TWI511184B - Control device for material gas, control method, control program and control system thereof - Google Patents

Description

Material gas control device, control method, control program and control system

The present invention relates to a material gas control device that controls a material gas that is vaporized by the material gas in a material vaporization device that introduces a carrier gas into a material contained in a housing and vaporizes the material.

For example, in the film formation process of a semiconductor, it is required to transport a material gas vaporized by a material vaporization device into a chamber where a film is formed at a predetermined concentration or flow rate.

For example, as a material gas control device for controlling a flow rate of a material gas to be constant, as disclosed in Patent Document 1 (Japanese Patent Laid-Open Publication No. Hei 08-153685) and FIG. 9, a material gas control device is disclosed. The material gas control device includes a quality flow controller (hereinafter also referred to as MFC), which is disposed on the introduction pipe for introducing the carrier gas into the housing containing the material, and a gas concentration monitor disposed on the outlet pipe The lead-out tube is configured to derive a mixed gas of the vaporized material gas and the carrier gas from the container, the material gas control device controlling the carrier gas based on the measured concentration measured by the gas concentration monitor flow.

More specifically, if the concentration of the material gas in the mixed gas is C, the flow rate of the material gas is Q _v , and the flow rate of the carrier gas is Q _c , then according to the concentration of the material gas C=Q _v /(Q _v +Q _c ) In this relationship, the flow rate of the material gas can be expressed as Q _v = C × Q _c / (1-C), so that the actual flow rate of the material gas can be calculated from the measured concentration. With this relationship, the material gas control device monitors the concentration of the material gas after vaporization, feeds back the actual flow rate of the material gas calculated according to the measured concentration to the MFC, and performs flow control of the carrier gas through the MFC. The flow rate Q _{v of the} material gas is substantially fixed to a predetermined set flow rate.

Here, the flow rate Q _v of the material gas depends on the amount of material vaporization, and the amount of material vaporization varies based on the flow rate Q _{c of the} carrier gas. Typically, in order to make the material gas flow rate Q _v increases, the carrier gas flow rate may be increased by the Q _c, thereby increasing the amount of bubbling liquid in the material, the carrier gas in contact with the surface of the material is a solid material Increase to increase the amount of material vaporized. Thus, while reducing the flow rate of the material gas, the MFC will be more carrier gas is introduced into the housing body movements, which can always maintain a certain flow rate of material gas Q _v.

However, in the above-described manner through the gas flow rate Q _c overload controls the flow rate of the material gas Q _v material gas control apparatus, as described below, when the presence of the reducing material reduces the efficiency of the material gas vaporized problem.

Specifically, if the amount of the liquid material is reduced, the liquid level in the container body becomes low, and the time during which the carrier gas comes into contact with the material liquid during the bubbling process becomes short, so that the carrier gas per unit flow rate reduces the amount of material vaporization. . That is, if the material is reduced, the gasification efficiency of the material is lowered. Even in the case of a solid material, if the material is vaporized and becomes small, the area in contact with the carrier gas becomes small, so that the gasification efficiency is lowered.

Even if such a reduction in the efficiency of gasification state, the material gas flow would also want to maintain the set flow rate Q _v, you need to import more carrier gas accommodating body. Thus, the contact time of the material with the carrier gas is shorter and shorter, and the gasification efficiency is further lowered. As a result, if the flow rate Q _{v of the} material gas is to be maintained in a state where the material is reduced, the flow rate Q _{c of the} carrier gas is accelerated to increase, and finally the valve in the MFC is completely opened, so that the gas cannot be further added on this basis. The flow rate Q _c . When the valve in the MFC is completely opened, since the amount of material vaporization cannot be increased even if the material remains in the housing, the flow rate Q _{v of the} material gas cannot be maintained at the set flow rate, resulting in an uncontrollable material. The state of the gas flow. In other words, even if a limited amount of material remains in the housing in accordance with the set flow rate, the material gas cannot be transported to the room or the like at a predetermined flow rate, and in order to prevent such a situation, it is necessary to frequently add materials.

Further, when it is in an uncontrollable state, the concentration control may be performed again by reducing the set value of the flow rate Q _v of the material gas. However, in this case, it is necessary to set the processing time in the film forming process of the semiconductor. It is difficult to use because of the long and large processing method changes. Further, even if the set value is changed, the same phenomenon as described above occurs, and the flow rate of the material gas cannot be kept constant.

In addition, in the material gas concentration control device described in the patent document 2 (Japanese Patent Laid-Open Publication No. 2010-109304), in the case where the flow rate of the material gas is kept constant, When the control is performed to keep the concentration or flow rate of the material gas in the mixed gas constant, the above problem also occurs.

In view of the above problems, an object of the present invention is to provide a material gas control device which can prevent an uncontrollable state, and when the material is reduced, the flow rate of the carrier gas is accelerated as the gasification efficiency is lowered. This causes the valve to become fully open state prematurely even if a large amount of material remains, resulting in an uncontrollable state as described.

That is, the present invention provides a material gas control device for a material gasification device, the material gasification device comprising at least: a receiving body, a receiving material; and an introduction tube for vaporizing the material a carrier gas is introduced into the housing; and a delivery tube for discharging a mixed gas of the carrier gas and the material gas vaporized by the material from the housing, wherein the material gas control device comprises: a concentration measuring mechanism that measures a concentration of the material gas in the mixed gas; a first valve control portion that controls an opening degree of a first valve provided on the outlet pipe, and an opening degree of the first valve Controlling such that the measured concentration of the material gas measured by the concentration measuring mechanism becomes the set concentration; and the second valve control portion controls the opening degree of the second valve provided on the introduction pipe, and for the The opening degree of the two valves is controlled such that when the opening degree of the first valve becomes a critical value opening degree, the opening degree of the second valve is changed to a later opening degree within a predetermined time, and the threshold value is opened. Smaller than the opening degree is fully opened opening degree of a first predetermined value, the opening ratio of the change of the opening degree of the first valve opening degree becomes a second predetermined value before the change when the opening degree threshold value.

