Liquid retaining device, semiconductor manufacturing system, and method for replenishing liquid

Abstract

To provide a technique that can accurately manage the liquid level of liquid for processing in a container body.SOLUTION: A liquid retaining device includes: a container body that retains therein liquid for processing; a liquid level sensor that is provided inside the container body and detects the liquid level of the retained liquid for processing; a replenishing unit that replenishes the liquid for processing into the container body; and a control unit that acquires detection information from the liquid level sensor and performs processing. The liquid level sensor comprises four or more sensors that can detect the liquid level of the liquid for processing along a height direction of the container body. The control unit sets at least three liquid level determination positions corresponding to the sensors different from each other, of the four or more sensors, and controls replenishment of the liquid for processing from the replenishing unit to the container body on the basis of detection information at the at least three set liquid level determination positions.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a liquid reservoir device, a semiconductor manufacturing system, and a method for replenishing liquid. [Background technology]

[0002] Patent Document 1 discloses a liquid storage device (liquid supply device) equipped with a liquid level sensor (detection unit) that detects the level of liquid stored in a container body (recharge tank). This liquid level sensor is configured to detect two liquid levels: a minimum liquid level and a maximum liquid level.

[0003] Patent Document 2 discloses a system in which a liquid (CVD precursor) is stored in a container body (precursor storage tank) and vapor of the liquid is supplied to a semiconductor manufacturing device while detecting the liquid level with a liquid level sensor (level detection means). This liquid level sensor is also configured to detect the liquid level at two set points (a first set point and a second set point). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-146397 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-522036 Summary of the Invention [Problem to be solved by the invention]

[0005] The present disclosure provides a technique that can accurately manage the liquid level of a processing liquid stored in a container body. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, there is provided a liquid storage device for storing a processing liquid for a substrate processing apparatus, the liquid storage device including: a container body for storing the processing liquid therein; a liquid level sensor provided inside the container body for detecting the level of the stored processing liquid; a replenishment unit for replenishing the processing liquid inside the container body; and a control unit for acquiring detection information from the liquid level sensor and performing processing, wherein the liquid level sensor has four or more detectors capable of detecting the level of the processing liquid along the height direction of the container body, and the control unit sets at least three liquid level determination positions corresponding to different detectors among the four or more detectors, and controls the replenishment of the processing liquid from the replenishment unit to the container body based on detection information from the set at least three liquid level determination positions. [Effects of the Invention]

[0007] According to one aspect, the liquid level of the processing liquid stored in the container body can be controlled with high precision. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram showing an example of a semiconductor manufacturing system having a liquid storage device according to a first embodiment. [Figure 2] Fig. 2(A) is a graph showing the relationship between the volume of liquid stored in the container body and the output value of the liquid level sensor, and Fig. 2(B) is a graph showing the shift of the liquid level determination position set for each detector. [Figure 3] Fig. 3(A) is a cross-sectional view showing a state in which the liquid in the container body has decreased, and Fig. 3(B) is a cross-sectional view showing a state in which the container body has been refilled with liquid. [Figure 4] FIG. 2 is a block diagram showing an example of a functional block formed in a controller. [Figure 5] 1 is a flowchart illustrating a method for supplying and replenishing a liquid in a semiconductor manufacturing system. [Figure 6] 10 is a flowchart showing a position correction method for correcting a liquid level determination position. [Figure 7]FIG. 10 is a diagram showing an example of a semiconductor manufacturing system 1 having a liquid storage device 10 according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and redundant explanations may be omitted.

[0010] [First embodiment] Fig. 1 is a diagram showing an example of a semiconductor manufacturing system 1 having a liquid storage device 10 according to the first embodiment. As shown in Fig. 1, the semiconductor manufacturing system 1 is configured as a system that supplies a processing liquid from the liquid storage device 10 to a substrate processing apparatus 50 and performs substrate processing on a substrate W in the substrate processing apparatus 50 with the processing liquid. The type of substrate processing performed by the substrate processing apparatus 50 is not particularly limited, and examples include film formation processing, etching processing, modification processing, stripping processing, washing processing, and cleaning processing.

[0011] The processing liquid may be selected appropriately depending on the type of substrate processing and the type of film on the substrate W to be processed. For example, if the substrate processing is a cleaning process for cleaning the surface of the substrate W, the processing liquid may be a chemical liquid for cleaning the substrate W or pure water for rinsing the surface of the substrate W. Examples of chemical liquids in this case include SPM, which is a mixture of sulfuric acid and hydrogen peroxide, APM, which is a mixture of ammonia and hydrogen peroxide, DHF, which is a mixture of hydrofluoric acid and pure water, and HPM, which is a mixture of hydrochloric acid and hydrogen peroxide. Examples of pure water include ultrapure water such as DIW (deionized water) from which ionic components have been removed. In the following description, the processing liquid may also be simply referred to as liquid.

[0012] In the first embodiment, an example of a semiconductor manufacturing system 1 that performs a cleaning process as a substrate processing will be described. Specifically, the semiconductor manufacturing system 1 includes a liquid storage device 10 that stores a cleaning liquid, a supply network 30 that supplies the liquid from the liquid storage device 10, and a substrate processing apparatus 50 that actually performs the substrate processing. Furthermore, the semiconductor manufacturing system 1 includes a controller 90 that manages the entire system and controls each component of the system.

[0013] Liquid storage device 10 is configured as a device that can temporarily store an appropriate amount of liquid and supply (outflow) the liquid. Specifically, liquid storage device 10 includes a container body 11, an inlet port 12 that allows liquid to flow into container body 11, an outlet port 13 that allows liquid to flow out of container body 11, and an on-off valve 14 provided in outlet port 13 (or in a supply path 31 connected to outlet port 13).

