JP2000150384A - Aggregate of semiconductor fine particles and manufacture thereof applied by same method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture an aggregate of semiconductor fine particles in a simple process which is capable of increasing the density and improving the grain size and shape accuracy of the semiconductor fine particles. SOLUTION: A amorphous crystalline semiconductor thin film 2 is formed on a substrate 1 whose interfacial energy with respect to the film 2 is increasing under a high temperature. In an atmosphere in which the surface of the film 2 can be kept clean, by heating the substrate 1 to a temperature equal to or higher than that at which the film 2 is crystallized, a plurality of semiconductor fine particles 3 are produced while crystallizing the amorphous crystalline semiconductor. An aggregate of the particles 3 to be obtained has an average grain size of 100 nm or lower, and the particles 3 are present on the substrate 1 at a high density of 50 particles/mm2 or higher.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a semiconductor fine particle aggregate used as quantum dots or luminescent materials, and a semiconductor fine particle aggregate to which the method is applied.

[0002]

2. Description of the Related Art Quantum-size devices using nano-order semiconductor fine particles are expected as candidates for future LSI technology. For example, quantum size effects such as quantum wire devices and quantum box devices using thin wires or box structures whose cross-sectional dimensions are comparable to the quantum mechanical wavelength of electrons, resonance tunnel effect devices and resonance tunnel devices using quantum wells, etc. Attempts have been made to realize a new semiconductor device (quantum-size device) by utilizing the tunnel effect and tunnel effect. Further, the use of nano-order semiconductor fine particles as a light-emitting material has been studied.

In order to more effectively use such a quantum size device or a light emitting material (light emitting element), the size of a unit element or the size of a light emitting portion is, for example, 10 to 100 nm, and moreover, 10 to 100 nm.
It is necessary to make it ultra-fine, such as below nm. By the way, as a conventional method of manufacturing semiconductor fine particles, a method of directly forming semiconductor fine particles on a substrate using a vapor phase growth method such as a CVD method is applied.

However, in the method of directly forming semiconductor fine particles from a gas phase, since the semiconductor fine particles are formed by using long-range diffusion of semiconductor atoms and semiconductor molecules deposited on the substrate, the number of semiconductor fine particles on the substrate is reduced. (Number density) cannot be sufficiently increased. Also, the particle size of the obtained semiconductor fine particles varies greatly,
There is a problem in that the precision of forming a quantum size device or a light emitting material using semiconductor fine particles cannot be sufficiently increased.

[0005]

As described above, application of semiconductor fine particles to quantum size devices, light emitting materials, and the like has been studied. In addition, there is a problem that the particle size of the obtained semiconductor fine particles is large.

[0006] In view of the above, there is a demand for the emergence of a technology that enables the formation of semiconductor fine particles (semiconductor dots) required for quantum size devices and light emitting materials with high precision and high density. In addition, by applying such a technique, a high-density semiconductor fine particle aggregate having excellent shape reproducibility such as a particle size and the like is required.

SUMMARY OF THE INVENTION The present invention has been made to address such a problem, and it has been proposed that semiconductor fine particles can be formed with high precision and high density.
It is intended to provide a method of manufacturing a semiconductor fine particle aggregate that has been able to be manufactured in a simple process,
Furthermore, by applying such a manufacturing method, it is an object to provide a high-density semiconductor fine particle aggregate having excellent shape reproducibility such as a particle diameter.

[0008]

According to a first aspect of the present invention, there is provided a method of manufacturing a semiconductor fine particle aggregate, comprising: converting an amorphous semiconductor thin film into an interface with the semiconductor thin film at a high temperature; Forming the amorphous thin film on the substrate at a temperature higher than the temperature at which the amorphous semiconductor thin film is crystallized in an atmosphere capable of keeping the surface of the semiconductor thin film clean; Generating a plurality of semiconductor fine particles while crystallizing a semiconductor in a quality state.

In the method for producing a semiconductor fine-particle aggregate according to the present invention, the semiconductor thin film may be made of S
Various semiconductors such as a semiconductor containing at least one selected from i, Ge, Se, Te and SiC, or a compound semiconductor can be used. As a substrate whose interface energy increases at a high temperature with an amorphous thin film of such a semiconductor, for example, an amorphous compound substrate or the like is used.

