Concentration control device, raw material consumption estimation method and program storage medium

Abstract

A concentration control device is provided for accurately estimating the consumption of raw materials in a vaporizer without adding new sensors, etc., and capable of performing high-precision concentration control corresponding to the remaining amount of the raw materials. The concentration of the raw material gas is controlled in a vaporizer. The vaporizer comprises at least: a vaporizer for accommodating liquid or solid raw materials, a carrier gas supply passage for supplying carrier gas to the vaporizer, and a raw material gas outlet passage for circulating the raw material gas that is vaporized from the vaporizer, the concentration control device comprises: a concentration monitor that is arranged in the raw material gas outlet passage and outputs an output signal corresponding to the concentration of the raw material gas; a concentration calculation unit that calculates the concentration of the raw material gas based on the output signal from the concentration monitor; and a raw material consumption calculator that calculates the consumption of the raw material that is outlet to the raw material gas outlet passage as raw material gas based on the calculated concentration and the flow rate of the carrier gas.

Description

Technical Field

[0001] The present invention relates to a concentration control device for controlling the concentration of the raw material gas by vaporizing the raw material contained in a vaporizer with a carrier gas and leading the raw material out together with the carrier gas. Background Art

[0002] In a semiconductor manufacturing process, a carrier gas is introduced into a liquid raw material contained in, for example, a vaporizer, and the raw material gas vaporized by bubbling is supplied to a film forming chamber or the like (see Patent Document 1).

[0003] In order to maintain the concentration of such raw gas at a desired concentration, a concentration control device is used. Such a concentration control device comprises: a concentration detection mechanism that is provided on the raw gas outlet passage connecting the vaporizer and the chamber and detects the concentration of the raw gas, a first mass flow controller that controls the flow rate of the carrier gas introduced into the vaporizer, a second mass flow controller that controls the flow rate of the dilution gas supplied to the raw gas supply passage, and a control mechanism that controls each mass flow controller. In addition, the control mechanism performs concentration feedback control on the set flow rate set in each mass flow controller in such a way that the deviation between the set concentration set by the user and the detected concentration detected by the concentration detection mechanism becomes smaller.

[0004] However, as the vaporization of the raw material in the vaporizer progresses and the remaining amount of the raw material decreases, the characteristics of the concentration feedback control system may change. As a result, even if the same control is continued, the desired concentration control may not be achieved.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2010-278167 Summary of the invention

[0008] Technical issues

[0009] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a concentration control device which can accurately estimate the consumption of the raw material in the vaporizer without adding a new sensor or the like, and can perform high-precision concentration control corresponding to the remaining amount of the raw material.

[0010] Technical Solution

[0011] That is, the concentration control device of the present invention is characterized in that it controls the concentration of the raw material gas in a vaporizer, and the above-mentioned vaporizer at least comprises: a vaporizer for containing liquid or solid raw materials, a carrier gas supply passage for supplying carrier gas to the above-mentioned vaporizer, and a raw material gas outlet passage for the flow of the above-mentioned raw material gas that is vaporized by the above-mentioned raw materials and outlet from the above-mentioned vaporizer, and the above-mentioned concentration control device comprises: a concentration monitor, which is arranged in the above-mentioned raw material gas outlet passage and outputs an output signal corresponding to the concentration of the above-mentioned raw material gas; a concentration calculation unit, which calculates the concentration of the above-mentioned raw material gas based on the output signal from the above-mentioned concentration monitor; and a raw material consumption calculator, which calculates the consumption of the above-mentioned raw material outlet to the above-mentioned raw material gas as the above-mentioned raw material gas based on the above-mentioned calculated concentration and the flow rate of the above-mentioned carrier gas.

[0012] Here, the flow rate of the carrier gas may be a value actually measured by a flow sensor or a set value set for a flow control device such as a mass flow controller.

[0013] If such a concentration control device is used, even if a sensor for detecting the consumption or remaining amount of the raw material is not separately provided, the consumption of the raw material can be estimated based on the output of the concentration monitor which is a necessary structure for performing concentration control. In addition, since the above-mentioned calculated concentration is obtained in each control cycle for performing concentration control, the consumption of the raw material can be obtained almost in real time, and the state of the concentration control system at that time point can be accurately obtained. As a result, it is possible to automatically set, for example, the optimal control parameters according to the state of the concentration control system, and to achieve concentration control with constant accuracy at all times regardless of the remaining amount of the raw material.

[0014] The concentration control device may be: when the vaporizer further comprises a dilution gas supply passage, the dilution gas supply passage merges with the raw gas outlet passage and supplies dilution gas to the raw gas outlet passage, and when the raw gas is diluted and concentration is controlled, in order to accurately estimate the consumption of the raw material, the raw material consumption calculator calculates the consumption of the raw material based on the calculated concentration and the total carrier flow, and the total carrier flow is the sum of the flow rate of the carrier gas and the flow rate of the dilution gas.

