Gasifier and gasification system

Abstract

The present invention provides a vaporizer and a vaporizing system, the vaporizer for vaporizing a liquid material comprising: a container for accommodating the liquid material; a heater that heats the liquid material by heating the container; and a porous structural member that is disposed in the container, divides air bubbles generated by the heating of the liquid material by the heater, and allows the air bubbles to pass therethrough.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority based on Japanese Patent Application No. 2023-171078 filed on October 2, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present invention relates to a gasifier and a gasification system. Background Art

[0003] Conventional heat-bake type vaporizers heat a container containing a liquid material with a heater to vaporize the liquid material and generate gas. For example, International Publication No. 2020 / 195349 discloses such a heat-bake type vaporizer.

[0004] In a heat-drying type vaporizer, when the container is heated, the liquid material in the container boils and generates bubbles. When bubbles are generated, the pressure in the container changes. The pressure change affects the output flow rate of the flow control device (also called a mass flow controller) arranged on the secondary side of the container. For example, if the pressure in the container changes, the stability of the above-mentioned flow rate will be impaired. In particular, in a small and compact vaporizer, since the container is also small, the generation of bubbles makes the pressure in the container easily fluctuate, which easily impairs the stability of the above-mentioned flow rate. Summary of the invention

[0005] The present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a vaporizer and a vaporization system capable of suppressing pressure fluctuations in a container caused by the generation of bubbles.

[0006] A vaporizer according to one embodiment of the present invention vaporizes a liquid material, and the vaporizer includes: a container for containing the liquid material; a heater for heating the liquid material by heating the container; and a porous structure arranged in the container for dividing bubbles generated by the heating of the liquid material by the heater and allowing the bubbles to pass through.

[0007] A vaporization system according to another aspect of the present invention includes: the vaporizer described above; and a flow rate control device for controlling a flow rate of gas of the liquid material vaporized in the vaporizer.

[0008] Other objects of the present invention and specific advantages obtained by the present invention will be further described from the embodiments described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a perspective view schematically showing the general structure of a gasification system according to one specific embodiment of the present invention.

[0010] Figure 2It is a perspective view schematically showing the structure of a vaporizer included in the above-mentioned vaporization system.

[0011] Figure 3 It is a cross-sectional view schematically showing the structure of the above-mentioned vaporizer.

[0012] Figure 4 It is a plan view showing the porous structure member provided in the above-mentioned vaporizer before and after being arranged in the container.

[0013] Figure 5 It is a top view showing another porous structural member before and after being arranged in the container.

[0014] Figure 6 It is a cross-sectional view schematically showing another structure of the above-mentioned vaporizer.

[0015] Figure 7 It is a perspective view schematically showing a modified example of the bottom plate portion of the container.

[0016] Figure 8 This is a cross-sectional view schematically showing another structure of the above-mentioned vaporizer. DETAILED DESCRIPTION

[0017] In the following, exemplary embodiments of the present invention are described with reference to the accompanying drawings. In addition, for ease of description, in each drawing, the vertical direction of the gasification system is referred to as the Z direction, and two directions perpendicular to the Z direction and perpendicular to each other are referred to as the X direction and the Y direction, respectively.

[0018] (1. Structure of gasification system) Figure 1 1 is a perspective view schematically showing a simplified structure of a gasification system 100 according to the present embodiment. The gasification system 100 includes a first valve 2, a gasifier 3, a pressure sensor 4, a second valve 5, a third valve 6, and a flow control device 7 in a substantially rectangular parallelepiped housing 1. Figure 1 In order to clarify the internal structure of the box body 1, the illustration of the side wall of the front side of the box body 1 is omitted.

