JP2001131735A - Functional material manufacturing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To deposit fine particles of high purity having single grain size and uniform structure which are manufactured in a less polluted or damaged condition on a substrate. SOLUTION: The time particles classified into desisted grain sizes are recovered on the substrate 111, a substance generated by radiating laser beams 103 on a medium 107 is recovered on the substrate 111 to deposit the classified particles and the substance generated by radiating the laser beam on the medium on the same substrate 111.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for producing a functional material, and more particularly to an apparatus for producing a functional material capable of controlling the particle diameter of fine particles and reducing contamination.

[0002]

2. Description of the Related Art Conventionally, semiconductor fine particles composed of a Si-based group IV material have been used for an optical functional element capable of emitting visible light or the like.

[0003] Since IV group semiconductors are originally indirect transition type,
The phonon intervention is indispensable in the band-to-band transition, and inevitably a large amount of heat is generated in the recombination process, and the probability of radiative recombination is extremely low. However, when the shape of the group IV semiconductor is fine particles having a particle size of several nm, effects such as relaxation of the wave number selection rule in transition between bands and increase in oscillator strength are produced. Thereby, the probability of occurrence of the radiative recombination process of the electron-hole pairs of the group IV semiconductor increases, and it becomes possible to exhibit strong light emission. By utilizing the characteristics of the group IV semiconductor, semiconductor fine particles composed of a Si-based group IV material can be used for an optical functional element capable of emitting visible light or the like.

Therefore, in order to use semiconductor fine particles composed of a Si-based group IV material for an optical functional device capable of emitting visible light or the like, it is indispensable to produce spherical fine particles whose particle diameter is controlled at the nm level. The laser ablation method is suitable for the production of fine particles at the nm level.

An apparatus for producing a functional material for depositing fine particles produced by subjecting a target material to laser ablation is disclosed in Japanese Patent Application Laid-Open No. 9-275075. FIG. 8 is a configuration diagram of a conventional functional material manufacturing apparatus. Hereinafter, a conventional functional material manufacturing apparatus will be described with reference to FIG.

First, a target material 80 is placed in a target folder 802 provided near the center of the vacuum reaction chamber 801.
Place 3. Next, the vacuum reaction chamber 801 is evacuated to 1 × 10
After evacuation to ^-8 Torr high vacuum, the high vacuum evacuation system 804 is closed.

Next, helium gas (He) is introduced into the vacuum reaction chamber 801 through the rare gas introduction line 805.
After that, the flow rate is controlled by the mass flow controller 806 and the working exhaust system 80 mainly including the dry rotary pump is used.
7, a constant pressure (1.0 to 20.0
Torr) low pressure rare gas (He) atmosphere in a vacuum reaction chamber 8
01 is held. The surface of the target material 803 is irradiated with a laser beam having a high energy density (for example, 1.0 J / cm ² or more) in a held He gas atmosphere of several Torr. After the laser light passes through the slit 808 and the condenser lens 809, the direction of the laser light is changed by 90 degrees by the mirror 810, and then the laser light introduction window 811 passes through the vacuum reaction chamber 8
01 and reaches the surface of the target material 803. Thus, the target material 803
Desorption and ejection of materials from

The desorbed substance dissipates kinetic energy to the atmosphere gas molecules, promotes condensation and growth in the air, and grows and deposits on the deposition substrate 812 into fine particles having a particle size of several nm to several tens nm. .

[0009] Here, the control of the emission wavelength (emission photon energy), utilizing the increased quantum confinement effect due to absorption edge emission energy with decreasing particle diameter shown in FIG. 9 (corresponding to the band gap E _g) are doing. Therefore, in order to obtain a single emission wavelength, it is essential to make the particle diameter of the fine particles uniform. That is, if fine particles having a particle size corresponding to the emission wavelength can be generated and deposited with the narrowest possible particle size distribution, it becomes possible to manufacture an optical functional device that emits monochromatic light.

[0010]

As described above, in order to manufacture an optical functional device that emits light of a single wavelength using semiconductor fine particles, the number n of single particle diameters having a suppressed particle size distribution must be increased.
Generation and deposition of m-level fine particles are required.

Even in a conventional functional material manufacturing apparatus, it is possible to control the average particle size to some extent by appropriately selecting the pressure of the atmospheric rare gas, the distance between the target material and the deposition substrate, and the like. However, in the conventional functional material manufacturing apparatus, since the width of the particle size distribution is still wide, it is difficult to obtain semiconductor fine particles having a uniform particle size such as a geometric standard deviation σ _g of 1.2 or less. is there. In other words, the functional material manufacturing apparatus needs more aggressive particle size control.

Further, fine particles at the nm level are very sensitive to impurities and defects due to their high surface atomic ratio (for example, about 40% at a particle diameter of 5 nm). For this reason, a cleaner and less damaged process is required as a generation and deposition method adopted by the functional material manufacturing apparatus.

Further, when semiconductor fine particles are directly adhered to and deposited on a deposition substrate as in the above-mentioned conventional functional material manufacturing apparatus, the structure of the deposit eventually forms a porous thin film composed of fine particles. Tend to be. As for such a porous shape, if it is assumed that an electrode is connected to form an optical functional element, a more optimized one may be required. Also, in order to bring out the original quantum size effect of such porous spherical fine particles and to exhibit new optical functions such as light emission, a more optimal shape and shape are required.
In some cases, a structure or the like is required.

In addition, as described above, fine particles of nm level are very sensitive in surface, so that it may be necessary to disperse them in a stable transparent medium or cover the surface with a transparent medium thin film.

The present invention has been made in view of the above, and it is possible to deposit high-purity fine particles having a single particle size and a uniform structure, which are manufactured in a state where contamination and damage are reduced, on a deposition substrate. It is an object to provide a functional material manufacturing apparatus.

[0016]

According to the present invention, fine particles classified into a desired particle size are collected on a substrate, and a substance generated by applying a laser beam to a medium is collected on the substrate. Then, the classified fine particles and a substance generated by applying a laser beam to the medium are deposited on the substrate.