[0015] As a specific configuration example for calculating the consumption of the above-mentioned raw materials, the concentration control device can be listed as: the above-mentioned raw material consumption calculator comprises: a raw material flow calculation unit, which calculates the flow rate of the above-mentioned raw material gas at each moment according to the above-mentioned calculated concentration at each moment and the above-mentioned total current carrying capacity; and a consumption calculation unit, which calculates the consumption of the above-mentioned raw material based on the flow rate of the above-mentioned raw material gas at each moment and the raw gas supply time of supplying the above-mentioned raw material gas to the above-mentioned raw gas outlet passage.

[0016] In order to reflect the result of concentration control so far in the calculated value of the consumption of the above-mentioned raw material, and to be able to grasp a more accurate control state, the above-mentioned concentration control device can be: it also includes: a first mass flow controller, which is arranged in the above-mentioned carrier gas supply passage, so as to control the flow rate of the above-mentioned carrier gas flowing in the carrier gas supply passage to become a first set flow rate; and a second mass flow controller, which is arranged in the above-mentioned dilution gas supply passage, so as to control the flow rate of the above-mentioned dilution gas flowing in the dilution gas supply passage to become a second set flow rate, and the above-mentioned raw material flow calculation unit calculates the total carrier flow rate based on the above-mentioned first set flow rate or the flow rate of the carrier gas detected by the first mass flow controller, and the above-mentioned second set flow rate or the flow rate of the dilution gas detected by the second mass flow controller.

[0017] In order to change the feedback control characteristics to achieve constant accuracy even if the state of the concentration control system changes according to the change of the remaining amount of the above-mentioned raw material, the above-mentioned concentration control device can be: it also has a concentration control unit, and the above-mentioned concentration control unit changes the above-mentioned first set flow rate set in the above-mentioned first mass flow controller and the above-mentioned second set flow rate set in the above-mentioned second mass flow controller based on the deviation between the preset set concentration and the above-mentioned calculated concentration, and the set control parameters, and controls the concentration of the above-mentioned raw material gas, and changes the above-mentioned control parameters according to the consumption of the above-mentioned raw material calculated by the above-mentioned raw material consumption calculator or the remaining amount of the above-mentioned raw material in the above-mentioned vaporizer.

[0018] In order to accurately estimate the consumption of the raw material when performing concentration control without using a dilution gas, the above-mentioned concentration control device may be: the above-mentioned raw material consumption calculator comprises: a raw material flow calculation unit, which calculates the flow rate of the above-mentioned raw material gas at each moment according to the above-mentioned calculated concentration at each moment and the flow rate of the above-mentioned carrier gas; and a consumption calculation unit, which calculates the consumption of the above-mentioned raw material based on the flow rate of the above-mentioned raw material gas at each moment and the raw gas supply time of the above-mentioned raw material gas to the above-mentioned raw gas outlet passage.

[0019] In order to accurately grasp the remaining amount of the above-mentioned raw material in the above-mentioned vaporizer even when the concentration of the above-mentioned raw material gas is achieved by pressure control, the above-mentioned concentration control device can be: it also includes: a first mass flow controller, which is arranged in the above-mentioned carrier gas supply passage to control the flow rate of the above-mentioned carrier gas flowing in the carrier gas supply passage to become a first set flow rate; and a pressure control valve, which is arranged in the above-mentioned raw material gas outlet passage, and the above-mentioned raw material consumption calculator calculates the consumption of the above-mentioned raw material based on the above-mentioned first set flow rate or the flow rate of the carrier gas detected by the first mass flow controller.

[0020] As a specific configuration example of a control characteristic that can be changed to correspond to the remaining amount of the raw material when the concentration of the raw material gas is controlled by the pressure control valve, the concentration control device can be listed as follows: it also includes a concentration control unit, and the concentration control unit controls at least the opening of the pressure control valve and the concentration of the raw material gas based on the deviation between a preset set concentration and the calculated concentration and a set control parameter, and changes the control parameter according to the consumption of the raw material calculated by the raw material consumption calculator or the remaining amount of the raw material in the vaporizer.

[0021] As a specific embodiment for realizing concentration control corresponding to the change of control characteristics according to the consumption of raw materials, the above-mentioned concentration control device can be listed as: it also comprises: a control parameter storage unit, which stores a plurality of control parameters corresponding to the consumption of the above-mentioned raw materials or the remaining amount of the above-mentioned raw materials; and a control parameter setting unit, which sets the corresponding control parameters for the above-mentioned concentration control unit with reference to the above-mentioned control parameter storage unit based on the consumption of the raw materials calculated by the above-mentioned raw material consumption calculator or the remaining amount of the above-mentioned raw materials.

