JP2006319207A - Flow rate control device and method, and thin film deposition device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flow rate control device, a thin film deposition device, and a flow rate control method, which can exactly control gas flow at a set flow rate even in environment of large pressure difference, especially, remarkably improve process accuracy in a process of thin film deposition. <P>SOLUTION: The flow rate control device has an on/off valve 14 which turns on/off gas flow, a flow rate adjuster 12 which is disposed upstream of the on/off valve 14 and adjusts a gas flow rate, and an inner pressure adjuster 13 which adjusts an inner pressure P<SB>3</SB>so that the inner pressure P<SB>3</SB>upstream of the on/off valve 14 is equal to a pressure Pc downstream of the on/off valve 14 with the on/off valve 14 closed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a flow rate control device, a thin film deposition device, and a flow rate control method, and, for example, relates to a flow rate control device, a thin film deposition device, and a flow rate control method used in semiconductor manufacturing.

  FIG. 6 is a diagram showing the configuration of a thin film deposition apparatus 90 conventionally used for depositing a predetermined thin film on the surface of a semiconductor substrate by chemical vapor deposition (CVD: Chemical Vapour Deposition). In FIG. 6, 91 is a chamber, 91 a is a main body of the chamber 91, 91 b is an upper plate provided at the upper part of the chamber, 92 is a substrate support provided below the inside of the chamber 91, and 93 is provided on the substrate support 92. The semiconductor substrate 94 mounted on the upper surface 91b is a plurality of nozzles arranged at equal intervals on the lower surface side of the upper plate 91b so as to divide the circumference of the chamber 91 equally.

  Also, 95 is a gas supply pipe for supplying gas to the plurality of nozzles 94, 95a and 95b are gas supply pipes branched on the downstream side of the gas supply pipe 95, and 95c is a plurality of gas supply pipes connected to the gas supply pipes 95a and 95b. It is a gas pipe. The nozzle 94 is connected to the downstream end of the supply pipe 95c.

96 is a gas switching unit connected to the gas supply pipe 95, 97a and 97b are gas flow paths for flowing different gases, and 98 is a gas box. The gas box 98 includes mass flow controllers 98a and 98b for controlling the flow rate of the gas flowing through the gas flow paths 97a and 97b. The gas switching unit 96 is configured to selectively select the gas flowing through the gas flow paths 97a and 97b and to flow to the gas supply pipe 95. That is, in the thin film deposition apparatus 90 configured as described above, two types of gases are alternatively selected and supplied into the chamber 91 from the plurality of nozzles 94, whereby a thin film can be formed on the semiconductor substrate 93.
JP 2004-327582 A

  As described above, since the gas box 98 and the chamber 91 are separately formed in the conventional thin film deposition apparatus 90, the gas flow paths 97a and 97b (gas flow paths) from the installation position of the gas box 98 to the installation position of the nozzle 94 are provided. 95, 96a to 95c) must be as long as several meters, for example, and even if the accuracy of the flow control by the mass flow controllers 98a and 98b is sufficient, the accuracy of the flow control is reflected in the accuracy of the process. There was a problem of not being.

  FIG. 7 is a diagram for explaining an example of the gas introduction process of the thin film deposition apparatus using the mass flow controllers 98a and 98b. In FIG. 7, the recipe A of the gas introduction process is a signal input to the mass flow controllers 98 a and 98 b, and as shown by the rectangular wave, the gas of the crisp gas is almost the same as the recipe A just below the gas box 98. A flow is formed. However, in the conventional thin film deposition apparatus, the flow rate B of the gas supplied from the nozzle 94 is the volume of the gas flow paths 95, 95a to 95c, 97a, 97b from the installation position of the gas box 98 to the installation position of the nozzle 94. Correspondingly, a response delay occurs, and the flow control becomes crisp. There is a concern that the deterioration of crispness may cause a decrease in process accuracy.