[0019] The first valve 2, the vaporizer 3, the pressure sensor 4, the second valve 5, the third valve 6 and the flow control device 7 are fixed to the side 1s of the main body module 1a disposed in the housing 1. The main body module 1a is extended in the vertical direction in the housing 1. The flow path of the liquid material (hereinafter, also referred to as the liquid flow path) and the flow path of the gas (hereinafter, also referred to as the gas flow path) are formed inside the main body module 1a. Figure 1 In the figure, in the main body module 1a, the flow direction of the liquid material is indicated by the solid arrow, and the flow direction of the gas is indicated by the dotted arrow. In addition, the above-mentioned liquid material is appropriately selected from various materials used in the semiconductor manufacturing process, for example.

[0020] The first valve 2 is a control valve (liquid material supply valve) for controlling the supply flow rate of the liquid material to the vaporizer 3, and is composed of, for example, an electromagnetic switch valve. When the first valve 2 is set to an open state, the liquid material is introduced into the main body module 1a from the liquid material supply port 1b located at the lower part of the main body module 1a. The introduced liquid material is supplied to the container 31 of the vaporizer 3 via the first valve 2 and the liquid flow channel in the main body module 1a. On the other hand, when the first valve 2 is set to a closed state, the supply of the above-mentioned liquid material to the container 31 is stopped.

[0021] The vaporizer 3 vaporizes the liquid material by a thermal baking method. The detailed structure of the vaporizer 3 will be described later. The pressure sensor 4 is a sensor for detecting the pressure in the container 31 of the vaporizer 3, and is provided to monitor the pressure.

[0022] The second valve 5 is an on-off valve for opening and closing the flow path of the gas (hereinafter, also referred to as the material gas) generated after the liquid material is vaporized in the vaporizer 3. When the second valve 5 is set to an open state, the material gas generated in the container 31 of the vaporizer 3 passes through the gas flow path in the main module 1a and is supplied to the flow control device 7. On the other hand, when the second valve 5 is set to a closed state, the supply of the material gas to the flow control device 7 is stopped.

[0023] The third valve 6 is an on-off valve for opening and closing the flow path of the purge gas. For example, after the flow control device 7 is replaced, when only the flow control device 7 is to be purged, the third valve 6 is set to an open state while the second valve 5 is closed. At this time, the purge gas supplied through the purge gas flow path (not shown) is introduced into the flow control device 7 through the gas flow path in the main module 1a with the help of the third valve 6. In addition, when the entire purge gasification system 100 is purified, both the second valve 5 and the third valve 6 are set to an open state to perform purification.

[0024] The flow control device 7 controls the gas flow rate of the liquid material vaporized in the vaporizer 3. Such a flow control device 7 is constituted by, for example, a mass flow controller. The material gas output by the flow control device 7 with the flow rate controlled is introduced into an external device (for example, a semiconductor manufacturing device) through a gas outlet 1c provided at the upper portion of the main module 1a.

[0025] (2. Detailed structure of the gasifier) Figure 2 It is a perspective view schematically showing the structure of the vaporizer 3 . Figure 3 3 is a cross-sectional view schematically showing the structure of the vaporizer 3. The vaporizer 3 includes a container 31, a heater 32, a porous structure 33, a liquid level detection sensor 34, and a temperature sensor 35.

[0026] The container 31 is used to receive the liquid material supplied from the liquid material supply port 1b (see Figure 1) is a metal container for supplying liquid material LQ. A heater 32 is disposed in the container 31. Figure 2 and Figure 3 In the example, the heater 32 is composed of a cartridge heater 32a, which is buried in the bottom plate portion 31A constituting the bottom of the container 31. That is, the container 31 has a bottom plate portion 31A on which the heater 32 is arranged. The cartridge heater 32a has a structure in which a nickel-chromium wire as a heating element is covered with a metal tube. When the heater 32 is energized to generate heat, the bottom plate portion 31A is heated, and the heat of the bottom plate portion 31A is transferred to the liquid material LQ. In this way, the liquid material LQ boils and vaporizes, generating a material gas, that is, bubbles BU. In this way, the vaporizer 3 is equipped with a heater 32, and the heater 32 heats the (internal) liquid material LQ by heating the container 31 (bottom plate portion 31A).