[0014] Furthermore, the liquid storage device 10 includes a refilling unit 15 upstream of the container body 11 that refills the container body 11 with liquid. The refilling unit 15 includes, for example, a liquid refill source 16, an inflow path 17, and an on-off valve 18, which are provided separately from the container body 11. The refilling source 16 may be a mother tank for liquid provided from another source, or may be a liquid generation device that generates liquid. The liquid generation device may be, for example, a device that distills liquid, mixes (adds) an appropriate substance with liquid, filters liquid, extracts liquid, or the like. The on-off valve 18 opens and closes the flow path of the inflow path 17 under the control of the controller 90. When the on-off valve 18 is open, the refilling unit 15 allows liquid to flow from the refilling source 16 to the inflow path 17, refilling the container body 11 with liquid via the inflow port 12.

[0015] The container body 11 is formed, for example, in the shape of an inverted truncated cone with the bottom tapering relative to the ceiling. A liquid storage space 11s is formed inside the container body 11, conforming to the shape of the container body 11. The size (volume) of the storage space 11s may be set according to the amount of liquid required for the cleaning process, etc. The shape of the container body 11 is not particularly limited, and may be a cylindrical shape with a constant cross-sectional area in the vertical direction, a rectangular cylindrical shape, or the like.

[0016] An inlet port 12 is provided in the ceiling of the container body 11, while an outlet port 13 is provided in the bottom of the container body 11. The inlet port 12 is connected to an inlet path 17 of the replenisher 15 and protrudes slightly from the ceiling into the storage space 11s. The inlet port 12 allows the liquid from the replenisher 15 to flow into the storage space 11s from an inlet at its lower end. Note that in order to suppress turbulence of the liquid in the storage space 11s, the inlet port 12 may protrude to near the bottom and discharge the liquid from the inlet at its lower end. Meanwhile, the outlet port 13 is located approximately in the center of the bottom of the container body 11. The liquid storage device 10 uses the weight (pressure) of the liquid stored in the storage space 11s to drain the liquid into the supply network 30. However, this configuration is not limited to this. The semiconductor manufacturing system 1 may also be configured such that the supply network 30 is provided with a pump or the like, and the pump pressure-feeds the liquid from the container body 11.

[0017] The liquid storage device 10 according to the first embodiment also includes a heating unit 19 that heats the liquid stored in the container body 11. In the illustrated example, the heating unit 19 is provided within the peripheral wall of the container body 11, but the installation location of the heating unit 19 is not limited thereto and the heating unit 19 may be provided on the bottom, ceiling, or outside. The heating unit 19 is connected to a controller 90 via a driver (not shown), and the driver controls the power supply in accordance with the target temperature instructed by the controller 90, thereby heating the liquid in the container body 11 to the target temperature. The liquid storage device 10 may also include a temperature sensor (not shown) in the container body 11 to provide feedback on the actual temperature of the liquid. The configuration of the heating unit 19 is not particularly limited, and examples thereof include an electric heating wire provided inside the container body 11 and a sheet heater covering the outside of the container body 11.

[0018] The liquid storage device 10 is provided with a liquid level sensor 20 in order to detect the level of the liquid stored in the storage space 11s of the container body 11. The configuration of this liquid level sensor 20 will be described in detail later.

[0019] The supply network 30 includes a liquid supply path 31, an on-off valve 32, and a flow rate controller 33. The supply path 31 of the supply network 30 has branched portions, confluence portions, and the like formed depending on the configuration of the substrate processing apparatus 50. For example, in the example of Fig. 1, the substrate processing apparatus 50 includes a plurality of nozzles 52, and the supply path 31 branches into a plurality of branch paths 311, 312 from an intermediate position in order to supply an appropriate amount of liquid to each nozzle 52. The supply network 30 includes an on-off valve 32 and a flow rate controller 33 in each of the plurality of branch paths 311, 312.

[0020] The supply network 30 also includes a gas supply unit 40 for each of the plurality of branch paths 311, 312 in order to supply an inert gas such as nitrogen (N2) gas to the substrate processing apparatus 50. The gas supply unit 40 has a gas supply path 41 connected to each of the branch paths 311, 312. The gas supply unit 40 also includes a gas tank 42 for storing the inert gas, an on-off valve 43, a flow rate controller 44, and the like, installed on each gas supply path 41. The gas supply unit 40 supplies the inert gas to the substrate processing apparatus 50 via the gas supply path 41 and the branch paths 311, 312 in order to purge liquid remaining in the flow paths of the branch paths 311, 312 and inside the substrate processing apparatus 50, for example.

[0021] The supply network 30 is not limited to a configuration in which liquid is supplied from one liquid storage device 10 to one substrate processing apparatus 50, but may be a configuration in which liquid is supplied from multiple liquid storage devices 10 to one substrate processing apparatus 50. Fig. 1 illustrates a configuration in which a first liquid (e.g., SPM) is supplied from a first liquid storage device 10A, and a second liquid (e.g., DIW) is supplied from a second liquid storage device 10B. The supply network 30 may also be configured to supply liquid from one liquid storage device 10 to multiple substrate processing apparatuses 50.

[0022] The substrate processing apparatus 50 includes a processing vessel 51 that accommodates a substrate W, a plurality of nozzles 52 provided inside the processing vessel 51 , and a substrate support 53 that supports the substrate W inside the processing vessel 51 .

[0023] Each nozzle 52 has a protruding portion extending vertically within the processing vessel 51, and ejects liquid from an ejection port 52o of the protruding portion toward the substrate W. The nozzles 52 are movable within the processing vessel 51 by a moving mechanism (not shown). For example, each nozzle 52 is configured to move between an ejection position at the center of the substrate support portion 53 (substrate W) and a standby position radially outward from the substrate support portion 53 under the control of the controller 90.

[0024] Branch paths 311, 312 leading to the first liquid storage device 10A and a supply path 31 leading to the second liquid storage device 10B are connected to the plurality of nozzles 52. This allows each nozzle 52 to eject the liquid supplied from the path connected thereto from the ejection port 52o and supply it onto the surface of the substrate W.

