a high degree of orientation, a one-dimensional electric conductor, a fine wire cluster, or the like (quantum fine wire). Provided are a method, an apparatus and a light-emitting element for producing a microstructured material, which have a great effect on the production of an opto-electronic element such as a nonlinear optical element having a high nonlinearity, and a light-emitting element utilizing an indirect transition type semiconductor substance such as a silicon crystal. The purpose is to do.

[0053]

In order to achieve the above object, a first aspect of the present invention is to provide a first step of forming clusters, and a method of forming raw material particles of a substance having a band gap larger than that of the clusters into atoms and molecules. A second step of generating the state in a state is provided independently, and both steps are performed simultaneously to deposit the raw material molecules in the atomic or molecular state as a uniform and continuous thin film. It has a configuration in which it is densely buried without generating. Or gold by laser ablation
First generation of clusters consisting of metals or semiconductors
And the first step by photochemical vapor deposition
Material with a larger band gap than the cluster
Raw material particles in atomic or molecular state of conductor or insulator
And a second step of generating, wherein both steps are performed simultaneously or
Alternately and repeatedly, the raw material particles in the atomic or molecular state
The particles are deposited as a uniform and continuous thin film
Creating the clusters in the thin film and gaps around them
Instead, it may have a configuration in which it is embedded precisely.

According to a second aspect of the present invention, there is provided a solid target, a means for irradiating the solid target with a laser beam, a gas introducing means,
Means for introducing light to atoms and molecules state and, generates clusters and, by Ri atom photolysis from the target
.Deposited in a molecular state and as a uniform and continuous thin film
Comprising a substrate holder were both placed in a position to be deposited on a substrate to produce material that was has a configuration such.

[0055] Incidentally, chopped generated clusters in synchronization with the laser pulse, comprising the step of selecting the particle size of the product cluster may have a configuration such.

According to a third aspect of the present invention, in a container capable of evacuating, a solid target, means for irradiating the solid target with pulsed laser light, and means for chopping generated clusters in synchronization with a laser pulse are provided . Chopping
Means to ionize the generated clusters
Laser pulse for steps and ionized clusters
Separate mass by applying electric or magnetic field pulse synchronized with
Means .

According to a fourth aspect of the present invention, a solid target, means for irradiating a pulse laser beam to the solid target, and a substrate on which clusters are deposited are rotated or reciprocated in a vacuum-evacuable container in synchronization with a laser pulse. that makes
Clusters having a specific particle size on the substrate
And a means for depositing at a fixed position .

[0058] Incidentally, the step of generating a cluster, a step of coating the product cluster surface in a more or the substance causing reformed to a substance having high band gap, a cluster of post-production cluster or modified-coating process to mass separation A method of providing a step is also possible .

Alternatively , means for generating a cluster,
It is also possible to have a configuration in which a means for modifying the surface of the generated cluster to a substance having a larger band gap or coating the substance with the substance and a means for mass-separating the generated cluster or the cluster after the modification / coating treatment are provided. Good
No.

According to a fifth aspect of the present invention, a high-concentration cluster material active particle is generated by photolysis of gas molecules at a laser beam converging point, and the substrate is disposed at a position away from the converging point and directly irradiated with the laser beam. Deposit clusters on top
Changing the distance between the focal point and the substrate.
By doing so, the particle size of the clusters deposited on the substrate
Control .

A first step in which planar electrodes having a plurality of needles having the same shape and dimensions arranged in parallel are arranged close to and parallel to the substrate surface, and an electric field is applied between the tip of each needle and the substrate surface; A second step of depositing a first substance on the substrate surface after the first step, a third step of removing the first substance, and a first substance on the substrate surface after the third step It is also possible to include a fourth step of depositing a second material having a larger band gap.

A substrate holder, a plane electrode having a plurality of needles having the same shape and dimensions arranged in parallel in a vacuum-evacuable container, and a plane electrode arranged close to and parallel to the surface of the substrate placed on the substrate holder. means for, one or more means for depositing a plurality of substances onto the substrate surface, comprising means for removing at least one of the materials may have a configuration such.

Alternatively, a substrate holder is provided in all of a plurality of containers that can be evacuated , and a plane electrode in which a plurality of needles having the same shape and size are arranged in parallel in any one of the plurality of containers, and the substrate holder is provided. Means for arranging a planar electrode close to and parallel to the substrate surface, one or more means for depositing a plurality of substances on the substrate surface, and means for removing at least one of the substances; It may be configured to include means for connecting substrates via a valve and transporting the substrate between the containers.

According to a sixth aspect of the present invention, there is provided an arrangement in which an electric field is applied in one direction parallel to the surface of a substrate, and a one-dimensional polymer material molecule or a cluster whose surface is coated with a foreign substance is supplied onto the surface of the substrate. have.

According to a seventh aspect of the present invention, an electric field is applied in the direction in which the steps provided on the surface of the substrate run, and the one-dimensional electric conductor containing the raw material particles supplied from the gas phase in its composition is moved in the direction in which the steps run. It grows along.

In addition , the terrace &
A substrate surface step is present at a high density, comprises a one-dimensional electrical conductor extending along said step includes silicon atoms in its composition, may have a configuration such.

[0067] Further, using cluster, the porous material to thin linear cluster or one-dimensional polymer more embedded in larger substance bandgap microstructure material or indirect transition type semiconductor material originated in emission source, an excitation source the use of a cold cathode, emitting source, emits light phenomena by directly or effectively irradiated and absorbed the electron beam emitted from the excitation source, may have a configuration such.

[0068]

With the above arrangement, the first aspect of the present invention comprises the first step and the second step independently, and enables independent control of the amount of clusters and particles of embedded material to be produced per unit time. Therefore, the density of the embedded cluster can be easily controlled. In addition, since the raw material particles in the second step are in an atomic / molecular state and the first and second steps are performed simultaneously , the clusters are densely embedded without generating a gap in the periphery. be able to.

The second aspect of the present invention includes both means for generating clusters by laser ablation and means for generating photo-decomposition of the embedded material raw material particles in the atomic / molecular state. The production of the structural material can be realized with the same apparatus and only by the photoexcitation process. In the means by laser ablation, the particle size of the generated cluster and the particle size distribution can be controlled by controlling the density of the irradiation laser beam, so that the particle size and the particle size distribution of the embedded cluster can be easily controlled.

Further, the first and second inventions basically do not require a thermal equilibrium process of depositing clusters by heat treatment of a mixed crystal material or the like deposited on a substrate by a vapor deposition method. As compared with, cluster embedding at a higher density is possible, and the controllability of the particle size and the particle size distribution is improved.

The third aspect of the present invention is provided with a step or means for selecting the particle size of the generated cluster by chopping, so that the particle size of the cluster generated by laser ablation can be controlled more finely and a sharper image can be obtained. A fine particle size distribution can be obtained. Furthermore, chopping itself is performed in synchronization with the laser pulse,
Accurate control becomes easy.

The fourth aspect of the present invention includes means for rotating or reciprocating the substrate in synchronization with the laser pulse, so that finer control of the particle size of clusters generated by laser ablation can be performed accurately and easily. And a sharper particle size distribution can be obtained.

[0073] Incidentally, by providing the step performed immediately after the cluster generating different materials modifying (or coating), it has a non-existent good interface characteristics, such as gaps or impurities, coated with a larger heterogeneous material bandgap It is possible to realize a cluster, in other words, a quantum box having a high quantum confinement effect. In addition, a mass separation process must be provided.
Thus, a plurality of cluster groups having a sharper particle size distribution can be provided.

In addition, the method for performing the modification / coating is as follows.
The same effect is achieved by realizing a manufacturing apparatus having means for performing step and mass separation .