In addition, the present invention also provides a material gas control system, comprising: a receiving body, a receiving material; an introduction tube, a carrier gas for vaporizing the material is introduced into the receiving body; and a lead-out tube for a mixed gas of a carrier gas and a material gas after vaporization of the material is led out from the housing; a first valve is disposed on the outlet tube; and a concentration measuring mechanism measures the material gas in the mixed gas a first valve control unit that controls an opening degree of the first valve such that a measured concentration of the material gas measured by the concentration measuring mechanism becomes a preset set concentration; a second valve is disposed in the And a second valve control unit that controls an opening degree of the second valve such that when the opening degree of the first valve becomes a critical value opening degree, the second valve is made within a predetermined time The opening degree is a changed opening degree, and the threshold opening degree is an opening degree that is smaller than a fully opened opening degree by a first predetermined value, and the changed opening degree is higher than the opening degree of the first valve Large opening before change in value opening Bis provides value.

In addition, the present invention also provides a material gas control method using a material gas control device for a material gasification device, the material gasification device comprising at least: a container, a receiving material a introducing tube for introducing a carrier gas for vaporizing the material into the housing; and a delivery tube for discharging a mixed gas of the carrier gas and the material gas vaporized by the material from the housing Deriving, wherein the material gas control device comprises at least a concentration measuring mechanism, the concentration measuring mechanism measures a concentration of the material gas in the mixed gas, and the material gas control method comprises: a first valve control step, Controlling an opening degree of the first valve disposed on the outlet pipe, and controlling an opening degree of the first valve such that a measured concentration of the material gas measured by the concentration measuring mechanism becomes a set concentration; And a second valve control step of controlling an opening degree of the second valve provided on the introduction pipe and controlling an opening degree of the second valve, When the opening degree of the first valve is the critical value opening degree, the opening degree of the second valve is changed to the opening degree after the predetermined time, and the threshold opening degree is smaller than the opening degree of the full opening. The opening degree of the predetermined value is greater than a second predetermined value of the change opening degree when the opening degree of the first valve is the threshold opening degree.

In addition, the present invention also provides a material gas control program for controlling a material gas control device for a material gasification device, the material gasification device comprising at least: a receiving body, a receiving material, and an introduction tube a carrier gas for vaporizing the material is introduced into the housing; and a delivery tube for discharging a mixed gas of the carrier gas and the material gas vaporized by the material from the container; Wherein the material gas control device includes at least a concentration measuring mechanism that measures a concentration of the material gas in the mixed gas, the material gas control program functions as a control portion, and the control portion includes a first valve control portion that controls an opening degree of the first valve provided on the outlet pipe, and controls an opening degree of the first valve such that the material gas measured by the concentration measuring mechanism The measured concentration becomes the set concentration; and the second valve control portion controls the opening degree of the second valve provided on the introduction pipe, and the opening degree of the second valve The line control is such that when the opening degree of the first valve becomes the critical value opening degree, the opening degree of the second valve is changed to the later opening degree within a predetermined time, and the threshold opening degree is more than the fully opened The degree of opening of the first predetermined value is smaller, and the degree of opening after the change is greater than a second predetermined value of the degree of opening before the opening of the first valve becomes the threshold opening.

According to the control device, the control system, the control method, and the control program, the concentration of the material gas in the mixed gas is continuously controlled by the first valve disposed on the outlet pipe, and is controlled such that When the material in the body is reduced and the gasification efficiency of the material is lowered to cause the first valve to be fully opened or nearly fully opened, the opening degree of the second valve provided on the introduction pipe is made large. Therefore, when the first valve approaches the control limit, since the flow rate of the carrier gas increases, the amount of material vaporization also increases, so the opening degree of the first valve returns from the fully open or near full opening to the intermediate side of the movable range. In this way, since the flow rate of the carrier gas is increased stepwise each time the first valve becomes the threshold opening degree of the opening degree which is fully opened or nearly fully opened, the vaporization efficiency of the accompanying material can be prevented from being lowered. The flow rate of the carrier gas is accelerated, and even if the material remains in a large amount, it becomes an uncontrollable state. That is, the measured concentration can be fixed to the set concentration until the material in the container is sufficiently used.

In order to utilize the apparatus of the existing material gasification apparatus, for example, a valve previously provided on the introduction pipe is used as the second valve, and only a minimum new structure is added, the effect can be achieved, and the present invention also provides a material gas. a control device for a material gasification device, the material gasification device comprising at least: a receiving body, a receiving material; an introduction tube for introducing a carrier gas for vaporizing the material into the receiving body; and a guiding tube a mixed gas for discharging the carrier gas and the material gas vaporized by the material, wherein the material gas control device includes: a concentration measuring mechanism that measures a portion of the mixed gas a concentration of the material gas; a first valve disposed on the outlet pipe; a first valve control portion that controls an opening of the first valve such that the measurement of the material gas measured by the concentration measuring mechanism The concentration becomes the set concentration; and the second valve control portion controls the opening degree of the second valve provided on the introduction pipe, and controls the opening degree of the second valve such that when When the opening degree of the one valve is the critical value opening degree, the opening degree of the second valve is changed to the opening degree after the predetermined time, and the threshold opening degree is smaller than the opening degree of the full opening by the first predetermined value. In the opening degree, the change opening degree is greater than a second predetermined value when the opening degree of the first valve becomes the threshold opening degree.