In the method for producing a semiconductor fine particle aggregate according to the present invention, the thickness of the semiconductor thin film in an amorphous state is preferably 30 nm or less. Furthermore, as described in claim 4, the heating of the amorphous semiconductor thin film is preferably performed in a vacuum atmosphere of 10 ^-5 Torr or less. The step of forming semiconductor fine particles is performed, for example, by subjecting an amorphous semiconductor thin film to a heat treatment at a temperature equal to or higher than its crystallization temperature in a vacuum atmosphere.

The method for producing a semiconductor fine particle aggregate according to the present invention is not limited to forming a single semiconductor fine particle on a substrate.
By laminating two or more types of amorphous semiconductor thin films on a substrate, it is possible to produce a mixture of two or more different types of semiconductor fine particles.

In the method for producing a semiconductor fine particle aggregate according to the present invention, an amorphous semiconductor thin film is formed on a substrate whose interface energy with a semiconductor thin film increases at a high temperature;
The amorphous semiconductor thin film is heated to a temperature higher than its crystallization temperature. In the course of this heat treatment, crystallization occurs from the surface side of the amorphous semiconductor thin film, and the interface energy between the substrate and the amorphous semiconductor thin film increases. Many semiconductor fine particles are formed.

At this time, by maintaining the atmosphere from the formation of the semiconductor thin film to the heat treatment so that the surface of the semiconductor thin film can be kept clean, crystallization from the surface side of the amorphous semiconductor thin film occurs uniformly. Further, since the semiconductor fine particles are formed by short-range diffusion of atoms based on the phase transformation (from an amorphous state to a crystalline state) in a solid phase, the semiconductor fine particles can be formed at a high density. In addition, since the particle size of the semiconductor fine particles depends on the initial thickness of the amorphous semiconductor thin film and the like, variation in the shape of the semiconductor fine particles can be suppressed, and a semiconductor fine particle aggregate having a uniform particle size can be obtained. .

As described above, in the method for producing a semiconductor fine particle aggregate of the present invention, not only is the shape reproducibility of the particle size of the semiconductor fine particles excellent, but also the particle size and number density of the initial amorphous semiconductor thin film are reduced. Because it can be controlled by the film thickness,
An aggregate of semiconductor fine particles according to the purpose can be obtained with high reproducibility by simple steps of forming a semiconductor thin film in an amorphous state and heating at a relatively low temperature.

The semiconductor fine particle aggregate of the present invention is obtained by applying the method of manufacturing the semiconductor fine particle aggregate of the present invention as described above, and is formed on a substrate as described in claim 8. A semiconductor fine particle aggregate having a plurality of semiconductor fine particles, wherein the semiconductor fine particles have an average particle diameter of 100 nm or less, and have 50 particles / particle on the substrate.
It is characterized by being present at a number density of at least mm ² .

[0016]

Embodiments of the present invention will be described below.

FIG. 1 is a cross-sectional view showing one embodiment of a manufacturing process of a semiconductor fine particle aggregate to which the present invention is applied. First,
As shown in FIG. 1A, an amorphous semiconductor thin film 2 is formed on a substrate 1. Various semiconductors can be used for the amorphous semiconductor thin film 2, for example, Si, Ge,
Elemental semiconductors such as Se and Te, semiconductors such as SiC, 3-5 group semiconductors such as GaAs and InP, ZnT
Various semiconductors such as a compound semiconductor such as a group 2-6 semiconductor such as e and CdSe can be used.

The method for forming the semiconductor thin film 2 in an amorphous state is not particularly limited. For example, EB-PVD, M
Various thin film forming methods such as a BE method can be applied. However, from the formation of the semiconductor thin film 2 to the heating step described later, a method capable of keeping the surface clean is used, and specifically, a method of forming a film in a vacuum atmosphere is preferably applied. Here, the clean state of the thin film surface refers to a state in which an oxide film, dirt, or the like does not exist.

The thickness of the amorphous semiconductor thin film 2 is
Preferably, the thickness is 30 nm or less. The thickness of the semiconductor thin film 2 is
If it exceeds 30 nm, there is a risk that the film will be crystallized in a film state when a heating step described later is performed, and semiconductor fine particles cannot be formed with good reproducibility. In particular, the thickness of the semiconductor thin film 2 is desirably 10 nm or less in order to enhance the particle size accuracy of the semiconductor fine particles. The lower limit of the thickness of the amorphous semiconductor thin film 2 is not particularly limited as long as a uniform film can be formed, and may be, for example, about several atomic layers.