According to the fifth aspect of the present invention, active particles having a high concentration are generated at the laser beam converging point, forming clusters by self-coupling with each other, and increasing the particle diameter. Reaches the substrate arranged at the position where the light is directly irradiated. That is, in the fifth aspect of the present invention, clusters can be generated only by the photochemical gas phase reaction, and the distance between the active particle generation unit and the substrate can be easily changed by moving the focal point or the substrate in the optical axis direction. Therefore, the particle size of the cluster deposited on the substrate can be controlled to a desired value. Furthermore, compared with the case where the laser beam irradiation direction is the horizontal direction above the substrate, the movement of the focal point for the change in the distance is simpler, and the uniform particle size and the particle size distribution are obtained by scanning the laser beam or the substrate. It is also possible to deposit clusters having a uniform distribution on a large-area substrate surface.

[0076] Incidentally, first, to the first step of using an electric field applied to the minute space between the equal plurality of needle tip and the substrate surface of the deployed shape and size in parallel with the flat electrode
Then , a plurality of micro holes (hole diameter: about several tens nm or less) having a uniform shape and dimensions can be formed on the substrate surface. Here, since the shape and size of the micropores can be controlled by the approach distance between the needle and the substrate surface and the electric field strength, the first substance is deposited on the substrate surface after the micropores are formed (second step) and removed (second step). 3
Together with the deposition of the second substance (fourth step), a cluster made of the first substance having a desired shape and dimensions can be embedded in the micropores. Further, by repeating the first to fourth steps, a microstructured material can be realized in which the three-dimensionally distributed clusters are embedded with a second substance. Regarding the burying density of the clusters, the density in the horizontal direction on the substrate surface is determined by the arrangement density of the needles on the plane electrode, and the density in the vertical direction is determined by the deposited film thickness of the second substance in the fourth step. That is, the embedding density can be controlled independently and flexibly from the control of the cluster shape and size, and the embedding density can be made anisotropic.

Further , the above first to fourth steps are respectively performed
Realized production device having means for performing further plurality of micropores: and means for removing means and materials for performing means and material deposition to form a (pore diameter below about several tens nm) on the substrate surface, 1
If it is configured to be provided in one container, the device structure is simplified. In addition, since the substrate is not transported between the steps of applying each means, the time required for switching between the steps is shortened. This applies repeated a fourth step from the first, a great advantage in the case of producing it, such as microstructure material embedded three-dimensionally distributed clusters second material. Meanwhile, the respective means, if configured to include a separate vessel, the process could completely eliminated mutually influence each other to apply using respective means. In addition, maintenance can be performed independently for each means, which brings great convenience in a vacuum apparatus provided with means having different functions.

According to a sixth aspect of the present invention, when a one-dimensional polymer material molecule or a cluster whose surface is coated with a heterogeneous substance is supplied onto the substrate surface, an electric field is applied in one direction parallel to the substrate surface. Therefore, electric polarization occurs in the same direction in all the source molecules or clusters adsorbed on the substrate surface, and the source molecules or clusters are bonded to each other in a portion where +-polarity is generated. As the molecules or the linear clusters grow, polarization also occurs in the growing one-dimensional polymer or the linear clusters, so that the orientation direction of the one-dimensional polymers or the linear clusters can be matched. In other words, high-density quantum wires with uniform arrangement directions can be easily manufactured.

In the seventh aspect of the present invention, since the terraces and steps are provided on the substrate surface, particles such as atoms, molecules or clusters adsorbed on the substrate surface from the gas phase stay on the terrace for a certain period of time. The diffusion reaches the step, and the step is arranged along the running direction on the step (linear arrangement). This is because the particles are usually more stable when present on a step than on a terrace. On the other hand, an electric field is applied in the direction in which the steps run, so that the linearly arranged particles are bonded by the action of electric polarization generated in the particles, so that a one-dimensional electric conductor can be grown. it can. That is, in the seventh aspect of the present invention, by supplying particles such as atoms, molecules or clusters from the gas phase, it is possible to grow a one-dimensional electric conductor arranged in accordance with the direction in which the steps run.

[0080] In addition, and a one-dimensional electrical conductor comprising a silicon atom in its composition, i.e., by using the quantum confinement effect in the quantum wire, it is also possible to obtain a light emitting element made of silicon material. In addition, since the one-dimensional electric conductor extends along the steps of terrace and step caused by the slight inclination from the stable crystal plane, the arrangement direction is controlled with atomic level accuracy,
The density of the arranged one-dimensional electric conductors is also easily controlled by the slight tilt angle control. These contribute to the realization of a light emitting element having high monochromaticity and high luminous efficiency. Further, such a light emitting device can be easily realized by the manufacturing method of the seventh aspect of the present invention.

[0081] Moreover, clusters, the porous material to thin linear cluster or one-dimensional polymer more embedded in larger substance bandgap microstructure material or indirect transition type semiconductor material originating in be used in actual light emitting source A light emitting device utilizing the quantum confinement effect of a quantum box or a quantum wire can be realized. On the other hand, since the cold cathode is used as the excitation source, unlike the current injection type light emitting element, there is no need to form further P-type and N-type electrically conductive layers on the material used for the light emission source, The structure of the light emitting source is simplified. Further, the light emitting source and the excitation source can be manufactured independently. In addition, a high quality light emitting source can be manufactured by using the manufacturing method or the manufacturing apparatus of the first to seventh aspects of the present invention, Since the excitation source is a cold cathode generally present in the world, a high quality light emitting device can be easily manufactured. Furthermore, miniaturization and integration similar to the current injection type element are possible.

[0082]

FIG. 1 is a schematic view showing one embodiment of a method for producing a microstructured material according to the present invention.

FIG. 1 shows that a group of clusters 101 generated in the first step and a group of raw material particles (atomic / molecular state) 103 of a substance 102 having a larger band gap than the cluster 101 generated in the second step are simultaneously. Or alternately, substrate 1
4 shows a situation in which the cluster 101 is embedded in the substance 102 by supplying it to the substance 102.

The first step of forming the cluster 101 includes, for example, laser ablation (laser ablation).
: ablative photodecomposition).

This is achieved by irradiating the surface of the solid material with a laser beam having a photon energy higher than the bonding energy between atoms or molecules constituting the solid material or a laser beam having a high energy density at which high-density multiphoton absorption occurs. This is a process in which atoms and molecules constituting a solid material are explosively blown off (removed) as particles by directly breaking bonds, and have recently been used in thin film production or etching processes.

Here, the morphology of the generated particles can be changed from clusters to molecules or molecules to atoms depending on the irradiation laser light density (in general, the higher the irradiation laser light density, the more the number of constituent atoms of the particles Is less).

Thus, by controlling the laser beam density using laser ablation, it is possible to control the particle size of the formed cluster and the particle size distribution. Also,
The amount of generated particles can be controlled by controlling the total light amount of the irradiation laser.

In addition, in the first step, particle size and particle size distribution control are more complicated than in laser ablation.
Other processes for generating a cluster ion beam can also be used.

On the other hand, the second step for producing the raw material particles 103 includes, for example, photochemical vapor deposition (photochemical vapor deposition).
vapor deposition).

This method has recently been used as a method for depositing a thin film using active particles generated by the photolysis of a reactive raw material gas.

This method is characterized in that a thin film having a uniform and continuous property (for example, free of crystal grains) can be easily obtained.

In this sense, thermal or electron beam evaporation, plasma or thermochemical vapor deposition, etc. may be used, but photochemical vapor deposition is a non-thermal equilibrium / low temperature process, so this method is used. Thus, in combination with the first step using the above-described laser ablation or cluster ion beam generation process, the entire embodiment of the manufacturing method of the present invention becomes a non-thermal equilibrium process, and the controllability of the embedding density, the particle size and the particle size distribution is controlled. Increase.

Further, since it is a non-plasma process, there is no fear of plasma damage to the interface between the cluster and the embedded material.

In the second step, laser ablation may be used. In this case, the intensity of the irradiation laser beam is controlled, and the generated particles are supplied onto the substrate 104 in the state of atoms or molecules.

