JP5506655B2 - Material gas control device, material gas control method, material gas control program, and material gas control system - Google Patents

Description

  The present invention relates to a device for controlling a vaporized material gas in a material vaporizer that introduces a carrier gas into a material accommodated in a container and vaporizes the material.

  For example, in the film formation process of a semiconductor, it is required that the material gas vaporized by the material vaporization apparatus is conveyed at a predetermined concentration or flow rate into a chamber in which film formation is performed.

  For example, as a material gas control device for controlling the flow rate of material gas at a constant level, a carrier gas as shown in Patent Document 1 and FIG. 9 is introduced into an introduction pipe for introducing the carrier gas into a container containing the material amount. A mass flow controller (hereinafter also referred to as MFC) provided, and a concentration monitor provided in a lead-out pipe for deriving a mixed gas of the material gas vaporized from the container and the carrier gas. There is one that controls the flow rate of the carrier gas based on the measured concentration measured in (1).

More specifically, when 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 , the concentration of the material gas is C = Q _v / (Q _v + Q _c ). Therefore, the flow rate of the material gas can be expressed as Q _v = C · Q _c / (1-C), and the actual flow rate of the material gas can be calculated from the measured concentration. Utilizing this relationship, the material gas control device monitors the concentration of the vaporized material gas, feeds back the actual flow rate of the material gas calculated from the measured concentration to the MFC, and flows the material gas flow rate Q _v. The carrier gas flow rate is controlled by MFC so that becomes constant at a predetermined set flow rate.

Here, the flow rate Q _v of the material gas is dependent on the amount of material is vaporized, the amount of material vaporized is changed by the flow rate Q _c of the carrier gas. Usually, in order to increase the flow rate Q _v of the material gas, by increasing the flow rate Q _c of the carrier gas, the material to increase the amount that is bubbled if liquid, if the material is a solid, the material By increasing the amount of carrier gas striking the surface, the amount of material vaporized can be increased. Therefore, when the flow rate of the material gas becomes small, MFC than operate to introduce into the housing body more carrier gases, it can always be maintained constant material gas flow rate Q _v.

However, a material gas control apparatus for controlling the flow rate Q _v of the material gas by the flow rate Q _c of the carrier gas as described above, due to the decrease in vaporization efficiency of the material gas at the time of the material as described below is reduced There is a problem.

  Specifically, as the amount of liquid material decreases, the liquid level in the container decreases and the time during which the carrier gas is in contact with the material liquid during bubbling is shortened. The amount of material vaporization is reduced. That is, if the material decreases, the vaporization efficiency of the material decreases. Even if it is a solid material, if the amount of the material is vaporized and reduced, the area in contact with the carrier gas is reduced, so that the vaporization efficiency also decreases.

Even when such a vaporization efficiency is lowered, and you keep the flow rate Q _v of the material gas at a set flow rate, it is necessary to introduce further a number of carrier gas containing body. As a result, the contact time between the material and the carrier gas is further shortened, and the vaporization efficiency is further reduced. As a result, if the material gas flow rate Q _v is maintained while the material is reduced, the carrier gas flow rate Q _c increases at an accelerated rate. it becomes impossible to increase the flow rate Q _c. When the valves in the MFC is fully opened, as a material was left in the containing body, the more can not increase the amount of material is vaporized, keep the flow rate Q _v of the material gas to the set flow rate The material gas flow rate cannot be controlled. In other words, depending on the set flow rate, the material gas cannot be sent into the chamber or the like at a predetermined flow rate even though a large amount of material remains in the container. Will have to be added.

Further, when it becomes uncontrollable state again by lowering the set value of the flow rate Q _v of the material gas, it is conceivable to perform density control, in which case, setting a longer process time in the semiconductor film formation step It becomes difficult to use because a large recipe change is required. In addition, 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 immediately.

  Furthermore, the above-described problem is not only caused when the flow rate of the material gas is kept constant, but also in the material gas concentration control device as shown in Patent Document 2, the concentration or flow rate of the material gas in the mixed gas is changed. It occurs even when it is controlled to keep constant.

Japanese Patent Application Laid-Open No. 08-15385 JP 2010-109304 A

  The present invention has been made in view of the above-described problems, and when the material decreases, the flow rate of the carrier gas increases at an accelerated pace in accordance with the decrease in vaporization efficiency, so that a large amount of material remains. Nevertheless, it is possible to provide a material gas control device that can prevent the valve from being fully opened at an early point, for example.

  That is, the material gas control device of the present invention includes a container in which a material is stored, an introduction pipe for introducing a carrier gas for vaporizing the material into the container, and the carrier gas and the material from the container. A material gas control device used in a material vaporization device comprising at least a lead-out pipe for deriving a gas mixture of vaporized material gas, wherein the material gas control device determines a concentration of the material gas in the gas mixture A concentration measuring mechanism for measuring and an opening degree of the first valve provided in the outlet pipe are controlled, and the measured concentration of the material gas measured by the concentration measuring mechanism is set to a set concentration. A first valve controller for controlling the opening of one valve, and an opening of a second valve provided in the introduction pipe, wherein the opening of the first valve is changed from a fully opened position to a first position. Place When the threshold opening is a small opening, the opening of the second valve is changed within a predetermined time from the opening before change when the opening of the first valve becomes the threshold opening. And a second valve control unit that controls the opening after change to be larger by a second predetermined value.

