JP2016196687A - Fine droplet generator for high melting-point material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fine droplet generator enabled to properly perform the injection of homogeneous fine droplets at a set flow rate of a liquid material, so that a precise mass flow rate control can be performed at a next step.SOLUTION: A fine droplet generator A comprises: a flow rate control part B for feeding out a liquid material L at a constant rate; and a liquid material supply part C for changing the liquid material L from the flow rate control part B, into minute liquid droplets S continuing in a pulse state, thereby to feed the minute liquid droplets S to a next step. The liquid material supply part C includes: a main passage 55 derived from the flow rate control part B; branch passages 55a and 55b branched from the main passage 55 and connected to a next step; and on-off valves V1 and V2 individually disposed in the branch passages 55a and 55b and controlled to repeat high speed valve opening and closing, and so controlled that either of the branch passages 55a and 55b may be opened.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a high-boiling liquid material micro-droplet generator capable of accurately ejecting a micro-droplet at a set flow rate and accurately supplying a mass flow rate even with a high-boiling liquid material. About things.

  In the production of silicon-based semiconductor devices and compound semiconductor devices, a vapor phase growth apparatus such as a CVD apparatus or an ALD apparatus is often used. In recent years, a material obtained by vaporizing a liquid compound instead of a conventional semiconductor gas has been used as a film forming raw material for these devices. At this time, in order to produce a good film, it is necessary to introduce the liquid raw material quantitatively and efficiently vaporize it, and then introduce it into a reaction chamber such as a CVD apparatus or an ALD apparatus.

  In recent years, examples of using a high molecular weight, high density, high boiling point compound or a simple substance in the film forming materials are increasing in order to meet the performance required for the target device. These materials are extremely difficult to vaporize due to their properties. When evaporating, it is known that the surface area of the droplet can be increased and the evaporation rate can be increased by making the liquid into fine droplets.

  In addition, as a film forming method, there is a coating method in which a liquid material is applied to a substrate and a reaction is generated on the surface thereof to form a film. However, a high-viscosity liquid material must be uniformly applied to the substrate surface. For this purpose, a liquid material is quantitatively supplied, and this is ejected in pulses to form a uniform microdroplet array, which is applied to the surface of the moving substrate. In either case, it is necessary to generate fine droplets in a pulse shape and eject them in a uniform droplet row.

  Pressurizing the liquid material in order to vaporize the liquid material with high molecular weight, high boiling point, and high viscosity, and controlling the flow rate and ejecting it from a small hole into the vacuum does not form a fine droplet row, but a linear beam. It is also known that the high boiling point liquid material is very difficult to vaporize because the surface area is small in this method.

  On the other hand, it is already known that when a high-boiling liquid material having a high viscosity is ejected in a pulse shape, it can be formed into droplets.

As described above, since it is very difficult to vaporize a high-boiling liquid material, the above-described atomizer is used to increase the vaporization rate, and a method of forming liquid material into droplets is widely adopted.
However, since the high boiling point liquid material has a high viscosity as described above, even if an atomizer is used, it has been extremely difficult to obtain a desired fine droplet.

  Therefore, from this finding, a method has been attempted in which the liquid material container is pressurized, opened and closed repeatedly using an injection valve of a flow rate controller (LFC), and the liquid material ejected from the outlet is ejected in pulses.