  Therefore, an on-off valve for intermittently flowing the gas is formed in the upstream portion 99 of the nozzle 94, and this on-off valve is controlled to open and close in accordance with the recipe A of the gas introduction process, so that at least the flow rate of the introduced gas is crisp. It is possible to control. However, even when such an on-off valve is formed, a response delay occurs in the flow rate control depending on the volume of the gas flow paths 95, 95a to 95c, 97a, 97b from the mass flow controllers 98a, 98b to the on-off valve. Therefore, it was not possible to prevent a decrease in accuracy due to this response delay.

  That is, when an opening / closing valve is provided in the upstream portion 99 of each nozzle 94, the pressure of the gas upstream from the opening / closing valve is, for example, about several Torr, whereas in the chamber 91 downstream from the opening / closing valve. The pressure difference becomes about 100 times, for example, the pressure of the gas is about tens of mTorr, and the flow rate of gas that is not controlled for the time corresponding to the response delay is supplied at the moment when the on-off valve is opened. Can be considered. That is, in FIG. 7, the supply gas flow rate C when the on-off valve is provided generates a flow Ca (hereinafter referred to as an inrush flow) into which a relatively large flow rate of gas flows when the on-off valve is opened. It is conceivable that the yield of the particles in 91 is increased and the yield is deteriorated. In order to relieve the inrush flow Ca, it is conceivable to limit the flow rate of the flowing gas by forming the flow path in the nozzle 94 narrow like a venturi. In this case, the flow rate of the gas that can be flowed by the nozzle 94 is limited. It is inevitable that you will be restricted.

  Further, when the on / off valves are formed immediately upstream of the nozzles 94, the pressure difference of about 100 times is applied to all the on / off valves with the on / off valves closed as described above. There is also a concern that an unexpected gas flow may occur due to leakage of the on-off valve.

  The present invention has been made in consideration of the above-mentioned matters, and its purpose is to accurately control the flow of gas so that the flow rate is set even in an environment where the pressure difference is large, In particular, it is to provide a flow rate control device, a thin film deposition device, and a flow rate control method capable of dramatically improving process accuracy in a thin film deposition process.

  In order to achieve the above object, the flow rate control device according to claim 1 is an on-off valve that interrupts the flow of gas, a flow rate adjusting unit that is arranged upstream of the on-off valve and adjusts the gas flow rate, And an internal pressure adjusting unit that adjusts the internal pressure so that the internal pressure on the upstream side of the on-off valve becomes equal to the pressure on the downstream side of the on-off valve with the on-off valve closed. (Claim 1). The internal pressure adjusting unit may be a pressure adjusting valve, but instead of this pressure adjusting valve, the opening degree of the nozzle upstream of the on-off valve is adjusted based on the measured value of the pressure sensor that measures the internal pressure. You may do it. Further, if necessary, a relief valve for lowering the internal pressure by exhaust may be provided. The thin film deposition apparatus is preferably contained in one package.

  At the start of gas supply, first, the flow rate of the gas is adjusted using the flow rate adjusting unit after opening the on-off valve, and at the time of shutting off the gas supply, first, the flow rate of the gas is set to 0 using the flow rate adjusting unit. A control unit for controlling the on-off valve and the flow rate adjusting unit may be provided so as to close the on-off valve.

  According to a third aspect of the present invention, a thin film deposition apparatus includes a plurality of gas supply units each including a flow rate control apparatus according to the first or second aspect and a nozzle connected to the flow rate control apparatus in an upper part of the chamber. Each gas supply unit is configured to deposit a predetermined thin film on a substrate provided in the chamber by blowing a gas uniformly or arbitrarily adjusted to an arbitrary value into the chamber. It is characterized by.

  The flow rate control method according to claim 4 is a method for controlling a state in which a gas having an arbitrarily set flow rate is allowed to flow and a state in which the gas flow is interrupted, and the gas flow is interrupted using an on-off valve. In addition, the internal pressure of the gas upstream of the on-off valve is adjusted to be equal to the external pressure downstream of the on-off valve while the gas flow is stopped.