In the first and second steps, laser ablation using ultraviolet laser light or photochemical vapor deposition can be used.

Thus, the first and second steps can be performed with only a single laser beam, thereby simplifying the entire manufacturing method.

FIG. 2 is a schematic view of an embodiment of the apparatus for producing a microstructured material according to the present invention. In FIG. 2, laser light introduction windows 105 and 106 and gas introduction nozzles 107 and 1
, A single-crystal silicon (Si) solid target 11 serving as a cluster material
0 and a substrate holder 111 are provided.

Here, the target 110 is arranged so that the laser beam (photon energy: hν ₁ ) 112 introduced through the window 105 is irradiated on the surface of the target 110. The substrate holder 111 holds the target 1
The particles ablated from 10 are arranged so as to irradiate the surface of the holder 111.

The window 106 is introduced through this
Laser light (photon energy: hν _Two) 113
Placed directly on the surface of the
Have been.

However, the window 106 has a laser beam 113
In order to pass in the horizontal direction near the surface of the holder 111,
In other words, near the surface of the holder 111 (at most a dozen
m) so as to allow irradiation.

Further, the nozzles 107 and 108 are located at positions where the gas introduced from the nozzles 107 and 108 can reach the surface of the substrate 114 by spraying or diffusing directly or in a state where the gas is photodecomposed by the laser beam 113 into active particles. To place.

In the case of manufacturing a microstructure material such as a single crystal Si cluster embedded in silicon oxide (SiO ₂ ) by the manufacturing apparatus having the above configuration, the following is performed.

First, the substrate 114 is set on the holder 111. The supply of the single-crystal Si cluster onto the surface of the substrate 114 is performed by ablation of a single-crystal silicon (Si) solid target 110 with a laser beam 112.

It is desirable that the laser beam 112 has a photon energy: hν ₁ that is high enough to directly break single crystal Si atomic bonds having a binding energy of 1.8 eV, and has a high absorption coefficient per unit deposition. The higher the ablation efficiency, the better the hν ₁ is.

More specifically, considering the practicality of the laser itself, the second harmonic (hν ₁ = 2.3e) of the YAG laser is used.
V), XeCl (hν ₁ = 4.0 eV), KrF (hν ₁
= 5.0 eV) or ArF excimer laser (hν ₁
= 6.4 eV).

The particle size and the particle size distribution of the clusters to be supplied on the surface of the substrate 114 are controlled by the irradiation density of the laser beam 112, and the cluster supply amount per unit time is controlled by the total irradiation light amount.

On the other hand, the nozzles 107, 1
From 08, disilane gas (Si ₂ H ₆ ) and laughing gas (N ₂ O), or oxygen gas (O ₂ ) of a low concentration that does not directly react with Si ₂ H ₆ are introduced, and into them. ArF excimer laser light (h
ν ₂ = 6.4 eV).

Since the light of hν ₂ = 6.4 eV directly decomposes the Si ₂ H ₆ gas molecules, it reacts with the generated Si active particles and oxygen-based particles (or photo-decomposed oxygen-based active particles). Then, a SiO ₂ thin film is deposited on the surface of the substrate 114.

The deposition rate is controlled by the gas supply amount (or gas pressure) per unit time or the laser light 113 irradiation amount.

As described above, it is possible to manufacture the microstructured material in which the cluster embedding density, the particle size, and the particle size distribution are controlled.

In this embodiment, also by using an ArF excimer laser for the ablation,
Only one laser light source is required.

FIG. 3 and FIG. 4 are process drawings of one embodiment of the method for producing a microstructure material according to the present invention.

FIG. 3A shows a row of cluster groups 115 having a distribution of particle size A.

Each cluster group is generated and caused to fly by laser ablation using a pulse laser. In addition,
A single pulse of the laser produces one of the clusters.

Generally, in such a cluster group,
Clusters with smaller particle sizes are located at the head of the group and fly.

By utilizing this property and chopping each cluster group in synchronization with the laser pulse, it is possible to select only clusters having a desired particle size in the cluster group.

More specifically, the chopping frequency is made equal to the repetition frequency of the pulse laser, or an integral multiple of the repetition frequency is used as the chopping frequency, and the chopping is performed with an appropriate phase delay. By changing the value of the phase lag, the particle size to be sorted can be controlled.

FIG. 3B shows a row of the cluster group 116 having a particle size distribution B which is sharper than the distribution A after the selection.

FIG. 4 is a schematic view of an embodiment of the apparatus for producing a microstructure material according to the present invention utilizing such a principle.

In FIG. 4, a container 117 that can be evacuated is shown.
Among them, a solid target 118 serving as a cluster material,
A substrate holder 119 and a rotary disk-type chopper 121 in which a gap 120 is cut out in part are provided, and a pulsed laser light source 122 is installed outside thereof.

Then, the container 117 is irradiated with a pulse laser beam (photon energy: hν ₁ ) 123 from the pulse laser light source 122 so that the surface of the target 118 is irradiated.
Is provided with a laser light introduction window 124 arranged in the first position.

The cluster group 125 ablated from the target 118 by a single pulse of the laser beam 123
Fly over the surface of the chopper 121 rotating at a rotation frequency: nf _C1 that is equal to or an integral multiple of the repetition frequency f _L of the laser light 123.

Here, the particle size can be selected by setting the relationship between the time t ₁ at which the cluster group should pass through the chopper and the time t ₂ at which the gap 120 crosses the cluster group such that t ₁ > t ₂ .

The time ratio: t₁/ T_TwoIs larger,
The subsequent particle size distribution becomes sharp. t ₁/ T_TwoThe size of
Change the size of the air gap 120 or the chopper rotation frequency
Control by The particle size is f_LAnd f_C1With
Control by changing the value of the phase delay
You.

As described above, cluster group 1 after particle size selection
26 are sequentially deposited on a substrate placed on a substrate holder 119.

FIG. 5 is a schematic diagram of one embodiment of the apparatus for producing a microstructured material according to the present invention based on the same principle as that of the third embodiment.

In FIG. 5, a container 127 capable of being evacuated is provided.
Among them, a solid target 128 serving as a cluster material,
A means for chopping the substrate holder 129 and the cluster group 130 described below is provided.

This means for chopping uses so-called mass separation. In this embodiment, an electron gun 131 for ionizing each cluster and an accelerating unit 132 for accelerating and accelerating the velocity of each ionized cluster. ,
And an electric or magnetic field applying unit 133 for mass-separating each cluster.

Furthermore, the pulse laser light source 122 is
A pulse laser beam (photon energy: hν ₁ ) 123 from the light source is provided outside the target 128.
A laser light introduction window 134 is provided in the container 127 so as to irradiate the surface of the container 127.

The cluster group 130 ablated from the target 128 by a single pulse of the laser beam 123
After being ionized and accelerated, the laser beam flies to the application section 133 to which the electric field or magnetic field pulse is applied at a repetition frequency equal to f _L or a repetition frequency nf _C2 that is an integral multiple of the laser light 123.

Here, the time required for the accelerating cluster group 135 to pass through the application unit 133: t ₃ and the applied electric or magnetic field pulse width: t ₄ are set to have a relationship of t ₃ > t ₄ , thereby selecting the particle size. Can be.

That is, by applying an electric field or a magnetic field to a part of the cluster group, the direction in which some clusters fly toward the substrate holder 129 is changed. In addition, time ratio:
As t ₃ / t ₄ is larger, the particle size distribution after sorting becomes sharper, and the size of t ₃ / t ₄ is controlled by changing the size of t ₄ . The particle size is controlled by changing the value of the phase delay provided between f _L and f _C2 .

The amount of displacement in the flying direction is determined by the particle size (to be exact, mass) of the cluster to be selected, the acceleration unit 132
Is determined by the accelerating voltage and the applied electric or magnetic field strength, so that only the clusters to be sorted can fly toward the substrate holder by controlling these physical quantities.