In order to change the opening of the second valve abruptly, the flow rate of the carrier gas is not changed abruptly, and the measured concentration is also fixed to the set concentration during the change period. Preferably, the second valve control unit controls the The second valve is configured to increase the opening degree of the second valve substantially in proportion to the time from the pre-change opening degree to the change-opening degree.

In order to match the amount of decrease in gasification efficiency caused by the decrease in the accompanying material, the first valve is returned from the threshold opening degree to the fully movable opening degree by increasing the amount of the carrier gas introduced into the housing, and The concentration may be kept constant without adding material for a long period of time. Preferably, the second predetermined value is changed according to the number of times the first valve becomes the threshold opening degree.

As a specific configuration for setting the opening degree of the second valve in accordance with the flow rate of the carrier gas, and more strictly performing the concentration control in accordance with the decrease in the gasification efficiency, it is also possible to include a flow rate measuring sensor. a flow measuring sensor for measuring a flow rate of a carrier gas flowing in the introduction pipe, the second valve control portion including: an opening degree control portion that controls an opening degree of the second valve such that a measured flow rate of the carrier gas measured by the flow rate measuring sensor becomes a set flow rate; and a flow rate setting unit that sets the set flow rate to the opening degree control unit, and when the opening degree of the first valve becomes In the threshold opening degree, the flow rate setting unit sets the changed set flow rate as the set flow rate in the opening degree control unit, and the changed set flow rate is that the opening degree of the first valve is the The value of the flow rate is set to α times before the change at the critical value opening degree, where α>1.

When the concentration of the material gas in the mixed gas is controlled by gradually controlling the flow rate of the carrier gas, in order to reduce the flow rate of the carrier gas even if the material in the housing is reduced and the gasification efficiency is lowered, the flow rate of the carrier gas is prevented from being increased, resulting in a short period of time. The invention also provides a material gas control device for a material gasification device, the material gasification device comprising at least: a receiving body, a receiving material; and an introduction tube for a carrier gas vaporized by the material is introduced into the housing; and a delivery tube for discharging a mixed gas of the carrier gas and the material gas vaporized by the material from the housing, wherein the material gas is controlled The apparatus includes: a flow measuring mechanism that measures a flow rate of the material gas in the mixed gas; a second valve control unit that controls an opening degree of a second valve provided on the introduction pipe, and the second valve The opening degree is controlled such that the measured flow rate of the material gas measured by the flow sensor measuring mechanism becomes a preset set flow rate; and the first valve control Controlling an opening degree of the first valve provided on the outlet pipe, and controlling an opening degree of the first valve such that when the opening degree of the second valve becomes a critical value opening degree, The opening degree of the first valve is changed to a degree of opening after a change, the threshold opening degree is an opening degree that is smaller than a fully opened opening degree by a first predetermined value, and the changed opening degree is longer than the second opening When the opening degree of the valve is the critical value opening degree, the opening degree before the change is larger than the second predetermined value. According to the material gas control device described above, even if the material in the housing is reduced and the gasification efficiency is lowered, the total pressure in the housing can be set to be low by the second valve, thereby returning the first valve again. It is within the movable range, so it is possible to prevent a state in which concentration control cannot be performed even if a large amount of material remains.

In addition, as another manner of the material gas control device, the present invention further provides a material gas control device for a material gasification device, the material gasification device comprising at least: a receiving body, a receiving material; Introducing a tube into which a carrier gas for vaporizing the material is introduced; and a discharge tube for mixing a gas of the carrier gas and the material gas vaporized from the material from the container Deriving; a flow measuring mechanism that measures a flow rate of the material gas in the mixed gas; and a second valve control portion that controls an opening degree of the second valve provided on the introduction pipe, and the second valve The opening degree is controlled such that the measured flow rate of the material gas measured by the flow measuring mechanism becomes a preset set flow rate, wherein the material gas control device includes a first valve control portion, the first valve The control unit controls an opening degree of the first valve provided on the outlet pipe, and controls opening degree of the first valve such that when the opening degree of the second valve becomes critical At the opening degree, the opening degree of the first valve is changed to a degree of opening after a predetermined time period, and the threshold opening degree is an opening degree that is smaller than a first opening value of the fully opened opening degree, and the change is opened. The degree of change is greater than a second predetermined value when the opening degree of the second valve becomes the threshold opening degree.

According to the material gas control device of the present invention, even if the gasification efficiency is lowered due to a decrease in the material in the housing, the opening of the second valve can be made stepwise, thereby opening the first valve for performing the concentration control. The degree remains within the movable range for a longer period of time. Therefore, it is possible to prevent the vaporization efficiency from being accelerated to fall, and even if a large amount of material remains, it becomes a state in which concentration control cannot be performed.

A first embodiment of the present invention will now be described with reference to the accompanying drawings.

The material gas control device 100 of the present embodiment is used, for example, to supply TMIn (trimethyl indium) to an MOCVD (Metal Organic Compound Chemical Vapor Deposition) film forming apparatus which is a semiconductor manufacturing apparatus at a constant concentration and flow rate. More specifically, the material gas control device 100 is used for the material gasification device 200 that vaporizes and supplies the solid material of TMIn to the chamber as a film forming chamber. In addition, TMIn corresponds to the material. Further, the material gas control system 300 is formed by combining the material gas control device 100 and the material gasification device 200.

As shown in the schematic view of Fig. 1, the material gasification apparatus 200 includes a bottle T in which a material for gasification is housed and surrounded by a thermostatic bath; an introduction tube L1 for the bottle A carrier gas is introduced into the T; and a discharge tube L2 for discharging the mixed gas of the vaporized material gas and the carrier gas from the bottle T. The material gas control device 100 is constructed by providing various structural components and control mechanisms to the material vaporization apparatus 200.