  When flowing a gas with a set flow rate from a state where the gas is shut off, first, the gas flow rate is adjusted after opening the on-off valve, and when shutting off the gas from a state where the gas with the set flow rate is flowing, The on-off valve may be closed after adjusting the flow rate of the supplied gas to 0 (Claim 5).

  In the flow control device according to claim 1, since the internal pressure is adjusted so that the internal pressure in the gas reservoir portion on the upstream side of the on-off valve becomes equal to the pressure on the downstream side when the on-off valve is closed, When the closed on-off valve is opened next and a predetermined flow rate of gas begins to flow, there is no gas flow that enters depending on the pressure difference between the upstream side and the downstream side of the on-off valve. In addition, when the on-off valve is closed, the internal pressure is adjusted so that the internal pressure on the upstream side of the on-off valve is equal to the pressure on the downstream side, so there is a pressure difference between the upstream side and the downstream side of the on-off valve. Therefore, even if a problem that causes a leak occurs in the on-off valve, the gas flow can be reliably stopped. That is, it is possible to give high reliability to the gas flow rate control.

  It is conceivable that the internal pressure adjusting unit is a pressure adjusting valve, whereby the internal pressure can be adjusted more reliably. However, it is possible to reduce the manufacturing cost of the flow rate control device by adjusting the opening degree of the nozzle upstream of the on-off valve based on the measured value of the pressure sensor that measures the internal pressure instead of this pressure regulating valve. Good. Further, if necessary, a relief valve for lowering the internal pressure by exhaust can be provided to eliminate the pressure difference.

  By housing the flow control device in one package, the volume from the flow control valve to the on-off valve can be made as small as possible, and the response speed can be increased accordingly. However, the flow rate adjusting unit, the internal pressure adjusting unit, and the on-off valve may be separated. In any case, it is desirable to keep the responsiveness high by minimizing the volume in the flow path from the flow rate controller to the on-off valve.

  At the start of gas supply, first, the flow rate of the gas is adjusted using the flow rate adjusting unit after opening the on-off valve, and at the time of shutting off the gas supply, first, the flow rate of the gas is set to 0 using the flow rate adjusting unit. In the case where a control unit for controlling the on-off valve and the flow rate adjusting unit is provided so as to close the on-off valve (Claim 2), the gas flow that enters when the gas of a predetermined flow rate starts to flow reliably It is possible to prevent the pressure on the upstream side from becoming unnecessarily high when the on-off valve is closed.

  Since the thin film deposition apparatus according to the third aspect includes the flow rate control apparatus according to the first or second aspect, the thin film deposition apparatus does not generate a flow of gas into the chamber and gently reaches a predetermined flow rate. Therefore, it is possible to prevent the particles in the chamber from rising due to gas intrusion. In addition, since the occurrence of gas leakage can be prevented, the gas can be flowed according to the recipe of the gas introduction process, and the gas flow rate control can be highly reliable.

  The nozzle blows out the gas whose flow rate is appropriately controlled by each flow rate control device in a predetermined direction in the chamber, and does not require a restriction that causes a flow path resistance as in the past, so it is controlled by the flow rate control device. Any given flow rate of gas can be introduced into the chamber. That is, a recipe for the gas introduction process can be freely set, and a desired thin film can be deposited on the substrate in the chamber.

  The flow rate control method according to claim 4 adjusts the internal pressure of the gas upstream of the on-off valve to be equal to the external pressure downstream of the on-off valve in a state where the gas flow is stopped. Therefore, even if the on-off valve is opened when the gas flow is started from the state where the gas flow is stopped, the gas flow that rushes in is not generated. In addition, even when a problem that may cause a leak occurs in the on-off valve when the gas flow is stopped, it is possible to reliably prevent the closed gas from flowing, so that the gas flow rate control is high. Reliability can be given.