[0022] As a method for estimating raw material consumption that accurately estimates the consumption of raw materials based on the output of a sensor for controlling the concentration of raw material gas without adding a separate sensor, there can be cited a method for estimating raw material consumption, which is a method for estimating the consumption of raw materials in a vaporizer, the vaporizer comprising at least: a vaporizer for accommodating liquid or solid raw materials, a carrier gas supply passage for supplying carrier gas to the vaporizer, and a raw material gas outlet passage for flowing the raw material gas that is vaporized by the raw material and outlet from the vaporizer, the raw material consumption estimating method comprising: a concentration calculation step for calculating the concentration of the raw material gas based on an output signal from a concentration monitor provided in the raw material gas outlet passage; and a raw material consumption calculation step for calculating the consumption of the raw material that is outlet to the raw material gas outlet passage as the raw material gas based on the flow rate of the carrier gas and the calculated concentration calculated by the concentration calculation step.

[0023] In order to add a function of estimating the consumption of raw materials to an existing concentration control device, a concentration control device program can be used, which is characterized in that the above-mentioned concentration control device is equipped with a concentration monitor in a vaporizer to control the concentration of the raw material gas, the above-mentioned vaporizer at least comprises: a vaporizer for containing liquid or solid raw materials, a carrier gas supply passage for supplying carrier gas to the above-mentioned vaporizer, and a raw material gas outlet passage for the flow of the above-mentioned raw material gas that is vaporized by the above-mentioned raw material and outlet from the above-mentioned vaporizer, the above-mentioned concentration monitor is arranged in the above-mentioned raw material gas outlet passage and outputs an output signal corresponding to the concentration of the above-mentioned raw material gas, the above-mentioned concentration control device program enables the computer to function as a concentration calculation unit and a raw material consumption calculator, the above-mentioned concentration calculation unit calculates the concentration of the above-mentioned raw material gas based on the output signal from the above-mentioned concentration monitor, and the above-mentioned raw material consumption calculator calculates the consumption of the above-mentioned raw material outlet to the above-mentioned raw material gas as the above-mentioned raw material gas based on the flow rate of the above-mentioned carrier gas and the calculated concentration calculated by the above-mentioned concentration calculation unit.

[0024] It should be noted that the concentration control device program may be a program transmitted electronically, or may be a program stored in a program storage medium such as a CD, a DVD, or a flash memory.

[0025] Technical Effects

[0026] Thus, according to the concentration control device of the present invention, it is possible to accurately estimate the consumption or remaining amount of the raw material in the vaporizer based on the output of the concentration monitor without adding a sensor other than the concentration control purpose. As a result, since the remaining amount of the raw material can be accurately grasped, it is possible to change the control parameters according to the change of the control state, etc., and realize the concentration control with constant accuracy at all times. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram showing a concentration control system according to the first embodiment of the present invention.

[0028] Figure 2 This is a functional block diagram of the control mechanism of the concentration control device in the first embodiment.

[0029] Figure 3 It is a schematic diagram showing a concentration control system according to a second embodiment of the present invention.

[0030] Figure 4 This is a functional block diagram of a control mechanism of the concentration control device in the second embodiment.

[0031] Explanation of symbols

[0032] 200…Concentration control system

[0033] 100…Carburetor

[0034] 101…Concentration control device

[0035] 40…Concentration monitor

[0036] MFC1…The first mass flow controller

[0037] MFC2…Second Mass Flow Controller

[0038] C1…Concentration calculation unit

[0039] C2…Concentration Control Unit

[0040] C3…Raw material consumption calculator

[0041] C4…Raw material flow calculation unit

[0042] C5…Consumption calculation unit

[0043] C6…Control parameter setting unit

[0044] C7…Control parameter storage unit DETAILED DESCRIPTION

[0045] A concentration control system 200 according to a first embodiment of the present invention will be described with reference to the drawings.

[0046] The concentration control system 200 of the present invention is a system for supplying a gas having a predetermined concentration to a chamber CH which is provided in, for example, a semiconductor production line and is used in a semiconductor manufacturing process.

[0047] The concentration control system 200 of this embodiment is a so-called dilution type (flow type) system. Figure 1 As shown, the concentration control system 200 is composed of a vaporizer 100 and a concentration control device 101 in which at least a part of the equipment is installed in the vaporizer 100 .

[0048] The vaporizer 100 includes: a vaporizer 10 for containing liquid or solid materials, a carrier gas supply passage L1 for supplying a carrier gas to the vaporizer 10, a raw gas outlet passage L2 for outleting a raw gas formed by vaporizing the material from the vaporizer 10, a dilution gas supply passage L3 for supplying a dilution gas for diluting the raw gas to the raw gas outlet passage L2, and a switching mechanism 20 for switching between supplying the raw gas to the chamber CH and stopping the supply of the raw gas to the chamber CH.

