Gasification tank

Abstract

The vaporization tank (10A) comprises: a housing (12) having a liquid inlet (10i) and a gas outlet (10o); a first storage section (14A) formed inside the housing and storing liquid raw material (L) supplied from the liquid inlet; a second storage section (14B) formed inside the housing and storing liquid raw material (L) overflowing from the first storage section; a first liquid level gauge (24A) suspended from the top plate (12a) of the housing and detecting the liquid level of the liquid raw material stored in the first storage section (14A); and a second liquid level gauge (24B) suspended from the top plate of the housing and detecting the liquid level of the liquid raw material stored in the second storage section (14B).

Description

Technical Field

[0001] This invention relates to a vaporization tank, and more particularly to a vaporization tank for a vaporization device configured to confirm the state of liquid material in the vaporization chamber and to generate a large flow rate of gas. Background Technology

[0002] In semiconductor manufacturing equipment or chemical plants, various processing gases, such as raw material gases and etching gases, are supplied to the processing chamber. Known devices for controlling the flow rate of the supplied gases include mass flow controllers (thermal mass flow controllers) and pressure flow control devices.

[0003] In semiconductor manufacturing apparatuses that utilize metal-organic vapor phase epitaxy (MOCVD) or similar methods to form films, a vaporization supply device is used to vaporize liquid materials and supply them as feed gas to the processing chamber. Patent Document 1 discloses a vaporization supply device that heats metal-organic raw materials such as TEOS (Tetraethyl orthosilicate) to a relatively high temperature, such as 200°C, to vaporize them, maintains the gas temperature, and supplies it to the processing chamber with controlled flow.

[0004] Furthermore, as a vaporization device for liquid materials, a scheme has been proposed that stores the liquid material in multiple trays arranged in a multi-stage vaporization chamber and then vaporizes it. In the vaporization device described in Patent Document 2, the liquid material is stored in multiple trays, and the liquid material in the trays is heated and vaporized by heaters provided in each tray or housing. In addition, Patent Document 3 discloses a vaporizer having multiple trays stacked vertically for supporting the source reagent.

[0005] Thus, by utilizing multiple storage trays located within the vaporization chamber, the surface area of ​​the liquid material stored in the vaporization chamber can be increased, thereby increasing the vaporization volume relative to its size. Furthermore, even when supplying a large flow rate of gas, there is no need to increase the size of the vaporization device, thus achieving space saving. In recent years, there has been a demand for further space-saving measures in devices arranged around the processing chamber, as well as for larger flow rates and larger exhaust volumes in processes such as ALD (Atomic Layer Deposition). Therefore, the development of vaporizers with a larger gas supply volume relative to their size is underway.

[0006] Existing technical documents Invention Patent Documents Invention Patent Document 1: International Publication No. 2019 / 021948 Invention Patent Document 2: Japanese Patent Application Publication No. 2023-87236 Invention Patent Document 3: Japanese Patent No. 5266227 Invention Patent Document 4: Japanese Patent Application Publication No. 2021-148496 Invention Patent Document 5: International Publication No. 2022 / 190711 Summary of the Invention

[0007] The problem that the invention aims to solve In the aforementioned gasification apparatus, it is preferable to be able to monitor the quantity of liquid material stored in the tank or tray at any time. During liquid supply, it is necessary to supply and store an appropriate amount of liquid to the tray. In addition, during gasification supply, it is necessary to monitor the decrease in liquid volume due to material consumption, and replenish liquid material if insufficient to prevent a decrease in gas supply and dry burning.

[0008] Patent document 4 describes a vaporization device configured to use a floating sensor installed inside a raw material container to detect the liquid level (volume) of the liquid raw material. Patent document 5 discloses a configuration in which a floating sensor for measuring the liquid level is installed inside a tank in an ultrapure water vaporization supply device.

[0009] If a floating sensor is used, the liquid level in the storage container can be monitored at any time, thus preventing excessive liquid feedstock from being supplied to the container during liquid supply. In addition, during gas supply, insufficient liquid in the container due to consumption can be detected, and a certain amount of liquid can be pre-stored in the vaporization chamber by opening the valve and replenishing the liquid.

[0010] However, the floating sensor is relatively large, making it difficult to accurately detect the liquid level in shallow trays. Therefore, the following problem exists: in conventional multi-stage tray-type vaporizers, it is difficult to detect the amount of liquid in each tray, making it impossible to perform action control corresponding to the liquid volume in the vaporizer.