JP 2000-31864 A

FIG. 10 is a flow rate-output waveform diagram when the injection valve of the liquid flow rate controller (LFC) is controlled to open and close at high speed in the conventional example. FIG. 10A shows an input setting example (example in which rectangular wave-like input is performed) when the LFC in that case is operated at high speed, and the valve opening / closing is performed in the order of milliseconds (msec). . FIG. 10B shows a flow rate output waveform at the time of high speed setting by the LFC with respect to this input waveform, and the fluctuation is severe as will be described later.
In this case, although not shown, if the pulse width is about 1 second, the droplet is formed in a pulse shape close to a rectangle. However, the generated droplets are too large and are not preferable for vaporizing and direct coating applications. Therefore, valve opening / closing in the millisecond order is required. However, in the millisecond order, the flow rate controller (LFC) cannot follow the high-speed opening / closing command as shown in FIG. The flow rate output waveform of the liquid material is distorted to exceed 100% and fluctuates (pulsates), the predetermined flow rate does not flow, and it is extremely difficult to control the droplet formation of the liquid material. This is due to the measurement speed of the flow rate sensor of the liquid flow rate controller (LFC), the response speed of the flow rate control valve, particularly the pressure propagation speed of the liquid.

  That is, when the injection valve that repeatedly opens and closes at high speed is “closed”, the liquid material is pressurized and supplied on the upstream side, so the upstream pressure in the vicinity of the valve is instantaneously caused by the water hammer effect. To rise. When it becomes “open” at the next moment, immediately after this “open” operation of the injection valve, a large amount of liquid material suddenly ejects from the valve at that pressure, and the vicinity of the valve The pressure at plunges. Since the viscosity of the liquid material is high, the liquid material on the upstream side follows this and does not flow smoothly, and internal pressure density is generated in the liquid material. In such a situation, the high-speed valve is opened and closed regardless of the state of the liquid material. As a result, the aforementioned large internal pressure fluctuation occurs. This is the main factor of the aforementioned pressure fluctuation (pulsation).

  However, this method cannot be said to be a desired state at all, but it is possible to eject a pulsed droplet for the time being. However, it is difficult to measure the flow rate of the liquid material, and it is difficult to set and control a desired flow rate. Therefore, it is hard to say that it is widely adopted.

  Even when the liquid material is directly applied to the substrate, if the liquid material is pressurized and jetted from the small hole toward the substrate while controlling the flow rate as described above, a linear liquid beam is formed. Can not be applied evenly. On the other hand, it is well known that an ink jet printer uses a low-viscosity ink and continuously ejects fine ink droplets onto an object to draw a desired character or figure clearly. However, as described above, it was impossible to continuously eject a high-viscosity liquid material as pulse-like fine and uniform fine droplets. It was thought that it could not be applied.

  The present invention has been made in view of the above-described conventional example, and can accurately eject uniform fine droplets at a set flow rate of a high-boiling high-viscosity liquid material, and can perform accurate mass flow control in the next step. An object of the present invention is to provide a microdroplet generator that can be used.

A high-boiling high-viscosity liquid material L microdroplet generator A according to claim 1 (Example 1: Figs. 1 to 5)
A flow rate control unit B for sending out a certain amount of the liquid material L;
The liquid material L from the flow rate control unit B is composed of a liquid material supply unit C that supplies the liquid material L to the next process as fine droplets S that are continuous in a pulse shape,
The liquid material supply unit C is installed in the main passage 55 derived from the flow rate control unit B, the branch passages 55a and 55b branched from the main passage 55, and connected to the next process, and the branch passages 55a and 55b, respectively. It is characterized by comprising open / close valves V1 and V2 that are repeatedly opened and closed and controlled so that any one of the branch passages 55a and 55b is opened.

  Here, there are two figures and symbols for the branch passage and the open / close valve, but of course, the present invention is not limited to this, and a plurality of branch passages and open / close valves may be provided. At least a pair is enough. Moreover, it is preferable that the performance of the on-off valve is substantially the same in order to avoid fluctuations in the internal pressure.

  The flow rate control unit B only needs to supply the liquid material L by a set mass flow. Here, the differential pressure flow rate control unit is a representative example.

A high-boiling liquid material L microdroplet generator A according to claim 2 (Example 2: FIG. 8)
A flow rate control unit B for sending out a certain amount of the liquid material L;
The liquid material L from the flow rate control unit B is made into a continuous fine droplet S and is configured with a liquid material supply unit C that supplies it to the next process,
The liquid material supply unit C includes a main passage 55 derived from the flow rate control unit B, branch passages 63 and 64 connected to the next process, the main passage 55 is connected to the inlet 60, and the branch passages 63 and 64 are connected to each other. The three-way valve V3 is connected to the first and second outlets 61 and 62, and alternately connects the branch passages 63 and 64 to the main passage 55, respectively.

