JPS61274106A - Flow controlling method of corpuscular flow - Google Patents

Abstract

PURPOSE:To regulate a state of contact between a gaseous molecule and a corpuscule accurately, by controlling the length of a flow passage at the downstream side of a contraction-expansion nozzle being installed in the flow passage. CONSTITUTION:A contraction-expansion nozzle 1 being installed in a flow passage is gradually throttle in its opening area toward an intermediate part from an inflow port 1a, coming to a throat part 2, while its opening area is gradually expanded toward an outflow port 1b from this throat part 2. A degree of contact of a corpuscule with a gaseous molecule while being transferred inside a downstream chamber 4 is controlled by what the length of a flow passage inside this downstream chamber 4 is regulated. Control of the passage length is carried out with a base body 6 moved in a passage direction. Therefore, a state of contact between the gaseous molecule and the corpuscule is accurately regulable.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a method for controlling the flow of particulates used for transporting and spraying of particulates. It is expected that it will be applied to the formation of materials, doping processing, and new formation sites for fine particles.

In this specification, fine particles refer to atoms-molecules, ultrafine particles, and general fine particles. Here, ultrafine particles are, for example,
Evaporation method in gas, plasma evaporation method using gas phase reaction,
Obtained by gas phase chemical reaction method, colloidal precipitation method, solution spray pyrolysis method, etc. using liquid phase reaction,
Ultra-fine (generally 0.5 Ji, g or less) particles. General fine particles refer to fine particles obtained by general methods such as mechanical crushing or precipitation precipitation treatment. A jet stream whose cross-sectional area is approximately constant in one direction, and its cross-sectional shape does not matter.

[Prior Art] Generally, fine particles are dispersed and suspended in a carrier gas and transported by the flow of the carrier gas.

Conventionally, the control of the flow of fine particles accompanying the transfer of fine particles has been carried out simply by dividing the entire flow path of the fine particles flowing together with the carrier gas with one pipe material or a housing based on the differential pressure between the upstream side and the downstream side. do not have. Therefore, although the flow of particles varies in strength and weakness, the flow of particles inevitably occurs in a dispersed state throughout the pipe material or casing that defines the flow path for particles.

Furthermore, when spraying fine particles onto a substrate, the fine particles are jetted out together with a carrier gas through a nozzle. The nozzle used to spray the fine particles is a simple parallel tube or a tapered nozzle, and the jet cross section of the fine particles immediately after being ejected is certainly narrowed down according to the area of the nozzle end face. However, since the jet is diffused at the exit surface of the nozzle, the flow path is merely temporarily constricted, and the speed of the jet does not exceed the speed of sound.

[Problems to be Solved by the Invention] By the way, it is possible to divide the entire flow path of fine particles with a pipe material or a casing, and to transport the fine particles together with a carrier gas along this flow path using a differential pressure between the upstream side and the downstream side. Therefore, it is impossible to expect such a high transfer speed. Further, it is difficult to avoid contact between the particles and the wall surface of the tube or casing that defines the flow path of the particles over the entire transfer section.

For this reason, when moving particularly active particulates to their collection position, it is easy for the activity to disappear over time or due to contact with the pipe material or the wall of the casing, and the activity tends to be lost due to contact with the reaction gas during the transfer. There is a problem that it is difficult to carry out processing such as causing a reaction. In addition, if the entire flow path for particles is divided by pipe material or a housing, the collection rate of transferred particles will decrease due to the generation of dead spaces in the flow, and the efficiency of using carrier gas for particle transfer will also decrease. .

On the other hand, in conventional parallel tubes and tapered nozzles, the jet stream that passes through it becomes a diffuse flow with a large density distribution of particles. Therefore, when spraying fine particles onto a substrate, it is difficult to control uniform spraying. Furthermore, uniform spraying makes it difficult to control the area.

[Means for Solving the Problems] The measures taken to solve the above problems are explained with reference to FIG. 1, which is an explanatory diagram of the basic principle of the present invention. , the above-mentioned problem is solved by a flow control method of a particulate flow that controls the length of the flow path on the downstream side of the contraction/expansion nozzle l.