[0049] The switching mechanism 20 includes a plurality of valves V1 to V3 that are opened and closed by receiving a valve switching signal output from a control mechanism C of a concentration control device 101 described later. The valves V1 to V3 of the switching mechanism 20 are opened and closed at a timing preset by a user, thereby repeatedly supplying and stopping the carrier gas to the vaporizer 10. As a result, the raw material gas is intermittently drawn out from the vaporizer 10 and intermittently supplied to the chamber CH. That is, in the concentration control system 200 of the present embodiment, a supply period during which the raw material gas (specifically, the mixed gas) is supplied to the chamber CH and a stop period during which the supply is stopped are alternately repeated.

[0050] Specifically, the switching mechanism 20 comprises: a detour flow path L4 connecting the carrier gas supply path L1 and the raw gas outlet path L2, a first valve V1 arranged in the carrier gas supply path L1 at a position closer to the downstream side than a connection point with the detour flow path L4, a second valve V2 arranged in the raw gas outlet path L2 at a position closer to the upstream side than a connection point with the detour flow path L4, and a third valve V3 arranged in the detour flow path L4.

[0051] Specifically, by opening the first valve V1 and the second valve V2 of the switching mechanism 20 and closing the third valve V3, the raw gas is in a supply period to the chamber CH, and by closing the first valve V1 and the second valve V2 of the switching mechanism 20 and opening the third valve V3, the raw gas is not in a stop period to the chamber CH.

[0052] The concentration control device 101 includes: a first mass flow controller MFC1 arranged in the carrier gas supply passage L1, a concentration monitor 40 arranged in the raw gas degassing passage L2, a second mass flow controller MFC2 arranged in the dilution gas supply passage L3, and a control mechanism that controls the first mass flow controller MFC1 and the second mass flow controller MFC2 based on the output of the concentration monitor 40 and controls the concentration of the raw gas.

[0053] The first mass flow controller MFC1 is a controller that controls the flow rate of the carrier gas flowing through the carrier gas supply passage L1. The first mass flow controller MFC1 includes, for example, a pressure flow sensor, a flow control valve such as a piezoelectric valve, and a control circuit having a CPU and / or a memory, etc. (the components are not shown). The first mass flow controller MFC1 performs feedback control on the opening of the flow control valve in such a way that the deviation between the first set flow rate set by the control mechanism C and the flow rate of the carrier gas detected by the flow sensor is reduced.

[0054] The concentration monitor 40 is provided in the raw gas outlet passage L2 at a position closer to the downstream side than the confluence point with the dilution gas supply passage L3. The concentration monitor 40 outputs a signal corresponding to the concentration of the raw gas contained in the mixed gas containing the raw gas, the carrier gas and the dilution gas. That is, the concentration monitor 40 of the present embodiment uses the ratio of the pressure (partial pressure) of the raw gas contained in the mixed gas to the pressure (total pressure) of the mixed gas to express the concentration (vol%) of the raw gas contained in the mixed gas. Specifically, the concentration monitor 40 includes: a pressure gauge 41 for detecting the total pressure of the mixed gas, and a pressure gauge 42 for detecting the partial pressure of the raw gas using, for example, a non-dispersive infrared absorption method (NDIR method).

[0055] The second mass flow controller MFC2 is a controller for controlling the flow rate of the dilution gas flowing through the dilution gas supply passage L3. Like the first mass flow controller MFC1, the second mass flow controller MFC2 includes: a flow rate regulating valve such as a pressure flow sensor and a piezoelectric valve, and a control circuit having a CPU and / or a memory, etc. (the components are not shown). The second mass flow controller MFC2 also performs feedback control on the opening of the flow rate regulating valve in such a way that the deviation between the second set flow rate set by the control mechanism C and the flow rate of the carrier gas detected by the flow rate sensor becomes smaller.

[0056] Specifically, the control mechanism C is a computer having a CPU, a memory, an A / D converter, a D / A converter, an input / output unit, etc., and the CPU executes a program stored in the memory, thereby Figure 2 As shown, it functions as at least a concentration calculation unit C1, a supply control unit (not shown), a concentration control unit C2, a raw material consumption calculator C3, a control parameter setting unit C6, a control parameter storage unit C7, and the like.

[0057] The concentration calculation unit C1 calculates the concentration of the raw gas contained in the mixed gas based on the output signal output from the concentration monitor 40. Specifically, the output signals are obtained from the pressure gauge 41 and the partial pressure gauge 42, respectively, and the ratio of the partial pressure detected by the partial pressure gauge 42 to the total pressure detected by the pressure gauge 41 is calculated as the concentration (vol%) of the raw gas contained in the mixed gas.

[0058] The supply control unit receives the valve opening / closing signal and determines whether it is the supply period of the raw material gas, and switches the state of the switching mechanism 20 based on the determination result.