Thus, high-purity fine particles having a single particle size and a uniform structure can be deposited on the substrate. As a result, a light-emitting element that emits light of a single wavelength can be manufactured. Further, since the high-purity fine particles are deposited on the substrate together with a medium different from the high-purity fine particles, contamination and damage of the functional material can be reduced.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A functional material manufacturing apparatus according to a first aspect of the present invention includes a fine particle generating means for generating fine particles by applying a laser beam to a first target body in a low-pressure medium gas atmosphere; A fine particle classifying means for classifying fine particles having a desired particle diameter from the fine particles generated by the fine particle generating means in a sheath gas; collecting the fine particles classified by the fine particle classifying means on a substrate; A substance generated by applying a laser beam to the substrate is collected on the substrate, and the classified fine particles and a substance generated by applying the laser beam to the second target body are deposited on the substrate. And deposition means for performing the deposition.

With this configuration, high-purity fine particles composed of the first target having a single particle size and a uniform structure can be deposited on the substrate. As a result, a light-emitting element that emits light of a single wavelength can be manufactured. Further, since high-purity fine particles are deposited on the substrate together with the substance generated by irradiating the second target body with the laser beam, contamination and damage of the functional material can be reduced.

According to a second aspect of the present invention, in the functional material manufacturing apparatus according to the first aspect, the deposition means collects the classified fine particles on a substrate substantially at the same time as collecting the classified fine particles on a substrate. A substance generated by applying a laser beam to the substrate is collected on the substrate, and the fine particles are dispersed and deposited in a substance composed of the second target body.

According to this configuration, high-purity fine particles composed of the first target having a single particle size and a uniform structure can be converted into the second target.
The target material can be deposited on the substrate while being buried in a substance generated by applying a laser beam to the target body, so that contamination and damage to the functional material can be effectively reduced.

According to a third aspect of the present invention, in the functional material manufacturing apparatus according to the first aspect, the depositing means deposits a laser beam on a second target body after depositing the classified fine particles on a substrate. The substance generated by the application is collected on the substrate, and the classified fine particles and the second
Are alternately deposited.

With this configuration, the high-purity fine particles composed of the first target and the second target, each of which has a single particle size and a uniform structure, are formed.
The substance generated by irradiating the target body with the laser beam can be alternately deposited on the substrate, so that contamination and damage of the functional material can be effectively reduced.

According to a fourth aspect of the present invention, in the functional material producing apparatus according to any one of the first to third aspects, the fine particle classifying means uses a differential electric mobility classifier.

With this configuration, it is possible to classify the fine particles of the first target with a high yield. Therefore, high-purity fine particles having a single particle size and a uniform structure can be efficiently collected and deposited.

According to a fifth aspect of the present invention, in the functional material manufacturing apparatus according to any one of the first to third aspects, the fine particle classifying means is configured to charge the fine particles using a radioactive isotope. It is provided with a charging means, and a differential electric mobility classification means for classifying the charged fine particles.

With this configuration, the fine particles can be charged, so that the yield of the classified fine particles can be improved.

According to a sixth aspect of the present invention, in the functional material manufacturing apparatus according to any one of the first to third aspects, the fine particle classifying means is configured to charge the fine particles using a vacuum ultraviolet light source. It is provided with a charging means, and a differential electric mobility classification means for classifying the charged fine particles.

According to this configuration, the charging efficiency can be improved, and the particles composed of the first target can be charged in a single pole.

According to a seventh aspect of the present invention, in the functional material manufacturing apparatus according to any one of the first to third aspects, the fine particle generating means generates fine particles generated by using the laser beam as a pulsed laser beam. Is charged in the ablation plume formed by the pulsed laser.

With this configuration, the fine particle charging section using a radioisotope, a vacuum ultraviolet light source, or the like can be omitted from the apparatus, and the apparatus can be reduced in size and cost. further,
With this configuration, the process of transporting the fine particles composed of the first target can be shortened, so that an effect of suppressing a phenomenon such as deposition or aggregation during transportation can be obtained.

According to an eighth aspect of the present invention, in the functional material manufacturing apparatus according to any one of the fifth to seventh aspects, the depositing means is provided when the classified charged fine particles are deposited. The transfer of electrons performed is measured as a current.

With this configuration, it is possible to confirm the deposition amount of the fine particles composed of the first target and to control the deposition amount.

According to a ninth aspect of the present invention, in the functional material manufacturing apparatus according to any one of the first to eighth aspects, the pressure of the fine particle generating means is generated from the first target body. The pressure is maintained at an optimal pressure for agglomeration and growth of the fine particles, and the pressure of the deposition means is maintained at an optimal pressure for depositing a substance generated from the second target body.

With this configuration, it is possible to generate and deposit the substance medium generated by applying the laser beam to the fine particles comprising the first target and the second target body under the optimum atmospheric gas pressure. Further, a pressure difference can be generated between the particle generation chamber and the deposition chamber, and the effect of efficiently transporting the particles using the generated pressure difference can be obtained.

According to a tenth aspect of the present invention, in the functional material manufacturing apparatus according to any one of the first to ninth aspects, the depositing means includes the second target body and a third target body. Further comprising a target exchange mechanism for exchanging, after depositing a substance composed of the classified fine particles and the second target body, exchanging the second target body with a third target body; A substance generated by irradiating a transparent electrode material as a target material with a laser beam is subjected to the classified fine particles and the second material.
To form a transparent electrode.

With this configuration, it is possible to form a transparent electrode connected to a functional material manufactured in a state where contamination and damage are reduced in the deposition means.

According to an eleventh aspect of the present invention, in the functional material manufacturing apparatus according to the tenth aspect, the depositing means deposits both or one of the second target body and the third target body. Is performed by sputtering.

Thus, the second target and the third target
When the target material is deposited by sputtering, the technology of the conventional semiconductor device can be used. Further, the mechanical components and optical components of the functional material manufacturing apparatus can be simplified.

According to a twelfth aspect of the present invention, in the functional material manufacturing apparatus according to any one of the first to eleventh aspects, the deposition means comprises the classified fine particles and a second target body. The material to be deposited is deposited in a direction normal to the substrate.

According to this configuration, it is possible to further improve the efficiency of attaching and depositing a substance generated by irradiating the laser beam to the fine particles comprising the first target and the second target body on the substrate.