[0011] The present invention was made to solve the above-mentioned problems, and its main objective is to provide a vaporizer for use in a relatively small vaporization device that can control the state of liquid materials in the vaporization chamber and stably generate and supply a large flow rate of raw material gas.

[0012] Methods for solving problems A vaporization tank according to an embodiment of the present invention comprises: a housing having a liquid inlet and a gas outlet; a first storage section formed inside the housing and storing liquid raw material supplied from the liquid inlet; a second storage section formed inside the housing and storing liquid raw material overflowing from the first storage section; a first liquid level gauge disposed vertically from the top plate of the housing and detecting the liquid level of the liquid raw material stored in the first storage section; and a second liquid level gauge disposed vertically from the top plate of the housing and detecting the liquid level of the liquid raw material stored in the second storage section.

[0013] In one embodiment, the second liquid level gauge has a plurality of liquid level detection units, which are arranged at intervals in the height direction.

[0014] In one embodiment, the vaporization tank further comprises: a bottom plate portion horizontally disposed at the middle height of the housing; and a partition plate portion vertically disposed from the bottom plate portion, wherein the first storage portion is configured to be surrounded by the bottom plate portion, the partition plate portion and the side wall of the housing.

[0015] In one embodiment, the vaporization tank further includes a tubular protrusion that protrudes upward from the bottom plate portion, the vaporization tank being configured such that liquid raw materials overflowing from the first storage portion are supplied to the second storage portion via the tubular protrusion.

[0016] In one embodiment, a level gauge insertion recess is formed on the bottom surface of the second storage section for inserting the second level gauge, and the bottom surface of the second storage section is inclined toward the level gauge insertion recess.

[0017] In one embodiment, in the vaporization tank, at least above the first storage section, a plurality of fins are provided hanging down from the top plate of the tank body.

[0018] In one embodiment, the housing is configured such that it further has a carrier gas inlet, the gas outlet is configured to communicate with the first storage section, the carrier gas inlet is configured to communicate with the second storage section, and the carrier gas flowing in from the carrier gas inlet flows through the second storage section to the tubular protrusion, and flows from the tubular protrusion through a gas flow path formed by the plurality of fins and the liquid surface of the liquid raw material stored in the first storage section to the gas outlet.

[0019] Invention Effects According to an embodiment of the present invention, a vaporization tank is provided, which is suitable for a vaporization device that has a large vaporization capacity and can appropriately detect the state of the liquid material in the vaporization chamber. Attached Figure Description

[0020] Figure 1This is a schematic diagram illustrating a gas supply system of a gasification apparatus for liquid materials having a gasification tank according to an embodiment of the present invention.

[0021] Figure 2 This is a schematic cross-sectional view of the gasification tank according to an embodiment of the present invention.

[0022] Figure 3 This is a top view showing the first storage section of the gasification tank according to an embodiment of the present invention.

[0023] Figure 4 This is a top view showing the inner bottom surface of the gasification tank according to an embodiment of the present invention.

[0024] Figure 5 This is a schematic diagram illustrating a vaporization tank according to other embodiments of the present invention.

[0025] Figure 6 This is a schematic diagram illustrating a vaporization tank according to yet another embodiment of the present invention.

[0026] Symbol Explanation 2 Liquid material supply source, 4 Processing chamber, 6 Vacuum pump, 7 Liquid replenishment valve, 8 Shut-off valve, 10 Vaporization device, 10A Vaporization tank, 10i Liquid inlet, 10o Gas outlet, 12 Box body, 12a Top plate, 14A First storage section, 14B Second storage section, 15 Flow control device, 16 Bottom plate, 18 Divider plate, 22 Tubular protrusion, 24A First liquid level gauge, 24B Second liquid level gauge, 26 Liquid level gauge insertion recess, 28 Height difference, 30 Carrier gas inlet, 32 Fins, L Liquid material, Go Exhaust gas (raw material gas and carrier gas), Gc Carrier gas. Detailed Implementation

[0027] The embodiments of the present invention will now be described with reference to the accompanying drawings, but the present invention is not limited to the embodiments described below.

[0028] Figure 1 This indicates that it includes a vaporization tank 10A according to an embodiment of the present invention (see reference). Figure 2 The gas supply system 100 of the vaporization device 10 includes a liquid material supply source 2, a vaporization device 10 for vaporizing the liquid material L from the liquid material supply source 2 to generate a raw material gas, a flow control device 15 for controlling the flow rate of the discharge gas Go, which includes the raw material gas generated by the vaporization device 10, a processing chamber 4 connected to the downstream side of the flow control device 15, and a vacuum pump 6 connected to the processing chamber 4.