  The valve switching speed of the three-way valve V3 is on the order of milliseconds, and the switching time is short enough not to change the internal pressure of the liquid material L in the main passage 55.

Claim 3 is the microdroplet generator A according to claim 1 or 2,
The next step is a vaporization space 30 for vaporizing the microdroplets S, and a heating unit H4 for receiving the continuous microdroplets S emitted into the vaporization space 30 and vaporizing the microdroplets S is provided at the bottom 31 thereof. It is characterized by that.

Claim 4 is the microdroplet generator A according to claim 1 or 2,
The next step is a vaporization space 30 for vaporizing the microdroplets S, and a heating part H5 for heating and vaporizing the continuous microdroplets S emitted into the vaporization space 30 is provided on the side wall 32. To do.

Claim 5 is the microdroplet generator A (FIG. 8) according to claim 1 or 2,
The next step is the substrate holder 40 on which the substrate 41 to which the microdroplets S are applied is mounted, and the substrate 41 is moved relative to the landing point of the continuous microdroplets S emitted to the substrate holder 40. The moving mechanism part 42 to be moved is provided.

  Here, the moving mechanism unit 42 is, for example, a well-known XY table that step-feeds the substrate holding unit 40 horizontally and vertically.

  According to the first aspect of the present invention, the on-off valves V1 and V2 are controlled so as to repeatedly open and close the high-speed valve and open one of the branch passages 55a and 55b. The material L always flows through one of the opening / closing valves V1 (V2). Even when one of the materials L is “closed”, the pressure in the main passage 55 does not increase shockingly, and the pressure of the liquid material L Variation will be suppressed. As a result, even if the high-speed valve is opened and closed and the viscosity of the liquid material L is high, the liquid flows smoothly from the main passage 55 to the on-off valves V1 and V2 via the branch passages 55a and 55b. S is fired alternately in pulses.

  This is the same even when the three-way valve V3 is used. Even if the three-way valve V3 performs high-speed valve switching between the branch passages 63 and 64, one of the branch passages 63 (64) is always the main passage. 55, pressure fluctuation does not occur in the liquid material L in the main passage 55, and even if the viscosity of the liquid material L is high, the liquid material L flows smoothly from the main passage 55 into the three-way valve V3, and the branch passage 63 (64). Thus, the micro droplets S are alternately and continuously emitted in a pulse shape.

  And even if the liquid material L is a high-viscosity and high-boiling point material as described above, it can be finely pulverized with an accurate and uniform mass flow rate and continuously emitted in a pulse shape, so the heating part H5 is provided on the side wall 32. When the vaporized part K is passed or when the micro droplet S is landed on the heating part H4 of the bottom part 31, these can be efficiently vaporized.

  When the substrate holding unit 40 having the moving mechanism unit 42 is provided, the substrate holding unit 40 is operated relative to the landing point of the micro droplet S by operating the moving mechanism unit 42. The liquid material L can be evenly applied on 41.

It is sectional drawing of 1st Example of this invention. It is sectional drawing of the XX arrow direction of FIG. It is sectional drawing of the YY arrow direction of FIG. It is an expanded sectional view of the differential pressure flow control part of FIG. It is sectional drawing of the ZZ arrow direction of FIG. It is sectional drawing of the modification of 1st Example of this invention. It is sectional drawing of the modification of this invention. It is principal part sectional drawing at the time of use of the three-way valve replaced with the on-off valve of this invention. It is a relationship graph of the valve | bulb opening / closing control waveform of this invention, the output change of a liquid flow controller, the change of the generation amount of a droplet, and the flow stability of a liquid flow controller. It is a relationship graph of the valve | bulb opening / closing control waveform and the output change of a liquid flow controller in a prior art example.

