JPH06128756A - Device for forming fine-particle film - Google Patents

Abstract

PURPOSE:To provide a device for forming a thin film of fine particles. CONSTITUTION:The raw gas 2 introduced into a gas decomposing chamber 1 is decomposed by a microwave generator 3 to form fine particles, the fine particles are passed through a contracting and expanding nozzle 6, the formed fine-particle current is ionized by a filament 8, and the ionized fine-particle current is deflected by a counter electrode 10 to form a fine-particle film of desired diameter on a substrate 12. Consequently, a fine-particle film reduced in particle diameter distribution and having a uniform physical property in the film plane is obtained.

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 thin film made of fine particles, and more particularly to an apparatus for producing a fine particle film made of fine particles having a uniform particle size and having uniform physical properties within the film surface. In the present specification, the fine particles mean ultrafine particles and general fine particles. Here, the ultrafine particles are ultrafine particles (generally 0.5% or less) obtained mainly by a gas phase reaction or a liquid phase reaction.
(μm or less) particles. General fine particles are mechanically pulverized,
Fine particles obtained by a method such as precipitation treatment.

[0002]

2. Description of the Related Art Fine particles have physical properties not found in bulk crystals and have received a great deal of attention. Since such fine particles have a small particle size, a quantum confinement effect appears, a quantum size effect appears with a decrease in the number of atoms, and the number of surface atoms increases compared to the number of internal atoms, so that the surface phenomenon becomes remarkable. The effect will appear. Further, recently, a technique has been developed in which Si, which does not emit light in a bulk, emits light by forming ultrafine particles due to an indirect transition semiconductor. In addition to this, there are application examples in which fine particles are used as a lubricant with low friction, and the application range of fine particles is extremely diverse.

As a method for producing the fine particles, vapor phase reaction, gas vaporization method, plasma vaporization method, gas phase chemical reaction method, and further liquid phase reaction, colloidal precipitation method, solution spraying heat are used. A decomposition method and the like can be mentioned. Among these manufacturing methods, a manufacturing method using a gas phase reaction is generally a method in which a fine particle material gas is mixed with a carrier gas and introduced into a growth chamber to generate fine particles in the growth chamber. In this vapor phase reaction method, a growth chamber and a high-vacuum chamber adjacent to the growth chamber are connected via a nozzle to extract fine particles as a particle beam from the nozzle and irradiate this beam on a substrate to grow a fine particle film. be able to. By using this method, the spread of the particle beam can be adjusted and the flow velocity can be changed by changing the nozzle shape.

[0004]

The fine particles have the property that their physical properties vary greatly depending on their particle size. Therefore, if the particle size has a distribution within the aggregate of particles, the physical properties also have a distribution. For example, in the light emission phenomenon of Si ultrafine particles, the emission peak wavelength shown by one Si fine particle changes depending on the particle size. Therefore, the emission spectrum from the ultrafine particle film, which is an aggregate of Si ultrafine particles, will be broad if the particle size is distributed. In the process of producing fine particles, it is possible to control the particle size to some extent by changing the parameters. For example, in the case of growing fine particles by a liquid phase reaction, the particle size is controlled by changing the solution concentration, liquid temperature, and the like. Further, in the production of fine particles in the gas phase reaction, the particle size can be controlled by a method such as adjusting the flow rates of the raw material gas and the carrier gas. However, even if these methods are applied, it is difficult to completely control the particle size, and it is also difficult to narrow the particle size distribution.

In view of the above problems, it is an object of the present invention to produce a fine particle film having a desired particle size, a small particle size distribution and uniform physical properties in the film plane.

[0006]

The above-mentioned objects can be achieved by the present invention described below.

That is, the first aspect of the present invention is that the means for producing a fine particle stream, the means for ionizing the fine particles in the fine particle stream produced by the fine particle stream producing means, and the deflection of the fine particle stream ionized by the ionizing means. The second aspect of the present invention is a device for producing a fine particle film, comprising: a means for ionizing the fine particles; an accelerating means for accelerating the fine particles ionized by the ionizing means; An apparatus for producing a fine particle film, which is provided with a means for deflecting a fine particle flow.

In the first aspect of the present invention, the means for producing a fine particle stream may be means for producing fine particles from a raw material gas and converting them into fine particle streams, or means for converting already produced fine particles into fine particle streams. . This fine particle stream is ionized into positive or negative ions by the ionization means.