  In addition, the material gas control system of the present invention includes a container in which a material is stored, an introduction pipe for introducing a carrier gas for vaporizing the material into the container, and the carrier gas and the material from the container. A deriving tube for deriving the mixed gas of the material gas vaporized, a first valve provided in the deriving tube, a concentration measuring mechanism for measuring the concentration of the material gas in the mixed gas, and the concentration measuring mechanism A first valve control unit that controls the opening of the first valve so that a measured concentration of the material gas to be measured is a preset concentration, a second valve provided in the introduction pipe, When the opening degree of the first valve becomes a threshold opening degree that is an opening degree that is smaller by a first predetermined value than the opening degree of the fully opened state, the opening degree of the second valve is set to the opening degree of the first valve within a predetermined time. Degree became the threshold opening And a second valve control unit that controls the opening after the change by a second predetermined value greater than the opening before the change at the time.

  Furthermore, the material gas control method of the present invention includes a container in which a material is stored, an introduction pipe for introducing a carrier gas for vaporizing the material into the container, and the carrier gas and the material from the container. A material gas control method using a material gas control device used in a material vaporization device comprising at least a lead-out pipe for deriving a gas mixture of vaporized material gas, wherein the material gas control device includes at least the material gas control device A concentration measuring mechanism for measuring a concentration of the material gas in the mixed gas, wherein the material gas control method is a step of controlling an opening degree of the first valve provided in the outlet pipe, and is measured by the concentration measuring mechanism; A first valve control step for controlling the opening of the first valve so that the measured concentration of the material gas to be set becomes a set concentration, and a second valve provided in the introduction pipe. The second valve is controlled within a predetermined time when the opening of the first valve reaches a threshold opening that is smaller by a first predetermined value than the fully opened opening. A second valve control step for controlling the opening of the first valve so that the opening after the change is larger by a second predetermined value than the opening before the change at the time when the opening of the first valve becomes the threshold opening. It is characterized by providing.

  In addition, the material gas control program of the present invention includes a container in which a material is stored, an introduction pipe for introducing a carrier gas for vaporizing the material into the container, the carrier gas from the container, and the carrier gas. A material gas control program for controlling a material gas control device used in a material vaporization device comprising at least a lead-out pipe for deriving a mixed gas of material gas vaporized from the material, wherein the material gas control device comprises: A concentration measuring mechanism for measuring at least the concentration of the material gas in the mixed gas, wherein the material gas control program controls the opening of the first valve provided in the outlet pipe, and the concentration measuring mechanism Provided in the introduction pipe, and a first valve control unit that controls the opening degree of the first valve so that the measured concentration of the material gas measured by the step becomes a set concentration. The opening of the second valve is controlled, and when the opening of the first valve becomes a threshold opening that is an opening smaller than the fully opened opening by a first predetermined value, within a predetermined time. Second valve control for controlling the opening degree of the second valve so that the opening degree after the change is larger by a second predetermined value than the opening degree before the change when the opening degree of the first valve reaches the threshold opening degree. And a section.

  In such a case, the concentration of the material gas in the mixed gas is continuously controlled by the first valve provided in the outlet pipe, the material in the container is reduced, and the vaporization efficiency of the material is reduced. When the first valve is fully open or close to full open, the opening of the second valve provided in the introduction pipe is controlled to be large. For this reason, when the first valve is close to the control limit, the flow rate of the carrier gas is increased and the amount of material vaporization is increased. It will return to the center side. As described above, the flow rate of the carrier gas is increased stepwise each time the first valve reaches a threshold opening that is fully open or close to full open. Thus, the flow rate of the carrier gas increases at an accelerating rate, and it is possible to prevent a situation in which control is impossible even though a large amount of material remains. In other words, the measured concentration can be kept constant at the set concentration until the material in the container is fully used.

  The above-described effects can be realized by adding a minimum necessary new configuration while using the existing material vaporizer equipment, for example, a valve provided in advance in the introduction pipe as the second valve. Includes a container in which a material is accommodated, an introduction pipe for introducing a carrier gas for vaporizing the material into the container, and a mixed gas of the carrier gas and the material gas in which the material is vaporized from the container A material gas control device used in a material vaporization device having at least a lead-out pipe for derivation, wherein the material gas control device measures a concentration of the material gas in the mixed gas, and the derivation And a first valve that controls the opening of the first valve so that the measured concentration of the material gas measured by the first valve provided in the tube and the concentration measuring mechanism becomes a set concentration. The control unit controls the opening degree of the second valve provided in the introduction pipe, and the opening degree of the first valve is a threshold opening degree that is smaller than the fully opened opening degree by a first predetermined value. In this case, the opening degree of the second valve is changed within a predetermined time by a second predetermined value larger than the opening degree before the change when the opening degree of the first valve becomes the threshold opening degree. A material gas control device including a second valve control unit that controls to be

  In order to prevent the change in the flow rate of the carrier gas from becoming abrupt when the opening degree of the second valve is changed and to keep the measured concentration constant at the set concentration even during the change period, the second valve The valve control unit may be configured so as to control the opening of the second valve so as to increase substantially in proportion to the time from the opening before the change to the opening after the change. .