[0025] The substrate support 53 has a substrate W placed on its upper surface. The substrate support 53 may be provided with a fixing means such as electrostatic adsorption, suction adsorption, or mechanical lock to hold the substrate W placed on its upper surface. The substrate support 53 may be configured to be rotatable around the center of its upper surface inside the processing vessel 51 by a rotation mechanism (not shown). For example, the substrate processing apparatus 50 supplies liquid from a nozzle 52 disposed above and at the center of the substrate W while rotating the substrate W using the substrate support 53. As a result, the liquid ejected onto the substrate W moves radially outward due to the centrifugal force of the substrate W, wetting and spreading outward, thereby immersing the entire surface of the substrate W in the liquid.

[0026] The controller 90 of the semiconductor manufacturing system 1 is a computer including a processor, memory, input / output interface, communication interface, etc. (not shown). The processor is an electronic circuit that combines one or more of a CPU (Central Processing Unit), GPU (Graphics Processing Unit), ASIC (Application Specific Integrated Circuit), FPGA (Field-Programmable Gate Array), and a circuit made up of multiple discrete semiconductors, and executes and processes programs stored in memory. The memory includes a main storage device made up of semiconductor memory, etc., and an auxiliary storage device made up of a disk, drive, semiconductor memory (flash memory), etc.

[0027] The controller 90 of the semiconductor manufacturing system 1 controls the operations of the liquid storage device 10, the supply network 30, and the substrate processing apparatus 50 to supply the liquid and perform substrate processing on the substrate W. At this time, the controller 90 also acquires detection information from the liquid level sensor 20 of the liquid storage device 10, manages the liquid stored in the container body 11, and performs outflow and inflow (replenishment) of the liquid. Note that in the embodiment, an example will be described in which the controller 90 of the semiconductor manufacturing system 1 controls each component of the liquid storage device 10. However, the semiconductor manufacturing system 1 may also include a control unit (not shown) dedicated to the liquid storage device 10, and each component of the liquid storage device 10 may be controlled by the control unit that receives commands from the controller 90.

[0028] The liquid level sensor 20 of the liquid storage device 10 is provided in the storage space 11s of the container body 11 and extends linearly along the height direction (vertical direction). The liquid level sensor 20 has multiple (25) detectors 21 at different positions along the height direction, and each detector 21 detects the presence or absence of the liquid level. This liquid level sensor 20 may be a float-type level sensor in which floats serving as detectors 21 are arranged at equal intervals on a frame 22 extending in the height direction. For example, the detectors 21 are formed of a magnet or the like, and float up due to the buoyancy of the liquid and descend when there is no liquid, thereby opening and closing a magnetic switch. The liquid level sensor 20 configured in this manner can detect the liquid level in the container body 11 in stages depending on the number of detectors 21. Note that the type of liquid level sensor 20 is not limited to a float type, and other types, such as optical, capacitance, electrode, and pressure (differential pressure) types, may also be used.

[0029] 2(A) is a graph showing the relationship between the volume of liquid stored in the container body 11 and the output value of the liquid-level sensor 20. FIG. 2(B) is a graph showing the shift of the liquid-level determination position set for each detector 21. The liquid-level sensor 20 is able to output output values ​​that are proportional to the volume of liquid in the container body 11 in stages by arranging the detectors 21 at equal intervals along the height direction, as shown in FIG. 2(A). The controller 90 has in advance information (such as map information) that associates the output value of the liquid-level sensor 20 with the volume (in other words, the amount of liquid), and is able to recognize the volume of liquid in the container body 11 during operation based on the output value of the liquid-level sensor 20.

[0030] The number of detectors 21 in the liquid level sensor 20 is not limited to 25, and may be more or less than this. However, it is assumed that the liquid level sensor 20 has at least n+1 detectors 21, where n is the number of liquid level determination positions described below. In the first embodiment, three liquid level determination positions are set. Therefore, it is sufficient for the liquid level sensor 20 to have four or more detectors 21 along the height direction of the container body 11.

[0031] 1 and 2(A), the controller 90 sets at least three liquid level determination positions among the multiple (25) detectors 21 of the liquid level sensor 20, and detects the presence or absence of the liquid surface at the set liquid level determination positions. The three liquid level determination positions are, in order from the top vertically to the bottom vertically, an upper limit position HP, a middle position MP, and a lower limit position LP.

[0032] The upper limit position HP is information indicating the storage limit position when storing liquid in the container body 11. When the liquid is stored beyond this upper limit position HP, the controller 90 issues an alarm or the like, stops the operation of the system, or the like, thereby stopping the supply of liquid to the container body 11.

[0033] The intermediate position MP is information indicating a determination threshold value for determining whether or not to replenish the liquid by the refilling unit 15. Control based on the intermediate position MP, which is the liquid level determination position, will be described below with reference to Figures 3(A) and 3(B). Figure 3(A) is a diagram showing a state in which the liquid level in the container body 11 is lower than the intermediate position MP. Figure 3(B) is a diagram showing a state in which the container body 11 has been replenished with liquid from the refilling unit 15.

[0034] During substrate processing, liquid storage device 10 supplies liquid from container body 11 to substrate processing apparatus 50, causing the level of liquid in container body 11 to decrease. Controller 90 constantly detects the level of liquid in container body 11 using liquid level sensor 20, and when it determines that the liquid level has fallen below intermediate position MP, it starts replenishing liquid from replenishing unit 15 to container body 11. As an example, liquid storage device 10 repeatedly replenishing a fixed amount of liquid from replenishing unit 15, and when it determines that the liquid level has exceeded intermediate position MP, it stops replenishing liquid from replenishing unit 15. Alternatively, liquid storage device 10 may replenishing a quantity (fixed amount) of liquid from replenishing unit 15 to container body 11 all at once, sufficient to raise the liquid level above intermediate position MP.