According to a thirteenth aspect of the present invention, in the functional material manufacturing apparatus according to any one of the first to twelfth aspects, the fine particle classifying means sets the bandgap energy of the fine particle material to a visible light region. Classification is performed with a suitable average particle size.

With this configuration, it is possible to manufacture a functional material that emits light of a wavelength in the visible light region.

The functional material according to the fourteenth aspect of the present invention is characterized in that the fine particles are generated in a medium gas atmosphere in a fine particle generating means, the fine particles are introduced into the fine particle classification means, and the fine particles are generated in the fine particle classification means. It is produced by classifying fine particles into a desired particle size in a sheath gas and depositing the classified fine particles on a substrate together with a substance generated by laser ablation.

Since the high-purity fine particles having a single particle size and a uniform structure are deposited on the functional material thus manufactured, it can be used for a light emitting device emitting light of a single wavelength. Further, since high-purity fine particles are deposited together with the substance generated by laser ablation, contamination and damage are reduced.

According to a fifteenth aspect of the present invention, in the functional material according to the fourteenth aspect, classification is performed with an average particle size such that the bandgap energy of the fine particles is in a visible light region.

The functional material thus manufactured can emit light of a wavelength in the visible light region.

The optical functional device according to a sixteenth aspect of the present invention is characterized in that the fine particles are generated in a medium gas atmosphere in the fine particle generation means, the fine particles are introduced into the fine particle classification means, and the fine particles are generated in the fine particle classification means. Fine particles are classified in a sheath gas with an average particle diameter such that the band gap energy of the fine particles is in a visible light region, and a layer in which the classified fine particles are dispersed in a substance generated by laser ablation is formed on a substrate. Created by doing.

The optical functional device manufactured as described above can emit light of a wavelength in the visible light region.

According to a seventeenth aspect of the present invention, in the optical function device according to the sixteenth aspect, the visible light region is red, blue,
And green wavelength regions respectively.

The optical functional device manufactured in this manner is red,
Wavelengths corresponding to blue and green can be emitted.

Hereinafter, an apparatus for producing a functional material according to the present invention will be described in detail as an embodiment with reference to FIGS.

FIG. 1 shows the internal structure of the deposition chamber of the functional material manufacturing apparatus according to the present embodiment. A fine particle deposition nozzle 102 is provided above the left side of the deposition chamber 101. From the fine particle deposition nozzle 102, a carrier gas having _a constant mass flow rate Q _a (standard state: 1 l / min.) Containing fine particles classified into a single particle size by a fine particle classification device described later is jetted into the deposition chamber 101. .

Further, a laser beam introduction window 104 for introducing an excimer laser beam 103 is provided at a position corresponding to the nozzle 102 for depositing fine particles with respect to the center of the deposition chamber 101. A mirror 1 for changing the traveling direction of the excimer laser beam 103 by 90 degrees is located near the laser beam introduction window 104 and outside the deposition chamber 101.
05 is provided. A condenser lens 106 for condensing the excimer laser light 103 is provided near the mirror 105.

Then, the excimer laser beam 103 condensed by the condensing lens 106 is
And is introduced into the deposition chamber 101 through the laser light introduction window 104. The excimer laser beam 103 introduced into the deposition chamber 101 is applied to the transparent medium target 10.
Reach 7

The transparent medium target 107 is fixed to a target drive / exchange mechanism 108 for driving / exchanging the target. The target drive / exchange mechanism 108
The excimer laser beam 103 is disposed at a position where the introduced excimer laser beam 103 can irradiate the transparent medium target 107.
Specifically, the target drive / exchange mechanism 108 is provided near the upper part of the side of the deposition chamber 101 opposite to the side where the fine particle deposition nozzle 102 is provided. Further, a transparent electrode material target 109 which is a transparent medium target is fixed to the target drive / exchange mechanism 108. By driving the target drive / exchange mechanism 108, the position of the transparent medium target 107 and the position of the transparent electrode material target 109 can be switched. Thus, the transparent electrode material target 109 can be irradiated with the excimer laser light 103.

The transparent medium target 107 is excited by the excimer laser beam 103 to form an ablation plume 110. Ablation bloom 110
The deposition substrate 1 on which the fine particles, the transparent medium, and the transparent electrode are deposited substantially in the center of the deposition chamber 101 in the growth direction of
The transparent medium target 107 and the transparent electrode material target 109 are arranged so that 11 is located. Also,
The deposition substrate 111 is fixed to a deposition substrate folder 112.

Further, a high vacuum evacuation for evacuating the deposition chamber 101 to an ultra-high vacuum of <1 × 10 ⁻⁷ Torr before producing the optical functional element is provided on the side of the deposition chamber 101 on the side of the fine particle deposition nozzle 102. A system 113 is provided. On the side of the deposition chamber 101 below the deposition substrate 111, a carrier gas differential exhaust system 114 for performing differential exhaust of the carrier gas so as to be kept at a constant pressure P2 is provided.

At the bottom of the deposition chamber 101, a minute current for measuring the transfer of charged particles performed when the charged particles classified by the particle classification device described later are deposited on the deposition substrate 111 is measured. A total of 115 is provided. The microammeter 115 measures the transfer of the electrons as a current.

The functional material manufacturing apparatus 2 in the present embodiment
Reference numeral 00 denotes a fine particle generation chamber 201, a fine particle classification chamber 204 including a fine particle charging unit 202 and a differential type electric mobility classification device 203 as shown in the overall configuration diagram shown in FIG.
1 and 1. The fine particle generation chamber 201 and the fine particle classification chamber 204 are connected by a fine particle intake pipe 209.

Here, the fabrication of an optical functional device having a sectional structure as shown in FIG. 3 will be described with reference to FIGS. First, before the manufacturing process of the optical function element, the valve 20 shown in FIG.
5 is closed, and the particle generation chamber 201 is filled with <1 × 10 ⁻⁸ T by an ultrahigh vacuum exhaust system 206 mainly composed of a turbo molecular pump.
After evacuating to orr ultra-high vacuum, the ultra-high vacuum evacuation system 206 is closed.

At the same time, after the fine particle classification chamber 204 and the deposition chamber 101 are evacuated to an ultra-high vacuum of <1 × 10 ⁻⁷ Torr by an ultra-high vacuum exhaust system 113 mainly composed of a turbo molecular pump, the ultra-high vacuum exhaust system 113 is opened. To close.