  Hereinafter, the present invention will be described in detail according to illustrated embodiments. The micro droplet generator A of the present invention is generally composed of a flow rate control unit B, a liquid material supply unit C, and heating units H1 to H3. And the board | substrate holding | maintenance part 40 which has the vaporization part K with the heating parts H4 and H5 or the moving mechanism part 42 according to a use is installed.

  Examples of the applicable material include the liquid material L, for example, tetraethoxysilane (TEOS) used in a chemical vapor deposition apparatus (CVD apparatus), and the solid material includes metal gallium, which is solid at room temperature. However, since it melts at about 28 ° C. to become a liquid and is heated to 40 ° C. to 50 ° C. and used, it is unified with the liquid material L in this specification.

  These liquid materials L have high viscosity and are stored in a raw material container 2 with a built-in thermostatic chamber. The raw material container 2 is a container for containing a high melting point liquid material L, but stainless steel or fluororesin is used. For raw materials that cannot use stainless steel, use fluororesin that can be heated to high temperatures. The raw material container 2 is connected with a pressure pipe 9 for pumping the liquid material L, and is pressurized with an inert gas. And it is supplied to the inlet nozzle 11 of the micro droplet generator A via the supply pipe 4.

  The first embodiment shown in FIGS. 1 to 5 is a case where the micro droplet generator A is a vaporizer. The main body portion 1 of the microdroplet generator A is a rectangular parallelepiped metal member, in which a flow path for the liquid material L that is a fluid to be measured is formed. In the present embodiment, a differential pressure type is applied to the flow rate control unit B. Of course, although not limited to this, a differential pressure type will be described as a representative example. The flow path in the flow rate control unit B includes an inlet nozzle 11, an inlet side space 12, a cylindrical space 16 that forms part of the differential pressure generating unit 10, an outlet side space 14, and an outlet passage 15. FIG. 4 schematically shows a cross section of the differential pressure flow control unit B of the present invention.

  The cylindrical space 16 is a space that is struck in a straight cave shape with a circular cross section as shown in FIG. An inlet-side space 12 is formed in the bottom front end of the main body portion 1 and an outlet-side space 14 is recessed in the bottom rear end portion. The inlet-side pressure sensor PG1 and the outlet-side pressure sensor PG2 are fitted in each, Each diaphragm is arranged so as to face the entrance side space 12 and the exit side space 14. Both pressure sensors PG1 and PG2 are for measuring the flow rate of the liquid material L, have heat resistance, and measure the differential pressure generated when the liquid material L flows by the differential pressure generator 10 described later. . Then, the relationship between the output and the flow rate Q is calculated by a relational expression described later, and the mass flow rate of the liquid material L is measured. Then, the output is given to the flow control valve CV to control to the target flow value.

  An inlet nozzle 11 and an outlet passage 15 are connected to the inlet side space 12 and the outlet side space 14, and the inlet side communication passage 17, which is a part of the inlet side space 12, is an inlet side of the cylindrical space 16. In addition, the outlet side space 14 is connected to the outlet side of the cylindrical space 16, which is a part of the outlet side communication passage 19, thereby forming a single flow path in the flow rate control unit B.

  Further, a core material mounting hole penetrating from the front surface to the inlet side of the cylindrical space 16 is formed in the upper portion of the main body portion 1 on the inlet side, and the columnar member 18 is hermetically inserted through an O-ring (not shown). Has been. The columnar member 18 is inserted concentrically with the cylindrical space 16 over the entire length of the cylindrical space 16. As a result, annular gaps are formed at equal intervals between the two. This annular gap is the flow gap T and becomes the differential pressure generating section 10 that provides flow resistance to the liquid material L that is the fluid to be measured. The passage of the differential pressure generating unit 10 has a length M from the inlet to the outlet of the flow gap T. The columnar member 18 and the cylindrical space 16 are preferably coaxial, but a slight deviation is substantially coaxial if it is within a range that does not affect the measurement. A relational expression between the differential pressure ΔP of the fluid flowing through the concentric circular pipe (flow gap T) and the flow rate Q is shown below.