The film thickness of the semiconductor thin film 2 in the amorphous state greatly affects the particle diameter and the number density of the generated semiconductor fine particles, as described later in detail. That is, as the thickness of the semiconductor thin film 2 is smaller, the particle diameter of the semiconductor fine particles can be reduced and the number density thereof can be increased. As described above, by adjusting the thickness of the semiconductor thin film 2 in the amorphous state, it is possible to control the particle diameter and the number density of the semiconductor fine particles. Since the specific particle size and the specific density vary depending on the type of semiconductor constituting the semiconductor thin film 2, the thickness of the semiconductor thin film 2 is controlled according to the type of semiconductor.

Semiconductor thin film 2 in an amorphous state as described above
Is used, the surface energy of which increases with the semiconductor thin film 2 at a high temperature. That is,
Assuming that the interfacial energy between the amorphous semiconductor thin film 2 and the substrate 1 at room temperature is e ₁ and the interfacial energy when heated is e ₂ , the present invention satisfies e ₁ <e ₂ . Substrate material to be used.

The specific constituent material of the substrate 1 is a-S
Amorphous compounds such as iO ₂ (so-called quartz glass) and a-GeO ₂ can be used, and other general glass substrates can also be used. Further, for example, a layer whose surface energy increases at a high temperature between the semiconductor thin film 2 and the semiconductor thin film 2 is formed on the surface on which the semiconductor thin film 2 is formed, such as a substrate provided with an amorphous layer such as SiO ₂ or Al ₂ O ₃ on the semiconductor substrate. A substrate as provided can also be used.

Next, the amorphous semiconductor thin film 2 formed on the substrate 1 is subjected to a heat treatment in an atmosphere capable of keeping its surface clean. The heating temperature is equal to or higher than the temperature at which the amorphous semiconductor thin film 2 is crystallized, and the temperature at which the semiconductor thin film 2 does not melt or evaporate. That is, the heating step in the present invention utilizes the phase transformation of the amorphous semiconductor thin film 2 in the solid state to remove the semiconductor fine particles 3 from the semiconductor thin film 2.
Generate Here, the heating step in the present invention is not limited to so-called heat treatment using a heating furnace, a heater, or the like, but may be local heating such as laser annealing.

The heating temperature is appropriately set according to the type of the semiconductor thin film 2. For example, when Si is used for the amorphous semiconductor thin film 2, a-Si (amorphous S
Since i) is crystallized from around 550 ° C., it is preferable to heat to a temperature higher than that and a temperature lower than a temperature at which a-Si becomes a molten state. When Ge is used for the semiconductor thin film 2 in an amorphous state, a-Ge is crystallized from about 350 ° C., so that it is heated to a temperature higher than that and lower than a temperature at which a-Ge becomes a molten state. Is preferred. The heating time is appropriately set so that the amorphous semiconductor thin film 2 is almost completely crystallized.

The heating atmosphere is such that the surface of the amorphous semiconductor thin film 2 can be kept clean. Specifically, the heating step is performed while maintaining a state in which an oxide film, dirt, or the like does not exist on the surface of the semiconductor thin film 2. If an oxide film or dirt is present on the surface of the semiconductor thin film 2, they inhibit crystallization from the surface side of the semiconductor thin film 2 and agglomeration accompanying the crystallization, so that the semiconductor fine particles 3 can be formed accurately. become unable. Such a clean surface state is maintained after the formation of the semiconductor thin film 2 until the heating step.

A specific heating atmosphere is a vacuum atmosphere in which no oxide film or dirt is formed on the surface of the semiconductor thin film 2 as described above, and a vacuum atmosphere in which residual atoms and molecules have no adverse effect, for example, a vacuum atmosphere of 10 ^-5 Torr or less. Preferably, the atmosphere is used. In some cases, an inert atmosphere such as argon or helium can be used.

When the semiconductor thin film 2 in an amorphous state is heated in a clean atmosphere as described above, crystallization starts from the surface side of the semiconductor thin film 2 as shown in FIG. FIG.
In (b), 2 'indicates a crystal nucleus. On this occasion,
Since the interfacial energy between the semiconductor thin film 2 in the amorphous state and the substrate 1 has increased since the time when the semiconductor thin film 2 was formed, the crystallized semiconductor aggregated so as to have a small surface area, and FIG. As shown in c), the semiconductor fine particles 3 'begin to grow.