Next, _a constant mass flow rate Q _a (200 s) is supplied to the fine particle generation chamber 201 using the mass flow controller 207.
Ccm), a carrier gas 208 (a high-purity rare gas, for example, He having a purity of 99.9999%) is introduced.

Here, the configuration of the particle generation chamber according to the above embodiment will be described in detail with reference to FIG. A gas introduction system 401 is connected to the left side surface of the particle generation chamber 201. At one end of the gas introduction system 401, a mass flow controller 207 is provided. Mass flow controller 207 is adapted to set for introducing the carrier gas 208 at a constant mass flow rate Q _a in microparticle generation chamber 201. The mass flow controller 207 is connected to an atmosphere rare gas introduction pipe 402 extending substantially perpendicularly to the inside of the particle generation chamber 201. Atmosphere rare gas introduction pipe 402
Is connected to a ring-shaped atmospheric rare gas ejection pipe 403 from the side of the center of the inside of the particle generation chamber 201 slightly. The atmosphere rare gas introduction pipe 402 is connected to the fine particle generation chamber 20.
1 is arranged in parallel with the side surface. The atmosphere rare gas ejection pipe 403 has eight atmosphere rare gas ejection ports 404a to 404.
4h are formed. Atmospheric rare gas outlet 404a-
Reference numerals 404h are provided at eight equal intervals in the ring-shaped atmosphere gas discharge pipe 403 so as to be disposed at substantially equal intervals with a semiconductor target 406, which is a solid target described later, interposed therebetween. In the drawings, for convenience of explanation, the atmosphere rare gas jets 404b and 404c and the atmosphere rare gas jet 40
Although 4d and 404e and the atmosphere rare gas ejection ports 404f and 404g are shown in close proximity to each other, since the atmosphere rare gas introduction pipe 402 is actually in a ring shape,
The atmosphere rare gas ejection port 404b is arranged before the drawing with respect to 404c, the atmosphere rare gas ejection port 404d is arranged with respect to 404e, and the atmosphere rare gas ejection port 404f is arranged with respect to 404g. Thereby, the semiconductor target 40
6, the carrier gas 208 forms a symmetrical flow.

A laser light introducing window 407 made of quartz is provided at the bottom of the particle generation chamber 201, and the pulse laser light 408 is condensed by the condenser lens 409, and passes through the laser light introducing window 407. It is introduced into the particle generation chamber 201. At substantially the center of the particle generation chamber 201, a semiconductor target 406 fixed to a target folder 410 having a rotation mechanism is arranged. Further, the semiconductor target 406 is configured to rotate at a speed of 8 rpm (rotation / minute) at the time of generating fine particles by the target folder 410. As the semiconductor target 406, a high-purity Si single crystal substrate (plane orientation (100), specific resistance 10 Ω · cm) is used.

As the focused irradiation of the pulse laser beam 408, the second harmonic (wavelength: 532 nm, pulse energy: 10 mJ, pulse width: 40 ns, repetition frequency: 10 Hz) of the Q-switch Nd: YAG laser is used as the semiconductor target. Focusing irradiation is performed on the surface of 406 so as to have an energy density of 10 J / cm ² .

The semiconductor target 406 is excited by the pulsed laser beam 408 introduced into the particle generation chamber 201. The semiconductor target 406 excited by the pulsed laser light 408 forms an ablation plume 411. Further, a particle intake pipe 412 is disposed in the growth direction of the ablation plume 411 of the particle generation chamber 201. Further, on the left side of the particle generation chamber 201, an ultra-high vacuum evacuation system 206 mainly composed of a turbo-molecular pump is provided, which evacuates the particle generation chamber 201 to an ultra-high vacuum before the fabrication process of the optical functional element. On the right side of the particle generation chamber 201, a differential exhaust system 413 mainly including a dry scroll pump is provided.

Next, the operation of the functional material manufacturing apparatus 200 will be described again. With the valve 205 shown in FIG. 2 closed, the differential exhaust system 413 mainly including the dry scroll pump shown in FIG.
(For example, 5.0 Torr).

Here, the focused pulse laser light 40
The surface of the semiconductor target 406 is excited by 8 to cause an ablation reaction. As a result, a natural oxide film formed on the surface of the semiconductor target 406,
And impurities such as metal and carbon compounds attached to the target surface are completely removed.
To close. At this point, the oscillation of the pulse laser beam 408 has stopped.

As described above, by removing the natural oxide film formed on the surface of the semiconductor target 406 and the impurities such as the metal and carbon compounds adhering to the surface of the semiconductor target 406, the impurities can be mixed into the semiconductor fine particles. It is possible to remove the influence of the oxide, which is an impurity for the semiconductor fine particles, and the metal and carbon compounds attached to the target surface.

Next, by opening the valve 205 shown in FIG. 2, to introduce particulate classifying chamber 204, and the deposition chamber 101 to carrier gas 208 at a constant mass flow rate Q _a.

[0072] At the same time, mass differential mobility classifier 203 using the mass flow controller 210 flow Q _c
A sheath gas 211 (a high-purity rare gas, for example, He having a purity of 99.9999%) is introduced at a standard condition of 5 l / min.

Here, the carrier gas differential evacuation system 114 mainly composed of the dry pump shown in FIG.
The carrier gas is exhausted at _a constant mass flow rate Qa so that the inside of 1 is maintained at a constant pressure P2 (for example, 2.0 Torr).

[0074] At the same time, open the sheath differential pumping system 212 consisting mainly of a dry pump shown in FIG. 2, to exhaust the sheath gas at a constant mass flow rate Q _c. At this point, the particle generation chamber 210 is at a constant pressure P1, and the deposition chamber 101 is at a constant pressure P1.
2 is held.

Next, the pulse laser beam 408 shown in FIG.
Is oscillated and introduced into the particle generation chamber 201. At this time,
In the particle generation chamber 201 shown in FIG. 4, the semiconductor target 406 is excited by the pulse laser light 408,
Cause an ablation reaction. The substance desorbed and ejected from the semiconductor target 406 in this manner dissipates kinetic energy to the rare gas molecules in the atmosphere, so that condensation and growth in the air are promoted, and the substance grows into fine particles of several nm to several tens nm. .