[0059] The concentration control unit C2 controls at least one of the first mass flow controller MFC1 and the second mass flow controller MFC2 based on the calculated concentration calculated by the concentration calculation unit C1, the set concentration set by the user, and the set control parameters during the supply of the raw gas, thereby performing concentration feedback control so that the calculated concentration of the raw gas approaches the set concentration. It should be noted that PID control is performed in the concentration control unit C2, and the control parameters correspond to various gains, for example.

[0060] Specifically, the set concentration of the material gas contained in the mixed gas and the target total flow rate of the gas supplied to the chamber CH, which are preset by the user, are input to the concentration control unit C2. The first set flow rate as the target flow rate of the carrier gas is gradually changed by the concentration feedback control based on the deviation between the set concentration and the detected concentration. In addition, the second set flow rate as the target flow rate of the dilution gas is set to be consistent with the total amount of the first set flow rate and the target total flow rate.

[0061] The raw material consumption calculator C3 calculates the consumption of the raw material based on the outputs of various sensors used for concentration control. In this embodiment, the raw material consumption calculator C3 calculates the consumption of the raw material based on the flow rate of the carrier gas, the flow rate of the dilution gas, and the concentration of the raw material gas.

[0062] Specifically, the raw material consumption calculator C3 includes: a raw material flow calculation unit C4 that calculates the flow rate of the raw material gas flowing in the raw material gas outlet passage L2, and a consumption calculation unit C5 that calculates the raw material consumption based on the calculated raw material gas flow rate and the time for supplying the raw material gas to the raw material gas outlet passage L2.

[0063] The raw material flow rate calculation unit C4 calculates the flow rate of the raw material gas using the value obtained by dividing the flow rate of the raw material gas flowing through the raw material gas outlet passage L2 by the flow rate of the entire mixed gas. Specifically, the following relationship holds.

[0064] C=Q V / Q T (1)

[0065] Q T =Q V +Q C +Q D (2)

[0066] Here, C is the concentration of the raw material gas (vol.%), Q V is the flow rate of raw gas (sccm), Q T is the flow rate of the mixed gas (sccm), Q C is the flow rate of carrier gas (sccm), QD is the flow rate of the dilution gas (sccm).

[0067] If we solve the raw material flow rate Q according to these equations (1) and (2): V , then it is as follows.

[0068] Q V = (Q C +Q D ){C / (1-C)} (3)

[0069] In this way, the raw material flow rate calculation unit C4 calculates the total carrier flow rate Q which is the sum of the carrier gas flow rate and the dilution gas flow rate based on equation (3): C +Q D And calculate the concentration C to calculate the flow rate Q of the raw material V In this embodiment, the total current carrying capacity is determined by the values ​​detected by the flow sensors of the first mass flow controller MFC1 and the second mass flow controller MFC2. It should be noted that instead of using the measured values ​​of the flow sensors, a set flow rate set by the control mechanism C or a set flow rate set by the user may be used.

[0070] The consumption amount calculation unit C5 calculates the flow rate Q of the raw material gas calculated by the raw material flow rate calculation unit in each control cycle. V The accumulated raw material flow rate from the concentration control start time to the current time point is calculated by multiplying the control cycle Δt. Specifically, the consumption amount calculation unit C5 calculates the accumulated raw material flow rate V using the following formula (4).

[0071] V=ΣQ Vi Δt i (4)

[0072] Furthermore, the consumption calculation unit C5 calculates the consumption m [g] of the raw material by converting the accumulated raw material flow rate V [cc] to grams based on the following equation (5) assuming that the raw material gas is an ideal gas. It should be noted that M is the molar mass [g / mol] of the raw material gas molecule.

[0073] m=VM / (1000×22.4) (5)

[0074] Furthermore, the consumption amount calculation unit C5 calculates the remaining amount of the raw material by subtracting the raw material consumption amount from the initial amount of the raw material.

[0075] In this way, the raw material consumption or the remaining amount of raw material calculated by the consumption calculation unit C5 is input to the control parameter setting unit C6. Then, the control parameter setting unit C6 appropriately sets the control parameter such as gain for the concentration control unit C2 according to the raw material consumption or the remaining amount of raw material calculated by the consumption calculation unit C5. In the present embodiment, the control parameter setting unit C6 sets the control parameter corresponding to the input raw material consumption or the remaining amount of raw material for the concentration control unit C2 with reference to the control parameter table, wherein the control parameter table is formed by pairing the raw material consumption or the remaining amount of raw material stored in the control parameter storage unit C7 with the control parameters corresponding to each value of the raw material consumption or the remaining amount of raw material. It should be noted that the control parameter setting unit C6 discretely converts the control parameter according to the raw material consumption or the remaining amount of raw material, but it is also possible to interpolate the value of the stored control parameter to make it change continuously.