More specifically, as shown in FIG. 1, the material gas control device 100 includes a quality flow controller 3 disposed on the introduction tube L1, and a piezoelectric valve 1 disposed on the outlet tube L2; The gas concentration monitor 2 controls the mass flow controller 3 and the piezoelectric valve by measuring the concentration of the material gas in the mixed gas derived from the bottle T and maintaining the concentration of the material gas constant 1, as a result, the flow rate of the material gas is kept constant.

Each part will be described. As shown in the detailed view of FIG. 2, the mass flow controller 3 is formed with an internal flow path as a part of the introduction pipe L1, for example, in a block-shaped base member, on the internal flow path. Provided is a flow measuring sensor 31 for measuring the flow rate of the carrier gas flowing in the introduction pipe L1: and a flow control valve 32 (corresponding to the second valve) for controlling the fluid passing through the internal flow path Flow rate, and the quality flow controller 3 further includes a flow rate control valve opening degree control unit 33 that controls the opening degree of the flow rate control valve 32 so that the flow rate measurement is sensed The measured flow rate of the carrier gas measured by the device 31 becomes the set flow rate. Further, the function of the flow rate control valve opening degree control unit 33 is realized by a microcomputer or the like provided in the quality flow controller 3.

The piezoelectric valve 1 can be finely adjusted by the piezoelectric element, and its opening degree is controlled by the piezoelectric valve control unit 24 which will be described later.

The gas concentration monitor 2 includes: a concentration measuring mechanism CS for measuring a concentration of a material gas in the mixed gas in the outlet pipe L2; and a flow control unit CC by controlling the quality flow controller 3 and the The piezoelectric valve 1 is described to control the flow rate of the material gas.

The concentration measuring mechanism CS includes a partial pressure sensor 21 disposed on the discharge tube L2 to measure a partial pressure of a material gas in the mixed gas, and a pressure gauge 22 that measures the pressure of the mixed gas in the bottle T The total pressure; and the concentration calculating unit 23 calculates the concentration of the material gas based on the partial pressure P _{v of the} material gas and the total pressure P _{t of the} mixed gas. As the voltage dividing sensor 21, NDIR (non-dispersive infrared analysis method), FTIR (Fourier transform infrared spectroscopy), or laser absorption spectroscopy may be employed. Further, the concentration calculating unit 23 calculates the measured concentration of the material gas based on the formula in which the concentration C is C=P _v /P _t . Further, the concentration measuring mechanism CS may measure the concentration of the material gas alone by an ultrasonic gas concentration sensor or the like.

The flow rate control unit CC includes a piezoelectric valve control unit 24 (corresponding to a first valve control unit) that controls the opening degree of the piezoelectric valve 1 so that the material gas measured by the concentration measuring unit CS The measured concentration becomes the set concentration; and the carrier gas flow rate setting unit 25 sets the carrier gas set flow rate in the flow rate control valve opening degree control unit 33 in the quality flow controller 3. Further, the function of the flow rate control unit CC is also realized by, for example, a microcomputer or the like in the gas concentration monitor 2. Further, the flow rate control valve opening degree control unit 33 in the mass flow controller 3 and the carrier gas flow rate setting unit 25 in the flow rate control unit CC correspond to the second valve control unit.

The piezoelectric valve control portion 24 controls the opening degree of the piezoelectric valve 1 so that the deviation between the measured concentration of the material gas and the set concentration tends to become small. More specifically, from the formula of C=P _v /P _t , it is clear that if the set concentration is set to be constant, when the amount of material gas is decreased and the value of the partial pressure P _v becomes small, it is necessary to cooperate with it. The value of the pressure P _t also becomes small. That is, when the measured concentration is lower than the set concentration (the partial pressure P _{v is} low), the piezoelectric valve control unit 24 performs control for increasing the opening degree of the piezoelectric valve 1 so that the total pressure P _t in the bottle T When the measured concentration is higher than the set concentration, the piezoelectric valve control unit 24 makes the opening degree of the piezoelectric valve 1 small. Further, although the set concentration can be set by directly performing the concentration setting, in the present embodiment, when the user inputs the flow rate of the material gas that is intended to flow in the outlet pipe L2, according to the The material gas sets the flow rate to convert the set concentration. Specifically, when the set concentration is C ₀ , the material gas set flow rate is Q _v0 , and the carrier gas set flow rate is Q _c0 , the conversion is performed based on C ₀ = Q _v0 / (Q _c0 + Q _v0 ). In addition, the carrier gas flow rate setting unit 25, which will be described later, resets the set concentration C ₀ set in the piezoelectric valve control unit 24 in accordance with the change in the carrier gas set flow rate.

When the opening degree of the piezoelectric valve 1 is the threshold opening degree, the carrier gas flow rate setting unit 25 sets the set flow rate of the flow rate control valve opening degree control unit 33 to the set flow rate after the change, and sets the change after the change. The flow rate is α times (α>1) of the set flow rate before the change when the opening degree of the piezoelectric valve 1 becomes the critical value opening degree, and the threshold opening degree is smaller than the fully opened opening degree by the first predetermined value. Opening degree. Further, the first predetermined value includes zero, and in the first embodiment, the critical value opening degree is a fully open opening degree. Further, the carrier gas flow rate setting unit 25 may detect the opening degree of the piezoelectric valve 1 by detecting the opening degree itself, or may detect the piezoelectric valve based on a command value or a current value or the like input to the piezoelectric valve 1. The opening of 1 .

The flow rate control operation of the material gas of the material gas control device 100 of the above configuration will be described with reference to the flowchart of Fig. 3 .