Here, by controlling and maintaining the particle generation chamber 201 at a constant pressure P1 by the above-described means, it becomes possible for the semiconductor particles to aggregate and grow under optimal conditions.

Next, high-purity semiconductor particles generated by the particle generation chamber 201 shown in FIG. 4, with a constant mass flow rate Q _a carrier gas through the particulate uptake pipe 412, the particle charging part 202 shown in FIG. 3 Transported and charged to both poles by radioisotopes.

The high-purity semiconductor fine particles charged by the fine particle charging unit 202 are sent to a differential type electric mobility classifier 203. In the above embodiment, the differential electric mobility classifier 2
In 03, a double cylindrical classifier is employed. An electrostatic field is applied to the double cylindrical portion of the differential type electric mobility classifier 203 by a DC power supply in a direction perpendicular to the flow direction of the sheath gas 211. Therefore, the charged high-purity semiconductor fine particles draw a trajectory corresponding to each electric mobility. Since this electric mobility depends on the particle size of the high-purity semiconductor fine particles,
Only the high-purity semiconductor fine particles having a specific particle diameter reach the slit provided on the downstream side of the sheath gas flow of the differential electric mobility classifier 203, are classified, and are taken out from the fine particle deposition nozzle 102 connected to the slit. It is. Fine particles having other particle diameters are exhausted from the sheath gas differential evacuation system 212 together with the sheath gas 211, or move and adhere to the collector electrode inside the double cylindrical portion. In this way,
The fine particles are classified into a desired single particle size.

Here, the high-purity semiconductor fine particles are irradiated with ArF excimer laser light (wavelength 193n) by the fine particle charging section 202.
By charging with a vacuum ultraviolet light source as in m), the particles can be monopolarly charged with high efficiency. This allows
The yield of the classified fine particles can be improved. Although an ArF excimer laser beam was used here, an excimer lamp or a vacuum ultraviolet (Deep
Ultra Violet (DUV) lamps can also be used.

In addition, by controlling the mass flow rate of the carrier gas / sheath gas introduced by the above-mentioned means and the mass flow rate of the carrier gas / sheath gas to be exhausted to be equal to each other, the differential electric mobility is controlled. The classification accuracy in the classification device 203 can be made close to a theoretical value.

Next, the high-purity semiconductor fine particles classified in the fine particle classification chamber 204 shown in FIG.
1 together with _a carrier gas having _a constant mass flow rate Qa via a fine particle deposition nozzle 102,
11 are collected and deposited.

At this time, the transparent medium target 107 is excited by the excimer laser beam 103. Here, the transparent medium ejected by the ablation reaction is collected and deposited on the deposition substrate 111 at the same time as the high-purity semiconductor particles are collected and deposited on the deposition substrate 111.

Here, by controlling and maintaining the deposition chamber 101 at a constant pressure P2 by the above-described means, it becomes possible to deposit the transparent medium under optimal conditions.

By simultaneously collecting and depositing the high-purity semiconductor fine particles and the transparent medium classified as described above, as shown in FIG.
01 in which the group IV semiconductor fine particles 302 are dispersed,
The lower electrode layer 303 can be formed on the deposition substrate 111 formed on the surface. The lower electrode layer 303 is formed on the deposition substrate 111 by sputtering or the like.
Further, the lower electrode layer 303 is made of a metal silicide or the like, and has high corrosion resistance and heat resistance.

In the above embodiment, the high-purity semiconductor fine particles and the transparent medium are simultaneously collected and deposited in the deposition chamber 101 shown in FIG. On the other hand, first, high-purity semiconductor fine particles are deposited from the fine particle deposition nozzle 102 to deposit a fixed amount of high-purity semiconductor fine particles. Then, a layered structure of fine particles and the transparent medium can be formed by depositing the transparent medium on the deposition substrate. Further, by alternately repeating the deposition of the high-purity semiconductor fine particles and the transparent medium a plurality of times, the group IV semiconductor fine particle layer 304 and the transparent medium layer 3 are formed as shown in FIG.
05 can be formed in a layered structure.

In the above embodiment, the structure in which the group IV semiconductor fine particles 302 are dispersed in the semiconductor fine particle dispersed transparent medium layer 301 is formed directly on the deposition substrate 111. A layer may be formed, and a semiconductor fine particle-dispersed transparent medium layer 301 having a structure in which group IV semiconductor fine particles 302 are dispersed may be formed on this medium layer.

Here, the current is measured by the microammeter 115 simultaneously with the collection and deposition of the high-purity semiconductor fine particles.
The current is measured by measuring the transfer of electrons performed when the classified charged fine particles are collected and deposited on the substrate. By measuring the current, the amount of deposited fine particles can be confirmed and controlled.

Next, after collecting and depositing the high-purity semiconductor fine particles and the transparent medium as described above, the transparent medium target 10 is moved using the target driving / exchange mechanism 108 shown in FIG.
7 is replaced with a transparent electrode material target 109.

Then, the transparent electrode material target 109 is excited by the excimer laser beam 103 and emits the transparent electrode material by an ablation reaction. As shown in FIG. 3, the ejected transparent electrode material is applied to the transparent electrode layer 306 on the semiconductor fine particle dispersion medium layer 301 or the transparent medium layer 305.
To form At this time, the type of atmosphere gas and the pressure P2 in the deposition chamber 101 are controlled so that the amount of the transparent electrode material can be deposited under optimal conditions (for example, the atmosphere gas is O.sub.99 having a purity of 99.999%). ₂ , pressure 10-200
mTorr).

As described above, the transparent electrode connected to the optical functional element can be formed by a single device while reducing contamination and damage.

Although the deposition of the transparent medium and the amount of the transparent electrode material has been performed by ablation using a laser beam, the transparent medium target 107 and the transparent electrode material target 10 are deposited in the deposition chamber 101 shown in FIG.
It is also conceivable to perform the deposition of 9 by multi-component sputtering. As a result, the technology of the conventional semiconductor device can be used, and the mechanical components and optical components can be simplified. This introduction of sputtering is effective because it can reduce the influence of oxidation on semiconductor fine particles particularly when forming a transparent electrode.