[0027] The porous structural member 33 is disposed in the container 31. Figure 2 and Figure 3 In the example of , the porous structural member 33 is arranged above the bottom plate portion 31A in the container 31 and at a position separated from the bottom plate portion 31A by a predetermined distance. Therefore, the porous structural member 33 is located above the heater 32 embedded in the bottom plate portion 31A and separated from the heater 32. In addition, the porous structural member 33 is in contact with the side wall 31W of the container 31 and is separated from the heating surface (bottom plate portion 31A) by a predetermined distance. The porous structural member 33 divides the above-mentioned bubbles BU generated by the heater 32 heating the liquid material LQ and allows them to pass.

[0028] In addition, the porous structural member 33 is arranged at a position where bubbles BU are not generated due to boiling even if it receives heat from the heater 32. That is, according to the present embodiment, even if heat is transferred from the heater 32 to the porous structural member 33, bubbles BU themselves are not generated at the position of the porous structural member 33 due to boiling of the liquid material LQ.

[0029] Figure 4 3 is a top view showing the porous structural member 33 before and after being arranged in the container 31. The porous structural member 33 is composed of a porous plate, for example. The porous plate has a structure in which a rectangular metal flat plate 33a is provided with a plurality of holes P penetrating in the up and down directions when viewed from above. The size (inner diameter) of the hole P is smaller than the size (outer diameter) of the generated bubble BU. In addition, if the hole P is too small, there is a risk of hindering the stable vaporization of the liquid material LQ. Therefore, it is preferred that the size of the hole P (especially the lower limit of the inner diameter) is set to a size that can achieve stable vaporization of the liquid material LQ. The density of the hole P (the number of holes P per unit area) can be appropriately set.

[0030] The size of the bubbles BU generated by heating the liquid material LQ varies depending on the type of liquid material LQ used, but the outer diameter is about 10 mm, for example, regardless of the liquid material used. Therefore, as long as the pores P are formed to have an inner diameter of 1 to 2 mm, for example, a common (one type) porous structural member 33 can be used regardless of the liquid material LQ used.

[0031] The porous structural member 33 is connected to the inner surface (side wall 31W) of the container 31 by welding, for example. Figure 4 In the example of FIG. 1 , the entire outer edge portion 33R constituting the outer shape of the porous structural member 33 in plan view is in contact with and welded to the inner surface of the container 31. Figure 2 and Figure 3 As shown, the porous structure member 33 is arranged so as to cover the bottom plate portion 31A of the container 31 from above.

[0032] The liquid level detection sensor 34 detects the liquid level S (see Figure 3 ) sensor, also called float sensor. Figure 2 As shown, the liquid level detection sensor 34 includes a low-position side detection sensor 34L and a high-position side detection sensor 34H. The low-position side detection sensor 34L has a low-position side float portion 34L1 that moves up and down within a predetermined moving range corresponding to the height of the liquid surface S. The high-position side detection sensor 34H has a high-position side float portion 34H1 that moves up and down within a predetermined moving range corresponding to the height of the liquid surface S. The moving range of the low-position side float portion 34L1 in the up-down direction is below the moving range of the high-position side float portion 34H1 in the up-down direction. The low-position side detection sensor 34L and the high-position side detection sensor 34H are welded and fixed to the upper wall of the container 31 and are arranged through the upper wall.

[0033] In this embodiment, the first valve 2 (see FIG. 1 ) is intermittently closed by a controller (not shown) so that the liquid level S of the liquid material LQ in the container 31 is located between the low-position side float portion 34L1 and the high-position side float portion 34H1. Figure 1 ) is switched on and off. In this way, the supply of the liquid material LQ into the container 31 is intermittently controlled.

[0034] The temperature sensor 35 is disposed between the heater 32 and the liquid level detection sensor 34 (particularly, the low-level detection sensor 34L), and detects the temperature of the liquid material LQ. The temperature sensor 35 is composed of, for example, a thermocouple. Based on the temperature detected by the temperature sensor 35, the controller controls the power supply to the heater 32 so that the liquid material LQ in the container 31 reaches a vaporization temperature.