Since the crystallization of the semiconductor proceeds while taking in the surrounding amorphous semiconductor, as shown in FIG. 1D, a grain corresponding to the thickness of the semiconductor thin film 2 in the initial amorphous state is formed. A large number of semiconductor fine particles 3 having a diameter are generated. That is,
As the thickness of the semiconductor thin film 2 is smaller, the semiconductor fine particles 3 having a smaller particle diameter are obtained, and the number of the generated semiconductor fine particles 3 is larger. In other words, when the thickness of the semiconductor thin film 2 is large, the semiconductor fine particles 3 grow correspondingly, and the number of the generated semiconductor fine particles 3 decreases.

At this time, if the semiconductor thin film 2 in the amorphous state is too thick, the crystallized semiconductor cannot be satisfactorily aggregated, and will be crystallized in the thin film state.
In addition, if an oxide film or dirt is present on the surface of the semiconductor thin film 2 in an amorphous state, they inhibit crystallization from the surface side of the semiconductor thin film 2 or agglomeration accompanying the crystallization. 3 is hindered from forming and growing, and the uniformity of the particle diameter and the number density of the semiconductor fine particles 3 are reduced.

As described above, the semiconductor fine particles 3 are generated from the amorphous semiconductor thin film 2 by a phase transformation from an amorphous state in a solid phase to a crystalline state. Such a phase transformation in the solid phase is based on the short-range diffusion of atoms, and the thickness of the semiconductor thin film 2 in the amorphous state at the beginning is sufficiently reduced, and the surface side of the semiconductor thin film 2 Since the crystallization from the particles occurs uniformly, the semiconductor fine particles 3 having a small particle diameter can be generated at a high density (number density). Furthermore, since the semiconductor fine particles 3 have a particle size according to the initial thickness of the semiconductor thin film 2 and the like, the variation can be reduced, and a large number of semiconductor fine particles 3 having a uniform particle size, that is, an aggregate of the semiconductor fine particles 3 Body can be formed.

According to the manufacturing method of the semiconductor fine particle aggregate of the present invention, the high-density and high-density particles can be formed only by the simple steps of forming the amorphous semiconductor thin film 2 and heating at a relatively low temperature. An aggregate of nano-sized semiconductor fine particles 3 having a uniform diameter can be obtained with good reproducibility. Further, since the particle diameter and the number density of each semiconductor fine particle 3 can be controlled by the thickness of the semiconductor thin film 2 in the initial amorphous state, not only the shape reproducibility such as the particle diameter is excellent, but also
An aggregate of the semiconductor fine particles 3 according to the purpose can be obtained with good reproducibility.

Although the particle diameter and the number density of the obtained semiconductor fine particles 3 vary depending on the initial thickness of the semiconductor thin film 2 and the like, the semiconductor fine particles 3 are prepared from the amorphous semiconductor thin film 2 under the above-described conditions. Average particle size is 100
An aggregate of semiconductor fine particles 3 having a diameter of not more than nm and a number density of not less than 50 particles / mm ² can be obtained with good reproducibility. Further, the variation in the particle size of the individual semiconductor fine particles 3 is small, and for example, the variation in the individual average particle size can be within ± 20%.

Although the particle diameter and the number density of the semiconductor fine particles 3 vary depending on the type of semiconductor, when Si is used, the average thickness of the semiconductor (Si) thin film 2 is particularly reduced to, for example, 3 nm or less. Ultrafine semiconductor (Si) fine particles 3 having a particle diameter of 40 nm or less and a number density of 300 particles / mm ² or more can be formed at a high density. When Ge is used, semiconductor particles 3 having a smaller particle size and a higher number density than Si can be obtained. Furthermore, the smaller the average particle diameter of the generated semiconductor fine particles 3 is, the more individual semiconductor fine particles 3
Since the variation in the particle size of the particles is small, an aggregate of ultrafine semiconductor particles 3 having a uniform particle size can be obtained.

The semiconductor fine particle aggregate of the present invention has the average particle diameter and the number density as described above, and furthermore, the individual particle diameter has a small variation with respect to the average particle diameter, that is, the semiconductor fine particles 3 having a uniform particle diameter. Are formed on the substrate 1 in a large number, and can be obtained with good reproducibility for the first time by applying the manufacturing method of the semiconductor fine particle aggregate of the present invention.