Here, a deposition chamber according to a modification of the above embodiment will be described with reference to FIG. FIG. 5 is a configuration diagram of another example of the deposition chamber according to the above embodiment. The same parts as those already described are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 5, a nozzle 502 for depositing fine particles is provided substantially at the center of the upper surface of the deposition chamber 501. The classified fine particles flow into the deposition chamber 501 from the fine particle deposition nozzle 502 together with the carrier gas having _a constant mass flow rate Qa, and are ejected.

On the other hand, the deposition substrate 111 is disposed substantially at the center of the deposition chamber 501. The deposition substrate 111 is fixed to a deposition substrate folder 112. For this reason, the ejection port of the fine particle deposition nozzle 502 is located in the normal direction of the deposition substrate 111.

The transparent medium target 107 is fixed to a target folder 503. The target folder 503 drives a target by a motor 504. Further, the transparent medium target 107 is excited by the excimer laser light 103. The excited transparent medium target 107 is ablation plume 1
Generate 10. Here, the ablation plume 11
The target folder 503 is arranged so that the growth direction of 0 is the normal direction of the deposition substrate 111. Also,
The transparent medium target 107 has a ring shape.

By configuring the inside of the deposition chamber 501 in this manner, the deposition of the high-purity semiconductor fine particles and the transparent medium are both performed in the radiation direction with respect to the deposition substrate 111. Thereby, the deposition efficiency of the high-purity semiconductor fine particles and the transparent medium is improved. Further, the distribution of the deposit composed of the high-purity semiconductor fine particles and the transparent medium can be homogenized.

As described above, according to the above embodiment, high-purity fine particles having a single particle size and a uniform structure are efficiently produced in a state in which contamination and damage are reduced, and a transparent medium is simultaneously formed on a substrate. It can be deposited, and an optical functional device having an optimized shape and structure can be manufactured.

Further, according to the above embodiment, contamination and
An optical functional device with optimized shape and structure that can efficiently produce high-purity semiconductor fine particles of a single particle size and uniform structure with reduced damage and can be alternately deposited on a substrate with a transparent medium. Can be made.

Next, FIG. 6A shows an example of the particle size distribution of nm region Si fine particles actually generated using the functional material manufacturing apparatus of the above embodiment. The classification and deposition conditions at this time are as follows.

He gas pressure in the production chamber: 5.0 Torr, He gas pressure in the deposition chamber: 4.5 Torr, carrier gas flow rate: He 0.33 SLM (standard condition, 1 / min),
Sheath gas flow rate: He 1.67 SLM, DMA classification region applied voltage: -2.5 V, deposition substrate applied voltage: -100
V and deposition substrate temperature: normal temperature. Other conditions related to the generation of Si fine particles, such as the excitation laser irradiation conditions, are as follows:
This is the same as that already described in the detailed description of FIG.

In FIG. 6A, the particle size distribution of the Si fine particles immediately after generation is represented by a black circle, and the particle size distribution of the classified Si fine particles is represented by a white histogram. Here, the particle size distribution of the Si fine particles immediately after generation is a value obtained by measuring the current due to the incidence of charged particles on the deposition substrate holder 112 by the microammeter 115 while sweeping the voltage applied to the DMA classification region (electrostatic field intensity). Was calculated based on On the other hand, the particle size distribution after the classification is determined by applying the fixed DMA classification region applied voltage (−
Si fine particles continuously deposited on the deposition substrate 111 at 2.5 V) were obtained by observing with an electron microscope.

The width of the particle size distribution of the generated Si fine particles is extremely wide (filled circle: geometric standard deviation s _g = 1.8). However, by subjecting the generated Si fine particles to DMA classification, an extremely sharp particle size distribution (white histogram: geometric standard deviation s _g = 1.2) can be obtained. Such a sharp particle size distribution is called a single particle size or monodispersion.

Also, in FIG. 6A, S
The average particle size of the i-particle group is 5.8 nm. Note that DM
When applying A classification, the voltage applied to the DMA classification area is -2.5V
The average particle size after classification can be shifted to a smaller particle size of 3.8 nm.

By the quantum mechanical principle, if the particle size of the semiconductor is reduced to a region equivalent to the de Broglie wavelength associated with the intrinsic carrier or the Bohr radius of the intrinsic exciton, the particle diameter d _m It is known that the energy band gap E _g changes in accordance with. That is, as d _m decreases, E _g is increased. When the material of the particles is Si, d _m is 2-10n
In the region of m, the effective mass approximation (effective-m
as approximation and tight-binding approximation
ion), an E _g of 1.7-3.
It has been found to change in the visible light range such as 0 eV. E _g is a physical quantity that determines the wavelength of light absorption or light emission (or photoenergy).

FIG. 6B is a diagram showing the distribution of the energy band gap (Eg) corresponding to the particle size (dm) distribution of the Si fine particles before and after classification in FIG. 6A. FIG.
From (b), it can be seen that the center of the Eg distribution of the Si fine particle group (black circles) immediately after generation (before classification) is in the near-infrared region (1.4 eV). This photon energy is 1.4 eV
Corresponds to the particle size of 5.8 nm in FIG. On the other hand, the center of the Eg distribution of the group of Si fine particles (white histogram) after classification is in the red wavelength region of the visible light region. This photon energy of 1.8 eV is shown in FIG.
This corresponds to a particle diameter of 3.8 nm in (a). This is because it is impossible for a group of Si fine particles immediately after the generation to have an optical function in the visible light range, but by performing DMA classification on the group of Si fine particles, the optical function in the visible light range is obtained. (E.g., light absorption and light emission). The fact that the Si microparticles can exhibit optical functions (light absorption, light emission, etc.) in the visible light range brings extremely useful value in industry.

As described above, the fine particles can be monodispersed by classifying the Si fine particles immediately after generation. As described above, when the fine particles are in a monodispersed state, that is, when a peak is present at a specific particle size in the particle size distribution, the energy band gap distribution corresponding to the particle size also becomes uniform. Therefore, the presence of a large number of classified fine particles makes it possible to strongly emit light having a wavelength corresponding to the energy band gap. Therefore, when classifying the fine particles, the fine particles exhibiting an optical function in the visible light region can be realized by classifying the fine particles into a particle size corresponding to an energy band gap corresponding to the wavelength of light in the visible light region. . Since the de Broglie wavelength varies depending on the material, the relative relationship between the particle size and the energy band gap varies depending on the material of the fine particles.