[0035] In this way, Figure 3As shown, in the structure in which the vaporizer 3 includes the liquid level detection sensor 34 and the temperature sensor 35 , the porous structure member 33 is arranged between the liquid level detection sensor 34 and the temperature sensor 35 .

[0036] In the above structure, the liquid material LQ is heated by the heater 32 in the container 31, and the liquid material LQ boils to generate bubbles BU. When the generated bubbles BU pass through the porous structural member 33, they are finely divided by a plurality of holes P. Thus, compared with the bubbles BU before passing through the porous structural member 33, i.e., the bubbles BU generated by heating, the bubbles BU after passing through the porous structural member 33 become smaller (see Figure 2 , Figure 3 ). Therefore, the pressure fluctuation in the container 31 caused by the generation of the bubbles BU can be suppressed. As a result, even when the flow rate of the gas of the liquid material LQ is controlled by configuring the flow control device 7 on the secondary side of the container 31, the gas can be output at a stable flow rate. In particular, the structure of this embodiment is very effective in the vaporizer 3 that adopts a heating vaporization method such as sudden boiling that easily generates a sudden pressure fluctuation instead of a bubbling vaporization method that continuously generates small bubbles.

[0037] In the structure of the present embodiment, the porous structural member 33 is located at a position separated upward from the heater 32, and due to the heating of the liquid material LQ by the heater 32, bubbles BU are temporarily generated between the porous structural member 33 and the heater 32. Then, the temporarily generated bubbles BU enter the porous structural member 33 and are finely divided through the porous structural member 33. Therefore, the function of the porous structural member 33 that allows the bubbles BU generated by the heating of the heater 32 to be finely divided and passed through can be ensured.

[0038] Furthermore, the porous structural member 33 is arranged so as to cover the bottom plate portion 31A of the container 31. Therefore, the bubbles BU generated between the bottom plate portion 31A and the porous structural member 33 in the container 31 by the heating of the heater 32 can be guided to the porous structural member 33 without omission and pass through the porous structural member 33. That is, all the bubbles BU generated by the heating of the heater 32 can be guided to the porous structural member 33 and pass through the porous structural member 33. In this way, the size of the generated bubbles BU can be surely reduced by the porous structural member 33.

[0039] In addition, the porous structural member 33 is disposed between the liquid level detection sensor 34 and the temperature sensor 35. Therefore, the liquid level detection by the liquid level detection sensor 34 and the temperature detection by the temperature sensor 35 are not hindered, and the generated bubbles BU can be reduced by the porous structural member 33. In addition, the limited space between the liquid level detection sensor 34 and the temperature sensor 35 can be effectively used as the arrangement space of the porous structural member 33.

[0040] The porous structural member 33 is a porous plate having a plurality of holes P on a flat plate 33a. Such a porous plate has a simple structure and is easy to manufacture. Therefore, the porous structural member 33 can be easily realized by using a porous plate.

[0041] (3. Another structure of the gasifier) Figure 5 3 is a top view showing another porous structural member 33 before and after being arranged in the container 31. As shown in the figure, the porous structural member 33 may be a structure in which an opening (cutout) P1 corresponding to a part of the hole P is provided in the outer edge 33R. In this case, a part of the outer edge 33R of the porous structural member 33, that is, a part of the outer edge 33R other than the opening P1, contacts the inner surface of the container 31 and is connected by welding. In this case, it can also be considered that the porous structural member 33 is arranged in a manner to cover the bottom plate 31A of the container 31.

[0042] Figure 6 : is a cross-sectional view schematically showing another structure of the gasifier 3. As shown in the figure, a part of the porous structural member 33 is arranged in contact with the bottom plate portion 31A. Specifically, the porous structural member 33 may have a first region F1 and a second region F2. Here, the first region F1 is a region in the porous structural member 33 that is arranged in a manner covering the heater 32 and is located at a position separated upward from the bottom plate portion 31A. The second region F2 is a region other than the first region F1 in the porous structural member 33, and is a region connected to the first region F1 and in contact with the bottom plate portion 31A.