The semiconductor fine particle aggregate of the present invention can effectively reduce the nano-order particle size and its small variation when the semiconductor fine particles 3 are applied to, for example, a quantum size device or a light emitting material (light emitting element). It works.
In other words, quantum size devices and luminescent materials need to be miniaturized so that the unit element size and the luminescent material size are, for example, 100 nm or less. Desired.
According to the semiconductor fine particle aggregate of the present invention, such a quantum size device and a light emitting material can be obtained with good reproducibility.

According to the method for producing an aggregate of semiconductor fine particles of the present invention, not only an aggregate of single semiconductor fine particles but
It is also possible to produce a semiconductor fine particle aggregate in which two or more types of semiconductor fine particles are mixed. When producing an aggregate of semiconductor particles in which two or more kinds of semiconductor particles are mixed, as shown in FIG. 2A, an amorphous thin film 2A made of a first semiconductor and a second thin film different from the amorphous thin film 2A are formed. An amorphous thin film 2B made of two semiconductors is laminated on the substrate 1.

A heat treatment similar to that of the above-described embodiment is performed on the laminated film 4 of the first amorphous thin film 2A and the second amorphous thin film 2B. When semiconductor particles are generated by heating the laminated film 4, semiconductor particles are generated from each of the amorphous thin films 2A and 2B. That is, FIG.
As shown in FIG. 3, the fine particles 3A made of the first semiconductor and the second
The semiconductor fine particle aggregate in which the semiconductor fine particles 3B are mixed on the substrate 1 is obtained. At this time, it is preferable to select semiconductors used as the first amorphous thin film 2A and the second amorphous thin film 2B that do not form a solid solution with each other.

The average particle diameter, number density, and variation in individual particle diameters of the semiconductor fine particles 3A and 3B are the same as in the case of forming the single semiconductor fine particle 3, and the initial amorphous thin films 2A and 2B Can be controlled by the thickness of the film. That is, it is possible to obtain an aggregate of the semiconductor fine particles 3A and the semiconductor fine particles 3B each having an average particle diameter of 100 nm or less and a total number density of 50 or more / mm ² or more.

The aggregated semiconductor fine particles of the present invention include those in which two or more kinds of semiconductor fine particles as described above are mixed. The mixed state of different kinds of semiconductor fine particles is not limited to the two kinds of semiconductor fine particles 3A and 3B as shown in FIG. 2, and depending on the properties of the semiconductor used, three or more kinds of semiconductor fine particles may be mixed. Is also possible.

[0040]

Next, specific examples of the present invention and evaluation results thereof will be described.

Example 1 First, an amorphous SiO ₂ substrate (quartz glass substrate) was prepared, and EB was placed on this amorphous SiO ₂ substrate in a vacuum atmosphere.
-An amorphous Si film having a thickness of about 1 nm was formed by the PVD method. While maintaining the surface cleanliness of the amorphous Si film, 1 × 10 ⁻⁸
The amorphous Si film was subjected to a crystallization heat treatment at a temperature of 600 ° C. for 30 minutes in an atmosphere of Torr.

In the course of the crystallization heat treatment, crystallization occurs from the surface side of the amorphous Si film and the interface energy between the amorphous SiO ₂ substrate and the amorphous Si film increases.
Aggregation of crystallized Si occurs, and a large number of Si fine particles are generated on the amorphous SiO ₂ substrate. Since Si fine particles are formed by short-range diffusion of atoms based on phase transformation in a solid phase, Si fine particles can be formed at a high density. In addition, the variation in shape of the Si fine particles is small, and the particle size is uniform.

FIG. 3 schematically shows a planar TEM image of Si fine particles formed from the above-mentioned amorphous Si film having a thickness of about 1 nm. As is apparent from FIG. 3, the amorphous SiO ₂ substrate 11
A large number of Si fine particles 12 are generated on the
The i microparticles 12 had a particle size of about 10 to 30 nm. The average particle size of these Si fine particles 12 was about 16 nm, and the variation in the particle size with respect to the average particle size of each Si fine particle 12 was extremely small. In addition, the number density was about 1150 particles / mm ² , and it was confirmed that ultrafine Si fine particles 12 having a uniform particle size were generated at a high density.