[0076] According to the concentration control device 101 and the concentration control system 200 of the first embodiment configured as above, it is possible to estimate the raw material consumption based only on the outputs of the flow sensor and the concentration monitor 40 which are components necessary for controlling the concentration of the raw material gas.

[0077] Furthermore, since the concentration control unit C2 changes the control parameter based on the estimated raw material consumption, even if the raw material decreases and the characteristics of the concentration control system change, control can be continued with constant accuracy.

[0078] Furthermore, since the used value is gradually updated in each control cycle, it is possible to always grasp the accurate raw material consumption.

[0079] Next, refer to Figure 3 and Figure 4 The concentration control system 200 of the second embodiment will be described. It should be noted that the same reference numerals are given to components corresponding to those described in the first embodiment.

[0080] The concentration control system 200 of the first embodiment is a dilution type (flow type) system, but may also be a pressure type as shown in the second embodiment. Figure 3 As shown, the pressure type concentration control system 200 does not include a dilution gas supply passage, but instead includes a pressure control valve PV at a position downstream of the concentration monitor 40 in the raw gas outlet passage L2.

[0081] In addition, the concentration control unit also controls the first mass flow controller MFC1 and the pressure control valve PV provided in the carrier gas supply passage L1. That is, the concentration control unit C2 performs feedback control on the opening of the pressure control valve PV based on the deviation between the calculated concentration calculated based on the output of the concentration monitor 40 and the set concentration. As a result, the concentration of the raw material gas in the raw material gas outlet passage L2 is maintained at the set concentration by adjusting the total pressure of the mixed gas.

[0082] In the case of a pressure-type concentration control system, the raw material consumption calculator C3 calculates the raw material consumption based on the calculated concentration and the carrier gas flow rate detected by the first mass flow controller MFC1. It should be noted that the specific formula is the same as that described in the first embodiment, where the flow rate Q of the dilution gas is used. D The same is true for zero.

[0083] As described above, also in the pressure-type concentration control system 200 according to the second embodiment, the remaining amount of the raw material in the vaporizer 10 can be accurately grasped using only the sensor used for concentration control.

[0084] Furthermore, since the control parameters set in the concentration control unit C2 are changed according to the remaining amount of the raw material as in the first embodiment, even in pressure-type concentration control, concentration control can be continued with substantially constant accuracy regardless of the remaining amount of the raw material.

[0085] Other embodiments will be described.

[0086] In each embodiment, the consumption or remaining amount of the raw material is calculated based on the output of the sensor for concentration control, but additional sensors may be provided separately, and the consumption or remaining amount of the raw material may also be calculated using their outputs. For example, a weight sensor and / or a liquid level sensor may be provided in the vaporizer, and the consumption or remaining amount of the raw material may be calculated based on their outputs.

[0087] The vaporizer may be separately provided with a pressure gauge for detecting the partial pressure of the raw material gas and / or a concentration sensor for detecting the concentration of the raw material gas, and the consumption of the raw material may be calculated based on changes in these.

[0088] Furthermore, various modifications may be made within the scope not departing from the spirit of the present invention, and parts of the embodiments may be combined with each other.

Claims

1. A concentration control device, characterized in that: The concentration of the raw material gas is controlled in a vaporizer, and the vaporizer at least comprises: a vaporizer for accommodating a liquid or solid raw material, a carrier gas supply passage for supplying a carrier gas to the vaporizer, and a raw material gas outlet passage for flowing the raw material gas that is vaporized by the raw material and is outlet from the vaporizer. The concentration control device comprises: a concentration monitor, which is disposed in the raw gas outlet passage and outputs an output signal corresponding to the concentration of the raw gas; a concentration calculation unit that calculates the concentration of the raw material gas based on an output signal from the concentration monitor; a raw material consumption calculator that calculates a consumption of the raw material that is led out to the raw material gas lead-out passage as the raw material gas based on the flow rate of the carrier gas and the calculated concentration calculated by the concentration calculation unit; a first mass flow controller provided in the carrier gas supply passage for controlling the flow rate of the carrier gas flowing in the carrier gas supply passage so as to be a first set flow rate; a second mass flow controller provided in a dilution gas supply passage that merges with the raw gas outlet passage and supplies dilution gas to the raw gas outlet passage, and controlling the flow rate of the dilution gas flowing through the dilution gas supply passage to be a second set flow rate; and a concentration control unit, wherein the concentration control unit changes the first set flow rate set in the first mass flow controller and the second set flow rate set in the second mass flow controller based on a deviation between a preset set concentration and the calculated concentration and a set control parameter, and controls the concentration of the raw gas, The control parameter is changed according to the consumption of the raw material calculated by the raw material consumption calculator or the remaining amount of the raw material in the vaporizer.

2. The concentration control device according to claim 1, characterized in that: The raw material consumption calculator calculates the consumption of the raw material based on the calculated concentration and a total carrier gas amount, the total carrier gas amount being a sum of a flow rate of the carrier gas and a flow rate of the dilution gas.