[0035] Furthermore, the lower limit position LP is information indicating a supply limit position when liquid is supplied from the container body 11 to the substrate processing apparatus 50. When the liquid falls below this lower limit position LP and begins to flow out, the controller 90 issues an alarm or stops the operation of the system to stop the supply of liquid from the container body 11. It is preferable that the lower limit position LP is set at a position some distance from the bottom of the container body 11 so that an amount of liquid required for one substrate processing can be secured. This allows the controller 90 to stop the supply of liquid after the substrate processing is completed, without immediately stopping the substrate processing when the liquid falls below the lower limit position LP.

[0036] Furthermore, the controller 90 is not limited to setting three liquid level determination positions, and may set four or more liquid level determination positions. As an example, in addition to the upper limit position HP and the lower limit position LP, the controller 90 may set two positions as intermediate positions MP (a refill start position that determines when the refill unit 15 should start refilling the liquid, and a refill stop position that determines when the refill unit 15 should stop refilling the liquid).

[0037] Fig. 4 is a block diagram showing the functional blocks of the controller 90. As shown in Fig. 4, the controller 90 forms a functional unit that processes detection information from the liquid level sensor 20 of the liquid storage device 10 by having a processor execute a program stored in memory. For example, the controller 90 internally configures a liquid level determination position setting unit 101, a detection information acquisition unit 102, a liquid level determination unit 103, a control processing unit 104, a liquid state estimation processing unit 105, etc.

[0038] The liquid level determination position setting unit 101 allows the liquid level determination positions of the liquid in the container body 11 to be set automatically by the controller 90 or by a user of the semiconductor manufacturing system 1. For example, the liquid level determination position setting unit 101 displays setting screen information for setting the liquid level on a monitor (not shown) or the like of the controller 90, and allows the user to operate the setting screen information to set each liquid level determination position.

[0039] Alternatively, the liquid level determination position setting unit 101 may adjust the liquid level determination position (e.g., intermediate position MP) based on the details of substrate processing in the substrate processing apparatus 50. The liquid level determination position setting unit 101 calculates the amount of liquid to be used in substrate processing according to a substrate processing recipe stored in memory, and sets the amount of liquid to be stored in the container body 11 during substrate processing, in other words, the intermediate position MP, based on the calculated amount of liquid used. As an example, the liquid level determination position setting unit 101 may raise the intermediate position MP when a large amount of liquid is used, and lower the intermediate position MP when a small amount of liquid is used.

[0040] The detection information acquisition unit 102 periodically or at appropriate timing acquires the detection information of the liquid level sensor 20 and stores it in memory. The memory may store the liquid level information of the liquid level sensor 20 in association with information such as the time of detection.

[0041] The liquid level determination unit 103 compares the acquired liquid level detection information (the actual liquid level of the liquid stored in the container body 11) with each preset liquid level determination position to determine the state of the liquid level. For example, the liquid level determination unit 103 determines whether the actual liquid level is equal to or greater than the intermediate position MP or less than the intermediate position MP.

[0042] The control processing unit 104 controls the operation of the liquid storage device 10 based on the status of substrate processing in the substrate processing apparatus 50, the determination result of the liquid level determination unit 103, etc. For example, the control processing unit 104 opens the on-off valve 14 upon start of substrate processing to supply liquid to the substrate processing apparatus 50, and closes the on-off valve 14 upon completion of substrate processing to stop the supply of liquid to the substrate processing apparatus 50.

[0043] Furthermore, when the actual liquid level falls below the intermediate position MP, the control processing unit 104 replenishes the container body 11 with liquid from the replenishment unit 15. Replenishment of the liquid from the replenishment unit 15 may be performed immediately during substrate processing, or may be performed after the substrate processing is completed. For example, when the liquid temperature is being adjusted by the heating unit 19, the liquid storage device 10 delays the timing of supplying the liquid until after the substrate processing is completed. This makes it possible to prevent the temperature of the liquid in the container body 11 from changing during substrate processing due to replenishment.

[0044] The liquid state estimation processing unit 105 is a functional unit that automatically adjusts the liquid level determination position, adjusts the amount of liquid replenished by the replenishment unit 15, requests replacement of the container body 11, etc., in accordance with various conditions of the liquid storage device 10 or the substrate processing apparatus 50. The liquid level determination position may be adjusted in the following cases (1) and (2), for example.

[0045] (1) Thermal expansion occurs in liquids depending on the temperature.

[0046] (2) Sediment accumulates in the container body 11.

[0047] An example of case (1) is a situation in which the liquid in the container body 11 is heated (temperature adjusted to a target temperature) by the heating unit 19. Liquid has an inherent coefficient of thermal expansion and expands according to the amount of heat received from the heating unit 19 and the coefficient of thermal expansion. Therefore, the liquid state estimation processing unit 105 performs processing to optimize (adjust) the liquid level determination position according to the target temperature of the container body 11 (heating unit 19) using the coefficient of thermal expansion of the liquid as a coefficient. For example, if the liquid in the container body 11 expands and the detector 21 corresponding to the intermediate position MP shifts, the liquid state estimation processing unit 105 performs processing to shift the intermediate position MP to another detector 21 in accordance with the expansion of the liquid. In this case, the liquid state estimation processing unit 105 may shift the upper limit position HP and / or the lower limit position LP in addition to the intermediate position MP, as shown in FIG. 2(B).

[0048] An example of case (2) is a situation in which, when the liquid contains impurities that are prone to settling, sediment accumulates in the container body 11 as a result of performing substrate processing multiple times and repeatedly refilling the container body 11 with liquid. The amount of sediment can be estimated by monitoring the cumulative refill amount of the liquid supplied to the container body 11 and / or the cumulative usage amount of the liquid used in the substrate processing. For example, the liquid state estimation processing unit 105 continuously stores the cumulative refill amount and cumulative usage amount to estimate the liquid level in the container body 11, and estimates the amount of sediment from the degree of deviation between the estimated liquid level and the actual liquid level (current liquid level). Alternatively, the liquid state estimation processing unit 105 may hold function or map information that associates the cumulative refill amount of the liquid with the amount of sediment by performing experiments, simulations, or the like, and estimate the amount of sediment from the cumulative refill amount.