Further, the above-mentioned formation of the Si fine particles was carried out by changing the film thickness of the initial amorphous Si film. FIG. 4 shows a plane T of Si fine particles generated from an amorphous Si film having a thickness of about 10 nm.
An EM image is schematically shown. As is clear from FIG. 4, it can be seen that many Si fine particles 13 are generated on the amorphous SiO ₂ substrate 11. These Si fine particles 13 are Si fine particles 12 formed from an amorphous Si film having a thickness of about 1 nm.
In comparison with, the particle size is large and the formation density (number density) is small. The average particle size of the Si fine particles 13 was about 60 nm, and the number density was about 200 particles / mm ² . The variation in the particle diameter was more uniform in the Si fine particles 12 than in the Si fine particles 13.

FIG. 5 shows the thickness of the amorphous Si film and the S film formed.
It is a figure which shows the relationship with the average particle diameter and number density of i microparticles | fine-particles. As is clear from FIGS. 3, 4 and 5, by reducing the thickness of the amorphous Si film, it is possible to form finer Si fine particles at a high density.
In other words, it is understood that the particle diameter and the number density of the Si fine particles can be controlled by the thickness of the amorphous Si film.

Example 2 First, an amorphous SiO ₂ substrate (quartz glass substrate) was prepared, and EB was placed on this amorphous SiO ₂ substrate in a vacuum atmosphere.
-An amorphous Ge film having a thickness of about 1 nm was formed by the PVD method. While maintaining the surface cleanliness of the amorphous Ge film, 1 × 10 ⁻⁸
The amorphous Ge film was subjected to a crystallization heat treatment at 350 ° C. for 30 minutes in an atmosphere of Torr.

In the course of the crystallization heat treatment, crystallization occurs from the surface side of the amorphous Ge film, and the interface energy between the amorphous SiO ₂ substrate and the amorphous Ge film increases.
Aggregation of the crystallized Ge occurs, and a large number of Ge fine particles are generated on the amorphous SiO ₂ substrate. Ge particles are formed by short-range diffusion of atoms based on phase transformation in a solid phase, so that Ge particles can be formed with high density. In addition, the Ge particles have a small variation in shape and have a uniform particle size.

When TEM observation of Ge fine particles formed from the above-mentioned amorphous Ge film having a thickness of about 1 nm, amorphous Si
A large number of Ge fine particles were generated on the O ₂ substrate, and these Ge fine particles had a particle size of about 5 to 20 nm. Ge
The average particle size of the fine particles was about 10 nm, and the variation in the particle size with respect to the average particle size of each Ge fine particle was extremely small. In addition, the number density was about 1300 particles / mm ² , and it was confirmed that ultrafine Ge particles having a uniform particle size were generated at a high density.

Ge particles were generated by changing the thickness of the amorphous Ge film in the same manner as in Example 1. When the thickness of the amorphous Ge film was reduced, the finer G particles were formed.
e Fine particles could be formed at a high density. Thus, it was confirmed that the particle diameter and the number density of the Ge particles can be controlled by the thickness of the amorphous Ge film.

Example 3 First, an amorphous SiO ₂ substrate (quartz glass substrate) was prepared, and EB was placed on this amorphous SiO ₂ substrate in a vacuum atmosphere.
-An amorphous Ge film having a thickness of about 1 nm was formed by a PVD method, and then an amorphous Si film having a thickness of about 1 nm was formed by an EB-PVD method while maintaining a vacuum state in the film forming chamber. . Crystallization of the amorphous Ge film and the amorphous Si film in a 1 × 10 ^-8 Torr atmosphere at 550 ° C. for 60 minutes in an atmosphere of 1 × 10 ⁻⁸ Torr while keeping the surface of this laminated film clean Heat treatment was applied.

The fine particles generated from such a laminated film are referred to as T
EM observation confirmed that a large number of Ge fine particles and a large number of Si fine particles were mixed and formed on the amorphous SiO ₂ substrate. The particle diameters of these Ge fine particles and Si fine particles are as small as in Examples 1 and 2, and their dispersion is extremely small. It was confirmed that they were mixed and generated.