[0043] Even in the above-described structure, the liquid material LQ between the first region F1 of the porous structural member 33 and the bottom plate portion 31A can be boiled and vaporized by the heating of the heater 32, thereby generating bubbles BU, and the generated bubbles BU can be finely divided when passing through the porous structural member 33 (for example, the first region F1). Therefore, it can be said that the vaporizer 3 of the present embodiment is not limited to a structure in which the entire porous structural member 33 is located at a position separated from the bottom plate portion 31A (heater 32).

[0044] Figure 7 31A is a perspective view schematically showing a modified example of the bottom plate portion 31A of the container 31. The bottom plate portion 31A has a heating surface 31S. The heating surface 31S is in contact with the liquid material LQ (see Figure 3 The heating surface 31S is heated by a heater 32 embedded in the bottom plate 31A. The heating surface 31S has grooves G above the heater 32. In the heating surface 31S, the grooves G are formed in a grid shape, for example, but the grooves G may be formed in only one direction (for example, Figure 7 The groove formed in the Y direction may also have a curved shape.

[0045] When the liquid material LQ is heated by the heater 32, the liquid material LQ evaporates from the vicinity of the heating surface 31S of the bottom plate portion 31A to generate bubbles BU. At this time, in the heating surface 31S, there is a groove G above the heater 32, so that small bubbles BU can be generated from the gaps in the groove G. That is, the bubbles BU themselves generated by the heating of the heater 32 can be reduced. Thus, by the synergistic effect of dividing the bubbles BU with the porous structural member 33, the size of the bubbles BU can be ensured to be reduced, and the pressure fluctuation in the container 31 can be ensured to be suppressed.

[0046] In the above, the embedded cartridge heater 32a (see Figure 3 etc.), but the heater 32 used is not limited to the cartridge heater 32a. Figure 8 3 is a cross-sectional view schematically showing another structure of the vaporizer 3. As shown in the figure, a rubber heater 32b can be used as the heater 32. In this case, the heater 32 (rubber heater 32b) is provided on the outside (outer surface) of the bottom plate portion 31A to heat the container 31 from the bottom. In this way, the liquid material LQ in the container 31 is heated to generate bubbles BU.

[0047] When the rubber heater 32b is used, a porous structural member 33 may be disposed in the container 31 so that the bubbles BU generated by heating the liquid material LQ by the rubber heater 32b are divided when passing through the porous structural member 33, thereby reducing the size of the bubbles BU. In this way, the pressure fluctuation in the container 31 caused by the generation of the bubbles BU can be suppressed.

[0048] (4.Supplement) The porous structural member 33 is not limited to the porous plate used in the present embodiment. For example, the porous structural member 33 may be a structural member having a metal mesh structure.

[0049] As described above, according to the present invention, it is possible to suppress the pressure fluctuation in the container caused by the generation of bubbles.

[0050] Although the embodiments of the present invention have been described above, the scope of the present invention is not limited thereto, and the present invention can be expanded or modified without departing from the spirit of the invention.

[0051] The present invention can be utilized in, for example, a vaporizer provided at a front stage of a semiconductor manufacturing apparatus.

Claims

1. A vaporizer for vaporizing a liquid material, characterized in that: include: A container for containing the liquid material; a heater for heating the liquid material by heating the container; as well as The porous structural member is disposed in the container and divides and allows bubbles generated by heating the liquid material by the heater to pass through.

2. The gasifier according to claim 1, characterized in that: The porous structure is located at a position separated from the heater.

3. The gasifier according to claim 1, characterized in that: The container has a bottom plate portion for arranging the heater. The porous structure is arranged to cover the bottom plate portion.

4. The gasifier according to claim 1, characterized in that: The porous structural member is a porous plate having a plurality of holes formed on a flat plate.