Q = ΔPπ [a ⁴ −b ⁴ − {(a ² −b ² ) ² / In (a / b)}] / 8 μM
Q = flow rate ΔP = differential pressure a = radius b of cylindrical space 16 = radius μ of columnar member 18 = fluid viscosity M = flow path length The arithmetic processing unit 5 measures the flow rate of the liquid material L and will be described later. The valve opening control of the flow control valve CV and the high-speed valve opening / closing control of the opening / closing valves V1 and V2 are performed. Therefore, in the flow rate measurement, as described above, the pressure data from the inlet side pressure sensor PG1 and the outlet side pressure sensor PG2 is received, the differential pressure ΔP is calculated, and the mass flow rate Q of the liquid material L is calculated according to the above relational expression. calculate. Based on this calculation result, a signal for controlling the valve opening degree is sent to the flow rate control valve CV so that the flow rate Q of the liquid material L sent to the open / close valves V1 and V2 becomes the set flow rate.

  Signals are sent to the open / close valves V1 and V2 such that the valves open alternately for a predetermined time (a minute time on the order of milliseconds).

  In addition, in order to measure the exact flow volume of various fluids (liquid material L), the method of measuring a flow volume timely using an electronic balance etc. and calibrating as needed is taken.

  A liquid material supply unit C is provided downstream of the flow rate control unit B. The flow rate control valve CV of the flow rate control unit B and the pair of on-off valves V1 and V2 of the liquid material supply unit C use actuators 6a to 8a such as piezo elements or electromagnetic solenoids, and are controlled by diaphragms 6d to 8d. This is a two-way valve structured to adjust the opening degree of the seats 6b to 8b (in the case of the flow control valve CV) or to open and close at high speed (in the case of the open / close valves V1 and V2). The performance of the open / close valves V1 and V2 is preferably almost the same for suppressing the pulsation of the liquid material L when the valve is opened / closed at high speed.

  The diaphragms 6d to 8d are stretched in the flow spaces 6c to 8c in which the valve seats 6b to 8b are provided. The flow rate control valve CV adjusts the opening, and the on-off valves V1 and V2 contact and separate from the valve seats 6b to 8b. The seats 6b to 8b are opened and closed at high speed.

Note that the number of the open / close valves V1 and V2 is two in this embodiment, but of course, the number is not limited to this and may be three or more. In this case, control is performed so that any one of the opening / closing valves is always “open”. Note that switching between “open” and “closed” between the open / close valves V1 and V2 is performed within a range in which pressure fluctuation hardly occurs in the liquid material L in the main passage 55.
The outlet passage 15 of the flow rate control unit B opens to the flow space 6c of the flow rate control valve CV, and supplies the liquid material L pushed out of the raw material container 2 at the set pressure to the flow space 6c of the flow rate control valve CV. ing.
On the other hand, the valve seat 6b of the flow rate control valve CV is connected to the main passage 55. This main passage 55 is branched in the middle to become branch passages 55a and 55b, and connected to the flow spaces 7c and 8c of the on-off valves V1 and V2. Yes. The on-off valves V1 and V2 are erected in parallel with the upper surface of the main body 1 as shown in FIG.

  The valve seats 7b and 8b of the on-off valves V1 and V2 open to communication spaces 71 and 81 that communicate with the vaporization space 30 of the vaporization section K attached to the lower surface of the main body portion 1. The communication spaces 71 and 81 extend in a conical shape from the valve seats 7b and 8b, and are connected to the vaporization space 30 as cylindrical holes on the lower edge thereof. Since the open / close valves V1 and V2 are erected in parallel, the communication spaces 71 and 81 are also drilled in parallel.