As described above, cluster group 1 after particle size selection
36 are sequentially deposited on a substrate placed on a substrate holder 129.

FIG. 6A is a schematic view of one embodiment of the apparatus for producing a microstructured material according to the present invention, and FIG. 6B is a diagram showing a fine structure produced by the production apparatus of this embodiment. It is a block diagram of an element.

In FIG. 6A, a solid target 1 serving as a cluster material is placed in a container 137 which can be evacuated.
38, and a substrate holder 139, and the holder 139 has a mechanism that can rotate at an arbitrary rotation frequency.

Further, a pulse laser light source 122 is provided outside the container 137, and the laser light introduction window 140 is set so that the pulse laser light (photon energy: hν ₁ ) 123 from the light source is irradiated on the surface of the target 138. Container 1
37.

The cluster group 141 ablated from the target 138 by a single pulse of the laser beam 123
The laser beam 123 comes to the holder 139 which is rotated at a repetition frequency: f _L or a rotation frequency: nf _C3 of an integral multiple.

Here, as shown in FIG. 6A, when the holder 139 has a tetrahedral shape and a substrate is provided on each surface, the cluster group 141 has a sharper particle size distribution. It is divided into clusters of different types and is sequentially deposited on the respective substrates: A, B, C, D.

In other words, the group of clusters is chopped by the holder 139 itself to select the particle size, and at the same time, the selected clusters are deposited.

Substrates A, B, C, D on which clusters were deposited
FIG. 6 (b) shows an outline of each cross section.

The average particle size of the deposited clusters decreases in the order of the substrates A, B, C and D.

Note that the holder 139 may be a polyhedron other than the tetrahedron, and in this case, the cluster group is divided and deposited accordingly.

FIG. 7A is a schematic view of one embodiment of the apparatus for producing a microstructured material according to the present invention, and FIG. 7B is a diagram showing a fine structure produced by the production apparatus of this embodiment. It is a block diagram of an element.

In FIG. 7A, a solid target 1 serving as a cluster material is placed in a container 142 capable of being evacuated.
43 and a substrate holder 144 are provided, and the holder 144 has a mechanism capable of reciprocating at an arbitrary frequency.

Further, a pulse laser light source 122 is provided outside the container 142, and the pulse laser light (photon energy: hν ₁ ) 123 from the light source is applied to the target 143.
A laser light introduction window 145 is provided in the container 142 so as to irradiate the surface of the container 142.

The cluster group 146 ablated from the target 143 by a single pulse of the laser beam 123
Flies to the holder 144 reciprocating at a frequency equal to the repetition frequency f _L of the laser beam 123 or at an integral multiple of the frequency nf _C4 , and is deposited on the substrate provided on the holder 144.

As a result, clusters having different grain types within the grain size distribution range of the cluster group 146 are sequentially deposited on the substrate in a reciprocating motion direction.

In other words, the group of clusters is selected by the holder 144 itself to select the particle size, and at the same time,
The selected clusters are being deposited.

FIG. 7B schematically shows a cross section of the substrate on which the clusters are deposited. The particle size of the deposited cluster decreases from right to left in the drawing.

As described above, in the third to sixth embodiments, in general, in a cluster group generated and scattered by pulsed laser ablation, a cluster having a smaller particle diameter is located at the head of the group and scatters. Using
Clusters having a uniform grain size and particle size distribution generated by ablation are further finely classified to provide clusters having a sharper particle size distribution.

In the method for manufacturing a microstructure material according to the present embodiment,
First, in the step of generating clusters, for example, laser ablation, which can control the generated cluster particle size and particle size distribution by controlling the irradiation laser beam density, is used.

Next, when the generated cluster is composed of, for example, a Si material, after the above-described process, the cluster surface is easily modified into an SiO ₂ layer having a larger band gap by irradiating the active particles with oxygen. can do.

Then, in the subsequent step of mass separation,
For example, a method of ionizing the reformed clusters and separating them by an electric or magnetic field, a method using a mechanical chopper, or a method based on physical movement of a cluster deposition or collection means is used.

By performing the above steps, it is possible to produce a cluster covered with a material layer having a larger band gap as well as a uniform particle size and particle size distribution as compared with the case where only laser ablation is used. You can do it.

FIG. 8 is a schematic view showing one embodiment of the apparatus for producing a microstructured material according to the present invention based on the above principle.

A solid target 148 serving as a cluster material is placed in a container 147 that can be evacuated, and a laser light introduction window 150 arranged at a position where the surface of the target 148 is irradiated with laser light (photon energy: hν ₁ ) 149.
An active particle source 151 as a surface modification or coating material source for the generated cluster, and a means for mass-separating the generated cluster are provided.

In this embodiment, the mass separation means is an electron gun 15 for ionizing the formed cluster.
2. It comprises an acceleration unit 153 for accelerating the ionized clusters at the same speed, and a magnetic field application unit 154 for mass separation of the clusters.

In the manufacturing apparatus having the above configuration, for example, SiO 2
_When manufacturing a single-crystal Si cluster coated with _two layers,
It is as follows.

First, a single crystal Si
Is used. In addition, as the laser beam 149, the second harmonic (hν ₁ = Yν = 2) of the YAG laser is used for the reason described in the description of the second embodiment of the apparatus for manufacturing a microstructure material according to the present invention.
2.3 eV), XeCl (hν ₁ = 4.0 eV), Kr
A high-power short-wavelength laser such as F (hν ₁ = 5.0 eV) or an ArF excimer laser (hν ₁ = 6.4 eV) is used.

Then, the target is irradiated with the laser beam 149.
148 produced from the active particles
Due to the active particles 156 from the source 151, the surface
iO _TwoCoated with layer 157.

Specifically, a microwave or radio frequency (RF) excited plasma source or the like is used as the active particle source 151, and the active particle source 151 irradiates the active particles with oxygen.
By oxidizing the cluster surface, the SiO ₂ layer can be easily coated.

A silane-based gas (Si _n H _{2n + 2} : n = 1,
Generated in the active particle source 151 using (2, 3,...)
Active particles and ground state oxygen-based molecules (eg, O ₂ , N ₂ O
Etc.), an amorphous SiO ₂ film may be deposited on the Si cluster.

Thereafter, the Si clusters coated with the SiO ₂ layer are ionized by the electrons 158 emitted from the electron gun 152, and accelerated by the accelerating unit 153 (acceleration voltage: V _a ).
The traveling direction is bent by a static magnetic field (magnetic flux density: B). When the cluster traveling direction is bent by the static magnetic field, the radius of curvature: r is generally represented by the following equation.

[0165]

(Equation 1)

Here, e is the elementary charge, and m is the mass of the cluster. Therefore, the traveling direction differs depending on the difference in the mass of the clusters, in other words, the difference in the particle size, so that the particle size can be selected.

Incidentally, regarding the particle size distribution of the clusters,
Particle size distribution A before particle size selection, particle size distribution B ₁ after particle size selection,
B ₂ and B ₃ are shown in FIG.

An embodiment of the method for producing a microstructured material according to the present invention will be described with reference to the schematic view of the production apparatus shown in FIG.

In FIG. 9, gas introduction nozzles 159, 160,
A vacuum-evacuable container 163 provided with a laser light introduction window 161 and a substrate 162 is provided.

In such a manufacturing apparatus, first, a Si ₂ H ₆ gas is introduced into the container 163 from the nozzle 159, and an ArF excimer laser (photon energy: hν ₂
= 6.4 eV) The beam is condensed and irradiated, and near the converging point, Si active particles having a higher concentration than other regions are Si ₂ H ₆
Generated by photolysis of gas.

This laser beam irradiation direction is a direction in which the laser beam passes through the active particle generator 164 and is directly irradiated onto the substrate 162.