In the second aspect of the present invention, the fine particles to be ionized may be a fine particle stream or may be stationary fine particles. The fine particles are ionized into positive or negative ions by the ionizing means, and the ionized fine particles are accelerated by the accelerating means to form a fine particle stream.

In the present invention, the above-mentioned ionized particle flow can be deflected by the deflecting means to irradiate the position determined according to the mass, or only the particles having a specific mass can be collected and deposited. .

As the deflecting means, for example, a magnetic field or / and an electric field applied in a direction perpendicular to the fine particle flow is used to irradiate a position determined according to the mass / charge ratio or to specify the position. Only fine particles with a mass / charge ratio of can be recovered.

As an example of the apparatus for producing a fine particle film of the present invention,
The Si ultrafine particle film manufacturing apparatus will be described. FIG. 1 shows the configuration diagram. This device is mainly used for gas decomposition chamber 1,
It comprises a deposition chamber 7. The deposition chamber 7 is connected to a turbo pump through a vacuum exhaust nozzle 13 and is in a high vacuum. A raw material gas 2 mixed with a carrier gas is introduced into the gas decomposition chamber 1. In the case of this device, SiH _{4 is used} as a source gas and H is used as a carrier gas.
₂ , Ar, etc. are used. On the other hand, the microwave generated by the microwave generator 3 is transmitted through the waveguide 4 and the microwave introduction window 5
Is introduced into the gas decomposition chamber 1. The microwave introduction window 5 is made of quartz glass for maintaining a vacuum and transmitting microwaves. Plasma is generated in the gas decomposition chamber 1 by this microwave, and SiH of the raw material gas is generated.
₄ is decomposed and activated Si ultrafine particles are generated. The activated Si ultrafine particles move toward the deposition chamber 7 due to the pressure difference between the gas decomposition chamber 1 and the deposition chamber 7. At this time, the ultrafine particles pass through the reduction / expansion nozzle 6, where the thermal energy is converted into kinetic energy, and at the outlet thereof, a fine particle flow having a velocity of about the speed of sound is formed. The reduction / expansion nozzle 6 may be any one as long as the opening area is gradually narrowed from the gas decomposition chamber 1 side and the opening area is gradually expanded again from the middle, but in order to suppress the spread of the ejected fine particle flow, the accumulation is performed. It is desirable that the inner peripheral surface of the chamber side outlet is substantially parallel to the central axis.

In the present apparatus, the particle flow is generated by utilizing the pressure difference between the two chambers. However, the present invention is not limited to such a structure, and as the particle generating means,
For example, a method of evaporating a raw material using a K cell in vacuum can be used.

The Si ultrafine particles introduced into the deposition chamber 7 after passing through the reduction / enlargement nozzle 6 have an ultrafine particle flow having a substantially constant flow velocity. The ultrafine particles are ionized by the filament 8. Ultrafine particles in filament 1
Filament power supply 9 adjusted to be valence ions
It is connected to the. Besides such filament,
As the ionization means for the fine particles, ionization by irradiation with electromagnetic waves such as ultraviolet light and X-rays can be applied. Further, the ultrafine particles ionized by the filament 8 pass between the counter electrodes 10 arranged so as to sandwich the flow of the ultrafine particles. A voltage is applied to this electrode by the power supply 11. The ultrafine particles that have passed through the counter electrode 10 reach the substrate 12 and are deposited.

FIG. 2 shows the periphery of the counter electrode 10 and the substrate 12. In this figure, the direction of the ultrafine particle flow is shown as the x direction, and the direction of the electric field generated by the counter electrode 10 is shown as the y direction.
The velocity of the ultrafine particles in the x direction is almost constant, and this is designated as v ₀ . Further, the weight of the ultrafine particles is m, the length of the counter electrode 10 in the x direction is l ₁ , the distance from the terminal end of the counter electrode 10 to the substrate in the x direction is l ₂ , and the magnitude of the electric field by the counter electrode 10 is Put E. At this time, the difference Δy between the arrival position of the Si ultrafine particles that have passed through the above system on the substrate 12 and the arrival position when there is no electric field due to the counter electrode 10 is

[0016]

[Equation 1] It is represented by. Here, e is the elementary charge. On the other hand, m is the radius a of ultrafine particles and the density ρ

[0017]

[Equation 2] Therefore, equation (1) is

[0018]

[Equation 3] Becomes That is, the arrival position differs depending on the particle size,
Further, the distribution of particle size at each position is reduced. Further, by disposing the substrate at a position where the desired particle size reaches, a Si ultrafine particle film having a desired particle size can be obtained.