  The vaporizing section K is composed of a bottomed cylindrical vaporizing cylinder section 3 having a flange section 33, and a ring plate 34 connecting the flange section 33 and the lower surface of the main body portion 1, and in the case of the first embodiment. The heating part H4 is installed in the center of the bottom part 31. And the droplet vaporization plate 35 is installed in the upper surface of the heating part H4. A vaporizing material outlet nozzle 36 is installed beside the droplet vaporizing plate 35.

  In addition, heating parts H1 and H2 are installed in parallel to both sides of the cylindrical space 16 of the main body part 1, and a heating part H3 is installed in three dimensions with respect to the communication spaces 71 and 81. 1 is kept at the set temperature. In addition, you may install the heating part H5 in the side wall 32 of the vaporization cylinder part 3. FIG.

  Next, the operation of the first embodiment (vaporizer) will be described. As described above, the liquid material L is supplied to the flow rate controller B from the raw material container 2 maintained at the set temperature and the set internal pressure. The supplied liquid material L flows in the order of the inlet side space 12 of the flow rate control unit B, the flow gap M, and the outlet side space 14 and exits from the outlet passage 15. During this time, a flow resistance (tube resistance) is applied to the liquid material L through the flow gap M, the inlet pressure P1 is measured by the inlet pressure sensor PG1 in the inlet space 12, and the outlet pressure in the outlet space 14 is measured. The pressure P2 on the outlet side is measured by the sensor PG2.

  Then, the flow rate Q of the liquid material L flowing through the concentric pipe (flow gap M) is calculated from the differential pressure ΔP between the outlet side pressure P2 and the inlet side pressure P1 by the arithmetic processing unit 5.

  The calculation result is compared with the set flow rate, the valve opening degree of the flow rate control valve CV of the liquid material supply unit C is controlled, and the liquid material L having the mass flow rate Q set from the liquid material supply unit C is always present. It comes to be supplied.

  The liquid material L exiting from the flow rate control valve CV flows through the main passage 55 into the branch passages 55a and 55b. The on-off valves V1 and V2 are controlled so that the valves are alternately opened for a predetermined time (a minute time on the order of milliseconds) according to a command from the arithmetic processing unit 5 as described above. As a result, the main passage 55 always communicates with the branch passages 55a and 55b of the one open / close valve V1 (V2), and the liquid material L in the main passage 55 is opened on the side of the branch passages 55a and 55b. ) Will be pushed out. As a result, even if the other on-off valve V2 (V1) is “closed”, the impact (water hammer) due to “closed” does not occur in the liquid material L in the main passage 55, and the liquid material in the main passage 55 L flows into the branch passages 55a and 55b of the one open / close valve V1 (V2) that is smoothly opened as it is.

  Then, the liquid material L is ejected from one open on-off valve V1 (V2), but at the next moment, the one open on-off valve V1 (V2) is switched to “closed”, and the ejected liquid The material L becomes a fine droplet S and drops into the communication space 71 (81).

  As soon as one open / close valve V1 (V2) is switched to “closed”, the other open / close valve V2 (V1) is switched from “closed” to “open”. Erupt. Since this switching between the on-off valve V2 (V1) is performed simultaneously or in a minute time, the fine droplets S of the liquid material L are continuously and alternately dropped from the pair of on-off valves V1 and V2.

  The dropped two rows of micro droplets S pass through the communication spaces 71 and 81 respectively, reach the vaporization space 30, and vaporize from the surface of the droplets on the droplet vaporization plate 35 provided at the bottom 31 of the vaporization space 30. collide. Since the droplet vaporizing plate 35 is always heated to an appropriate temperature by the heating unit H4, the micro droplet S that has contacted the droplet vaporizing plate 35 is vaporized almost instantaneously, and the vaporized material outlet nozzle 36 in the vaporizing space 30 is externally exposed. Sucked into. The sucked vaporized material is supplied to a semiconductor manufacturing apparatus such as a CVD apparatus through a gas mass flow controller (not shown) which is the next process.