[0049] The liquid state estimation processing unit 105 can perform processing to shift each liquid level determination position (upper limit position HP, middle position MP, lower limit position LP) based on the estimated amount of sediment. For example, if the liquid level rises due to sediment, causing the corresponding positions between each detector 21 of the liquid level sensor 20 and each liquid level determination position to shift by one step, the liquid state estimation processing unit 105 adjusts each liquid level determination position to rise by one step. Alternatively, if the amount of sediment in the container body 11 becomes large, the liquid state estimation processing unit 105 can request the user to replace the container body 11 via a user interface such as the monitor of the controller 90.

[0050] Furthermore, when replenishing the liquid from the replenishing unit 15, the liquid state estimation processing unit 105 may monitor the liquid level using the liquid level sensor 20 and perform processing to change the amount of liquid replenished by the replenishing unit 15. Specifically, when replenishing the liquid, the detection information from each detector 21 of the liquid level sensor 20 indicates the current liquid level relative to the target liquid level, allowing the replenishing status of the liquid to be roughly estimated. Therefore, the liquid state estimation processing unit 105 can increase the replenishing amount at the beginning of replenishing the liquid from the replenishing unit 15, and decrease the replenishing amount as the liquid approaches the target liquid level. This allows the liquid storage device 10 to shorten the replenishing time of the liquid and suppress fluctuations in the liquid surface after replenishing, thereby improving the efficiency of the entire operation, including substrate processing.

[0051] The liquid storage device 10 and semiconductor manufacturing system 1 according to the embodiment are basically configured as described above, and their operation will be described below with reference to Figures 5(A) and 5(B). Figure 5(A) is a flowchart showing a method for refilling liquid. Figure 5(B) is a flowchart showing a method for correcting the liquid level determination position.

[0052] The controller 90 of the semiconductor manufacturing system 1 controls steps S101 to S109 shown in FIG. 5(A) to perform substrate processing in the substrate processing apparatus 50 and to manage the liquid in the liquid storage device 10.

[0053] In detail, before starting substrate processing in the substrate processing apparatus 50, the controller 90 sets each liquid level determination position (upper limit position HP, middle position MP, lower limit position LP) corresponding to each different one of the detectors 21 of the liquid level sensor 20 (step S101). For example, the liquid level determination position setting unit 101 of the controller 90 sets the reference liquid level determination position based on the content of the substrate processing as described above.

[0054] Furthermore, the liquid state estimation processor 105 determines whether a correction start condition for performing a correction method for adjusting the liquid level determination position is met before the start of substrate processing (step S102). Examples of the correction start condition include when the duration or number of substrate processing runs (in other words, the cumulative amount of liquid used) exceeds a preset threshold, or when the liquid in the container body 11 is heated depending on the substrate processing. If the correction start condition is met (step S102: YES), the controller 90 proceeds to a subroutine for the correction method. On the other hand, if the correction start condition is not met (step S102: NO), the controller 90 does not perform the correction method at this timing and proceeds to step S103. Note that the timing for determining whether the correction start condition is met is not limited to before the start of substrate processing, but may be any appropriate timing, such as when the liquid level in the container body 11 falls below the intermediate position MP after the substrate processing is completed. If the controller 90 performs correction other than before the start of substrate processing, it only needs to store the corrected liquid level determination position in memory.

[0055] In step S103, the controller 90 controls the temperature adjustment of the liquid in the container body 11 (heating of the heating unit 19) according to the substrate processing, and the pressure adjustment and temperature adjustment of the substrate processing apparatus 50, and then controls the substrate processing apparatus 50 to perform the substrate processing. In this substrate processing, the liquid storage device 10 supplies the liquid from the container body 11 to the substrate processing apparatus 50 via the supply network 30. As the substrate processing progresses, the liquid level in the container body 11 gradually decreases.

[0056] During substrate processing, the controller 90 monitors the liquid level in the container body 11 by acquiring detection information on the liquid level from the liquid level sensor 20, and determines whether the liquid level is equal to or higher than the intermediate position MP (step S104). If the liquid level is equal to or higher than the intermediate position MP (step S104: YES), the process proceeds to step S105. In step S105, the controller 90 determines whether to terminate the substrate processing. If the substrate processing is to continue (step S105: NO), the process returns to step S103 and repeats the same processes thereafter. On the other hand, if the substrate processing is to be terminated (step S105: YES), termination processes such as stopping the supply of liquid from the liquid storage device 10 and removing the substrate W from the substrate processing apparatus 50 are performed in step S106, thereby terminating the substrate processing.

[0057] On the other hand, if the liquid level is below the intermediate position MP (step S104: NO), the controller 90 proceeds to step S107. Then, in step S107, the controller 90 determines whether or not to terminate the substrate processing. If the substrate processing is to continue (step S107: NO), the controller 90 returns to step S103 and repeats the same processes thereafter. On the other hand, if the substrate processing is to be terminated (step S107: YES), termination processes such as stopping the supply of liquid from the liquid storage device 10 and removing the substrate W from the substrate processing apparatus 50 are performed in step S108, thereby terminating the substrate processing.

[0058] Furthermore, based on the fact that the liquid level is below the preset intermediate position MP, controller 90 causes refilling unit 15 to refill container body 11 with liquid (step S109). As a result, container body 11 is refilled with liquid that has exceeded intermediate position MP, and liquid storage device 10 can stably supply liquid even in the next substrate processing.