First, after the predetermined carrier gas set flow rate _{Qc0 is} set in the quality flow controller 3, the flow rate control of the carrier gas is started to fix the measured flow rate of the carrier gas to the set flow rate. Further, the opening degree of the piezoelectric valve 1 is controlled by the gas concentration monitor 2 so that the measured concentration becomes the set concentration C ₀ of the predetermined value (step S1). Since the flow rate of the carrier gas is constant, and the piezoelectric valve 1 is controlled so that the concentration of the material gas in the mixed gas is constant, the result is based on the relationship of the concentration formula Q _v = C × Q _c / (1-C) It is determined that the material gas flow rate Q _v is controlled to be constant. Here, the carrier gas set flow rate Q _c0 at the initial setting is set such that the opening degree of the flow rate control valve 32 is a small opening degree which is greatly different from the opening degree at which the flow rate control valve 32 is fully opened.

Then, as the material in the bottle T decreases, and as the gasification efficiency decreases, the opening degree of the piezoelectric valve 1 gradually increases (step S2). When the opening degree of the piezoelectric valve 1 is the fully open opening degree as the threshold opening degree (step S3), the carrier gas flow rate setting unit 25 is loaded in the flow rate control valve opening degree control unit 33. The gas set flow rate is reset to α times the current value (step S4). Here, if the carrier gas setting flow rate is reset to α times the current value, the set concentration C ₀ set in the piezoelectric valve control unit 24 is also updated. Specifically, since the material gas set flow rate Q _{v0 is} kept constant, if a new set concentration is set to C ₀ ', C ₀ '=Q _v0 /(Q _v0 +αQ _c0 ) becomes the reset gas carrier setting. The set concentration used in the piezoelectric valve control unit 24 after the flow rate Q _c0 .

Further, when the measured flow rate is equal to the set flow rate after the change in the predetermined time period (step S5), the opening degree of the flow rate control valve 32 is larger than the opening degree before the change. After the second predetermined value is changed, the opening degree is maintained and the state is maintained, and the process returns to step S2. When the measured flow rate does not coincide with the set flow rate after the lapse of the predetermined time (step S5), it is judged that the flow rate control valve 32 is fully opened and is the control limit, so that the gas concentration monitor 2 is ended. Concentration control performed (step S6).

Therefore, if attention is paid to the concentration control of one loop, as shown in FIG. 4, the opening degree of the flow rate control valve 32 and the piezoelectric valve 1 is shown, and the opening degree of the piezoelectric valve 1 for controlling the concentration of the material gas in the mixed gas is changed from The first fully open state is substantially completely closed, and the total pressure in the bottle T is increased. Thereafter, the total pressure is lowered due to the decrease in the gasification efficiency, so that the opening degree of the piezoelectric valve 1 is gradually increased. Open completely. On the other hand, since the flow rate of the carrier gas is kept constant, the opening degree of the flow rate control valve 32 is also maintained at a substantially constant opening degree. Further, when the opening degree of the piezoelectric valve 1 is completely opened, the opening degree of the flow rate control valve 32 becomes an opening degree which becomes a second predetermined value.

Since the above operation is repeated as a single cycle, as shown in FIG. 4, the opening degree of the piezoelectric valve 1 changes in a substantially sinusoidal waveform, and the opening degree of the flow rate control valve 32 changes in a step function. In addition, the smaller the amount of residual material, the larger the amount of decrease in the gasification efficiency of the material, so the subsequent cycle is shorter.

Thus, since the flow rate control valve 32 is controlled every time the piezoelectric valve 1 is fully opened, the flow rate of the carrier gas flowing into the bottle T is gradually increased, so that even if the material is reduced, gas The reduction in efficiency can also prevent the flow rate of the carrier gas from increasing rapidly. Therefore, it is possible to prevent the state from being uncontrollable quickly, so that the material gas of the set concentration can be supplied to the subsequent process for a long period of time, and the uncontrollable state is that the concentration or the flow rate of the material gas cannot be made desirable even if the material remains in a large amount. Concentration or flow rate.

Next, the material gas control device 100 of the second embodiment will be described. In addition, components corresponding to the material gas control device 100 of the first embodiment are denoted by the same reference numerals.

As shown in the schematic view of Fig. 5, the material gas control device 100 of the second embodiment is different from the first embodiment in that the operation of the mass flow controller 3 and the piezoelectric valve 1 is not monitored by gas concentration. The device 2 controls, but is controlled uniformly by another control mechanism. That is, although the gas concentration monitor 2 of the first embodiment has at least two components of the concentration measuring mechanism CS and the flow rate control unit CC, the gas concentration monitor 2 has only the concentration measuring mechanism CS in the second embodiment. The function of the flow control unit CC is implemented in the control device 4.

The control device 4 is a so-called computer composed of, for example, an I/O device, a CPU, a memory, an input interface, and the like, and the control device 4 functions as at least a flow rate control unit CC.

The cooperation of the respective parts is more specifically explained. As shown in the detailed diagram of FIG. 6, the control device 4 issues an instruction to the quality flow controller 3 to cause the carrier gas to flow at a certain flow rate, and the control The device 4 takes the measured concentration of the material gas concentration in the mixed gas from the gas concentration monitor 2, and controls the opening degree of the piezoelectric valve 1 so that the measured concentration becomes the set concentration. Then, when the opening degree of the piezoelectric valve 1 is fully opened, the control device 4 issues an instruction to the quality flow controller 3 to increase the flow rate of the carrier gas by only a predetermined amount. Then, since the amount of material vaporization increases, the opening degree of the piezoelectric valve 1 can be returned to the movable range, and the concentration control can be performed again. The operation is repeated until the opening degree of the flow rate control valve 32 in the mass flow controller 3 is completely opened and the measured concentration cannot be made to match the set concentration.

Thus, the control unit can be provided in each part as in the first embodiment. The concentration and flow rate control can be uniformly performed by a computer or the like as in the second embodiment.