3. The concentration control device according to claim 2, characterized in that: The raw material consumption calculator has: a raw material flow rate calculation unit, which calculates the flow rate of the raw material gas at each moment according to the calculated concentration at each moment and the total current carrying capacity; as well as A consumption amount calculation unit calculates the consumption amount of the raw material based on the flow rate of the raw material gas at each time and the raw material gas supply time for supplying the raw material gas to the raw material gas outlet passage.

4. The concentration control device according to claim 3, characterized in that: The raw material flow rate calculation unit calculates a total carrier gas flow rate based on the first set flow rate or the flow rate of the carrier gas detected by the first mass flow controller and the second set flow rate or the flow rate of the dilution gas detected by the second mass flow controller.

5. A concentration control device, characterized in that: The concentration of the raw material gas is controlled in a vaporizer, and the vaporizer at least comprises: a vaporizer for accommodating a liquid or solid raw material, a carrier gas supply passage for supplying a carrier gas to the vaporizer, and a raw material gas outlet passage for flowing the raw material gas that is vaporized by the raw material and is outlet from the vaporizer. The concentration control device comprises: a concentration monitor, which is disposed in the raw gas outlet passage and outputs an output signal corresponding to the concentration of the raw gas; a concentration calculation unit that calculates the concentration of the raw material gas based on an output signal from the concentration monitor; a raw material consumption calculator that calculates a consumption of the raw material that is led out to the raw material gas lead-out passage as the raw material gas based on the flow rate of the carrier gas and the calculated concentration calculated by the concentration calculation unit; a first mass flow controller provided in the carrier gas supply passage for controlling the flow rate of the carrier gas flowing in the carrier gas supply passage so as to be a first set flow rate; A pressure control valve, which is arranged in the raw gas outlet passage; as well as a concentration control unit, which controls at least the opening of the pressure control valve and the concentration of the raw material gas based on a deviation between a preset set concentration and the calculated concentration and a set control parameter, The control parameter is changed according to the consumption of the raw material calculated by the raw material consumption calculator or the remaining amount of the raw material in the vaporizer.

6. The concentration control device according to claim 5, characterized in that: The raw material consumption calculator calculates the consumption of the raw material based on the first set flow rate or the flow rate of the carrier gas detected by the first mass flow controller.

7. The concentration control device according to claim 6, characterized in that: The raw material consumption calculator has: a raw material flow rate calculation unit, which calculates the flow rate of the raw material gas at each time point based on the calculated concentration at each time point and the flow rate of the carrier gas detected by the first mass flow controller; as well as A consumption amount calculation unit calculates the consumption amount of the raw material based on the flow rate of the raw material gas at each time and the raw material gas supply time for supplying the raw material gas to the raw material gas outlet passage.

8. The concentration control device according to claim 1 or 5, characterized in that: The concentration control device also includes: a control parameter storage unit storing a plurality of control parameters corresponding to the consumption amount of the raw material or the remaining amount of the raw material; and A control parameter setting unit sets a corresponding control parameter for the concentration control unit by referring to a control parameter storage unit according to the consumption of the raw material calculated by the raw material consumption calculator or the remaining amount of the raw material.

9. A method for estimating raw material consumption, characterized in that: The invention relates to a method for estimating the consumption of a raw material in a vaporizer, wherein the vaporizer comprises at least a vaporizer for accommodating a liquid or solid raw material, a carrier gas supply passage for supplying a carrier gas to the vaporizer, and a raw material gas outlet passage for flowing a raw material gas which is vaporized from the raw material and is outlet from the vaporizer. The method for estimating raw material consumption comprises: The step of providing a concentration monitor in the raw gas outlet passage for outputting an output signal corresponding to the concentration of the raw gas; The step of providing a first mass flow controller in the carrier gas supply passage, wherein the first mass flow controller controls the flow rate of the carrier gas flowing in the carrier gas supply passage so as to become a first set flow rate; The step of providing a second mass flow controller in the dilution gas supply passage, wherein the second mass flow controller controls the flow rate of the dilution gas flowing through the dilution gas supply passage that merges with the raw gas outlet passage and supplies the dilution gas to the raw gas outlet passage so as to become a second set flow rate; A step of calculating the concentration of the raw gas based on an output signal from the concentration monitor provided in the raw gas outlet passage; a step of calculating a consumption amount of the raw material led out to the raw material gas lead-out passage as the raw material gas based on the calculated concentration of the raw material gas calculated based on the output signal from the concentration monitor and the flow rate of the carrier gas; A step of changing the first set flow rate set in the first mass flow controller and the second set flow rate set in the second mass flow controller based on a deviation between a preset set concentration and the calculated concentration and a set control parameter, and controlling the concentration of the raw gas; and The step of changing the control parameter according to the calculated consumption of the raw material or the remaining amount of the raw material in the vaporizer.