  By increasing the amount of carrier gas introduced into the container in accordance with the amount of decrease in vaporization efficiency due to the decrease in material, the first valve can be moved from a threshold opening to an opening that can move sufficiently. In order to return and maintain a constant concentration without adding material for a long period of time, the second predetermined value is changed according to the number of times the first valve has reached the threshold opening. Anything is acceptable.

  As a specific configuration for setting the opening degree of the second valve according to the flow rate of the carrier gas so that the concentration control can be performed more strictly in accordance with the lowering of the vaporization efficiency, it flows through the introduction pipe. A flow rate measuring sensor for measuring the flow rate of the carrier gas is further provided, and the measured flow rate of the carrier gas measured by the second valve control unit based on the flow rate measuring sensor is the set flow rate. An opening degree control unit for controlling the opening degree of the second valve, and a flow rate setting unit for setting the set flow rate in the opening degree control unit, wherein the flow rate setting unit opens the first valve. When the degree becomes the threshold opening, the set flow rate is changed by α times (α> 1) larger than the set flow before change at the time when the opening degree of the first valve becomes the threshold opening. Set the set flow rate to the opening control section The thing comprised so that may be mentioned.

  In the case where the concentration of the material gas in the mixed gas is controlled by sequentially controlling the flow rate of the carrier gas, the flow rate of the carrier gas increases at an accelerated rate even if the material in the container is reduced and the vaporization efficiency is reduced. In order to prevent loss of control in a short period of time, a container in which a material is stored, an introduction pipe for introducing a carrier gas for vaporizing the material into the container, the carrier gas from the container and the carrier gas A material gas control device used in a material vaporization apparatus having at least a lead-out pipe for deriving a mixed gas of material gas vaporized from the material, wherein the material gas control device controls a flow rate of the material gas in the mixed gas. A flow rate measuring mechanism for measuring, and an opening degree of the second valve provided in the introduction pipe, and measuring a material gas measured by the flow rate measuring mechanism A second valve control unit for controlling the opening of the second valve so that the amount becomes a preset flow rate, and the opening of the first valve provided in the outlet pipe; When the opening degree of the second valve reaches a threshold opening degree that is an opening degree that is smaller by a first predetermined value than the opening degree that is fully open, the opening degree of the first valve is set within a predetermined time. A material gas control, comprising: a first valve control unit that performs control so that the opening after the change is larger by a second predetermined value than the opening before the change when the opening reaches the threshold opening. Any device may be used. In such a case, even if the material in the container is reduced and the vaporization efficiency is lowered, the total pressure in the container is set low by the second valve accordingly, and the first valve is again in the movable range. Since it returns to the inside, it is possible to prevent a situation where concentration control cannot be performed even if a large amount of material remains.

  Further, as another aspect of the material gas control device described above, a container in which a material is accommodated, an introduction pipe for introducing a carrier gas for vaporizing the material into the container, and the carrier from the container An outlet tube for deriving a mixed gas of the gas and the material gas vaporized from the material, a flow rate measuring mechanism for measuring a flow rate of the material gas in the mixed gas, and an opening degree of the second valve provided in the introduction tube A second valve control unit that controls the opening of the second valve so that the measured flow rate of the material gas measured by the flow rate measurement mechanism becomes a preset set flow rate. A material gas control device used in at least a material vaporization device, wherein the material gas control device controls an opening degree of a first valve provided in the outlet pipe, and opens the second valve. Is a threshold opening which is an opening smaller by a first predetermined value than a fully opened opening, the opening of the first valve is set within a predetermined time, and the opening of the second valve is set to the threshold opening. The material gas control device may include a first valve control unit that performs control so that the opening after the change is increased by a second predetermined value from the opening before the change at that time.

  As described above, according to the material gas control device of the present invention, even if the vaporization efficiency is lowered due to the reduction of the material in the container, the concentration of the second valve is greatly changed by gradually changing the opening degree of the second valve. The opening degree of the first valve performing the control can be kept within the movable range over a long period of time. Therefore, it is possible to prevent a situation where the vaporization efficiency is accelerated and the concentration control is disabled despite a large amount of material remaining.

The schematic diagram which shows the outline | summary of the material gas control system which concerns on 1st Embodiment of this invention. The typical fluid circuit diagram and functional block diagram which show the material gas control system which concerns on 1st Embodiment. The flowchart which shows operation | movement of the material gas control system which concerns on 1st Embodiment. The graph which shows the change of the opening degree of each valve | bulb in the material gas control system which concerns on 1st Embodiment. The schematic diagram which shows the outline | summary of the material gas control system which concerns on 2nd Embodiment of this invention. The typical fluid circuit diagram and functional block diagram which show the material gas control system which concerns on 2nd Embodiment. The typical fluid circuit diagram and functional block diagram which show the material gas control system which concerns on 3rd Embodiment. The graph which shows operation | movement of the 2nd valve | bulb in other embodiment of this invention. The schematic diagram which shows the outline | summary of the conventional material gas control system.

  Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

  For example, the material gas control apparatus 100 of this embodiment is used to supply TMIn (trimethylindium) at a constant concentration and flow rate to an MOCVD film forming apparatus which is a kind of semiconductor manufacturing apparatus. More specifically, it is used in a material vaporizer 200 that vaporizes a solid material of TMIn and supplies it to a chamber that is a film forming chamber. TMIn corresponds to the material in the claims. Further, a material gas control system 300 is formed by combining the material gas control device 100 and the material vaporization device 200.

  As shown in the schematic diagram of FIG. 1, the material vaporization apparatus 200 contains a material to be vaporized therein and is surrounded by a thermostatic bath, and a carrier gas is introduced into the bottle T. An introduction pipe L1 and a lead-out pipe L2 for leading a mixed gas of the material gas vaporized from the bottle T and the carrier gas are provided. The material gas control apparatus 100 is configured by providing various component parts and a control mechanism for the material vaporization apparatus 200.

  More specifically, as shown in FIG. 1, the material gas control device 100 is led out from the mass flow controller 3 provided in the introduction pipe L1, the piezo valve 1 provided in the lead-out pipe L2, and the bottle T. By measuring the concentration of the material gas in the mixed gas and controlling the mass flow controller 3 and the piezo valve 1 so as to keep the concentration of the material gas constant, the gas concentration that keeps the flow rate of the material gas constant as a result. The monitor 2 is constituted.

  Each part will be described. As shown in the detailed view of FIG. 2, the mass flow controller 3 has an internal flow path that is a part of the introduction pipe L1, for example, formed in a block-shaped basic body, and on the internal flow path. A flow rate measurement sensor 31 for measuring the flow rate of the carrier gas flowing through the introduction pipe L1, and a flow rate control valve 32 for controlling the flow rate of the fluid passing through the internal flow path (corresponding to the second valve in the claims) And a flow rate control valve opening degree control unit 33 for controlling the opening degree of the flow rate control valve 32 so that the measured flow rate of the carrier gas measured by the flow rate measurement sensor 31 becomes a set flow rate. It is equipped with. The function of the flow control valve opening control unit 33 is realized by a microcomputer or the like provided in the mass flow controller 3.

  The piezo valve 1 is configured such that a fine opening degree can be adjusted by a piezo element, and the opening degree is controlled by a piezo valve control unit 24 described later.

  The gas concentration monitor 2 controls the concentration measuring mechanism CS for measuring the concentration of the material gas in the mixed gas in the outlet pipe L2, the mass flow controller 3, and the piezo valve 1 to control the flow rate of the material gas. And a flow rate control unit CC for controlling.

The concentration measuring mechanism CS is provided on the outlet pipe L2, and measures the partial pressure sensor 21 that measures the partial pressure of the material gas in the mixed gas, and the total pressure that is the pressure of the mixed gas in the bottle T. a pressure gauge 22, are composed of a concentration calculator 23 that calculates the concentration of the material gas on the basis of the total pressure P _t of the mixed gas with the partial pressure P _v of the material gas. The partial pressure sensor 21 may be NDIR (non-dispersive infrared analysis), FTIR (Fourier transform infrared spectroscopy), laser absorption spectroscopy, or the like. Further, the concentration calculation unit 23 calculates the measured concentration of the material gas based on the equation where the concentration C is C = Pv / Pt. Note that the concentration measurement mechanism CS may be a device that can measure the concentration of the material gas by itself using an ultrasonic gas concentration sensor or the like.

  The flow rate controller CC is a piezo valve controller 24 that controls the opening of the piezo valve 1 so that the measured concentration of the material gas measured by the concentration measuring mechanism CS becomes a set concentration. And a carrier gas flow rate setting unit 25 that sets a set flow rate of the carrier gas for the flow rate control valve opening degree control unit 33 in the mass flow controller 3. The function of the flow rate control unit CC is also realized by a microcomputer in the gas concentration monitor 2, for example. 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 in the claims.

The piezo valve control unit 24 controls the opening of the piezo valve 1 in such a direction that the deviation between the measured concentration of the material gas and the set concentration becomes smaller. More specifically, as is clear from the equation C = P _v / P _t , if the set concentration is set to be constant, the amount of material gas generated decreases and the partial pressure P _v decreases. when it becomes, it is necessary to reduce the value of the total pressure P _t accordingly. That is, the piezo valve control unit 24 sets the opening degree of the piezo valve 1 so that the total pressure P _t in the bottle T is decreased when the measured concentration is lower than the set concentration (the partial pressure P _t is decreased). In addition to being largely controlled, the opening degree of the piezo valve 1 is reduced when the measured concentration rises above the set concentration. Further, the set concentration may be directly set, but in this embodiment, when the flow rate of the material gas to be flowed into the outlet pipe L2 is input by the user, the set concentration is calculated from the set flow rate of the material gas. It is supposed to be converted. Specifically, when the set concentration is C ₀ , the set flow rate of the material gas is Q _v0 , and the set flow rate of the carrier gas is Q _c0 , it is converted from C ₀ = Q _v0 / (Q _c0 + Q _v0 ). A carrier gas flow rate setting unit 25 (described later) is configured so that the set concentration C ₀ set in the piezo valve control unit 24 is also set again each time the set flow rate of the carrier gas is changed. Has been.