The contracting/expanding nozzle l in the present invention is a throat section 2 whose opening area is gradually narrowed from the inlet 1a toward the middle section, and whose opening area is gradually expanded from the throat section 2 toward the outlet 1b. This refers to the nozzle that is In Figure 1,
For convenience of explanation, the inflow side and outflow side of the contraction/expansion nozzle 1 are as follows.
It is connected to an upstream chamber 3 and a downstream chamber 4, each of which is a closed system. However, the inflow side and the outflow side of the contraction/expansion nozzle l in the present invention can be a closed system if a differential pressure can be generated between the two and the particles can be passed along with the carrier gas while being exhausted on the downstream side. It may also be an open system.

[Function] For example, as shown in FIG.
When the inside is evacuated by the vacuum pump 5, a pressure difference is created between the upstream chamber 3 and the downstream chamber 4. Therefore, the supplied carrier gas containing fine particles flows from the upstream chamber 3 through the contraction/expansion nozzle 1 and flows into the downstream chamber 4 .

By the way, the contraction/expansion nozzle 1 has a pressure ratio P/P between the pressure Po of the upstream chamber 3 and the pressure P of the downstream chamber 4, and the opening surface of the throat portion 2! ! By adjusting the ratio A/A'' between A' and the opening area A of the outlet 1b, the flow of particles ejected together with the carrier gas can be increased.Then, the pressure ratio in the upstream chamber 3 and downstream chamber 4 can be If P/Pa is larger than the critical pressure ratio, the outlet flow velocity of the contraction-expansion nozzle l becomes a subsonic flow,
The fine particles are decelerated and ejected together with the carrier gas. Further, if the pressure ratio is below the critical pressure ratio, the contraction/expansion nozzle 1
The outlet flow velocity becomes a supersonic flow, and the fine particles can be ejected together with the carrier gas at a super high speed.

Here, the velocity of the particle flow is U, and the sound velocity at that point is a.
, the specific heat ratio of the particulate flow is γ, and assuming that the particulate flow is a compressible one-dimensional flow and expands adiabatically, the Matzuha number M reached by the particulate flow is given by the following equation from the pressure Po in the upstream chamber and the pressure P in the downstream chamber. It is determined by the formula, especially when P/P is less than the critical pressure ratio, M
is 1 or more.

Note that the sound velocity a can be determined by the following equation, where T is the local temperature and R is the gas constant.

a = "i" Also, the opening area A of the outflow hole 1b and the opening area A of the throat part 2
・and Matsuha's number M have the following relationship.

Therefore, the opening area ratio A/A is determined according to the number M determined from equation (1) by the pressure ratio P/Pa of the pressure Po of the upstream chamber 3 and the pressure P of the downstream chamber 4, By adjusting P/Pa according to M determined from equation (2), it is possible to adjust the flow velocity of the particulate flow ejected from the expansion/contraction nozzle l.The velocity U of the particulate flow at this time is determined by the following (3). ) can be obtained using the formula.

The flow state of the above-mentioned particulate flow can be controlled by keeping the pressure ratio P/P of the pressure Po of the upstream chamber 3 and the pressure P of the downstream chamber 4 constant, provided that the temperature inside the upstream chamber 3 is constant. /A”
A constant state determined by will be maintained.

In the above-mentioned ejection where the pressure ratio is less than the critical pressure ratio, the ejected carrier gas and the particles form a uniform diffusion flow, making it possible to uniformly spray the particles over a relatively wide range at once.

On the other hand, when particles are ejected in a fixed direction along with carrier gas as a supersonic flow as described above, the carrier gas and particles travel straight while maintaining almost the jet cross section immediately after ejection.
Beamed. Therefore, the flow of particles carried by this carrier gas is also converted into a beam, which moves through the space within the downstream chamber 4 with minimal diffusion, in a spatially independent state without interference with the wall surface of the downstream chamber 4, and at supersonic speeds. It will be transported by

For this reason, it is possible, for example, to form active particles in the upstream chamber 3 and transfer them directly into a beam through the contraction/expansion nozzle 1, or to activate them within the contraction/expansion nozzle 1 or immediately after the contraction/expansion nozzle 1. If we form fine particles with 1 and directly transport them into a beam, we can transport them as supersonic beams that are spatially independent.
For example, it can be deposited and collected on a substrate 6 provided in the downstream chamber 4. Therefore, it becomes possible to collect fine particles in a good active state. Further, since the fine particles are sprayed onto the substrate 6 as a beam whose jet cross section is substantially constant in the flow direction, the area of this spraying can be easily controlled.