[0059] Furthermore, when the correction start condition is met in step S102, the controller 90 corrects the liquid level determination position by executing a subroutine of the correction method as shown in Fig. 6. For example, in the correction method, the liquid state estimation processing unit 105 of the controller 90 first estimates the amount of sediment accumulated in the container body 11 based on the cumulative refill amount, cumulative usage amount, and actual liquid level as described above (step S201).

[0060] Next, the liquid state estimation processing unit 105 determines whether the estimated amount of sediment has changed by more than a certain value (step S202). In this case, the certain value is, for example, the amount by which it is desirable to shift the detector 21 of the liquid-level sensor 20, which sets the liquid-level determination position, and can be set in advance through experiments, simulations, etc. If the amount of sediment has changed by more than a certain value (step S202: YES), the liquid state estimation processing unit 105 proceeds to step S203, but if the change in the amount of sediment is less than the certain value (step S202: NO), the liquid state estimation processing unit 105 skips step S203 and proceeds to step S204.

[0061] In step S203, the controller 90 changes the liquid level determination positions depending on the estimated amount of sediment. For example, if the detectors 21 are shifted upward by one position due to the amount of sediment, the controller 90 performs processing to shift the detectors 21 corresponding to the set liquid level determination positions (upper limit position HP, middle position MP, lower limit position LP) upward by one position.

[0062] Furthermore, the controller 90 determines whether the liquid will undergo significant thermal expansion when the temperature of the liquid in the container body 11 is changed by heating with the heating unit 19 (step S204). For example, the controller 90 calculates the degree of expansion of the liquid when the temperature of the liquid is raised to a target temperature by heating with the heating unit 19 based on the thermal expansion coefficient of the liquid, the target temperature, the volume and cross-sectional area of ​​the container body 11, etc. The expansion degree is an index representing the change in the height direction of the liquid in the container body 11, and the greater the expansion degree, the higher the liquid becomes. If the degree of expansion of the liquid affects the position of the detector 21 of the liquid level sensor 20, the controller 90 determines that the thermal expansion is large (step S204: YES) and proceeds to step S205. On the other hand, if the controller 90 determines that the thermal expansion is small (step S204: NO), step S205 is not performed. Note that even if the thermal expansion coefficient of the liquid changes when the liquid stored in the container body 11 is changed, the controller 90 may also determine the thermal expansion of the liquid at this timing.

[0063] In step S205, the controller 90 changes the liquid level determination positions depending on the degree of expansion of the liquid. For example, if the detector 21 shifts upward by one position due to thermal expansion of the liquid, the controller 90 performs processing to shift each of the detectors 21 corresponding to the set liquid level determination positions (upper limit position HP, middle position MP, lower limit position LP) upward by one position. Of course, the controller 90 may calculate the total amount of change in the liquid level by adding the amount of change in the height position of the liquid surface based on the amount of sediment and the amount of change in the height position of the liquid surface based on thermal expansion, and set the amount of shift of the detector 21.

[0064] By using the above correction method, the liquid storage device 10 and the semiconductor manufacturing system 1 can correct the liquid level determination position of the liquid level sensor 20 in the container body 11 to an appropriate detector 21. After this correction, the controller 90 returns to step S103 in Fig. 5, thereby enabling the liquid in the container body 11 to be appropriately managed using the corrected liquid level determination position during substrate processing in the substrate processing apparatus 50.

[0065] The liquid storage device 10, semiconductor manufacturing system 1, and correction method of the present disclosure are not limited to the first embodiment described above and may take various forms. For example, the semiconductor manufacturing system 1 may adjust the timing and supply amount (replenishment amount) of liquid replenishment from the replenishment unit 15 to the container body 11 by recognizing the amount of liquid used for each substrate processing. As an example, the semiconductor manufacturing system 1 may want to avoid replenishment during continuous substrate processing if there is a concern that replenishment may cause a drop in the liquid temperature. In this case, the controller 90 can adjust the liquid level before substrate processing to be high in advance (increasing the amount of liquid replenished from the replenishment unit 15) while setting the intermediate position MP low, thereby reducing the number of times the liquid is replenished.

[0066] Furthermore, liquid storage device 10 is not limited to heating the liquid in container body 11 using heating unit 19, and may be configured to lower the temperature of the liquid by circulating a refrigerant using a flow path and chiller formed in container body 11. Even if the liquid level changes due to a decrease in temperature of the liquid, liquid storage device 10 can appropriately deal with the change in liquid level by adjusting the liquid level determination position.

[0067] 7 is a diagram showing a semiconductor manufacturing system 1A according to a second embodiment. The semiconductor manufacturing system 1A according to the second embodiment differs from the semiconductor manufacturing system 1 described above in that the processing gas vaporized from the liquid in the liquid storage device 10 is supplied to the substrate processing apparatus 50 via a supply network 30 to perform substrate processing on the substrate W. Examples of this substrate processing include film formation processing using atomic layer deposition (ALD) and molecular layer deposition (MLD). The following describes the semiconductor manufacturing system 1 that performs ALD.

[0068] Similar to the first embodiment, the semiconductor manufacturing system 1A includes a liquid storage device 10, a supply network 30, and a substrate processing apparatus 50. However, the outlet port 13 of the liquid storage device 10 is attached to the ceiling of the container body 11, thereby transporting the processing gas vaporized from the liquid to the supply path 31 of the supply network 30. The liquid supplied to the substrate processing apparatus 50 may be an appropriate liquid depending on the type of substrate processing. For example, an example of a liquid suitable for performing a film formation process to form a silicon nitride film is tris(dimethylamino)silane SiH"N(CH3)2"3, or so-called 3DMAS.

[0069] The supply network 30 may also include a carrier gas supply unit 35 capable of supplying a carrier gas to the storage space 11s of the container body 11. The carrier gas supply unit 35 supplies a carrier gas to the container body 11, thereby transporting the vaporized liquid together with the carrier gas from the container body 11 to the supply network 30. Examples of the carrier gas that can be used include an inert gas such as N2 gas or a noble gas.