[0107] In addition, E _g is a physical quantity that determines the wavelength of the light absorption and emission, by utilizing the change according to the particle diameter d _m of Si fine particles, classifying the Si particles group to the desired particle size Thus, an optical functional element that emits light of a desired wavelength can be manufactured. That is, a group of Si fine particles classified to a particle size that can express an optical function in the visible light region is deposited on the deposition substrate 11.
By depositing on the optical element 1, an optical function element that exhibits an optical function in the visible light region can be manufactured.

Using the continuous production-classification-deposition process system in the above embodiment, three Si fine particle groups as shown in FIG. 7A are produced. These Si fine particles have an average particle size of 3.9 nm, 2.4 nm, and 1.
Classification was performed at 9 nm. Each Si
The sg of the fine particle group is all within 1.2.
The control of the average particle diameter of the Si fine particle group can be performed by controlling the voltage applied to the DMA classification region when performing the DMA classification. According to the same analysis as in FIG. 6, these three Si microparticle groups correspond to the center values of the Eg (corresponding photon energy) distributions of 1.91 eV, 2.25 eV, and 2.76 eV, respectively (FIG. 7 (b)). )). These Eg
Are 650 nm and 550 n, respectively, as wavelengths.
m, and 450 nm. These wavelengths are the wavelengths of light of the three primary colors red, green and blue. By depositing the Si fine particles grouped with such a particle size together with the medium on the deposition substrate 111 by laser ablation and forming an optical functional layer on the deposition substrate 111, red,
An optical functional element that emits light of green and blue wavelengths can be manufactured.

As described above, the realization of an optical functional device that emits three primary colors in the visible light region by Si fine particles is of great significance in the optical and electronic industries.

As described above, the above embodiment is
When the fine particles generated and classified from the semiconductor target 406 are collected on the deposition substrate 111, they are substantially simultaneously collected on the deposition substrate 111 generated by the ablation reaction of the transparent medium target 107. Thus, the fine particles generated and classified from the semiconductor target 406 can be dispersed and deposited in the material composed of the transparent medium target 107. As a result, high-purity fine particles having a single particle size and a uniform structure can be efficiently produced in a state in which contamination and damage are reduced, and can be simultaneously deposited on the substrate with the transparent medium. Thereby, it is possible to have an effect that the shape and structure of the optical functional element can be highly configured.

In the above embodiment, the thin film composed of the fine particles generated and classified from the semiconductor target 406 and the transparent medium target 107 is alternately deposited.
Also in this case, high-purity fine particles having a single particle size and a uniform structure can be efficiently produced in a state where contamination and damage are reduced, and can be alternately deposited on a substrate with a transparent medium.

Further, a differential electric mobility classifier 203 is employed in the particle classifying chamber 204 according to the above embodiment. Thereby, the fine particles can be classified with a high yield. As a result, high-purity fine particles having a single particle size and a uniform structure can be efficiently collected and deposited.

Further, according to the above embodiment, the pressure in the particle generation chamber 201 can be maintained at a pressure optimal for the aggregation and growth of the particles generated from the semiconductor target 406. Further, the pressure of the deposition chamber 101 is changed to the transparent medium target 1.
07 can be maintained at an optimal pressure for the deposition of the substance produced. As a result, the fine particles and the transparent medium can be generated and deposited under the optimum atmospheric gas pressure. Further, a pressure difference can be generated between the particle generation chamber 201 and the deposition chamber 101. By utilizing the generated pressure difference, it is possible to have an effect of efficiently transporting the fine particles from the fine particle generation chamber 201 to the deposition chamber 101.

Further, according to the above embodiment, the deposition chamber 1
01 by the target drive / exchange mechanism 108 provided in
Transparent medium target 107 and transparent electrode material target 10
9 can be exchanged. Thus, after depositing a substance composed of the semiconductor target 406 and the transparent medium target 107, the transparent electrode material target 1
09 can be excited by the excimer laser beam 103. Then, a substance generated by causing the ablation reaction of the excited transparent electrode material target 109 to deposit on a substance composed of the semiconductor target 406 and the transparent medium target 107 can form a transparent electrode. This makes it possible to form a transparent electrode that is brought into contact with the optical functional element in a state where contamination and damage are reduced without exposing the active region as a functional material to the atmosphere by a single device.

Further, in the modification of the above-described embodiment, the substance composed of the semiconductor target 406 and the transparent medium target 107 can be deposited in the normal direction to the substrate. This makes it possible to improve the efficiency of attaching and depositing the fine particles and the transparent medium to the substrate.

Further, the above-described embodiment has the fine particle charging section 202 of the type in which the fine particles are charged using radioactive isotopes. In addition, by adopting a mode in which the fine particle charging unit 202 charges the fine particles using a vacuum ultraviolet light source, the charging efficiency can be improved.

Further, as a modified example of the above-described embodiment, a form in which the generated fine particles are charged in an ablation plume by a pulsed laser may be considered. This allows
Particulate charging unit 2 using radioisotope, vacuum ultraviolet light source, etc.
02 can be omitted from the apparatus. As a result, the size and cost of the device can be reduced. Further, the process of transporting the fine particles can be shortened. As a result, it has an effect of suppressing phenomena such as deposition and aggregation of fine particles during transportation.

Further, in the above embodiment, the transparent medium target 107 and the transparent electrode material target 109
It is also conceivable to perform the deposition by sputtering. As a result, the technology of the conventional semiconductor device can be used, and the mechanical components and optical components can be simplified.

[0119]

As described above, according to the present invention,
Single particle size produced with reduced contamination and damage,
High-purity fine particles having a uniform structure can be deposited on a deposition substrate.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a deposition chamber of a functional material manufacturing apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a functional material manufacturing apparatus according to the embodiment.

FIG. 3A is an enlarged cross-sectional view of a first functional material manufactured by the functional material manufacturing apparatus according to the embodiment. FIG. 3B is a second functional material manufactured by the functional material manufacturing apparatus according to the embodiment. Enlarged sectional view of functional material

FIG. 4 is a diagram showing a configuration of a particle generation chamber of the functional material manufacturing apparatus according to the embodiment.