In addition to transferring the particles as described above, for example, a gas that reacts with the particles is supplied into the downstream chamber 4 within a range that does not damage the low pressure of the downstream chamber 4, and while the particles are being transferred, this gas and the particles When the particles are collected on the substrate 6 through a contact reaction, it is necessary to control the particles so that they come into sufficient contact with the gas molecules. By the way, if the mean free path length of the gas molecules in the downstream chamber 4 is expressed as a sentence, it can be considered that the gas molecules exist in the downstream chamber 4 at intervals of beams. Therefore, assuming that the mean free path length of the gas molecules in the downstream chamber 4 is constant, the degree to which fine particles come into contact with the gas molecules while being transferred within the downstream chamber 4 depends on the length of the flow path within the downstream chamber 4. Can be controlled by adjusting. This flow path length can be controlled, for example, by moving the base 6 in the flow path direction.

Here, if the diameter of the gas molecules in the downstream chamber 4 is σ, and the number of molecules per unit volume is n, then the mean free path length intersection can be approximately determined by the following equation (4).

Also, if the mass of a gas molecule is m, its density ρ is ρ=
Since m n, the above equation (4) can be transformed into the following equation (4').

In equation (4') above, m and σ are constant values determined by the type of gas, so the sentence can be adjusted by ρ, and ρ
By keeping constant, the sentence can be kept constant.

On the other hand, ρ is determined by the following equation (5), where the gas constant is R1 and the temperature in the downstream chamber 4 is t.

Therefore, ρ can be controlled by adjusting the pressure P or temperature t of the downstream chamber 4. Further, as described above, if the temperature in the upstream chamber 3 is constant, the velocity of the particulate flow ejected from the same contraction/expansion nozzle 1 is determined by P/Pa. Therefore, if P/Po is kept constant when controlling the gas molecule density ρ to be constant, the same velocity of the particle flow can be maintained. Especially when the active life of fine particles is short, at a rate determined by A/A'' and P/PO,
If the length of the flow path in the downstream chamber 4 is set so that the flow can flow within this life, and if the gas molecule density p is controlled and P/Pa is kept constant, it is possible to sufficiently bring the particles into contact with the gas molecules in the active state of the particles. can.

[Example] Fig. 2 is a schematic diagram of an example in which the present invention is applied to a film forming apparatus using ultrafine particles.
is an upstream chamber, 4a is a first downstream chamber, and 4b is a second downstream chamber.

The upstream chamber 3 and the first downstream chamber 4a are configured as an integrated unit, and the first downstream chamber 4a also has a unit/unit, respectively.
), the gate valve 8, and the second downstream chamber 4b are sequentially connected to each other so as to be connectable and separable via a flange having a common diameter (hereinafter referred to as "common flange"). The upstream chamber 3, the first downstream chamber 4a, and the second downstream chamber 4b are kept at a lower pressure stepwise from the upstream chamber 3 to the second downstream chamber 4b by an exhaust system described later.

A gas phase excitation device 9 is attached to one side of the upstream chamber 3 via a common flange. This gas phase excitation device 9 generates active ultrafine particles using plasma, and sends out the ultrafine particles together with a carrier gas such as hydrogen, helium, argon, nitrogen, etc. to the contraction/expansion nozzle 1 located on the opposite side. It is. In order to prevent the formed ultrafine particles from adhering to the inner surface of the upstream chamber 3, an anti-adhesion treatment may be applied to the inner surface of the upstream chamber 3. In addition, the ultrafine particles that were generated were
Since the first downstream chamber 4a is under a lower pressure than the upstream chamber 3, the pressure difference between the two causes the carrier gas to flow directly through the contraction/expansion nozzle 1 and into the first downstream chamber 4a. It turns out.

As shown in FIG. 3(a), the gas phase excitation device 9 includes a rod-shaped first electrode 8a disposed within a tubular second electrode Sb, and a carrier gas and a raw material gas supplied into the second electrode sb. Thus, a discharge is caused between both electrodes 9a and 9b. Further, the gas phase excitation device 9, as shown in FIG. 3(b),
The first electrode 8a provided in the second electrode 9b may be a porous tube to supply carrier gas and raw material gas between the two electrodes 9a and 9b through the inside of the first electrode 8a. As shown, both half-tubular electrodes 9a, 9
b are joined in a tubular shape via an insulating material 9C, and both electrodes 9a,
It is also possible to supply the carrier gas and source gas into the tube formed by 9b.