[0029] A liquid replenishment valve 7 is provided between the liquid material supply source 2 and the vaporization device 10. The liquid replenishment valve 7 is configured to control the supply of liquid material L from the liquid material supply source 2 to the vaporization device 10, for example, to pressurize a desired amount of liquid material L to the vaporization device 10 only during the period when the liquid replenishment valve 7 is open. The liquid replenishment valve 7 may also be fixed to a pipe connected to the cover of the vaporization device 10. For example, an air-driven valve (AOV) can be used as the liquid replenishment valve 7.

[0030] A shut-off valve 8 is provided between the flow control device 15 and the processing chamber 4, which is configured to reliably stop the supply of raw material gas to the processing chamber 4. For example, an air-driven valve (AOV) can be used as the shut-off valve 8. Additionally, a vacuum pump 6 can evacuate the processing chamber 4 and the flow path. The flow control device 15 can control the flow rate of the gas supplied to the processing chamber 4 while the downstream side is under reduced pressure.

[0031] The flow rate of the raw material gas (or, including the exhaust gas Go) generated by the gasification unit 10 is controlled to a desired flow rate by the flow control device 15. For example, a well-known pressure flow control device or a thermal flow control device can be used as the flow control device 15.

[0032] Next, refer to Figure 2 as well as Figure 3 This section describes the detailed configuration of the vaporization tank 10A included in the vaporization apparatus 10 of this embodiment. The vaporization tank 10A includes a housing 12, which is used to dissipate gas from... Figure 1 The liquid material L in the liquid material supply source 2 shown is stored and vaporized inside. A liquid inlet 10i for receiving the liquid material L and a gas outlet 10o for discharging the raw material gas obtained by vaporizing the liquid material L and the introduced carrier gas as exhaust gas Go are provided on the top plate 12a of the housing 12.

[0033] Furthermore, inside the housing 12, there is a first storage section 14A that directly supplies liquid material L from the liquid inlet 10i, and a second storage section 14B that stores liquid material L overflowing from the first storage section 14A. In the vaporization device 10, each storage section 14A and the second storage section 14B, either individually or jointly, is equipped with a heater (not shown) to heat and vaporize the liquid material stored in these storage sections. Temperature sensors 20A and 20B, respectively, are provided in the first storage section 14A and the second storage section 14B for measuring the temperature of the stored liquid material. Additionally, a connection portion 21 for measuring the internal gas pressure is provided on the top plate 12a of the housing 12.

[0034] As a heater for vaporizing liquid material L, a space heater or a jacketed heater configured to heat the vaporization chamber from the outside of the housing 12 can be used, for example. By using a temperature regulator to operate the heater based on the outputs of temperature sensors 20A and 20B, the temperature of the liquid material L and the vaporization chamber can be set to the desired temperature.

[0035] In this embodiment, the first storage section 14A is a space horizontally disposed above the bottom plate 16 at the middle height of the housing 12, and is formed by a space separated from the second storage section 14B by a partition plate (partition wall) 18, which extends vertically upward from the bottom plate 16 to the top plate 12a of the housing 12. The first storage section 14A is surrounded by the bottom plate 16, the partition plate 18, and the side wall of the housing 12. The second storage section 14B is formed by a space inside the housing 12 outside the first storage section 14A, including the space below the bottom plate 16 and the space on the outer side of the first storage section 14A separated by the partition plate 18.

[0036] Here, as Figure 3 As shown, in this embodiment, when viewed from above, the partition plate portion 18 is arranged in an L-shape. In this configuration, the first storage portion 14A is defined as a space located above the bottom plate portion 16 on the outer side of the L-shaped partition plate portion 18. Furthermore, the second storage portion 14B is defined as a space extending through the bottom plate portion 16 from the inner side of the L-shaped partition plate portion 18, and extending downwards from the bottom plate portion 16 directly below the first storage portion 14A. It should be noted that, in order to prevent a large difference in gas pressure between the first storage portion 14A and the second storage portion 14B, multiple through holes or other connecting portions may be provided in the upper part of the partition plate portion 18.

[0037] In this embodiment, liquid material L overflowing from the first storage section 14A is transported to the lower second storage section 14B via a tubular protrusion 22. This tubular protrusion 22 extends upward from the bottom plate section 16, and its upper opening is located near the top plate 12a. Furthermore, the lower opening of the tubular protrusion 22 is located near the bottom plate section 16, and liquid material L passing through the inside of the tubular protrusion 22 falls into the second storage section 14B directly below the first storage section 14A. Figure 3 As shown, when viewed from above, the tubular protrusion 22 is, for example, positioned at a corner opposite to the corner (which constitutes part of the second storage section 14B) separated by the L-shaped partition section 18.