Next, the material gas control device 100 of the third embodiment will be described. In the third embodiment, the components corresponding to the material gas control device 100 of the first embodiment are given the same reference numerals.

The third embodiment is different from the first embodiment and the second embodiment in that, in the third embodiment, the valve whose gradation change is gradually changed in order to maintain the material gas concentration is The opening degree is a substantially fixed valve during the period from the threshold opening degree, which is opposite to that of the material gas control device 100 of the first embodiment and the second embodiment. The configuration of the mass flow controller 3, the gas concentration monitor 2, and the piezoelectric valve 1 is the same except for the above differences.

The respective portions will be described. As shown in the detailed diagram of FIG. 7, the quality flow controller 3 obtains the measured concentration of the material gas concentration from the gas concentration monitor 2 provided on the outlet pipe L2, and according to the current flow. The flow rate of the carrier gas and the measured concentration are used to calculate the flow rate of the material gas to control the flow rate of the carrier gas so that the measured flow rate of the material gas becomes a preset set flow rate. More specifically, if the measured flow rate of the material gas is decreased, the mass flow controller 3 increases the opening degree of the internal flow control valve 32 (corresponding to the second valve) so that the flow rate of the added gas is used to make More materials are vaporized. The gas concentration monitor 2 obtains information relating to the opening degree of the flow control valve 32, and when the flow control valve 32 is fully opened, opens the piezoelectric valve 1 (corresponding to the first valve) The degree is changed to become the second predetermined amount. That is, each time the opening degree of the flow rate control valve 32 is fully opened, the piezoelectric valve 1 operates to lower the total pressure in the bottle T. When the total pressure of the mixed gas is lowered, the concentration of the material gas can be maintained at the set concentration even if the amount of the material gas is reduced and the partial pressure of the material gas is lowered, so that the opening degree of the flow rate control valve 32 is completely Open to return to the movable range. Therefore, it is possible to continue the concentration control while maintaining the concentration of the material gas at the set concentration again, thereby preventing the premature occurrence of a state in which the material remains uncontrollable even if the material remains. Further, the present embodiment can be implemented by a valve, a gas concentration monitor, or the like provided on a conventional material vaporization device. Specifically, when a second valve is provided on the introduction pipe of the material gasification device, and the flow rate measuring mechanism that has measured the flow rate of the material gas and the second valve control portion that controls the second valve based on the measured flow rate When the first valve is newly provided on the outlet pipe and the first valve control portion is newly provided, the first valve control portion acquires the opening degree information of the second valve, and when the second valve is opened When the degree becomes the critical value opening degree, the opening degree of the first valve is gradually changed each time by a predetermined amount.

Other embodiments will be described. In addition to controlling the opening of the flow control valve in the mass flow controller to be changed in a complete step function, the opening of the flow control valve in the mass flow controller may be controlled to : Only the difference between the second predetermined value is generated between the pre-change opening degree and the post-change opening degree within the predetermined time. In other words, it is also possible to perform appropriate improvement (filling) between the change opening degree and the change opening degree. For example, as shown in FIG. 8( a ), the second valve control unit may control the second valve such that the second valve is opened from the pre-change opening degree to the changed opening degree. The opening is substantially proportional to the time. Further, in order to make the rate of change of the opening degree gentle and to quickly stabilize at a desired set concentration, as shown in FIG. 8(b), S-shape perfecting (S-fill completion) may be performed between the opening degrees.

Further, in the embodiment, for the opening degree of the piezoelectric valve provided on the outlet pipe, the critical value opening degree of the piezoelectric valve is set to the fully open opening degree, and the piezoelectric valve is fully opened as a trigger. To change the opening of the flow control valve stepwise, but the threshold opening is not limited to the fully open opening. For example, it is also possible to set the opening degree which is smaller than the opening degree of the fully open by the first predetermined value as the threshold opening degree, thereby maintaining the margin. For example, the first predetermined value may be determined in such a manner that the threshold opening degree is a certain degree of opening from an intermediate opening degree of the movable range of the piezoelectric valve to a fully opened opening degree. According to this aspect, since the concentration control can be performed while maintaining the material gas in a certain gasification efficiency state for a sufficiently long period of time, it is possible to prevent the deterioration of the vaporization efficiency from being deteriorated.

Further, in the above-described embodiment, the opening degree of the flow rate control valve is set to be gradually increased by a substantially equal amount each time. For example, the difference between the opening degree before the change and the degree of opening after the change may be set. The second predetermined value is changed according to the number of times the first valve becomes the critical value opening degree. More specifically, as shown in (c) of FIG. 8, as the number of times the first valve becomes the critical value opening degree increases, the second predetermined value increases, and the gasification efficiency decreases, so that a sufficient amount is obtained. Material gas.

Further, as a specific embodiment of the first valve, it is not limited to the piezoelectric valve. For example, other valves such as solenoid valves may be used.

In the material gas control device according to each embodiment, the mass flow controller is not provided on the introduction pipe, and only the flow rate control valve (second valve) is provided, as long as the second valve control portion is set at the gas concentration The second valve control unit may be controlled such that the opening degree of the first valve provided on the outlet pipe becomes the first predetermined value smaller than the opening degree of the full opening. When the threshold value is opened, the opening degree of the second valve is changed to a degree of opening after a predetermined time period, and the degree of opening after the change is higher than the opening degree of the first valve. The second specified value.

Even if the material is a liquid material, the material gas control device of each embodiment can obtain the same effect. Further, the material gas control device of the present invention is not limited to the concentration control of the material gas after solidification of TMIn. For example, it can also be used for a CVD (Chemical Vapor Deposition) film forming apparatus or the like, or for providing IPA (isopropyl alcohol) in a stable concentration in a drying treatment tank of a wafer cleaning apparatus used in a semiconductor manufacturing process. Further, the material gas control device of the present invention is not limited to use in a manufacturing process of a semiconductor, an FPD (Flat Panel Display), an optical device, a MEMS (Micro Electro Mechanical System), or the like, and may be used for a gas using a material vaporization device. Supply device.