The contraction/expansion nozzle 1 has an inlet 1a opened in the upstream chamber 3 at the side end of the first downstream chamber 4a on the upstream chamber 3 side, and the first downstream chamber 4
The outflow port 1b is opened at a, and the upstream chamber 3 is protruded into the upstream chamber 3, and is attached via a common flange. However, the contraction/expansion nozzle 1 may be installed in a state in which it projects into the first downstream chamber 4a. The direction in which the contraction/expansion nozzle 1 should be projected may be selected depending on the size, amount, properties, etc. of the ultrafine particles to be transferred.

As mentioned above, the contraction/expansion nozzle l is the inlet 1a.
It is sufficient if the opening area is gradually narrowed down to form the throat part 2, and then the opening area is gradually expanded again to form the outflow port 1b, which is shown enlarged in Fig. 4(a). As such, it is preferable that the inner circumferential surface near the outlet lb is substantially parallel to the central axis. This is because the direction of flow of the carrier gas and ultrafine particles to be ejected is influenced to some extent by the direction of the inner circumferential surface near the outlet lb, so that it is possible to make the flow parallel to each other as easily as possible. However, as shown in FIG. 4(b), if the angle α of the inner circumferential surface from the throat portion 2 to the outlet 1b with respect to the central axis is set to 7° or less, preferably 5° or less, a peeling phenomenon occurs. In this case, it is not necessary to form the above-mentioned parallel portion, since the flow of the ejected carrier gas and ultrafine particles is maintained substantially uniformly. By omitting the formation of the parallel portion, the contraction/expansion nozzle 1 can be manufactured easily. Also, the reduction/expansion nozzle 1
If it is rectangular as shown in Figure 4(C),
Carrier gas and ultrafine particles can be ejected in a slit shape.

Here, the separation phenomenon is a phenomenon in which when there is a protrusion or the like on the inner surface of the contraction/expansion nozzle 1, the boundary layer between the inner surface of the contraction/expansion nozzle 1 and the flowing fluid becomes large and the flow becomes non-uniform. The faster the jet flow, the more likely it is to occur. In order to prevent this peeling phenomenon, the above-mentioned angle α is preferably made smaller as the inner surface finish accuracy of the reduction and expansion nozzle 1 is inferior.
0.1, three or more inverted triangular marks representing surface finish accuracy, optimally four or more, are preferred. In particular, the peeling phenomenon at the enlarged part of the contraction/expansion nozzle 1 may cause damage to the subsequent carrier gas and ultrafine particles. Since this greatly affects the flow, the reduction/expansion nozzle 1 can be manufactured easily by determining the finishing accuracy with emphasis on this enlarged portion. In addition, in order to prevent the occurrence of peeling phenomenon, the throat part 2
must be a smooth curved surface, and the differential coefficient in the cross-sectional area change rate must not be (1).

The material of the contraction/expansion nozzle l is, for example, iron.

In addition to stainless steel and other metals, acrylic resin,
A wide variety of materials can be used, including synthetic resins such as polyvinyl chloride, polyethylene, polystyrene, and polypropylene, ceramic materials, quartz, and glass. This material may be selected in consideration of non-reactivity with the generated ultrafine particles, processability, gas release properties in a reduced pressure system, etc. Furthermore, the inner surface of the contraction/expansion nozzle 1 can be plated or coated with a material that is less likely to cause adhesion or reaction of ultrafine particles. Specific examples include polyfluoroethylene coating.

The length of the contraction/expansion nozzle 1 can be arbitrarily determined depending on the size of the device and the like. By the way, contraction/expansion nozzle 1
When flowing through the carrier gas and ultrafine particles, the thermal energy they possess is converted into kinetic energy. Particularly when ejected at supersonic speed, the thermal energy becomes significantly small, resulting in a supercooled state. Therefore, if the carrier gas contains condensed components, it is also possible to actively condense them by the supercooled state, thereby forming ultrafine particles. Since the formation of ultrafine particles by this is homogeneous nucleation, it is easy to obtain homogeneous ultrafine particles. Further, in this case, in order to perform sufficient condensation, it is preferable that the contraction/expansion nozzle 1 be long. On the other hand, when condensation occurs as described above, thermal energy increases and velocity energy decreases. Therefore, in order to maintain high-speed jetting, it is preferable that the contraction/expansion nozzle 1 be short.