[0070] For example, the carrier gas supply unit 35 includes an inlet path 36 capable of introducing a carrier gas into the container body 11, a carrier gas source 37 provided on the inlet path 36, an on-off valve 38, and a flow rate controller 39. The controller 90 controls the on-off valve 38 and the flow rate controller 39 to supply an appropriate amount of carrier gas from the carrier gas source 37 to the container body 11, and transports the process gas vaporized from the liquid by this carrier gas.

[0071] The substrate processing apparatus 50 has a shower head (not shown) or the like on the upper part of the processing container 51, and distributes the processing gas supplied from the supply network 30 substantially uniformly and supplies it to the substrate W. As a result, a film based on the supplied processing gas is formed on the surface of the substrate W. The substrate processing apparatus 50 may be configured to perform plasma processing in which plasma is generated from the processing gas.

[0072] Similarly to the first embodiment, the semiconductor manufacturing system 1A according to the second embodiment also manages the evaporation, supply, replenishment, etc. of the liquid by detecting the liquid level of the liquid stored in the liquid storage device 10 using the liquid level sensor 20. In particular, the liquid level sensor 20 has a large number (four or more) of detectors 21, and the controller 90 sets three or more liquid level determination positions for each of these detectors 21 and is also capable of adjusting the liquid level determination positions. This allows the semiconductor manufacturing system 1 to stably supply the liquid (process gas) to the container body 11 and replenish the container body 11 with liquid.

[0073] The technical ideas and effects of the present disclosure explained in the above embodiments will be described below.

[0074] A first aspect of the present disclosure is a liquid storage device 10 for storing processing liquid for a substrate processing apparatus 50, comprising: a container body 11 for storing the processing liquid therein; a liquid level sensor 20 provided inside the container body 11 for detecting the level of the stored processing liquid; a replenishment unit 15 for replenishing the processing liquid inside the container body 11; and a control unit (controller 90) for acquiring and processing detection information from the liquid level sensor 20, wherein the liquid level sensor 20 has four or more detectors 21 capable of detecting the level of the processing liquid along the height direction of the container body 11, and the control unit sets at least three liquid level determination positions corresponding to different detectors 21 among the four or more detectors 21, and controls the replenishment of the processing liquid from the replenishment unit 15 to the container body 11 based on the detection information of the set at least three liquid level determination positions.

[0075] As described above, the liquid storage device 10 can accurately manage the level of the processing liquid in the container body 11 by using the liquid level sensor 20 having four or more detectors 21. That is, by using four or more detectors 21, the liquid storage device 10 can detect the liquid level at various height positions in the container body 11. Then, by associating at least three liquid level determination positions with the respective detectors 21, the liquid storage device 10 can appropriately control the timing of outflow of the processing liquid from the container body 11 (including evaporation of the processing liquid) and replenishment of the processing liquid to the container body 11. Furthermore, since the liquid storage device 10 can vary at least three liquid level determination positions for the four or more detectors 21, it is possible to set liquid level determination positions optimized according to the type of substrate processing, the state of the processing liquid in the container body 11, etc.

[0076] Furthermore, the at least three liquid level determination positions include an intermediate liquid level determination position (intermediate position MP) sandwiched between the uppermost liquid level determination position (upper limit position HP) and the lowermost liquid level determination position (lower limit position LP), and the control unit (controller 90) replenishes the processing liquid from the replenishing unit 15 to the container body 11 when the processing liquid falls below the intermediate liquid level determination position. This allows the liquid storage device 10 to easily replenish the processing liquid in the container body 11.

[0077] Furthermore, the control unit (controller 90) adjusts the intermediate liquid level determination position (intermediate position MP) based on the substrate processing performed by the substrate processing apparatus 50. This allows the liquid storage device 10 to stably supply the processing liquid in an amount corresponding to the substrate processing.

[0078] Furthermore, when substrate processing is performed continuously, the control unit (controller 90) sets the intermediate liquid level determination position (intermediate position MP) lower than a preset position, while increasing the amount of processing liquid replenished from the replenishment unit 15 to the container body 11. This allows the liquid storage device 10 to perform substrate processing continuously without having to replenish the container body 11 with processing liquid in between, thereby facilitating stabilization of substrate processing.

[0079] The container body 11 also includes a heating unit 19 that heats the processing liquid stored in the container body 11, and a control unit (controller 90) adjusts the liquid level determination position based on the target temperature of the processing liquid and the thermal expansion coefficient of the processing liquid. As a result, the liquid storage device 10 can appropriately manage the amount of processing liquid in the container body 11 by changing the liquid level determination position even if thermal expansion occurs in the processing liquid due to heating by the heating unit 19.

[0080] Furthermore, the processing liquid contains sediment, and the control unit (controller 90) estimates the amount of sediment and adjusts the liquid level determination position. As a result, even if sediment accumulates in the container body 11, the liquid storage device 10 can appropriately manage the amount of processing liquid in the container body 11 by changing the liquid level determination position.

[0081] Furthermore, the control unit (controller 90) estimates the amount of sediment based on the cumulative amount of processing liquid replenished into the container body 11. This allows the liquid storage device 10 to accurately estimate the amount of sediment accumulated in the container body 11.

[0082] Furthermore, the control unit (controller 90) notifies the user of the timing to replace the container body 11 based on the estimated amount of sediment. This allows the liquid storage device 10 to request the user to replace the container body 11 at an appropriate timing.

[0083] Furthermore, when replenishing the processing liquid from the replenishing unit 15 to the container body 11, the control unit (controller 90) changes the replenishing amount of the processing liquid over time based on the detection information from the liquid level sensor 20. By changing the replenishing amount of the processing liquid over time in this manner, the liquid storage device 10 can replenishing the liquid in a short time and can easily stabilize the liquid level in the container body 11.