[0038] In addition, the vaporization tank 10 is equipped with a first liquid level gauge 24A for detecting the liquid level of the liquid material stored in the first storage section 14A and a second liquid level gauge 24B for detecting the liquid level of the liquid material stored in the second storage section 14B. Both the first liquid level gauge 24A and the second liquid level gauge 24B are installed vertically from the top plate 12a of the tank body 12.

[0039] Here, as Figure 2 As shown, the first liquid level gauge 24A has a single liquid level detection unit 24LL, while the second liquid level gauge 24B has three liquid level detection units 24L, 24M, and 24H arranged at intervals in the height direction. For example, the same device as the floating sensor described in Patent Document 4 can be used for both the first liquid level gauge 24A and the second liquid level gauge 24B.

[0040] In this configuration, the liquid level detection section 24LL of the first liquid level gauge 24A is used to confirm whether a minimum amount of liquid material is present in the first storage section 14A. Furthermore, in the second liquid level gauge 24B, the lowermost liquid level detection section 24L is used to confirm whether liquid material is present in the second storage section 14B; the middle liquid level detection section 24M is used to confirm whether liquid material is present in the main storage section of the second storage section 14B (here, the space below the bottom plate 16); and the uppermost liquid level detection section 24H is used to confirm whether liquid material is present in the secondary storage section of the second storage section 14B (here, the space above the bottom plate 16).

[0041] As described above, since liquid level gauges are respectively installed in the first storage section 14A and the second storage section 14B, the amount of liquid material supplied to the vaporization tank 10A can be detected in detail. For example, during processing, if the liquid level detection unit 24L fails to detect liquid, it can be assumed that there is almost no liquid material inside the vaporization tank 10A, and thus an abnormality is determined, and the vaporization operation is stopped. Alternatively, if the liquid level detection unit 24L fails to detect liquid, it can be determined that there is insufficient liquid material for continuing processing, and the processing is temporarily terminated, switching to a liquid replenishment mode.

[0042] Furthermore, when supplying liquid material to the vaporization tank 10A, if the liquid level detection unit 24M detects liquid, it can determine that sufficient liquid has been supplied and begin processing. Alternatively, if the liquid level detection unit 24H detects liquid, it can determine that excessive liquid has been supplied, indicating an abnormal state that may lead to overflow.

[0043] As described above, liquid material L is first supplied to the first storage section 14A through the liquid inlet 10i. When the liquid material L accumulates to the height of the upper opening of the tubular protrusion 22, the liquid material L is then supplied to the second storage section 14B via the tubular protrusion 22. At this time, in this embodiment, as... Figure 4 As shown, the bottom shape of the second storage section 14B is designed so that liquid is guided into the area in the second storage section 14B in which the second liquid level gauge 24B is disposed.

[0044] like Figure 4 As shown, a recess is provided at the corner of the second liquid level gauge 24B on the bottom surface of the second storage section 14B. A liquid level gauge insertion recess 26 for inserting the second liquid level gauge 24B is formed in this bottom surface. Furthermore, along the first corner (upper right corner in the figure) where the liquid level gauge insertion recess 26 is located, and... Figure 3 A height difference 28 is provided along the diagonal connecting the second corner (lower left corner in the figure) directly below the tubular protrusion 22, and the bottom surface as a whole slopes slightly downward from the second corner toward the first corner (i.e., toward the level gauge insertion recess 26). It should be noted that in the illustrated example, the area forming the height difference 28 is higher in the upper left and lower in the lower right.

[0045] Thus, by providing a height difference and inclination on the bottom surface of the second storage section 14B, the liquid material L overflowing from the first storage section 14A and supplied to the second storage section 14B can be guided towards the second level gauge 24B. This allows for more accurate liquid level detection based on the second level gauge 24B. It should be noted that the position of the height difference and the direction of the inclination are not limited to the example shown in the figure, and can be appropriately set according to the positional relationship between the tubular protrusion 22 and the second level gauge 24B.