The relationship between the pressure ratio P/P of the pressure Po in the upstream chamber 3 and the pressure P in the first downstream chamber 4a, and the ratio A/A'' between the opening area A of the throat portion 2 and the opening area of the outflow port 1b is expressed as follows: By making appropriate adjustments and allowing it to flow through the contraction/expansion nozzle 1, the carrier gas containing ultrafine particles is converted into a beam and flows at supersonic speed from the first downstream chamber 4a to the second downstream chamber 4b. .

The simmerer 7 is configured to adjust the opening area between the first downstream chamber 4a and the second downstream chamber 4b so that the second downstream chamber 4b can maintain a lower pressure than the first downstream chamber 4d. belongs to. Specifically, as shown in FIG. 5, two adjustment plates 11.11' each having a dogleg-shaped notch 10°10' can be slid past each other with their notches 10.10' facing each other. It has been established in This adjustment plate 11.11'' can be slid from the outside, and the opening degree can be adjusted to allow the passage of the beam and maintain a low pressure in the second downstream chamber by adjusting the overlapping condition of the two central portions 10 and 10'. It should be noted that the notch i of the skimmer 7
The shapes of o, io' and the adjustment plates 11, 11' may be semicircular or other shapes in addition to the shapes shown in the drawings.

The gate valve 8 has a weir-shaped valve body 13 that is raised and lowered by turning a handle 12, and is open when the beam is traveling. By closing this gate valve 8, the unit in the second downstream chamber 4b can be replaced while maintaining the low pressure in the upstream chamber 3 and the first downstream chamber 4a. Further, in the apparatus of this embodiment, the ultrafine particles are collected in the second downstream chamber 4b, but if the gate valve 8 is a pole valve or the like, especially when the ultrafine particles are metal particles that are easily oxidized, By replacing the unit of the second downstream chamber 4b together with this Pall valve, there is an advantage that the unit can be replaced without the risk of rapid oxidation.

A base body 6 is located in the second downstream chamber 4b for receiving and depositing ultrafine particles transferred as a beam, and collecting the ultrafine particles in a film-formed state. This base body 6 is attached to the second downstream chamber 4b via a common flange, and is attached to the cylinder 1.
4 is attached to a base holder 16 at the tip of a slide shaft 15 that is slid by a slide shaft 15. A shutter 17 is located on the front side of the base 6, so that the beam can be blocked whenever necessary. Further, the substrate holder 16 is capable of heating or cooling the substrate 6 under optimal temperature conditions for collecting ultrafine particles.

The second downstream chamber 4b includes a leak and purge valve 24e.
A gas that reacts with the ultrafine particles is supplied through the second downstream chamber 4b, and the second downstream chamber 4b is placed under a low pressure in which a reaction gas of a predetermined density exists. Therefore, the ultrafine particles transferred to the second downstream chamber 4b in the form of a beam react with the gas in the second downstream chamber 4b, and then adhere to and be collected on the substrate 6. At this time, by adjusting the position of the base body 6 by expanding and contracting the slide shaft 15, the length of the flow path in the second downstream chamber 4b is controlled, and the frequency of collisions between the transported ultrafine particles and gas molecules is adjusted. can.

Incidentally, glass windows 18 are attached to the upper and lower sides of the upstream chamber 3 and the second downstream chamber 4b through common flanges, respectively, as shown in the figure, so that the inside can be observed. Although not shown, the upstream chamber 3 and the first downstream chamber 4a
Similar glass windows (similar to 18 in the figure) are also installed at the front and rear of the second downstream chamber via common flanges. These glass windows 18 can be removed and replaced with various measuring devices, load lock chambers, etc. via a common flange.

Next, the exhaust system in this embodiment will be explained.

The upstream chamber 3 is connected to a main valve 20 via a pressure regulating valve 19.
connected to a. The first downstream chamber 4a is directly connected to a main valve 20a, and this main valve 20a is connected to a vacuum pump 5a. The second downstream chamber 4b is connected to a main valve 20b, which in turn is connected to a vacuum pump 5b. Furthermore, 2
1a and 21b are main valves 20a and 20b, respectively.
The auxiliary valve 23a is connected to the immediate upstream side of the auxiliary valve 22a and 22b.