[0052]

As described above, according to the method for manufacturing a semiconductor fine particle aggregate of the present invention, semiconductor fine particles having a uniform particle diameter useful as a quantum size device or a light emitting material can be obtained in a relatively simple process. It can be formed with high precision and high density. Further, since the particle size and number density of the obtained semiconductor fine particles can be controlled by the thickness of the semiconductor thin film in the initial amorphous state, an aggregate of semiconductor fine particles according to the purpose can be obtained with good reproducibility. It becomes possible.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing a manufacturing process of a semiconductor fine particle aggregate according to an embodiment of the present invention and a semiconductor fine particle aggregate obtained thereby.

FIG. 2 is a cross-sectional view schematically showing a manufacturing process of a semiconductor fine particle aggregate according to another embodiment of the present invention and a semiconductor fine particle aggregate obtained thereby.

FIG. 3 shows an amorphous Si having a thickness of about 1 nm in Example 1 of the present invention.
FIG. 3 is a diagram schematically illustrating a planar TEM image of an aggregate of Si fine particles generated from a film.

FIG. 4 shows an amorphous Si having a thickness of about 10 nm in Example 1 of the present invention.
FIG. 3 is a diagram schematically illustrating a planar TEM image of an aggregate of Si fine particles generated from a film.

FIG. 5 is a diagram showing the relationship between the thickness of an amorphous Si film and the average particle size and number density of generated Si fine particles.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Substrate 2, 2A, 2B ... Semiconductor thin film in an amorphous state 3, 3A, 3B ... Semiconductor fine particles 12, 13 ... Si fine particles

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4K029 AA01 AA08 BA32 BA35 BA56 BD01 CA01 GA01 5F103 AA01 AA04 DD01 DD03 DD11 DD16 DD17 DD30 GG03 HH10 LL01 LL17 PP03 PP18 RR04 RR10

Claims (10)

[Claims] A step of forming a semiconductor thin film in an amorphous state on a substrate whose interface energy with the semiconductor thin film is increased at a high temperature; and in an atmosphere capable of keeping the surface of the semiconductor thin film clean. hand,
Heating the semiconductor thin film in the amorphous state to a temperature higher than the crystallization temperature to crystallize the semiconductor in the amorphous state and generate a plurality of semiconductor fine particles. A method for producing a fine particle aggregate. 2. The method according to claim 1, wherein the semiconductor thin film is formed of Si, Ge, Se, Te, and Si.
C. A method for producing an aggregate of semiconductor fine particles, comprising a semiconductor or a compound semiconductor containing at least one selected from C, and wherein the substrate is a compound substrate in an amorphous state. 3. The method according to claim 1, wherein the semiconductor thin film in an amorphous state has a thickness of 30 nm or less. 4. The method according to claim 1, wherein the heating of the amorphous semiconductor thin film is performed in a vacuum atmosphere of 10 ⁻⁵ Torr or less. Manufacturing method of aggregate. 5. The method of manufacturing a semiconductor fine particle aggregate according to claim 1, wherein the step of forming the semiconductor fine particles comprises the step of: forming a semiconductor thin film in an amorphous state in a vacuum atmosphere at a temperature equal to or higher than the crystallization temperature A method for producing a semiconductor fine particle aggregate, wherein the method is performed by performing a heat treatment on the substrate. 6. The method for producing a semiconductor fine particle aggregate according to claim 1, wherein the semiconductor fine particles having an average particle diameter of 100 nm or less are formed on the substrate at a number density of 50 particles / mm ² or more. Of producing a semiconductor fine particle aggregate to be manufactured. 7. The method for producing a semiconductor fine particle aggregate according to claim 1, wherein two or more types of said amorphous semiconductor thin films are laminated on said substrate, and two or more types of said semiconductor fine particles are mixed. A method for producing a semiconductor fine particle aggregate, comprising: 8. An aggregate of semiconductor fine particles having a plurality of semiconductor fine particles formed on a substrate, wherein the semiconductor fine particles have an average particle diameter of 100 nm or less, and
An aggregate of semiconductor fine particles, which is present at a number density of 50 particles / mm ² or more. 9. The semiconductor fine particle aggregate according to claim 8, wherein the semiconductor fine particles are Si, Ge, Se, Te and S.
An aggregate of semiconductor fine particles, comprising a semiconductor containing at least one selected from iC or a compound semiconductor. 10. The method for producing a semiconductor fine particle aggregate according to claim 8, wherein two or more kinds of the semiconductor fine particles are mixed on the substrate.