5. The gasifier according to claim 1, characterized in that: Also includes: a liquid level detection sensor for detecting the liquid level of the liquid material in the container; as well as a temperature sensor, disposed between the heater and the liquid level detection sensor, for detecting the temperature of the liquid material; The porous structural member is arranged between the liquid level detection sensor and the temperature sensor.

6. The gasifier according to claim 2, characterized in that: The container has a bottom plate portion for arranging the heater. The porous structure is arranged to cover the bottom plate portion.

7. The gasifier according to claim 2, characterized in that: The porous structural member is a porous plate having a plurality of holes formed on a flat plate.

8. The gasifier according to claim 2, characterized in that: Also includes: a liquid level detection sensor for detecting the liquid level of the liquid material in the container; as well as a temperature sensor, disposed between the heater and the liquid level detection sensor, for detecting the temperature of the liquid material; The porous structural member is arranged between the liquid level detection sensor and the temperature sensor.

9. The gasifier according to claim 3, characterized in that: The porous structural member is a porous plate having a plurality of holes formed on a flat plate.

10. The gasifier according to claim 3, characterized in that The heater is embedded in the bottom plate. The bottom plate has a heating surface that contacts the liquid material in the container and is heated by the heater. The heating surface has a groove above the heater.

11. The gasifier according to claim 3, characterized in that Also includes: a liquid level detection sensor for detecting a liquid level of the liquid material in the container; and a temperature sensor, disposed between the heater and the liquid level detection sensor, for detecting the temperature of the liquid material; The porous structural member is arranged between the liquid level detection sensor and the temperature sensor.

12. The gasifier according to claim 4, characterized in that Also includes: a liquid level detection sensor for detecting the liquid level of the liquid material in the container; as well as a temperature sensor, disposed between the heater and the liquid level detection sensor, for detecting the temperature of the liquid material; The porous structural member is arranged between the liquid level detection sensor and the temperature sensor.

13. The gasifier according to claim 6, characterized in that The porous structural member is a porous plate having a plurality of holes formed on a flat plate.

14. The gasifier according to claim 6, characterized in that The heater is embedded in the bottom plate. The bottom plate has a heating surface that contacts the liquid material in the container and is heated by the heater. The heating surface has a groove above the heater.

15. The gasifier according to claim 6, characterized in that Also includes: a liquid level detection sensor for detecting the liquid level of the liquid material in the container; as well as a temperature sensor, disposed between the heater and the liquid level detection sensor, for detecting the temperature of the liquid material; The porous structural member is arranged between the liquid level detection sensor and the temperature sensor.

16. The gasifier according to claim 7, characterized in that Also includes: a liquid level detection sensor for detecting a liquid level of the liquid material in the container; and a temperature sensor, disposed between the heater and the liquid level detection sensor, for detecting the temperature of the liquid material; The porous structural member is arranged between the liquid level detection sensor and the temperature sensor.

17. The gasifier according to claim 9, characterized in that Also includes: a liquid level detection sensor for detecting the liquid level of the liquid material in the container; as well as a temperature sensor, disposed between the heater and the liquid level detection sensor, for detecting the temperature of the liquid material; The porous structural member is arranged between the liquid level detection sensor and the temperature sensor.

18. The gasifier according to claim 10, characterized in that Also includes: a liquid level detection sensor for detecting the liquid level of the liquid material in the container; as well as a temperature sensor, disposed between the heater and the liquid level detection sensor, for detecting the temperature of the liquid material; The porous structural member is arranged between the liquid level detection sensor and the temperature sensor.

19. The gasifier according to claim 13, characterized in that Also includes: a liquid level detection sensor for detecting the liquid level of the liquid material in the container; as well as a temperature sensor, disposed between the heater and the liquid level detection sensor, for detecting the temperature of the liquid material; The porous structural member is arranged between the liquid level detection sensor and the temperature sensor.

20. A gasification system, characterized in that: include: The gasifier according to claim 1; as well as A flow rate control device controls the flow rate of the gas of the liquid material vaporized in the vaporizer.

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