FIG. 5 is a diagram showing a configuration of a deposition chamber of another example of the functional material producing apparatus according to the embodiment.

FIG. 6 (a) shows the particle size distribution of fine particles immediately after generation and the particle size distribution of fine particles after classification. (B) The distribution of the optical gap of fine particles immediately after generation and the distribution of the optical gap of fine particles after classification. Diagram shown

FIG. 7 (a) shows a graph of 3 prepared for multicolor emission.
Diagram showing the particle size distribution of a group of Si fine particles (b) Three types of Si produced for the purpose of multicolor emission
Diagram showing optical gap distribution of particle group

FIG. 8 is a diagram showing a configuration of a conventional functional material manufacturing apparatus.

FIG. 9 is a correlation diagram between the particle diameter of fine particles and the emission energy at the absorption edge.

[Explanation of symbols]

 101, 501 Deposition chamber 102, 502 Particle deposition nozzle 103 Excimer laser light 104 Laser light introduction window 107 Transparent medium target 108 Target drive / exchange mechanism 109 Transparent electrode material target 110 Ablation plume 111 Deposition substrate 112 Deposition substrate folder 113 Ultra high vacuum Exhaust system 114 Carrier gas differential evacuation system 115 Micro ammeter 201 Particle generation chamber 202 Particle charging unit 203 Differential type electric mobility classifier 204 Particle classification chamber 205 Valve 206 Ultra high vacuum exhaust system 207, 210 Mass flow controller 209 Particle intake pipe 212 Sheath gas differential exhaust system 503 Target folder

Continued on the front page (72) Inventor Toshiharu Makino 3-10-1, Higashi-Mita, Tama-ku, Kawasaki-shi, Kanagawa Prefecture Inside Matsushita Giken Co., Ltd. (72) Yuka Yamada 3-1-1, Higashi-Mita, Tama-ku, Kawasaki-shi, Kanagawa Prefecture No. Matsushita Giken Co., Ltd. F term (reference) 4K029 BC07 CA05 DB20 DC16 EA03 5F103 AA08 BB12 BB22 BB26 DD16 LL01 NN04 RR06

Claims (17)

[Claims] 1. A fine particle generating means for generating fine particles by applying a laser beam to a first target body in a low-pressure medium gas atmosphere; and a fine particle having a desired particle diameter from the fine particles generated by the fine particle generating means. A fine particle classifying means for classifying in a sheath gas; collecting fine particles classified by the fine particle classifying means on a substrate; and collecting a substance generated by applying a laser beam to a second target body on the substrate. And a depositing means for depositing the classified fine particles and a substance generated by applying a laser beam to the second target body on the substrate. . 2. The depositing means collects, on the substrate, a substance generated by applying a laser beam to a second target body at substantially the same time as collecting the classified fine particles on the substrate. The functional material manufacturing apparatus according to claim 1, wherein the fine particles are dispersed and deposited in a substance composed of the second target body. 3. The deposition means, after depositing the classified fine particles on a substrate, collects a substance generated by applying a laser beam to a second target body on the substrate, and collects the substance on the substrate. 2. The functional material producing apparatus according to claim 1, wherein the substance composed of the fine particles and the second target body are alternately deposited. 4. The functional material producing apparatus according to claim 1, wherein said fine particle classifying means uses a differential type electric mobility classifying means. 5. The fine particle classification means includes fine particle charging means for charging the fine particles using a radioisotope, and differential electric mobility classification means for classifying the charged fine particles. The functional material producing apparatus according to any one of claims 1 to 3. 6. The fine particle classification means includes fine particle charging means for charging the fine particles using a vacuum ultraviolet light source, and differential electric mobility classification means for classifying the charged fine particles. The functional material producing apparatus according to any one of claims 1 to 3. 7. The method according to claim 1, wherein said fine particle generating means uses said laser beam as a pulse laser beam and charges the generated fine particles in an ablation plume formed by a pulse laser. A functional material manufacturing apparatus according to any one of the above. 8. The method according to claim 5, wherein the deposition unit measures, as a current, the transfer of electrons performed when the classified charged fine particles are deposited. Functional material production equipment. 9. The method according to claim 1, wherein the pressure of the fine particle generating means is set to the first pressure.
And maintaining the pressure of the deposition means at an optimal pressure for depositing a substance generated from the second target body. The functional material manufacturing apparatus according to any one of claims 1 to 8, wherein 10. The depositing means further comprises a target exchange mechanism for exchanging the second target object with a third target object, wherein the substance composed of the classified fine particles and the second target object is provided. After the deposition, the second target body is replaced with a third target body, and a substance generated by irradiating a transparent electrode material as a third target material with a laser beam is subjected to the classified fine particles and the second target material. 10. The functional material producing apparatus according to claim 1, wherein the transparent electrode is formed by depositing the transparent electrode on a substance composed of the second target body. 11. The functional material producing apparatus according to claim 10, wherein the deposition unit performs deposition on both or one of the second target body and the third target body by sputtering. . 12. The apparatus according to claim 1, wherein the depositing means deposits a substance composed of the classified fine particles and a second target body in a direction normal to the substrate. 12. The functional material production apparatus according to any one of items 11 to 12. 13. The method according to claim 1, wherein the fine particle classification means classifies the fine particles with an average particle diameter such that the band gap energy of the material of the fine particles is in a visible light region. The functional material production apparatus according to the above. 14. In a fine particle generating means, fine particles are generated under a medium gas atmosphere, and said fine particles are introduced into said fine particle classifying means. A functional material produced by classifying and depositing the classified fine particles together with a substance generated by laser ablation on a substrate. 15. The functional material according to claim 14, wherein classification is performed with an average particle size such that the band gap energy of the fine particles is in a visible light region. 16. The fine particles are generated in a medium gas atmosphere in the fine particle generating means, and the fine particles are introduced into the fine particle classifying means. In the fine particle classifying means, the fine particles have a band gap energy in the sheath gas. Light is characterized by being classified by an average particle size such that it becomes a visible light region, and formed by forming a layer in which the classified fine particles are dispersed in a substance generated by laser ablation on a substrate. Functional element. 17. The optical function device according to claim 16, wherein the visible light region is a wavelength region corresponding to each of red, blue, and green.