  The carrier gas flow rate setting unit 25 sets the flow rate control valve opening control unit 33 when the opening of the piezo valve 1 reaches a threshold opening that is an opening smaller than the fully opened opening by a first predetermined value. The set flow rate is configured to be set to the set flow rate after change that is larger by α times (α> 1) than the pre-change set flow rate when the opening degree of the piezo valve 1 becomes the threshold opening degree. Note that the first predetermined value is a concept including zero, and in the first embodiment, the threshold opening is a fully open opening. The carrier gas flow rate setting unit 25 may detect the opening of the piezo valve 1 based on the command value, current value, or the like input to the piezo valve 1. The degree may be detected.

  The material gas flow rate control operation of the material gas control apparatus 100 configured as described above will be described with reference to the flowchart of FIG.

First, after a predetermined carrier gas set flow rate Q _v0 is set in the mass flow controller 3, the flow control of the carrier gas is started, and the measured flow rate of the carrier gas is fixed to the set flow rate. Then, the opening degree of the piezo valve 1 is controlled by the gas concentration monitor 2 so that the measured concentration becomes the above-mentioned predetermined concentration C ₀ (step S1). Since the piezo valve 1 is controlled so that the flow rate of the carrier gas is constant and the concentration of the material gas in the mixed gas is constant, as a result, the material gas flow rate Q _v is a concentration relational expression Q _v = CQ _c. As is clear from / (1-C), control is constant. Here, the carrier gas set flow rate Q _c0 at the time of initial setting is set to be a small opening sufficiently separated from the fully opened opening of the flow control valve 32.

Next, as the material in the bottle T decreases, the opening degree of the piezo valve 1 gradually increases as the vaporization efficiency decreases (step S2). When the opening degree of the piezo valve 1 reaches a fully open opening degree that is a threshold opening degree (step S3), the carrier gas flow rate setting unit 25 sets the carrier gas flow rate to the flow rate control valve opening degree control unit 33. The set flow rate is reset to α times (step S4). Here, when the set flow rate of the carrier gas is reset to α times, the set concentration C0 set in the piezo valve control unit 24 is also updated. Specifically, since the material gas set flow rate Q _v0 is kept constant, _assuming a new set concentration C ₀ ′, C ₀ ′ = Q _v0 / (Q _v0 + αQ _c0 ) becomes the carrier gas set flow rate Q After setting _c0 again, the set concentration is used by the piezo valve control unit 24.

  When the measured flow rate matches the changed set flow rate within a predetermined time (step S5), the carrier gas flow rate setting unit 25 determines that the opening degree of the flow rate control valve 32 is as a result from the pre-change opening degree. The changed opening is increased by a second predetermined value, and this state is maintained, and the process returns to step S2. If the measured flow rate does not match the set flow rate after the change even after a predetermined time has elapsed (step S5), it is determined that the flow rate control valve 32 is fully open and is at the control limit, and the concentration by the gas concentration monitor 2 is determined. Control is terminated (step S6).

  Accordingly, when attention is paid to the concentration control in sequence, as shown in the graph showing the opening degree of the flow rate control valve 32 and the piezo valve 1 in FIG. 4, the opening degree of the piezo valve 1 for controlling the concentration of the material gas in the mixed gas is the first. In order to increase the total pressure in the bottle T from the fully open state to increase the total pressure in the bottle T, and then to decrease the total pressure in accordance with the decrease in vaporization efficiency, the opening gradually increases and is fully opened. 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 kept at a substantially constant opening degree. Then, when the opening degree of the piezo valve 1 is fully opened, the opening degree is increased by a second predetermined value.

  Since the above-described operation is repeated a plurality of times as one cycle, the opening degree of the piezo valve 1 changes in a substantially sine wave shape as shown in FIG. 4, and the opening degree of the flow rate control valve 32 is It will change to a step-like function. The reason why the period becomes shorter as the subsequent period is reached is that the amount of decrease in the vaporization efficiency of the material increases as the remaining amount of the material decreases.

  In this way, each time the piezo valve 1 is fully opened, the flow rate control valve 32 is controlled so that the flow rate of the carrier gas flowing into the bottle T increases stepwise, so that the material is reduced and the vaporization efficiency is improved. Even if it decreases, it is possible to prevent the flow rate of the carrier gas from increasing at an accelerated rate. Therefore, it is possible to prevent an uncontrollable state in which the concentration or flow rate of the material gas cannot be set to the desired concentration or flow rate even though the amount of the material is excessive. It becomes possible to supply a material gas having a set concentration.

  Next, the material gas control apparatus 100 of 2nd Embodiment is demonstrated. In addition, the same code | symbol shall be attached | subjected to the member corresponding to the material gas control apparatus 100 of 1st Embodiment.

  Unlike the first embodiment, the material gas control apparatus 100 of the second embodiment does not control the operation of the mass flow controller 3 and the piezo valve 1 by the gas concentration monitor 2 as shown in the schematic diagram of FIG. It is designed to be controlled centrally by a separate control mechanism. That is, the gas concentration monitor 2 in the first embodiment has at least two components, that is, the concentration measurement mechanism CS and the flow rate controller CC. However, in the second embodiment, only the function as the concentration measurement mechanism CS is provided. The flow rate control unit CC has its function realized in the control device 4.