The vacuum pump 23b is connected to the vacuum pump 5a and is used to check the inside of the upstream chamber 3, the first downstream chamber 4a, and the second downstream chamber 4b. In addition, 24a-24h are each chamber 3, 4a, 4b and pump 5a, 5b, 21
a, 21b are leak and purge valves.

First, the interference valves 21a and 21b and the pressure regulating valve 1
8, the upstream chamber 3, the first and second downstream chambers 4a, 4
The check in b is performed using the vacuum pumps 20a and 20b.

Next, the auxiliary valves 23a, 23b and the main valves 20a, 2 are closed.
0b is opened, and the vacuum pumps 5a, 5b are used to bring the insides of the upstream chamber 3, the first and second downstream chambers 4a, 4b to the required low pressure.

At this time, by adjusting the opening degree of the pressure regulating valve 19, the pressure in the first downstream chamber 4a is lowered than that in the upstream chamber 3, the carrier gas and the raw material gas are passed through the first downstream chamber 4a, and the pressure in the first downstream chamber 4a is lowered.
-7 in order to lower the pressure in the second downstream chamber 4b.
Adjust with. This adjustment can also be performed by adjusting the opening degree of the main valve 20b. During the process of forming ultrafine particles and forming a film by beam injection, each chamber 3
, 4a and 4b are controlled to maintain a constant low pressure. This control may be done manually, but the pressure inside each chamber 3, 4a, 4b is detected and the pressure regulating valve 1 is controlled based on the detected pressure.
9. This may be done by automatically controlling the opening and closing of the main valves 20a, 20b, skimmer 7, etc. Also,
If the carrier gas and fine particles supplied to the upstream chamber 3 are directly transferred to the downstream side via the contraction/expansion nozzle l, the exhaust gas during transfer will be transferred to the downstream side, that is, the It may be possible to perform only chambers 4a and 4b.

The pressure may be controlled by separately providing the vacuum pumps 5a for the upstream chamber 3 and the first downstream chamber 4a for each chamber 3.4a. If the vacuum pump 5a on the stand is used to exhaust air in the direction of beam flow and the degree of vacuum in the upstream chamber 3 and the first downstream chamber 4a is controlled, even if there is some pulsation in the vacuum pump 5a, there will be a difference in pressure between the two. It is easy to keep constant.

Therefore, there is an advantage that it is easy to maintain a constant flow state that is susceptible to fluctuations in differential pressure.

The suction by the vacuum pumps 5a, 5b is preferably performed from above, especially in the first and second downstream chambers 4a, 4b.By suctioning from above, the descent of the beam due to gravity can be suppressed to some extent. can.

Although this embodiment is as described above, the following modifications are possible.

First, the contraction/expansion nozzle l can be tilted vertically and horizontally, and can be scanned at regular intervals, so that film formation can be performed over a wide range. Particularly, this tilting and scanning is advantageous when combined with the rectangular nozzle shown in FIG. 4(C).

The contraction/expansion nozzle l is formed of an insulator such as quartz.

Microwaves are applied there to form active ultrafine particles in a contraction/expansion nozzle l, or a transparent material is used to irradiate the flow with light having various wavelengths such as ultraviolet, infrared, and laser light. You can also do that. It is also possible to provide a plurality of contraction/expansion nozzles l to generate a plurality of beams at once. In particular, when a plurality of contraction/expansion nozzles l are provided, by connecting each to an independent upstream chamber 3, beams of different particles can be run at the same time. By crossing comrades. It is also possible to form new particles by collisions between different particles.

The base body 6 is held movably or rotatably in the vertical and horizontal directions,
It is also possible to receive the beam over a wide range. Further, by winding up the base body 6 into a roll and sending it out one after another so as to receive the beam, a long base body 6 can also be treated with fine particles. Furthermore, the treatment with fine particles may be performed while rotating the drum-shaped base 6.