As another example of the apparatus for producing a fine particle film of the present invention, an example of an apparatus for producing a Si ultrafine particle thin film will be given. The configuration of this device is as shown in FIG. This apparatus mainly comprises a gas decomposition chamber 1, an ionization / acceleration chamber 16, an electric field application chamber 17, a magnetic field application chamber 22, and a substrate chamber 27.
It consists of The electric field applying chamber 17 and the magnetic field applying chamber 22 have structures similar to those of the electric field and magnetic field applying portions of the double focusing mass spectrometer. In the apparatus shown in FIG. 1, since the flow velocity of the ultrafine particles ejected from the reduction / enlargement nozzle 6 has a slight distribution, the particle size of the ultrafine particle film deposited on the substrate 12 varies depending on the formula (3). Although the distribution remains, the present apparatus suppresses the influence of this flow velocity distribution and narrows the particle size distribution, so that a film composed of fine particles having a more uniform particle size can be produced. The structure and operation of the gas decomposition chamber 1 are the same as those of the apparatus shown in FIG. The ultrafine Si particles ejected from the contraction / expansion nozzle 6 are ionized by the filament 8 as in the apparatus shown in FIG. The ionized Si ultrafine particles are accelerated by the acceleration electrode 14.

Similarly to the above, if the density of Si is ρ, the radius of the Si ultrafine particles is a, the velocity of the Si ultrafine particles at the outlet of the contraction / expansion nozzle 6 is v ₀ , and the acceleration voltage of the acceleration electrode 14 is V ₁ , acceleration is performed. The velocity of the subsequent Si ultrafine particles is v ₁ .

[0021]

[Equation 4] And by increasing the accelerating voltage, v in v ₁
The influence of ₀ becomes small. That is, even if there is a distribution in the velocity of the fine particles ejected from the reduction / enlargement nozzle 6, the electric field acceleration at the acceleration electrode 14 significantly reduces the error rate. The accelerated Si ultrafine particles are introduced into the electric field application chamber 17. The electric field applying chamber 17 has an arc shape, and an electric field is applied in a direction perpendicular to the particle flow by an electrode 18 connected to a power source 19 for an electrode in the electric field chamber. Further, a slit 21 is installed at the outlet of the electric field applying chamber 17. When the magnitude of the electric field formed by the electrode 18 is E and the radius of the arc of the electric field applying chamber 17 is r ₁ ,

[0022]

[Equation 5] Ultrafine particles that satisfy the requirements pass through the center. The electric field application chamber 17 has an effect of correcting the energy distribution obtained by the particles at the acceleration electrode 14. The Si ultrafine particles that have passed through the center of the electric field application chamber 17 are introduced into the magnetic field application chamber 22 through the slit 21. The magnetic field application chamber 22 also has an arc shape, and a magnetic field is applied in the direction perpendicular to the particle flow by the electromagnet 23 connected to the electromagnet power supply 24. Further, a slit 26 is installed at the outlet of the magnetic field applying chamber 22. When the magnitude of the magnetic field formed by the electromagnet 23 is B and the radius of the arc of the magnetic field applying chamber 22 is r ₂ ,

[0023]

[Equation 6] The ultra-fine particles satisfying the condition pass through the center of the magnetic field application chamber 22. Si passing through the center of the magnetic field applying chamber 22
The ultrafine particles pass through the slit 26 and are deposited on the substrate 28. The radii of ultrafine particles deposited by this device are the same as those in (5) and (6)
Depending on the formula, by adjusting E and B, a Si ultrafine particle film having a desired particle size can be obtained. In the figure, reference numerals 20, 25 and 29 are vacuum exhaust nozzles. In this device, an electric field applying means including an electric field applying chamber 17 is provided as a means for deflecting the ionized particle flow.
Further, although a magnetic field applying means composed of the magnetic field applying chamber 22 is provided, in the present invention, the particle size of the particles can be controlled even if such a deflecting means for the particle flow is constituted by only the magnetic field applying means. However, in this case
It is inferior in controllability to the device shown in FIG.