Further, the present invention can be carried out by using a conventional material vaporization apparatus, a valve used in the material vaporization apparatus, or the like. For example, when a second valve is previously provided in the material gasification device, a material gas control device may be added to the material gasification device to constitute a material gas control system, and the material gas control device includes the first valve The concentration measuring mechanism, the first valve control unit, and the second valve control unit. In addition, a material gas control program may be installed in the gas concentration monitor or the control device to perform concentration or flow rate control as described above, and the material gas control program functions as the first valve control portion and the second The function of the valve control unit. Further, such a program can be installed either through a network or by a recording medium such as a CD storing a material gas control program.

In each of the above embodiments, the flow rate control of the material gas is performed based on the concentration, but the flow rate measuring mechanism that directly measures the material gas flow rate may be used instead of the concentration measuring mechanism that measures the material gas concentration in the mixed gas. Control device and material gas control system. For example, it is also possible to measure the flow rate of the carrier gas in the introduction pipe and the flow rate of the mixed gas in the outlet pipe, and measure the material gas flow rate based on the difference therebetween.

Further, various modifications and combinations of the embodiments may be made without departing from the spirit and scope of the invention.

1. . . Piezoelectric valve

100. . . Material gas control device

2. . . Gas concentration monitor

twenty one. . . Partial pressure sensor

twenty two. . . pressure gauge

twenty three. . . Concentration calculation department

twenty four. . . Piezoelectric valve control unit

25. . . Carrier gas flow setting unit

200. . . Material gasification unit

3. . . Quality flow controller

31. . . Flow measurement sensor

32. . . Flow control valve

33. . . Flow control valve opening control unit

300. . . Material gas control system

C. . . concentration

CC. . . Flow control department

CS. . . Concentration measuring mechanism

L1. . . Inlet tube

L2. . . Export tube

S. . . material

T. . . bottle

S1 ~ S6. . . Flow chart step description

Fig. 1 is a schematic view schematically showing a material gas control system according to a first embodiment of the present invention.

Fig. 2 is a fluid circuit diagram and a functional block diagram schematically showing a material gas control system of the first embodiment.

3 is a flow chart showing the operation of the material gas control system of the first embodiment.

4 is a view showing changes in opening degree of each valve of the material gas control system according to the first embodiment.

Fig. 5 is a schematic view schematically showing a material gas control system according to a second embodiment of the present invention.

Fig. 6 is a fluid circuit diagram and a functional block diagram schematically showing a material gas control system of a second embodiment.

Fig. 7 is a fluid circuit diagram and a functional block diagram schematically showing a material gas control system of a third embodiment.

Fig. 8 is a view showing the operation of a second valve according to another embodiment of the present invention.

Fig. 9 is a schematic view schematically showing a conventional material gas control system.

1. . . Piezoelectric valve

100. . . Material gas control device

2. . . Gas concentration monitor

200. . . Material gasification unit

3. . . Quality flow controller

300. . . Material gas control system

L1. . . Inlet tube

L2. . . Export tube

S. . . material

T. . . bottle

Claims (10)