Then, the high-concentration Si active particle generation section 164
A desired distance is provided between the Si active particles and the substrate 162 so that the Si active particles mutually self-bond to form clusters having the desired particle size before reaching the substrate 162 by diffusion.

In other words, the diameter of the cluster deposited on the substrate 162 is controlled by changing the distance between the active particle generation unit and the substrate (for example, by moving the focal point).

At this time, in order to obtain high-quality clusters, it is important to remove the surrounding impurity gas particles as much as possible in advance. For example, the container 163 is made of an all-metal seal and the Si ₂ H ₆ Before the gas introduction, a treatment such as performing ultra-high vacuum evacuation (for example, 10 ^-9 Torr or less) is performed.

When the direction of laser beam irradiation is directly
Since the direction of irradiation is above the substrate 62, compared with the case where the irradiation direction is the horizontal direction above the substrate 162, the focusing point can be easily moved, and the uniform particle size and An advantage is that clusters having a particle size distribution can be deposited in a uniform distribution on a large-area substrate surface.

Further, after generation of clusters having a desired particle size, that is, in a region closer to the substrate 162, for example, hydrogen gas 165 is introduced from the nozzle 160, and the surface is terminated by hydrogen atoms: terminated. Cluster 166 is obtained.

However, if the gas introduced from the nozzle 160 is an oxygen-based gas, it is possible to obtain a cluster covered with a SiO ₂ layer.

As described above, according to the method for producing a microstructured material of this example, clusters having a controlled particle size and particle size distribution can be provided only by a photochemical gas phase reaction.

Further, if the method for manufacturing a microstructured material according to the first embodiment described above is used in combination, a gap is not generated around the periphery.
It becomes possible to embed the above clusters densely in different materials.

FIG. 10 and FIG. 11 show process diagrams of one embodiment of the method for producing a microstructure material according to the present invention.

First, in the first step shown in FIG. 10A, a plane electrode 168 in which a plurality of metal needles 167 having the same shape and size are arranged in parallel is kept parallel to a plane substrate 169. A high electric field of the same magnitude is applied between the tip of each needle 167 and the surface of the substrate 169.

The approach distance and the magnitude of the electric field strength are
Nine substances are removed by electric field evaporation in a desired amount.

In this case, the smaller the approach distance or the higher the electric field strength, the larger the removal amount.
By changing these physical quantities, the shape and size of the hole after removing the substance can be controlled.

Therefore, by the evaporation due to the applied high electric field, a plurality of holes 170 (hole diameter: having the same shape and size determined by the shape and size of the needle 167, the approaching distance and the electric field strength) are obtained.
Tens nm or less) can be formed on the surface of the substrate 169.
This state is shown in FIG.

The hole 170 is formed by introducing a reactive gas between the electrode 168 and the substrate 169 in advance, and using the reactive gas and the substrate 1 by a tunnel current generated as a result of an applied electric field.
A method of inducing a chemical reaction with the surface 69 and performing gas phase etching may be used.

This is suitable when the substrate 169 is made of a conductive material. For example, when the substrate 169 is made of a semiconductor such as Si, Cl _{2 is used.}
Or the like may be used.

Next, as shown in FIG. 10C, a first substance 171 different from this substance is formed on the surface of the substrate 169.
A second step of depositing is performed.

That is, the raw material particles 172 of the substance 171 are supplied onto the surface of the substrate 169. Specifically, chemical vapor deposition (CVD) and molecular beam epitaxy (M
A method such as a vapor deposition method such as the BE) method may be used.

In general, in thin film deposition using such a technique, it is easier to increase the apparent deposition rate in a groove such as the minute hole 170 than in a flat surface of the substrate surface. That is, it is possible to fill the groove as the deposition proceeds and to flatten the surface of the deposited thin film.

Therefore, as shown in FIG.
At least the first substance 171 is deposited until the surface of the deposited thin film becomes flat.

Next, in a third step shown in FIG. 11B, the first substance deposited in the second step is removed.

Specifically, a vapor phase etching technique such as photochemical vapor phase etching, plasma etching, and reactive ion etching may be used.

By using this etching method, the first substance 171 can be removed while the flatness of the surface of the deposited thin film is maintained. The removal is performed until a flat portion on the surface of the substrate 169 is exposed.

In the fourth step shown in FIG. 11C, the second material having a larger band gap than the first material 171 is used.
Is deposited.

Specifically, a deposition technique similar to that used in the second step may be used. FIG. 11 (c)
Among them, reference numeral 174 denotes a portion composed of the raw material particles of the second substance 173. It is.

As described above, by performing the steps shown in FIGS. 10 and 11, the first substance 1 distributed on the two-dimensional plane is obtained.
The uniform particle size cluster 175 composed of
It is embedded between 69 and the second substance 173.

The substrate 169 material and the second material 173
Are the same, a microstructured material is produced in which the uniform particle size cluster 175 is embedded with a substance 173 having a larger band gap.

By repeating the steps shown in FIGS. 10 and 11, the uniform particle size cluster 1 distributed three-dimensionally is obtained.
A microstructured material is produced, such as embedding 75 with a substance 173 having a larger bandgap.

The shape and size of the cluster 175 are as follows.
It is determined in the first step of forming the hole 170.

Regarding the burying density of the clusters 175, the horizontal density on the surface of the
The density in the vertical direction is determined by the arrangement density of the needles 167 on the substrate 8, and the deposition thickness of the second substance 173 in the fourth step is determined.

As described above, in the method for manufacturing a microstructure material according to the present embodiment, the burying density of the cluster 175 can be controlled independently and flexibly independently of the particle size control, and the burying density can be made anisotropic. It is. The microstructured material having buried density anisotropy contributes to providing a light emitting element having optical anisotropy and a nonlinear optical element.

FIG. 12 is a schematic view of an embodiment of the apparatus for producing a microstructure material according to the present invention. In FIG. 12, a substrate electrode 177 in which a plurality of needles having the same shape and dimensions are arranged in parallel in a container 176 which can be evacuated.
8, a coarse movement mechanism 179 and a fine movement mechanism 180 for parallelly moving the plane electrode 178 in the direction of the substrate holder, and vapor deposition sources 182 and 183 for depositing two kinds of substances on the substrate 181 on the substrate holder. An ion source 184 is provided for supplying reactive ions for etching when one of the substances is etched away.

Further, reference numeral 185 denotes a plane electrode 178 and the substrate 1
This is a power supply for applying a high electric field during the period 81.

The coarse movement mechanism 179 and the fine movement mechanism 18
For 0, for example, a mechanism generally used in a scanning tunneling microscope (STM), that is, a mechanical mechanism and a piezoelectric element may be used.

For example, in the case of manufacturing a microstructured material such as a Si particle having a uniform particle size embedded in SiO ₂ by the manufacturing apparatus of this embodiment, the evaporation sources 182 and 183 are used.
Are filled with Si and SiO ₂ raw materials, respectively, and the gas to be supplied into the ion source 184 is a chlorine-based gas for generating chlorine-based ions since the etching-removed symmetric substance is Si.

Specifically, the steps performed by the manufacturing apparatus of this embodiment are steps in which the respective steps of the method for manufacturing a microstructured material of the above embodiment are repeatedly performed.

Then, the second embodiment of the embodiment in which the substance is deposited is used.
In the third and third steps, the evaporation sources 182 and 183 shown in FIG. 12 are used, respectively.

FIG. 13 is a schematic view of one embodiment of the apparatus for producing a microstructured material according to the present invention.

Referring to FIG. 13, a container 18 capable of evacuating
6, 187 and 188 are connected via gate valves 189 and 190.

Each container has a substrate holder 1.
91, 192 and 193 are provided.

Further, in the container 186, a plane electrode 194 in which a plurality of needles having the same shape and size are arranged in parallel, a coarse movement mechanism 195 and a fine movement mechanism 196 for moving the plane electrode 194 in parallel to the substrate holder. Is provided.