FIG. 10 is a flow rate-output waveform diagram of this apparatus. In FIG. 10A, the flow rate output from the arithmetic processing unit 5 in that case was changed stepwise from 100, 60, 20, and 0%. The flow rate control valve CV changes the flow rate Q of the liquid material L to 100, 60, 20, 0% by this signal. In the figure, the horizontal axis represents time, and the vertical axis represents the flow rate value in units of% full scale.
FIG. 7B shows the operation state of each valve in a rectangle when the opening and closing valves V1 and V2 are alternately opened and closed in conjunction with FIG. That is, when both of the open / close valves V1 and V2 are closed, it is expressed as zero (0), when the open / close valve V1 is “open”, (+1), and when the open / close valve V2 is “open”, it is expressed as (−1). ing.
FIG. 4C shows the amount of micro droplets S generated when the opening and closing valves V1 and V2 are opened and closed at regular intervals as shown in FIG.
FIG. 4D shows the output of the arithmetic control unit 5 of the flow rate control unit B after the opening / closing valves V1 and V2 are actuated. In the present invention, the on-off valves V1 and V2 are operated, so that the on-off valve V1 is "opened" and then "closed". At the same time, the other on-off valve V2 is "opened", so The outlet pressure of the flow control valve CV does not change. Since this outlet pressure is detected as the pressure of the outlet side pressure sensor PG2 of the flow rate control unit B, the pressure difference ΔP between the inlet side pressure P1 and the outlet side pressure P2 naturally does not change unless there is a pressure fluctuation as described above. Therefore, the output of the arithmetic control unit 5 of the flow rate control unit B is not disturbed, and the same waveform as in FIG. In this respect, the same result can be obtained when a three-way valve V3 described later is used.

  As a modification of FIG. 1, a heating unit H <b> 5 may be further provided on the side wall 32 of the vaporizing cylinder unit 3 as indicated by a broken line in FIG. 1, and heating is performed while the micro droplet S is dripping the vaporizing space 30. And will be vaporized more quickly.

  Further, as shown in FIG. 6, if the pulsed beam of the micro droplet S is passed through the heated cylindrical vaporizing cylinder portion 3, it can be efficiently vaporized. The smaller the droplet size, the faster the droplet evaporation rate. In such a case, only the heating part H4 in the side wall 32 is sufficient, the heating part H4 in the bottom part 31 is omitted, and the vaporized material sufficiently vaporized in the vaporization space 30 is discharged from the vaporized material outlet nozzle 36. can do.

  FIG. 7 shows a further modification of the first embodiment in which fine droplets S dropped in a pulse shape toward a droplet vaporizing plate 35 provided at the center of the bottom 31 of the vaporizing space 30 are concentrated. In this example, the opening / closing valves V1 and V2 are installed on the main body portion 1 at an inclination. In addition, the example which the main-body part 1 comprised by the upper part 1a and the lower part 1b is shown. Of course, if processing is possible, it is possible to integrate both. By doing in this way, the vaporization cylinder part 3 can be reduced in size. In this case, the film formation rate increases. About the point other than that, there exists the same effect as Example 1. FIG.

  Further, a three-way valve V3 can be used in place of the on-off valves V1 and V2 of the first embodiment (FIG. 8: second embodiment). In this case, the main passage 55 is connected to the inlet 60 of the three-way valve V3, and the first outlet 61 and the second outlet 62 of the three-way valve V3 are connected to the branch passages 63 and 64 that open to the communication spaces 71 and 81. . The three-way valve V3 can instantly switch between the first outlet 61 and the second outlet 62 by moving the valve, and has the same function as the on-off valves V1 and V2 of the first embodiment. Therefore, in this case as well, the same operational effects as in the first embodiment are obtained.