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

  More specifically, as shown in the detailed view of FIG. 6, the control device 4 instructs the mass flow controller 3 to flow a carrier gas at a constant flow rate, and the gas concentration monitor 2. The measured concentration, which is the concentration of the material gas in the mixed gas, is obtained, and the opening degree of the piezo valve 1 is controlled so that the measured concentration becomes the set concentration. Then, when the opening degree of the piezo valve 1 is fully opened, the control device 4 instructs the mass flow controller 3 to increase the flow rate of the carrier gas by a predetermined amount. Then, since the amount of material vaporization increases, the opening degree of the piezo valve 1 returns to the movable range, and the concentration can be controlled again. This operation is repeated until the opening degree of the flow control valve 32 in the mass flow controller 3 is fully opened and the measured concentration cannot be matched with the set concentration.

  As described above, the control unit may be provided in each unit as in the first embodiment, or the concentration and flow rate may be controlled centrally by a computer or the like as in the second embodiment. Absent.

  Next, the material gas control apparatus 100 of 3rd Embodiment is demonstrated. Also in the third embodiment, the same reference numerals are assigned to members corresponding to the material gas control apparatus 100 of the first embodiment.

  In the third embodiment, a valve that sequentially changes its opening degree for the material gas concentration and a valve whose opening degree is substantially fixed until one of the valves reaches the threshold opening degree, The difference is that the material gas control apparatus 100 of the first embodiment and the second embodiment is reversed. Except for this point, the arrangement of the mass flow controller 3, the gas concentration monitor 2, and the piezo valve 1 is the same.

  Explaining each part, as shown in the detailed view of FIG. 7, the mass flow controller 3 obtains the measured concentration of the material gas concentration from the gas concentration monitor 2 provided in the outlet pipe L2, and the carrier gas currently flowing The flow rate of the carrier gas is calculated from the flow rate of the gas and the measured concentration, and the flow rate of the carrier gas is controlled so that the measured flow rate of the material gas becomes a predetermined set flow rate. More specifically, when the measured flow rate of the material gas decreases, the mass flow controller 3 increases the internal flow rate control valve 32 (in the claims) so as to increase the flow rate of the carrier gas in order to vaporize more material. Is equivalent to the second valve).

  The gas concentration monitor 2 acquires information related to the opening degree of the flow control valve 32, and when the flow control valve 32 is fully opened, the piezo valve 1 (corresponding to the first valve in the claims) is opened. The degree is greatly changed by a second predetermined amount. That is, every time the opening degree of the flow control valve 32 is fully opened, the piezo valve 1 operates so as to reduce the total pressure in the bottle T. When the total pressure of the mixed gas is reduced, even if the generation amount of the material gas is reduced and the partial pressure of the material gas is reduced, the concentration of the material gas can be maintained at the set concentration. The opening degree of the valve 32 returns from the fully open position to the movable range. Accordingly, it is possible to continue the concentration control while keeping the concentration of the material gas at the set concentration again, and it is possible to prevent the occurrence of an uncontrollable situation despite the remaining material from occurring at an early stage. . Moreover, this embodiment may also be implemented using a valve, a concentration monitor, or the like provided in an existing material vaporizer. Specifically, a second valve is provided in the introduction pipe of the material vaporizer, and further a flow rate measuring mechanism that measures the flow rate of the material gas, and a second valve that controls the second valve based on the measured flow rate. If the control unit already exists, a new first valve is provided in the outlet pipe, and the opening information of the second valve is acquired, and when the threshold opening is reached, the first valve is opened. A first valve control unit that changes the degree by a predetermined amount may be provided.

  Other embodiments will be described. The opening of the flow control valve in the mass flow controller is controlled so as to change into a complete step function, and within a predetermined time, a second predetermined value between the opening before the change and the opening after the change. As long as it is controlled so that only a difference is produced. That is, an appropriate complement may be performed between the opening before change and the opening after change. For example, as shown in FIG. 8A, the opening degree of the second valve increases substantially in proportion to time until the second valve control unit reaches the opening degree after the change from the opening degree before the change. As long as it is configured so as to be controlled. Further, in order to make the rate of change of the opening degree gradual and to stabilize quickly at a desired set concentration, an S-shape is complemented between the openings as shown in FIG. It doesn't matter.

  In the above embodiment, the threshold opening is set as the fully open position for the opening of the piezo valve provided in the outlet pipe, and the opening of the flow control valve is changed step by step when the piezo valve is fully opened. However, the threshold opening is not limited to the fully open opening. For example, an opening that is smaller than the fully opened opening by a first predetermined value may be provided as a threshold opening. As the first predetermined value, for example, the threshold opening may be determined to be an opening between a central opening and a fully opened opening in the movable range of the piezo valve. If it is such, since density | concentration control can be performed, keeping the state of vaporization efficiency with material gas for a sufficiently long time, the acceleration | stimulation deterioration of vaporization efficiency can be prevented.

  In addition, the opening degree of the flow control valve is set to increase stepwise by substantially the same amount every time in the embodiment, but for example, the second opening which is the difference between the opening degree before change and the opening degree after change. The predetermined value may be changed according to the number of times the first valve has reached the threshold opening. More specifically, as shown in FIG. 8C, the second predetermined value is increased as the first valve is increased in threshold opening degree and the number of times, and a sufficient amount according to the decrease in the vaporization efficiency. The material gas may be obtained.