The coarse movement mechanism 195 and the fine movement mechanism 19
For example, a mechanism generally used in a scanning tunneling microscope (STM), that is, a mechanical mechanism and a piezoelectric element may be used for 6, respectively.

Reference numeral 197 denotes a plane electrode 194 and the substrate 1
This is a power supply for applying a high electric field during the period 98.

Next, inside the container 187, there are provided evaporation sources 199 and 200 for two kinds of substances.

Further, the container 188 is provided with an ion source 201 for supplying reactive ions for etching when one of the two kinds of substances is removed by etching.

Also, 202 and 203 are substrates 198
Is a substrate transport mechanism that transports the wafers between the containers and arranges them in each substrate holder.

For example, in the case of manufacturing a microstructured material in which a uniform particle size Si cluster is embedded in SiO ₂ by the manufacturing apparatus of this embodiment, the evaporation sources 199 and 200
Are filled with Si and SiO ₂ raw materials, respectively, and the gas to be supplied into the ion source 201 is a chlorine-based gas that generates chlorine-based ions since the etching-removed symmetric material is Si.

Specifically, the steps performed by the manufacturing apparatus of the present embodiment are steps in which each step of the method for manufacturing a microstructured material of Embodiment 9 is repeatedly performed.

Then, in the second and third steps of the ninth embodiment in which the substance is deposited, the evaporation sources 199 and 200 shown in FIG. 13 are used, respectively.

FIG. 14 is a flow chart showing one embodiment of the method for producing a microstructured material according to the present invention. First, in FIG. 14A, an electric field in one direction parallel to the surface of the substrate 301: E (vector amount: this electric field only needs to have a component in a direction parallel to the substrate surface, and a component in a direction perpendicular to the substrate surface. May be provided, and a one-dimensional polymer raw material molecule is supplied.

At this time, as a supply material molecule, for example, a dichlorosilane derivative: R ¹ R ² SiCl ₂ is used. R ¹ and R ² are organic groups such as an alkyl group such as a methyl group and an ethyl group.

On the other hand, the surface of the substrate 301 on which the R ¹ R ² SiCl ₂ molecules are adsorbed is irradiated with at least a first photon group 302 having an energy: hν ₃ enough to break the Si—Cl bond. The photochemical reaction shown by the formula is caused.

[0223]

(Equation 2)

In other words, a one-dimensional polymer having R ¹ and R ² as side chains: (R ¹ R ² Si) _n [n is 2 or more] grows.

The step shown in FIG. 14A may be performed as a gas phase process in a container that can be evacuated, or may be performed as a liquid phase process in an appropriate solvent (for example, toluene or methanol).

In the case of the former, Cl ₂ molecules generated by the reaction of the formula (2) evaporate as Cl ₂ molecules, and in the latter case, the Cl ₂ molecules are dissolved in the solvent as Cl ions or become Cl ₂ molecules outside the solvent. Evaporate.

When the one-dimensional polymer: (R ¹ R ² Si) _n is produced by a liquid phase process in a solvent, as in the prior art, the following formula is applied by utilizing Na atoms. The chemical reactions shown may be used.

[0228]

(Equation 3)

Since an electric field: E (vector quantity) is applied to the surface of the substrate 301, the one-dimensional polymer (R ¹ R ² Si) _n growing on the surface of the substrate 301 is shown in FIG.
As shown in (a), polarization occurs internally from the stage where n is 2 or 3, and a polarity of +-is generated.
Orient in the direction of electric field application.

A sufficient amount of carriers (electrons or holes) for inducing and promoting the polarization and orientation is a one-dimensional polymer:
If the (R ¹ R ² Si) is not present in the _n is 1 dimensional polymer: (R ¹ R ² Si) _n higher energy than the band gap of: substrate and the second photon group 303 having hv ₄ 30
Irradiate on one surface.

As a result, carriers are generated, and the polarization and orientation are induced and promoted (FIG. 14B).

As described above, FIG. 14A or FIG.
By performing the steps shown in the above, R ¹And R^TwoThe side chain and
One-dimensional polymer having: (R¹R^TwoSi)_nColumn is the base
It is formed so as to be oriented in one direction on the plate 301 (FIG. 13).
(C)).

In other words, R ¹ and R ^{2 in the same} direction
Then, the Si quantum wire 304 terminated with the above is easily manufactured.

In the above embodiment, it is also possible to use the same group of photons having photon energies of hν ₃ and hν ₄ or more. These photon energy is preferably less than the respective binding energies of Si-R ¹ and Si-R ^2.

FIG. 15 is a flow chart showing one embodiment of the method for producing a microstructure material according to the present invention. First, as shown in FIG. 15A, an electric field is applied in one direction parallel to the surface of the substrate 305:
E (vector quantity: field may be present directional component parallel to the substrate surface, some with may also be a vertical component to the substrate surface) with added, surface different materials: coated with R ^X The supplied cluster (for example, Si as a nucleus) 306 is supplied.

Here, R ^X is hydrogen, SiO _2, or a material layer having a larger band gap than a substance serving as a nucleus of the cluster 306.

Such a cluster can be manufactured by the microstructure material manufacturing apparatus of the seventh embodiment or the microstructure material manufacturing method of the eighth embodiment.

In FIG. 15A, the cluster 306 adsorbed on the surface of the substrate 305 is polarized inside by the electric field: E (vector quantity), and has a positive or negative polarity.

Therefore, in the portion where the polarity is generated, the clusters 306 are connected to each other as shown by the portion indicated by “A” in FIG. 15A to form a fine line cluster 307 and the electric field application direction. Orientation.

When a fine line cluster is not formed only by the electric field: E (vector quantity), the cluster nucleus and R
^By irradiating the first photon group 308 having an energy corresponding to the binding energy with ^X : hν ₅ onto the surface of the substrate 305, the formation of the fine-line cluster 307 is induced and promoted.

When the sufficient amount of carriers (electrons or holes) for inducing and promoting the polarization and orientation is not present in the linear clusters 307, the energy h: larger than the band gap of the linear clusters 307 is obtained.
A second group of photons 309 having ν ₆ is irradiated on the surface of the substrate 305.

As a result, carriers are generated, and the polarization and orientation are induced and promoted (FIG. 15B).

The process shown in FIG. 15A or FIG. 15B can be performed as a gas phase process in a container capable of evacuating, or a liquid phase process in an appropriate solvent (for example, toluene or methanol). You may go as.

As described above, FIG. 15A or FIG.
By process implementing the shown, as shown in FIG. 15 (c), the column of the R ^X above was coated with layer cluster nuclear constituents of quantum wires 310, oriented in the upper direction the substrate 305 Formed.

In the above embodiments, it is also possible to use the same group of photons having photon energies of hν ₅ and hν ₆ or more.

FIG. 16 is a flow chart showing one embodiment of the method for producing a microstructure material according to the present invention. In FIG. 16A,
The substrate 311 has a stable crystal plane having a surface, for example,
It is slightly inclined from the (100) plane of single crystal silicon.

Therefore, a large number of terraces 312 and steps 313 (with a width of about several tens nm or less) are present on the substrate surface (FIG. 16A).

Further, hereinafter, the longitudinal direction of the terrace 312
The direction in which step 313 runs is defined.

Further, the electric field in the running direction of step 313: E (vector amount: the electric field only needs to have a component in the substrate surface that matches the running direction in step 313, and may have a component in the direction perpendicular to the substrate surface. No problem).

The substrate 311 to which the electric field: E (vector amount) is applied has silane-based gas molecules (Si _n H _{2n + 2} : n = 1,2,
3, ...) 314 and the energy: hν ₇
Irradiate a photon group 315 having

For example, disilane gas (Si ₂ H ₆ ) is used for the gas molecules 314, and ArF excimer laser light (hν ₇ = 6.4 eV) is used for the photon group 315.