  Although the case where the next process is a “vaporizer” has been described above, the substrate holding unit 40 that directly applies the liquid material L onto the substrate 41 in the next process may be used. In this case, the substrate 41 is mounted on the substrate holding unit 40, is installed immediately below the liquid material supply unit C, and moves vertically and horizontally on a horizontal plane. Then, the fine liquid droplets S land on the substrate 41 installed on the substrate holding unit 40 while slightly shifting vertically and horizontally. The liquid material L can be uniformly applied onto the substrate 41 by appropriately selecting the timing of landing of the micro droplet S and the moving speed of the substrate holding unit 40.

  The present invention can also be applied to a high-temperature fluid. In this case, a pressure sensor that can withstand high temperatures is used, and the entire flowmeter (excluding the arithmetic processing unit) is heated to a high temperature to adjust the temperature.

  A: micro droplet generator, B: flow rate control unit, C: liquid material supply unit, K: vaporization unit, H1 to H5: heating unit, L: liquid material, M: length of flow path, P1: inlet side Pressure, P2: Outlet side pressure, PG1: Inlet side pressure sensor, PG2: Outlet side pressure sensor, PD1, PD2: Diaphragm, S: Fine droplet, T: Flow gap, CV: Flow control valve, V1, V2: Open / close valve, V3: three-way valve, 1: body part, 2: raw material container, 3: vaporization cylinder part, 4: supply pipe, 5: arithmetic processing part, 6a-8a: actuator, 6b-8b: valve seat, 6c -8c: Distribution space, 6d-8d: Diaphragm, 9: Pressure piping, 10: Differential pressure generating part, 11: Inlet nozzle, 12: Inlet side space, 14: Outlet side space, 15: Outlet passage, 16: Cylindrical shape Space, 17: Entrance side communication passage, 18: Columnar member, 19: Exit Communication passageway, 30: vaporization space, 31: bottom part, 32: side wall, 33: flange part, 34: ring plate, 35: droplet vaporization plate, 36: vaporization material outlet nozzle, 40: substrate holding part, 41: substrate, 42: moving mechanism section, 55: main passage, 55a / 55b: branch passage, 60: inlet, 61: first outlet, 62: second outlet, 63/64: branch passage, 71/81: communication space.

Claims (5)

A flow control unit for sending a certain amount of liquid material;
The liquid material from the flow rate control unit is composed of a liquid material supply unit that supplies continuous liquid in the form of pulses to the next process,
The liquid material supply unit is installed in each of the main passage derived from the flow rate control unit, the branch passage branched from the main passage and connected to the next process, and the branch passage, and repeatedly opens and closes the high-speed valve. A micro-droplet generator for a high-boiling-point liquid material, comprising an open / close valve controlled so that any one of 55a and 55b is opened. A flow control unit for sending a certain amount of liquid material;
It is composed of a liquid material supply unit that supplies liquid material from the flow rate control unit to the next process as a continuous fine droplet,
The liquid material supply unit includes a main passage derived from the flow rate control unit, a branch passage connected to the next process, a main passage connected to the inlet, and a branch passage connected to the first and second outlets. And a three-way valve that alternately connects the branch passages to the main passage. In the micro droplet generator according to claim 1 or 2,
A high boiling point characterized in that the next step is a vaporization space for vaporizing microdroplets, and a heating part for vaporizing the microdroplets by receiving continuous microdroplets emitted into the vaporization space is provided at the bottom thereof A micro droplet generator for liquid materials. In the micro droplet generator according to claim 1 or 2,
A high-boiling liquid material characterized in that the next step is a vaporization space for vaporizing microdroplets, and a heating section for heating and vaporizing continuous microdroplets emitted into the vaporization space is provided on the side wall. Micro droplet generator. In the micro droplet generator according to claim 1 or 2,
The next step is a substrate holding unit on which a substrate to which microdroplets are applied is mounted, and the substrate holding unit is provided with a moving mechanism that moves the substrate relative to the landing point of the emitted continuous microdroplets. A high-boiling-point liquid material microdroplet generator.

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