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

  In the material gas control device of each embodiment, not the mass flow controller but only the flow control valve (second valve) is provided in the introduction pipe, and the opening degree of the first valve provided in the outlet pipe is fully opened. When the threshold opening is smaller than the first opening by the first predetermined value, the opening of the second valve is changed to the threshold opening within the predetermined time. It is only necessary that the second valve control unit that controls the opening degree after the change by the second predetermined value to be larger than the opening degree before the change at the time point is configured in the gas concentration monitor or the control device.

  The material gas control apparatus of each embodiment can produce the same effect even if the material is a liquid material. Further, the material gas control device of the present invention is not limited to the concentration control of the material gas in which the TMIn solid is vaporized. For example, it can also be used to stably supply an IPA (isopropyl alcohol) concentration in a drying treatment tank of a CVD film forming apparatus or the like or a wafer cleaning apparatus used in a semiconductor manufacturing process. In addition, the present invention is not limited to manufacturing processes of semiconductors, FPDs, optical devices, MEMS, and the like, and can be used for gas supply apparatuses using a material vaporizer.

  Moreover, you may implement this invention using the existing material vaporizer, the valve | bulb currently used there, etc. For example, when the material vaporizer is provided with a second valve in advance, the material gas control includes the first valve, the concentration measurement mechanism, the first valve control unit, and the second valve control unit. A material gas control system may be configured by adding a device to the material vaporizer. In addition, a material gas control program that functions as the first valve control unit and the second valve control unit is installed in the concentration monitor or control device so that the concentration or flow rate control as described above is performed. It doesn't matter. Further, such a program may be installed via a network, or may be performed via a recording medium such as a CD in which a material gas control program is recorded.

  In each of the above embodiments, the flow rate of the material gas is controlled based on the concentration. However, the flow rate of directly measuring the flow rate of the material gas, not using the concentration measurement mechanism that measures the concentration of the material gas in the mixed gas. You may comprise a material gas control apparatus and a material gas control system using a measurement mechanism. For example, the carrier gas flow rate in the introduction pipe and the mixed gas flow rate in the outlet pipe may be measured, and the material gas flow rate may be measured from the difference therebetween.

  In addition, various modifications and combinations of embodiments may be performed without departing from the spirit of the present invention.

300 ... Material gas control system 200 ... Material vaporizer L1 ... Introducing pipe L2 ... Outlet pipe T ... Bottle (container)
100 ... Material gas control device 1 ... Piezo valve (first valve)
CS: concentration measuring mechanism 24: piezo valve control unit (first valve control unit or second valve control unit)
25 ... Flow rate setting unit 31 ... Flow rate measuring sensor 32 ... Flow rate control valve (second valve)
33... Opening control unit

Claims (10)