[0024]

EXAMPLES Examples of the present invention will be described below.

Example 1 In this example, an apparatus for producing a fine particle film of the present invention as shown in FIG. 1 was produced, and an ultrafine Si particle film was formed using the apparatus.

In this apparatus, it was possible to deposit Si ultrafine particles having a desired particle size on the substrate 12 in a state where the particle size distribution was small. Si with a small particle size distribution formed in this example
The ultrafine particle film showed a PL spectrum having a narrower peak than the Si ultrafine particle film formed by the conventional apparatus.

Example 2 In Example 1, an electric field was used to deflect the moving direction of the fine particles, but the same effect can be obtained by using a magnetic field. In the case of an electric field, the particle size distribution is parallel to the electric field, but when a magnetic field is used, the distribution is perpendicular to the magnetic field.

In this embodiment, an electromagnet was used instead of the counter electrode 10, and a magnetic field was applied in the direction perpendicular to the particle flow to deflect the particle flow.

The Si ultrafine particle film formed in this example showed a PL spectrum having a narrow peak, as in Example 1.

Example 3 In this example, an apparatus for producing a fine particle film of the present invention as shown in FIG. 3 was prepared, and an ultrafine Si particle film was formed using the apparatus.

In the present apparatus, the magnitude of the electric field formed by the electrode 18 in the electric field application chamber 17 and the magnitude of the magnetic field formed by the electromagnet 23 in the magnetic field application chamber 22 are adjusted to obtain an arbitrary particle size. An ultrafine particle film could be formed.

The Si ultrafine particle film formed in this example showed a PL spectrum having a much narrower peak than those in Examples 1 and 2.

Fourth Embodiment In the third embodiment, the influence of the energy distribution of the fine particles obtained by the acceleration electrode 14 is eliminated by providing the electric field application chamber 17, but without the electric field application chamber. The particle size of the fine particles can be controlled. However, the monochromaticity of the particle size distribution is not so good as in Example 3.

[0034]

As described above, by using the apparatus of the present invention, a fine particle film having a desired particle size, a small particle size distribution, and uniform physical properties in the film surface can be obtained.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an example of an apparatus for producing a fine particle film of the present invention.

FIG. 2 is a diagram for explaining deflection of a fine particle flow in the peripheral portion of a counter electrode 10 and a substrate 12 of the apparatus of FIG.

FIG. 3 is a configuration diagram showing another example of the apparatus for producing a fine particle film of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Gas decomposition chamber 2 Raw material gas, carrier gas 3 Microwave generator 4 Waveguide 5 Microwave introduction window 6 Reduction / expansion nozzle 7 Deposition chamber 8 Filament 9 Filament power supply 10 Counter electrode 11 Power supply 12 Substrate 13 Vacuum exhaust nozzle 14 Acceleration Electrode 15 Accelerating electrode power supply 16 Ionization / acceleration chamber 17 Electric field applying chamber 18 Electrode 19 Electric field chamber inner electrode power supply 20 Vacuum exhaust nozzle 21 Slit 22 Magnetic field applying chamber 23 Electromagnet 24 Electromagnet power supply 25 Vacuum exhaust nozzle 26 Slit 27 Substrate Chamber 28 Substrate 29 Vacuum exhaust nozzle

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kasatoshi Kawade 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (5)

[Claims] 1. A means for producing a stream of fine particles, a means for ionizing the fine particles in the stream of fine particles produced by the means for producing fine particle flow, and a means for deflecting the stream of fine particles ionized by the ionizing means. Fine particle film manufacturing equipment. 2. A fine particle film production comprising means for ionizing fine particles, accelerating means for accelerating the fine particles ionized by the ionizing means, and means for deflecting the fine particle flow accelerated by the accelerating means. apparatus. 3. The means for deflecting the particulate stream comprises:
The fine particle film manufacturing apparatus according to claim 1 or 2, which is a means for applying an electric field in a direction perpendicular to the fine particle flow. 4. A means for deflecting the particulate stream comprises:
The fine particle film production apparatus according to claim 1 or 2, which is a means for applying a magnetic field in a direction perpendicular to the fine particle flow. 5. The means for deflecting the particulate stream comprises:
3. The apparatus for producing a fine particle film according to claim 1, which is a means for applying an electric field in a direction perpendicular to the particle flow and a means for applying a magnetic field in a direction perpendicular to the particle flow.