In this embodiment, the generation chamber 3, the first downstream chamber 4a, and the second downstream chamber 4b are configured, but the second downstream chamber 4b is omitted and the reaction gas is supplied to the first downstream chamber 4a, and the second downstream chamber 4b is omitted. It is also possible to further connect third, fourth, . . . downstream chambers to the downstream side of the second downstream chamber. Further, by pressurizing the upstream chamber 3, the first downstream chamber 4a can be made into an open system, and by reducing the pressure in the first downstream chamber 4a, the upstream chamber 3 can be made into an open system. In particular, like an autoclave, the upstream chamber 3 is pressurized and the first downstream chamber 4 is pressurized.
It is also possible to reduce the pressure below a.

In this embodiment, active ultrafine particles are formed in the upstream chamber 3, but this is not necessarily necessary, and separately formed particles may be sent to the upstream chamber 3 together with the carrier gas. Further, it is also possible to provide a valve for opening and closing the contraction/expansion nozzle l, and to obtain fine particles by intermittently opening and closing the valve while temporarily storing fine particles in the upstream chamber 3 side. If the valve is opened and closed in synchronization with energy application on the downstream side including the throat section 2 of the contraction/expansion nozzle 1, the burden on the exhaust system can be significantly reduced, and the pulse can be maintained while effectively utilizing the raw material gas. It is possible to obtain a particle flow of . Note that under the same exhaust conditions, the above-mentioned intermittent opening and closing has the advantage that it is easier to maintain a high vacuum on the downstream side. In case of intermittent opening and closing,
A chamber may be provided between the upstream chamber 3 and the contraction/expansion nozzle 1 to temporarily store fine particles.

In addition, a plurality of contraction/expansion nozzles 1 are arranged in series, and the pressure ratio on the upstream side and the downstream side is adjusted respectively.

It is also possible to maintain the beam speed or make each chamber spherical to prevent dead spaces as much as possible.

[Effects of the Invention] According to the present invention, fine particles can be transported as a supersonic beam in a uniformly dispersed state, so that fine particles can be transported in a spatially independent state at super high speed.

Therefore, the active particles can be reliably transported as they are to the collection position, and the contact state between the gas molecules and the particles can be adjusted accurately by controlling the length of the downstream flow path.
Furthermore, by controlling the irradiation surface of the beam, the spraying area can be precisely controlled. In addition, it becomes a focused ultra-high-speed parallel flow called a beam, and when it is made into a beam, thermal energy is converted to kinetic energy, and the particles in the beam become frozen, so we can create a new reaction field that utilizes these. I have high hopes for what I will achieve. Furthermore, according to the flow control device of the present invention,
Since the above-mentioned frozen state occurs, it is also possible to define the microscopic state of molecules in the fluid and handle the transition from one state to another. In other words, it is possible to perform chemical reactions in the gas phase using a new method in which various energy levels of molecules are defined and energy corresponding to those levels is imparted. Furthermore, by providing a field for energy exchange different from conventional ones, it is also possible to easily create intermolecular compounds formed by relatively weak intermolecular forces such as hydrogen bonds and van der Waals bonds.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the basic principle of the present invention, Fig. 2 is a schematic diagram showing an example of the application of the present invention to a film forming method using ultrafine particles, and Figs. 3 (a) to (C) are Each figure shows an example of a gas phase excitation device, FIGS. 4(a) to 4(C) each show an example of the shape of a contraction/expansion nozzle, and FIG. 5 is an explanatory diagram of a skimmer. 1: Reduction/expansion nozzle, la 2 inlet lb 2 outlet, 2: throat, 3: upstream chamber, 4: downstream chamber,
4a: first downstream chamber, 4b: second downstream chamber, 5, 5a, 5b: vacuum pump,
6: Substrate, 7: Skimmer, 8: Gate valve, 9: Gas phase excitation device, 8a: First electrode, 9b: Second electrode, 10.10': Notch, 11, 11''
: Adjustment plate, 12: Handle, 13: Valve body, 14 Niji cylinder, 15 Nishi slide shaft, 16: Substrate holder, 17: Shutter, 18 Ni glass window, 18: Pressure regulating valve, 20a, 20b: Main valve, 21a, 21b :Reducing pump, 22a, 22b :Rabiki valve, 23a, 23
b: Auxiliary valve, 24a to 24h: Leak and purge valve.

Claims (1)

[Claims] 1) A method for controlling the flow of particulates, characterized by providing a contraction/expansion nozzle in a flow path and controlling the length of the flow path on the downstream side of the contraction/expansion nozzle.