Of course, the gas molecules 314 are placed on the terrace 3 on the substrate.
Although it is adsorbed on the substrate 12 and stays for a certain period of time, it reaches step 313 due to surface diffusion.

Then, on step 313, gas molecules 314 are arranged along the running direction (highly oriented linear arrangement).

The reason for this is that the gas molecules 314 are more stable when present on the steps than on the terraces.

By the electric polarization generated in the gas molecules by the electric field E and the action of the photon group 315, the gas molecules 314 arranged in a highly oriented linear array are combined to grow a one-dimensional electric conductor 316 (FIG. 16). (B)).

Normally, a linear substance grown in this way may be displaced from the step due to thermal motion, especially when the molecular weight is still small at the beginning of growth. Those deviated from the steps are difficult to react with the gas molecules because they exist in the terrace region where the gas molecules do not exist at high density.

However, such an effect is improved in the present embodiment by the action of the electric field: E, and the linear substance polarized by the electric field: E is stabilized in a form extended in the direction of the electric field.

That is, the direction of the electric field is the direction in which the step 313 runs, and the linear substance that is going to deviate from the step 313 due to thermal motion is kept in place.

As described above, according to this embodiment, the terrace and the step are provided on the substrate, and the electric field having the in-plane component in the direction in which the step runs provides the one-dimensional electric conductor with a high reaction probability. Can be manufactured (FIG. 16C).

The one-dimensional electric conductor 316 made of a silicon material manufactured in this embodiment is a quantum wire having a width of several nm or less, and is used as a light emitting element material.

That is, as shown in FIG. 16C, a stable crystal plane, for example, (10
The element which is composed of a surface of the substrate 311 which is slightly inclined from the 0) plane and has terraces and steps at a high density, and a one-dimensional electric conductor extending along the step 313 containing silicon atoms in its composition is described in the present invention. This is also one embodiment of the light emitting device of the present invention.

FIG. 17 is a schematic view showing one embodiment of the light emitting device of the present invention. The light-emitting device of this embodiment shown in FIG. 17A includes a light-emitting source 401 and an excitation source 402.

The light emitting source 401 is basically composed of a substrate 403
And a porous silicon material formed on the microstructured material or the indirect transition type semiconductor material manufactured by any of the manufacturing method or the manufacturing apparatus of the present invention according to any one of Embodiments 1 to 14. The light emitting layer 404 is made of a material.

In the substrate 403, a groove 405 having a depth at which the light emitting layer 404 is exposed or close thereto is formed.
The electron beam 406 is directly or efficiently irradiated and absorbed by the light emitting layer 404.

The light-emitting layer 404 is electrically grounded to prevent charge-up by the irradiation electron beam as much as possible.

On the other hand, the excitation source 402 is a so-called cold cathode, and basically comprises a substrate 407 and an emitter 408, an insulating layer 409 and a gate 410 formed thereon. An electric field (electric field intensity: for example, 100 V /
μm), and the electron beam 40 directed toward the light emitting layer 404 is applied.
Release 6.

For the substrates 403 and 407, for example, single crystal silicon is used. Then, the light emitting source 401 and the excitation source 402 may be manufactured independently and then bonded together.

The light emitting device of this embodiment has a thickness of 1 m.
m or less, the size in the direction in the substrate surface: several μm × several μm or so can be easily downsized.

Therefore, the light emitting source 401 and the excitation source 402
Are manufactured monolithically on the same substrate, respectively, and then the substrates 411 and 412 are attached to each other, so that a large number of light emitting portions 413 are integrated at a high density, or a large area thin film type light emitting device is manufactured. Element (FIG. 17)
It is also possible to manufacture (b)).

This has a great effect on the application of, for example, a thin film display or a parallel optical information processing system.

As described above, a fine structure material in which a cluster, a fine linear cluster, a one-dimensional electric conductor, or a one-dimensional polymer is embedded in a material having a larger band gap, or a porous material derived from an indirect transition type semiconductor material is used. It is possible to provide a light emitting element that utilizes and does not rely on current injection as described in the seventh problem with the conventional technique.

[0272]

As described above, according to the present invention, a cluster having a uniform particle size and particle size distribution, and a dense and high-density embedding or coating with a different substance, and a one-dimensional height having a high orientation can be obtained. By providing a process and means for producing molecules, one-dimensional electric conductors or fine linear clusters, it is particularly suitable for the production of optoelectronic devices such as light emitting devices with high monochromaticity and high luminous efficiency and nonlinear optical devices with high nonlinearity. It is possible to realize an excellent method and apparatus for producing a microstructured material having a great effect.

Furthermore, the present invention can provide a light emitting device or the like which does not rely on so-called current injection while utilizing the above-mentioned microstructure material or a porous material derived from an indirect transition type semiconductor substance. .

[Brief description of the drawings]

FIG. 1 is a schematic view of one embodiment of a method for producing a microstructured material according to the present invention.

FIG. 2 is a schematic view of one embodiment of the apparatus for producing a microstructured material according to the present invention.

FIG. 3 is a process diagram of one embodiment of the method for producing a microstructured material according to the present invention.

FIG. 4 is a schematic view of a first embodiment of the apparatus for producing a microstructured material according to the present invention.

FIG. 5 is a schematic view of a second embodiment of the apparatus for producing a microstructured material according to the present invention.

FIG. 6 (a) is a schematic view of a first embodiment of the apparatus for producing a microstructured material according to the present invention. (B) Substrates A, B and C after clusters are deposited by the embodiment of FIG. 6 (a). And D

FIG. 7A is a schematic view of a second embodiment of the apparatus for producing a microstructured material according to the fifth aspect of the present invention. FIG. 7B is a cross-sectional view of a substrate after clusters are deposited according to the embodiment of FIG. Schematic

FIG. 8 is a schematic view of one embodiment of the apparatus for producing a microstructured material according to the present invention.

FIG. 9 is a schematic view of one manufacturing apparatus for embodying one embodiment of the method for manufacturing a microstructure material of the present invention.

FIG. 10 is a process chart of one embodiment of the method for producing a microstructured material according to the present invention.

FIG. 11 is a process diagram of one embodiment of a method for producing a microstructured material according to the present invention.

FIG. 12 is a schematic view of one embodiment of the apparatus for producing a microstructured material according to the present invention.

FIG. 13 is a schematic view of one embodiment of an apparatus for producing a microstructured material according to the present invention.

FIG. 14 is a process chart of the first embodiment of the method for producing a microstructured material according to the present invention.

FIG. 15 is a process chart of a second embodiment of the method for producing a microstructured material according to the present invention.

FIG. 16 is a process diagram of one embodiment of a method for producing a microstructure material of the present invention, and a schematic diagram of one embodiment of a one-dimensional electric conductor constituting a light emitting device of the present invention.

FIG. 17A shows a light emitting device of the present invention (single light emitting device).
(B) Schematic diagram of one embodiment of the light emitting device of the present invention (when a large number of light emitting portions are two-dimensionally integrated at high density)

FIG. 18 is a schematic view showing an example of a conventional cluster (ultrafine particle) film manufacturing apparatus.

FIG. 19 is a schematic cross-sectional view of a cluster (ultrafine particle) film manufactured by the manufacturing apparatus of FIG. 18;

FIG. 20: Conventional one-dimensional linear polysilane: (R ¹ R ²
Schematic diagram of chemical synthesis of Si) _n [R ¹ and R ² are organic groups such as alkyl groups such as methyl group and ethyl group].