[0046] In addition, such as Figure 3 As shown, in the vaporization tank 10A of this embodiment, a carrier gas inlet 30 is provided for introducing a carrier gas Gc (or auxiliary gas) such as an inert gas into the interior. The carrier gas inlet 30 is provided in a manner that communicates with the second storage section 14B inside the partition plate section 18. On the other hand, the gas outlet 10o is provided in a manner that communicates with the first storage section 14A outside the partition plate section 18. It should be noted that, in the illustrated arrangement, although the carrier gas inlet 30 is positioned above the first storage section 14A, it is not directly connected to the first storage section 14A, but is directly connected to the second storage section 14B via a pipe or the like.

[0047] Furthermore, such as Figure 2 As shown, in the first storage section 14A of the vaporization tank 10A, a plurality of fins 32 are provided hanging from the top plate 12a of the housing 12. Figure 3As shown, multiple fins 32 extend from the opposing sidewalls of the housing 12, forming a meandering flow path in the middle, and alternately forming gaps with the front sidewall, respectively.

[0048] In this configuration, the carrier gas flowing in from the carrier gas inlet 30 flows through the second storage section 14B below the bottom plate section 16 to the annular protrusion 22, and then flows into the first storage section 14A through the annular protrusion 22. Next, in the first storage section 14A, it flows through a meandering flow path formed by multiple fins 32, and finally flows out to the outside from the gas outlet 10o.

[0049] Thus, by allowing the carrier gas Gc to flow through the second storage section 14B and the first storage section 14A in a longer flow path, its mixability with the vaporized material gas is improved, resulting in a mixed gas with less concentration unevenness as the exhaust gas Go. It should be noted that by providing multiple fins 32 (typically made of metal) as described above, heat from the heater can be more easily transferred to the stored liquid, thereby improving vaporization performance.

[0050] The above describes a vaporization tank according to an embodiment of the present invention. However, as long as it has a first storage section and a second storage section and corresponding first liquid level gauges and second liquid level gauges, the vaporization tank can be in various forms.

[0051] For example, such as Figure 5 As shown in the vaporization tank 10B, it can also be configured such that the first storage section 14A and the second storage section 14B are arranged side by side, and the liquid material L overflowing from the first storage section 14A beyond the upper end surface of the partition plate section 18 flows to the second storage section 14B and is stored there.

[0052] In addition, such as Figure 6 As shown in the vaporization tank 10C, a first storage section 14A may be provided inside the tray 19, which has side walls and a bottom, and a second storage section 14B may be provided below it. In this case, liquid material L that overflows from the side wall of the tray beyond the first storage section 14A falls downward and is stored in the second storage section 14B.

[0053] Industrial applications The vaporization vessel according to an embodiment of the invention is, for example, suitable for generating various gases from liquid materials and supplying them to a processing chamber in a semiconductor manufacturing apparatus.

Claims

1. A gasification tank, comprising: The enclosure has a liquid inlet and a gas outlet; A first storage section is formed inside the housing and stores the liquid raw material supplied from the liquid inlet; A second storage section is formed inside the housing and stores liquid raw materials that overflow from the first storage section; A first liquid level gauge is installed vertically from the top plate of the housing and detects the liquid level of the liquid raw material stored in the first storage section; and A second liquid level gauge is installed vertically from the top plate of the housing and detects the liquid level of the liquid raw material stored in the second storage section.

2. The gasification tank according to claim 1, wherein, The second liquid level gauge has multiple liquid level detection units, which are spaced apart in the height direction.

3. The gasification tank according to claim 2, comprising: The base plate is horizontally positioned at the midpoint of the housing; and A partition plate portion, which is vertically disposed from the bottom plate portion. The first storage section is surrounded by the bottom plate section, the partition plate section, and the side wall of the box body.

4. The vaporization tank according to claim 3, comprising: A tubular protrusion that protrudes upward from the bottom plate portion. Liquid raw materials overflowing from the first storage section are supplied to the second storage section via the tubular protrusion.

5. The gasification tank according to claim 4, wherein, A level gauge insertion recess is formed on the bottom surface of the second storage section for inserting the second level gauge. The bottom surface of the second storage section is inclined toward the level gauge insertion recess.

6. The gasification tank according to claim 4, wherein, At least above the first storage section, a plurality of fins are provided hanging down from the top plate of the box.

7. The vaporization tank according to claim 6, wherein, The enclosure also has a carrier gas inlet. The gas outlet is configured to communicate with the first storage unit, and the carrier gas inlet is configured to communicate with the second storage unit. The carrier gas flowing in from the carrier gas inlet flows through the second storage section to the tubular protrusion, and from the tubular protrusion flows through a gas flow path formed by the plurality of fins and the liquid surface of the liquid raw material stored in the first storage section to the gas outlet.

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