A material gas control device for a material gasification device, the material gasification device comprising at least: a receiving body, a receiving material; and an introduction pipe for introducing a carrier gas for vaporizing the material into the receiving body; a lead-out tube for extracting a mixed gas of the carrier gas and a material gas vaporized by the material from the container, wherein the material gas control device includes: a concentration measuring mechanism that measures the mixed gas a concentration of the material gas; a first valve control portion that controls an opening degree of the first valve provided on the outlet pipe, and controls an opening degree of the first valve such that the concentration measuring mechanism The measured concentration of the measured material gas becomes the set concentration; and the second valve control portion controls the opening degree of the second valve provided on the introduction pipe, and controls the opening degree of the second valve so that When the opening degree of the first valve is a critical value opening degree, the opening degree of the second valve is changed to a later opening degree within a predetermined time, and the threshold opening degree is smaller than a fully open opening degree. Specified value Opening, after the opening ratio of the change of the opening degree of the first valve opening degree becomes a second predetermined value before the change when the opening degree threshold value. The material gas control device according to claim 1, wherein the second valve control unit controls the second valve so as to be from the pre-change opening degree to the change-opening degree The opening degree of the second valve becomes substantially proportional to the time. The material gas control device according to claim 1, wherein the second predetermined value is changed according to the number of times the first valve becomes the threshold opening degree. The material gas control device according to claim 1, wherein the second valve control unit includes: an opening degree control unit that controls an opening degree of the second valve so that a flow measurement feeling is obtained The measured flow rate of the carrier gas measured by the detector becomes a set flow rate, the flow rate measuring sensor is for measuring a flow rate of the carrier gas flowing in the introduction pipe; and a flow rate setting unit is configured to set the flow rate In the opening degree control unit, when the opening degree of the first valve is the threshold opening degree, the flow rate setting unit sets the changed set flow rate as the set flow rate at the opening degree control. In the portion, the set flow rate after the change is α times the set flow rate before the change when the opening degree of the first valve is the threshold opening degree, wherein α>1. A material gas control device for a material gasification device, the material gasification device comprising at least: a receiving body, a receiving material; and an introduction pipe for introducing a carrier gas for vaporizing the material into the receiving body; a lead-out tube for extracting a mixed gas of the carrier gas and a material gas vaporized by the material from the container, wherein the material gas control device includes: a concentration measuring mechanism that measures the mixed gas a concentration of the material gas; a first valve disposed on the outlet pipe; a first valve control portion that controls an opening degree of the first valve such that the material gas measured by the concentration measuring mechanism The measured concentration becomes the set concentration; and the second valve control portion controls the opening degree of the second valve provided on the introduction pipe, and controls the opening degree of the second valve such that when the first valve When the opening degree is the critical value opening degree, the opening degree of the second valve is changed to the opening degree after the predetermined time, and the threshold opening degree is an opening degree smaller than the opening degree of the full opening by the first predetermined value. , the change The opening degree of the second predetermined value than the front opening degree of the first valve opening degree becomes changed when the opening degree threshold value. A material gas control method using a material gas control device for a material gasification device, the material gasification device comprising at least: a receiving body, a receiving material; and an introduction tube for use Introducing a carrier gas for vaporizing the material into the housing; and a delivery tube for discharging a mixed gas of the carrier gas and the material gas vaporized by the material from the container; The material gas control device includes at least a concentration measuring mechanism that measures a concentration of the material gas in the mixed gas, the material gas control method including: a first valve control step in which control is set in the export An opening degree of the first valve on the tube, and controlling an opening degree of the first valve such that a measured concentration of the material gas measured by the concentration measuring mechanism becomes a set concentration; and a second valve control step Controlling an opening degree of the second valve provided on the introduction pipe, and controlling an opening degree of the second valve such that when the first valve is When the degree becomes the critical value opening degree, the opening degree of the second valve is changed to the opening degree after the predetermined time, and the threshold opening degree is an opening degree that is smaller than the opening degree of the full opening by the first predetermined value. The change after opening is greater than a second predetermined value when the opening degree of the first valve becomes the threshold opening degree. A material gas control program for controlling a material gas control device for a material gasification device, the material gasification device comprising at least: a receiving body, a receiving material; and an introduction tube for use in a carrier gas vaporized by the material is introduced into the housing; and a delivery tube for discharging a mixed gas of the carrier gas and the material gas vaporized by the material from the housing, wherein the material gas The control device includes at least a concentration measuring mechanism that measures a concentration of the material gas in the mixed gas, the material gas control program functions as a control portion, wherein the control portion includes: a first valve a control unit that controls an opening degree of the first valve provided on the outlet pipe, and controls an opening degree of the first valve such that a measured concentration of the material gas measured by the concentration measuring mechanism becomes Setting a concentration; and a second valve control unit that controls an opening degree of the second valve provided on the introduction pipe, and controls an opening degree of the second valve to When the opening degree of the first valve is the critical value opening degree, the opening degree of the second valve is changed to the opening degree after the predetermined time, and the threshold opening degree is smaller than the opening degree of the full opening. The opening degree of the predetermined value is greater than a second predetermined value of the change opening degree when the opening degree of the first valve is the threshold opening degree. A material gas control system comprising: a receiving body, a receiving material; an introduction tube for introducing a carrier gas for vaporizing the material into the receiving body; and a discharge tube for the carrier gas and the material a gas mixture of the vaporized material gas is led out from the container; a first valve is disposed on the outlet tube; a concentration measuring mechanism measures a concentration of the material gas in the mixed gas; and the first valve is controlled Controlling the opening degree of the first valve such that the measured concentration of the material gas measured by the concentration measuring mechanism becomes a preset set concentration; a second valve is disposed on the introduction tube; The two-valve control unit controls the opening degree of the second valve such that when the opening degree of the first valve becomes a critical value opening degree, the opening degree of the second valve is changed after a predetermined time In the opening degree, the threshold opening degree is an opening degree that is smaller than a first opening value that is smaller than a fully opened opening degree, and the change opening degree is changed when the opening degree of the first valve becomes the threshold value opening degree. The front opening is greater than the second specified value. A material gas control device for a material gasification device, the material gasification device comprising at least: a receiving body, a receiving material; and an introduction pipe for introducing a carrier gas for vaporizing the material into the receiving body; a discharge tube for extracting a mixed gas of the carrier gas and a material gas vaporized by the material from the container, wherein the material gas control device includes: a flow measuring mechanism that measures the mixed gas a flow rate of the material gas; a second valve control portion that controls an opening degree of the second valve provided on the introduction pipe, and controls an opening degree of the second valve such that the flow rate measuring mechanism The measured flow rate of the material gas is measured to be a preset set flow rate; and a first valve control portion controls an opening degree of the first valve provided on the outlet pipe, and an opening degree of the first valve Controlling such that when the opening degree of the second valve becomes the critical value opening degree, the opening degree of the first valve is changed to the later opening degree within a predetermined time, and the threshold opening degree is more than the fully opened open Small opening degree of a first predetermined value after the opening degree change ratio of the opening degree of the second valve opening degree becomes a second predetermined value before the change when the opening degree threshold value. A material gas control device for a material gasification device, the material gasification device comprising at least: a receiving body, a receiving material; and an introduction pipe for introducing a carrier gas for vaporizing the material into the receiving body; a tube for extracting a mixed gas of the carrier gas and a material gas vaporized by the material from the container; a flow measuring mechanism that measures a flow rate of the material gas in the mixed gas; and a second a valve control portion that controls an opening degree of the second valve provided on the introduction pipe, and controls an opening degree of the second valve such that a measured flow rate of the material gas measured by the flow rate measuring mechanism a predetermined set flow rate, wherein the material gas control device includes a first valve control portion, the first valve control portion controls an opening degree of the first valve disposed on the outlet pipe, and The opening degree of the valve is controlled such that when the opening degree of the second valve becomes the critical value opening degree, the opening degree of the first valve is changed to the opening degree after the predetermined time, the threshold opening degree Is more than finished Open to open a small opening degree of the first predetermined value after the opening degree change ratio of the opening degree of the second valve opening degree becomes a second predetermined value before the change when the opening degree threshold value.