[0084] A second aspect of the present disclosure is a semiconductor manufacturing system 1 including a liquid storage device 10 that stores a processing liquid and a substrate processing apparatus 50 that performs substrate processing on a substrate W using the processing liquid, wherein the liquid storage device 10 includes a container body 11 that stores the processing liquid therein, a liquid level sensor 20 provided inside the container body 11 and detecting the level of the stored processing liquid, a replenishment unit 15 that replenishes the processing liquid into the container body 11, and a control unit (controller 90) that acquires and processes detection information from the liquid level sensor 20, wherein the liquid level sensor 20 has four or more detectors 21 that can detect the level of the processing liquid along the height direction of the container body 11, and the control unit sets at least three liquid level determination positions corresponding to different detectors among the four or more detectors 21, and controls the replenishment of the processing liquid from the replenishment unit 15 to the container body 11 based on the set at least three liquid level determination positions. This allows the semiconductor manufacturing system 1 to accurately manage the level of the processing liquid in the container body 11.

[0085] A third aspect of the present disclosure is a liquid replenishing method for replenishing a processing liquid into a liquid storage device 10 that stores the processing liquid in a substrate processing apparatus 50, the liquid storage device 10 including a container body 11 that stores the processing liquid therein, a liquid level sensor 20 provided inside the container body 11 and detecting the level of the stored processing liquid, and a replenishing unit 15 that replenishing the processing liquid into the container body 11, the replenishing method comprising the steps of: setting at least three liquid level determination positions in the liquid level sensor 20, each corresponding to a different one of four or more detectors 21 that can detect the level of the processing liquid along the height direction of the container body 11; and replenishing the processing liquid from the replenishing unit 15 to the container body 11 based on detection information from the at least three liquid level determination positions. Even in this case, the replenishing method can accurately manage the level of the processing liquid in the container body 11.

[0086] The liquid storage device 10, semiconductor manufacturing system 1, and refilling method according to the presently disclosed embodiments are illustrative in all respects and not restrictive. The embodiments may be modified and improved in various ways without departing from the spirit and scope of the appended claims. The features described in the above embodiments may be configured differently and may be combined within a consistent range. [Explanation of symbols]

[0087] 1. Semiconductor manufacturing systems 10 Liquid storage device 11 Container body 15 Replenishment Department 20 Liquid level sensor 21 Detector 50 Substrate processing equipment 90 Controller

Claims

1. A liquid storage device for storing a processing liquid for a substrate processing apparatus, a container body for storing the processing liquid therein; a liquid level sensor provided inside the container body for detecting the liquid level of the stored processing liquid; a refilling unit that refills the processing liquid into the container body; a control unit that acquires and processes detection information from the liquid level sensor, the liquid level sensor includes four or more detectors capable of detecting the liquid level of the processing liquid along a height direction of the container body, the control unit sets at least three liquid level determination positions corresponding to different detectors among the four or more detectors, and controls the replenishment of the processing liquid from the replenishment unit to the container body based on detection information of the at least three liquid level determination positions that have been set. Liquid storage device.

2. the at least three liquid level determination positions include an intermediate liquid level determination position sandwiched between an uppermost liquid level determination position and a lowermost liquid level determination position, the control unit replenishes the treatment liquid from the replenishing unit to the container body when the treatment liquid falls below the intermediate liquid level determination position. The liquid storage device according to claim 1 .

3. the control unit adjusts the intermediate liquid level determination position based on the substrate processing of the substrate processing apparatus. The liquid storage device according to claim 2 .

4. When the substrate processing is continuously performed, the control unit sets the intermediate liquid level determination position lower than a preset position, while increasing the refill amount of the processing liquid refilled from the refill unit to the container body. The liquid storage device according to claim 3 .

5. a heating unit that heats the processing liquid stored in the container body, the control unit adjusts the liquid level determination position based on a target temperature of the processing liquid and a thermal expansion coefficient of the processing liquid. The liquid storage device according to any one of claims 1 to 4.

6. the processing liquid contains sediment; The control unit estimates the amount of the sediment and adjusts the liquid level determination position. The liquid storage device according to any one of claims 1 to 4.

7. the control unit estimates the amount of the sediment based on an accumulated amount of the treatment liquid replenished into the container body. The liquid storage device according to claim 6 .

8. The control unit notifies the timing of replacing the container body based on the estimated amount of sediment. The liquid storage device according to claim 6 .

9. the control unit changes the refill amount of the processing liquid over time based on the detection information of the liquid level sensor when refilling the processing liquid from the refill unit into the container body. The liquid storage device according to any one of claims 1 to 4.

10. a liquid storage device for storing a processing liquid; a substrate processing apparatus that performs substrate processing on a substrate using the processing liquid, The liquid storage device is a container body for storing the processing liquid therein; a liquid level sensor provided inside the container body for detecting the liquid level of the stored processing liquid; a refilling unit that refills the processing liquid into the container body; a control unit that acquires and processes detection information from the liquid level sensor, the liquid level sensor includes four or more detectors capable of detecting the liquid level of the processing liquid along a height direction of the container body, the control unit sets at least three liquid level determination positions corresponding to different detectors among the four or more detectors, and controls the replenishment of the processing liquid from the replenishment unit to the container body based on the set at least three liquid level determination positions. Semiconductor manufacturing systems.

11. 1. A liquid replenishment method for replenishing a processing liquid to a liquid storage device that stores the processing liquid in a substrate processing apparatus, the method comprising: The liquid storage device is a container body for storing the processing liquid therein; a liquid level sensor provided inside the container body for detecting the liquid level of the stored processing liquid; a refilling section that refills the processing liquid into the container body, The replenishment method comprises: setting at least three liquid level determination positions corresponding to different detectors among four or more detectors capable of detecting the liquid level of the processing liquid along the height direction of the container body in the liquid level sensor; and refilling the container body with the processing liquid from the refilling unit based on detection information of the at least three liquid level determination positions that have been set. How to refill the fluid.

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