10. A method for estimating raw material consumption, characterized in that: The invention relates to a method for estimating the consumption of a raw material in a vaporizer, wherein the vaporizer comprises at least a vaporizer for accommodating a liquid or solid raw material, a carrier gas supply passage for supplying a carrier gas to the vaporizer, and a raw material gas outlet passage for flowing a raw material gas which is vaporized from the raw material and is outlet from the vaporizer. The method for estimating raw material consumption comprises: The step of providing a concentration monitor in the raw gas outlet passage for outputting an output signal corresponding to the concentration of the raw gas; The step of providing a first mass flow controller in the carrier gas supply passage, wherein the first mass flow controller controls the flow rate of the carrier gas flowing in the carrier gas supply passage so as to become a first set flow rate; A pressure control valve is provided in the raw gas outlet passage; A step of calculating the concentration of the raw gas based on an output signal from the concentration monitor provided in the raw gas outlet passage; a step of calculating a consumption amount of the raw material led out to the raw material gas lead-out passage as the raw material gas based on the calculated concentration of the raw material gas calculated based on the output signal from the concentration monitor and the flow rate of the carrier gas; The step of providing a concentration control unit, the concentration control unit controls at least the opening of the pressure control valve and the concentration of the raw material gas based on the deviation between the preset set concentration and the calculated concentration and the set control parameter; The step of changing the control parameter according to the calculated consumption of the raw material or the remaining amount of the raw material in the vaporizer.

11. A program storage medium, characterized in that: A concentration control device program is stored, and a concentration monitor, a first mass flow controller, and a second mass flow controller are provided in a vaporizer to control the concentration of a raw material gas. The vaporizer at least comprises: a vaporizer for accommodating a liquid or solid raw material, a carrier gas supply passage for supplying a carrier gas to the vaporizer, and a raw material gas outlet passage for flowing the raw material gas that is vaporized by the raw material and outlet from the vaporizer. The concentration monitor is provided in the raw material gas outlet passage and outputs an output signal corresponding to the concentration of the raw material gas. The first mass flow controller is provided in the carrier gas supply passage to control the flow rate of the carrier gas flowing in the carrier gas supply passage to be a first set flow rate. The second mass flow controller is provided in a dilution gas supply passage that merges with the raw material gas outlet passage and supplies a dilution gas to the raw material gas outlet passage to control the flow rate of the dilution gas flowing in the dilution gas supply passage to be a second set flow rate. The concentration control device program causes the computer to function as a concentration calculation unit, a raw material consumption calculator, and a concentration control unit. The concentration calculation unit calculates the concentration of the raw gas based on an output signal from the concentration monitor, The raw material consumption calculator calculates the consumption of the raw material to be led out to the raw material gas lead-out passage as the raw material gas based on the flow rate of the carrier gas and the calculated concentration calculated by the concentration calculation unit, The concentration control unit changes the first set flow rate set in the first mass flow controller and the second set flow rate set in the second mass flow controller based on a deviation between a preset set concentration and the calculated concentration and a set control parameter, and controls the concentration of the raw gas. The control parameter is changed according to the consumption of the raw material calculated by the raw material consumption calculator or the remaining amount of the raw material in the vaporizer.

12. A program storage medium, characterized in that: A program for a concentration control device is stored, and a concentration monitor, a first mass flow controller, and a pressure control valve are provided in a vaporizer to control the concentration of a raw material gas. The vaporizer at least comprises: a vaporizer for accommodating a liquid or solid raw material, a carrier gas supply passage for supplying a carrier gas to the vaporizer, and a raw material gas outlet passage for flowing the raw material gas that is vaporized by the raw material and outlet from the vaporizer. The concentration monitor is provided in the raw material gas outlet passage and outputs an output signal corresponding to the concentration of the raw material gas. The first mass flow controller is provided in the carrier gas supply passage to control the flow rate of the carrier gas flowing in the carrier gas supply passage to a first set flow rate. The pressure control valve is provided in the raw material gas outlet passage. The concentration control device program causes the computer to function as a concentration calculation unit, a raw material consumption calculator, and a concentration control unit. The concentration calculation unit calculates the concentration of the raw gas based on an output signal from the concentration monitor, The raw material consumption calculator calculates the consumption of the raw material to be led out to the raw material gas lead-out passage as the raw material gas based on the flow rate of the carrier gas and the calculated concentration calculated by the concentration calculation unit, The concentration control unit controls at least the opening of the pressure control valve and the concentration of the raw material gas based on a deviation between a preset set concentration and the calculated concentration and a set control parameter. The control parameter is changed according to the consumption of the raw material calculated by the raw material consumption calculator or the remaining amount of the raw material in the vaporizer.

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