[Explanation of symbols]

Reference Signs List 101 Cluster 103 Raw material particles of substance 102 (atomic / molecular state) 104 Substrate 105 Laser light introduction window 106 Laser light introduction window 107 Gas introduction nozzle 108 Gas introduction nozzle 109 Vacuum exhaustible vessel 110 Solid target 111 Substrate holder 114 Substrate 115 Cluster Group 116 Cluster group after particle size selection 117 Vacuum evacuable container 118 Solid target 119 Substrate holder 121 Rotating disk type chopper 124 Laser beam introduction window 125 Cluster group 126 Cluster group after particle size selection 127 Vacuum evacuable container 128 Solid target 129 Substrate holder 130 Cluster group 133 Pulse electric field or magnetic field application unit for mass separation of clusters 134 Laser light introduction window 136 Cluster group after particle size selection 137 Vacuum Evacuable container 138 Solid target 139 Substrate holder 140 Laser light introduction window 141 Cluster group 142 Vacuum evacuable container 143 Solid target 144 Substrate holder 145 Laser light introduction window 146 Cluster group 147 Vacuum evacuable container 148 Solid target 150 Laser light Introducing window 154 Magnetic field applying unit for separating the mass of cluster 155 Si cluster 156 Active particles from active particle source 151 157 SiO ₂ layer 159 Gas introducing nozzle 160 Gas introducing nozzle 161 Laser light introducing window 162 Substrate 163 Container that can be evacuated 164 High-concentration Si active particle generation unit 165 Hydrogen gas 166 Cluster whose surface is terminated by hydrogen atoms 167 Plurality of metal needles having the same shape and size 169 Substrate 170 Micropore (pore diameter: 172 Raw material particles of the first substance 171 174 Raw material particles of the second substance 173 175 Uniform particle size cluster 176 Vacuum evacuable container 177 Substrate holder 178 A plurality of needles having the same shape and size are arranged in parallel. Planar electrode 181 Substrate 182 Deposition source 183 Deposition source 184 Ion source 186 Vacuum evacuable container 187 Vacuum evacuable container 188 Vacuum evacuable container 191 Substrate holder 192 Substrate holder 193 Substrate holder 194 A plurality of needles having the same shape and size 198 substrate 199 evaporation source 200 evaporation source 201 ion source 202 substrate transport mechanism 203 substrate transport mechanism 301 substrate 304 Si quantum wires terminated by R ¹ and R ² 305 substrate 306 coated with R ^X a cluster ( The nuclei coated with e.g. Si) 307 thin wires cluster 310 R ^X layer, a quantum wire 311 substrate 312 Terrace 313 step 314 silane-based gas molecules of the cluster 306 nuclear constituents (e.g. _{Si) (Si n H 2n +} 2: n = 1,2,3, ...
・) 316 one-dimensional electric conductor 401 light emitting source 402 excitation source 403 substrate 404 light emitting layer 406 electron beam 407 substrate 411 substrate 412 substrate 413 light emitting unit 507 substrate

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Takeshi Kenta 3-10-1 Higashi-Mita, Tama-ku, Kawasaki-shi, Kanagawa Matsushita Giken Co., Ltd. (56) References JP-A-4-346282 (JP, A) JP-A-3-76110 (JP, A) JP-A-60-119710 (JP, A) JP-A-4-41666 (JP, A) JP-A-3-18013 (JP, A) JP-A-3-245523 ( JP, A) JP-A-3-16992 (JP, A) JP-A-5-206018 (JP, A) JP-A-4-155819 (JP, A) JP-A-6-244113 (JP, A) Hei 5-56954 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21 / 203,21 / 205 H01L 21 / 363,21 / 365 C23C 14/00-14/58 C23C 16/00-16/56

Claims (15)

(57) [Claims] 1. A first step of generating clusters made of a metal or a semiconductor, and raw material particles in a state of atoms or molecules of a semiconductor or an insulator made of a substance having a larger band gap than that of the clusters in the first step. And a second step, wherein both steps are performed simultaneously to deposit the raw material particles in the atomic or molecular state as a uniform and continuous thin film, and to form the cluster in the thin film,
A method for producing a microstructured material that is densely embedded without creating a gap in the periphery. 2. A first step of generating a metal or semiconductor cluster by laser ablation, and a semiconductor or insulator formed of a substance having a band gap larger than that of the first step by photochemical vapor deposition. A second step of generating raw material particles in an atomic or molecular state, wherein both steps are performed simultaneously or alternately repeatedly to deposit the raw material particles in an atomic or molecular state as a uniform and continuous thin film, Without forming the cluster in the surroundings,
A method of manufacturing a finely structured microstructure material. 3. The method for manufacturing a microstructured material according to claim 1, wherein both the first and second steps use an ultraviolet laser beam. 4. A solid target serving as a cluster material, means for irradiating a laser beam to the solid target, means for introducing a gas to be photodecomposed, and means for decomposing the gas into atoms in a container capable of being evacuated. A means for introducing light into a molecular state, a cluster formed from the target, and a product which is formed into an atomic / molecular state by photolysis and deposited as a uniform and continuous thin film on a substrate. An apparatus for manufacturing a microstructured material having an arranged substrate holder. 5. A solid target serving as a cluster material, a means for irradiating a pulsed laser beam to the solid target, and a means for chopping clusters generated in synchronization with the pulse of the laser light in a container capable of being evacuated. An apparatus for producing a microstructured material, comprising: means for chopping, means for ionizing generated clusters, and means for applying an electric field or magnetic field pulse synchronized with a laser pulse to the ionized clusters to perform mass separation. A microstructured material manufacturing apparatus. 6. A solid target serving as a cluster material, means for irradiating a pulsed laser beam to the solid target, and a substrate on which clusters are deposited are rotated or rotated in synchronization with a pulse of the laser beam in a container which can be evacuated. Means for reciprocatingly depositing a group of clusters having a specific particle size at a specific position on a substrate. 7. A step of irradiating a gas molecule with a converging laser beam to generate high-concentration cluster material active particles at the converging point, and directly irradiating the laser beam away from the converging point. Depositing clusters on a substrate disposed at a position, the method comprising the steps of: changing the condensing point and the distance between the substrates to change the particle size of the clusters deposited on the substrate. A method for producing a microstructured material, characterized by controlling. 8. A method for producing a microstructured material for supplying a one-dimensional polymer raw material molecule or a cluster whose surface is coated with a different substance onto a surface of a substrate while applying an electric field in one direction parallel to the surface of the substrate. . 9. When supplying a one-dimensional polymer raw material molecule or cluster, a first material having energy to cut a bond between the raw material molecule on the side forming the one-dimensional polymer main chain or a bond between the cluster and the coated heterogeneous substance is provided. 9. The method for producing a microstructured material according to claim 8, wherein the photons are irradiated onto the substrate surface. 10. When supplying a one-dimensional polymer raw material molecule or cluster, a second one having an energy larger than the band gap of the one-dimensional polymer or cluster deposited on the surface of the substrate or a fine-line cluster bonded to the one-dimensional polymer or cluster.
The method for producing a microstructured material according to claim 8, wherein the photon group is irradiated onto the substrate surface. 11. When supplying a one-dimensional polymer material molecule or cluster, the energy for breaking the bond of the material molecule on the side forming the one-dimensional polymer main chain or the bond between the cluster and the coated heterogeneous substance, 1 deposited on the surface
9. The method for producing a microstructured material according to claim 8, wherein a group of photons having energy greater than the larger value of the band gap of the one-dimensional polymer, cluster, or a fine linear cluster to which the cluster is bonded is irradiated onto the surface of the substrate. Method. 12. An electric field is applied in the longitudinal direction of a terrace provided on the surface of a substrate, that is, in the direction in which a step runs, and one-dimensional electric conduction including a material particle material such as atoms, molecules or clusters supplied from a gas phase in its composition. A method for producing a microstructured material in which a body is grown along the running direction of the step. 13. The method for producing a microstructured material according to claim 12, wherein a group of photons having energy such as contributing to the bonding and growth of the raw material particles on the surface of the substrate is irradiated on the surface of the substrate. 14. The method for producing a microstructured material according to claim 12, wherein terraces and steps are provided by slightly inclining the surface of the substrate from a stable crystal plane. 15. The method for producing a microstructured material according to claim 12, wherein the main component of the raw material particle substance is silicon.