A container in which the material is accommodated, an introduction pipe for introducing a carrier gas for vaporizing the material into the container, and a mixed gas of the carrier gas and the material gas in which the material is vaporized is derived from the container. A material gas control device for use in a material vaporizer comprising at least a lead-out pipe for
A concentration measuring mechanism for measuring a concentration of the material gas in the mixed gas by the material gas control device;
The opening degree of the first valve provided in the outlet pipe is controlled, and the opening degree of the first valve is controlled so that the measured concentration of the material gas measured by the concentration measuring mechanism becomes a set concentration. A first valve control unit,
When the opening degree of the second valve provided in the introduction pipe is controlled, and the opening degree of the first valve becomes a threshold opening degree which is an opening degree that is smaller by a first predetermined value than the opening degree of full opening. The opening of the second valve is set to a post-change opening that is larger by a second predetermined value than the pre-change opening at the time when the opening of the first valve reaches the threshold opening within a predetermined time. And a second valve control unit for controlling the material gas control device.   The second valve control unit controls the second valve so that the opening degree of the second valve becomes substantially proportional to time until the opening degree before the change becomes the opening degree after the change. The material gas control apparatus according to claim 1 or 2, wherein the material gas control apparatus is configured.   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 has reached a threshold opening. The second valve control unit controls the opening degree of the second valve so that the measured flow rate of the carrier gas measured by a flow rate measuring sensor for measuring the flow rate of the carrier gas flowing through the introduction pipe becomes a set flow rate. An opening control unit for controlling, and a flow rate setting unit for setting the set flow rate in the opening control unit,
When the opening degree of the first valve reaches the threshold opening degree, the flow rate setting unit sets the setting flow rate as a pre-change setting flow rate when the opening degree of the first valve reaches the threshold opening degree. 4. The material gas control device according to claim 1, 2, or 3, wherein the changed set flow rate that is larger by α times (α> 1) is set in the opening degree control unit. A container in which the material is accommodated, an introduction pipe for introducing a carrier gas for vaporizing the material into the container, and a mixed gas of the carrier gas and the material gas in which the material is vaporized is derived from the container. A material gas control device for use in a material vaporizer comprising at least a lead-out pipe for
A concentration measuring mechanism for measuring a concentration of the material gas in the mixed gas by the material gas control device;
A first valve provided in the outlet pipe;
A first valve control unit that controls the opening of the first valve so that the measured concentration of the material gas measured by the concentration measuring mechanism becomes a set concentration;
When the opening degree of the second valve provided in the introduction pipe is controlled, and the opening degree of the first valve becomes a threshold opening degree which is an opening degree that is smaller by a first predetermined value than the opening degree of full opening. The opening of the second valve is set to a post-change opening that is larger by a second predetermined value than the pre-change opening at the time when the opening of the first valve reaches the threshold opening within a predetermined time. And a second valve control unit for controlling the material gas control device. A container in which the material is accommodated, an introduction pipe for introducing a carrier gas for vaporizing the material into the container, and a mixed gas of the carrier gas and the material gas in which the material is vaporized is derived from the container. A material gas control method using a material gas control device used in a material vaporization device comprising at least a lead-out pipe for
The material gas control device comprises a concentration measurement mechanism for measuring at least the concentration of the material gas in the mixed gas,
The material gas control method is a step of controlling an opening degree of a first valve provided in the outlet pipe, and the measurement concentration of the material gas measured by the concentration measurement mechanism is set to a set concentration. A first valve control step for controlling the opening of one valve;
When the opening degree of the second valve provided in the introduction pipe is controlled, the opening degree of the first valve becomes a threshold opening degree that is an opening degree that is smaller by a first predetermined value than the opening degree of the fully open state. The opening of the second valve is set to a post-change opening that is larger by a second predetermined value than the pre-change opening at the time when the opening of the first valve reaches the threshold opening within a predetermined time. And a second valve control step for controlling the material gas control method. A container in which the material is accommodated, an introduction pipe for introducing a carrier gas for vaporizing the material into the container, and a mixed gas of the carrier gas and the material gas in which the material is vaporized is derived from the container. A material gas control program for controlling a material gas control device used in a material vaporizer comprising at least a lead-out pipe for
The material gas control device comprises a concentration measurement mechanism for measuring at least the concentration of the material gas in the mixed gas,
The material gas control program controls the opening degree of the first valve provided in the outlet pipe, and the first concentration is measured so that the measured concentration of the material gas measured by the concentration measuring mechanism becomes a set concentration. A first valve controller for controlling the opening of the valve;
When the opening degree of the second valve provided in the introduction pipe is controlled, and the opening degree of the first valve becomes a threshold opening degree which is an opening degree that is smaller by a first predetermined value than the opening degree of full opening. The opening of the second valve is set to a post-change opening that is larger by a second predetermined value than the pre-change opening at the time when the opening of the first valve reaches the threshold opening within a predetermined time. A material gas control program comprising: a second valve control unit for controlling. A container in which the material is stored;
An introduction pipe for introducing a carrier gas for vaporizing the material into the container;
An outlet tube for deriving a mixed gas of the carrier gas and the material gas in which the material is vaporized from the container;
A first valve provided in the outlet pipe;
A concentration measuring mechanism for measuring the concentration of the material gas in the mixed gas;
A first valve control unit that controls the opening degree of the first valve so that the measured concentration of the material gas measured by the concentration measuring mechanism becomes a preset concentration;
A second valve provided in the introduction pipe;
When the opening degree of the first valve becomes a threshold opening degree that is an opening degree that is smaller by a first predetermined value than the opening degree that is fully open, the opening degree of the second valve is set within a predetermined time. A material gas control, comprising: a second valve control unit configured to control the opening after the change by a second predetermined value greater than the opening before the change when the opening reaches the threshold opening. system. A container in which the material is accommodated, an introduction pipe for introducing a carrier gas for vaporizing the material into the container, and a mixed gas of the carrier gas and the material gas in which the material is vaporized is derived from the container. A material gas control device for use in a material vaporizer comprising at least a lead-out pipe for
A material gas control device for measuring a flow rate of the material gas in the mixed gas;
The opening of the second valve provided in the introduction pipe is controlled, and the second valve is controlled so that the measured flow rate of the material gas measured by the flow rate measurement mechanism becomes a preset set flow rate. A second valve control unit for controlling the opening;
When the opening degree of the first valve provided in the outlet pipe is controlled, and the opening degree of the second valve becomes a threshold opening degree that is smaller than the fully opened degree by a first predetermined value. The opening of the first valve within a predetermined time is set to a post-change opening that is larger by a second predetermined value than the pre-change opening at the time when the opening of the second valve reaches the threshold opening. A material gas control device comprising: a first valve control unit for controlling. A container in which the material is accommodated, an introduction pipe for introducing a carrier gas for vaporizing the material into the container, and a mixed gas of the carrier gas and the material gas in which the material is vaporized is derived from the container. And a flow rate measuring mechanism for measuring the flow rate of the material gas in the mixed gas, and an opening degree of the second valve provided in the introduction pipe, and is measured by the flow rate measuring mechanism. A material gas control device used in a material vaporizer comprising at least a second valve control unit for controlling an opening degree of the second valve so that a measured flow rate of the material gas becomes a preset flow rate set in advance. And
The material gas control device controls the opening degree of the first valve provided in the outlet pipe, and the threshold value is such that the opening degree of the second valve is smaller by the first predetermined value than the fully opened opening degree. When the opening is reached, the opening of the first valve is changed within a predetermined time by a second predetermined value larger than the opening before the change when the opening of the second valve reaches the threshold opening. A material gas control device comprising: a first valve control unit that controls the opening degree.