  When flowing a gas with a set flow rate from a state where the gas is shut off, first, the gas flow rate is adjusted after opening the on-off valve, and when shutting off the gas from a state where the gas with the set flow rate is flowing, In the case where the on-off valve is closed after adjusting the flow rate with the flow rate of the supplied gas set to 0 (Claim 5), the operation can be ensured.

  1 to 4 show a first embodiment of the present invention, FIG. 1 is a diagram showing a configuration of a main part of a flow control device 1 according to the first embodiment, and FIG. FIG. 3 is a view showing an example of a flow rate control device 2 provided in the thin film deposition apparatus 1, and FIG. 4 is a view showing an example of a flow rate control method using the flow rate control device 2. .

  In FIG. 1, 2, 3 is a chamber which comprises the principal part of the thin film deposition apparatus 1, This chamber 3 is the chamber main body 3a, the upper-plate cover body 3b provided horizontally in the upper part, and the chamber shown in FIG. An exhaust port 3c formed in the main body 3a, a vacuum pump 3d, and a pressure sensor 3e are provided. Reference numeral 4 denotes a substrate support provided in the lower part of the chamber body 3 a, and reference numeral 5 denotes a semiconductor substrate as an example of an object placed on the substrate support 4.

  The flow rate control device 2 of the present invention is equally arranged on the lower surface side of the upper plate lid 3b, for example, in two stages, upper and lower, and circumferentially. The flow rate control device 2 is connected to the downstream end of the flow rate control device 2 into the chamber 3. A nozzle 6 for guiding the supply of gas is formed. That is, the flow rate control device 2 and the nozzle 6 constitute a gas supply unit 1a, and in this embodiment, for example, 24 gas supply units 1a are attached in a staggered manner at equal intervals in two upper and lower stages, and The nozzle 6 of each gas supply unit 1 a is configured to supply gas toward the center of the chamber 3. In the present embodiment, an example in which the gas supply unit 1a is formed in two upper and lower stages is shown, but the present invention is not limited to this configuration.

  7a and 7b are gas supply pipes for supplying two different kinds of gases, 7c and 7d are gas pipes branched from the respective gas supply pipes 7a and 7b and connected to the respective gas supply units 1a, and 8 is a gas supply pipe. 7a and 7b are gas switching units for switching the gas to be supplied to the chamber 3 by opening and closing the gas flow channels, and 9a and 9b are gas flow channels for the respective gases connected to the gas switching unit 8, 10a and 10b. Is a supply source comprising gas cylinders flowing through the gas flow paths 9a and 9b.

  In FIG. 2, reference numeral 1 b denotes a thin film deposition control unit of the thin film deposition apparatus 1. The thin film deposition apparatus 1b outputs the drive signal Pd to the vacuum pump 3d while monitoring the measured value Pc of the pressure in the chamber 3 measured by the pressure sensor 3e. The pressure on the downstream side of the control device 2) Pc is adjusted so as to be suitable for thin film deposition. Further, the thin film deposition apparatus 1b outputs a gas selection signal Gs to the gas switching unit 8 to select a gas to be supplied to the chamber 3, and sets a flow rate Fs that is uniformly or arbitrarily set to each gas supply unit 1a. It also has a function of controlling the flow rate of the gas that is output and supplied into the chamber 3.

  Next, the configuration of the gas supply unit 1a, particularly the flow rate control device 2 will be described with reference to FIG. In FIG. 3, reference numeral 11 denotes an input pressure adjusting unit that determines an upper limit of the gas pressure supplied from the gas pipe 7 c (7 d) and performs intermittent switching of gas flowing into the flow rate control device 2, and 12 is downstream of the input pressure adjusting unit 11. A mass flow controller (flow rate adjusting unit) provided on the side, 13 an internal pressure adjusting unit provided on the downstream side of the mass flow controller 12, 14 an on-off valve provided on the downstream side of the internal pressure adjusting unit 13, and 15 a flow rate The interface 16 enables input of the set value Fs and the measurement value Pc of the pressure downstream of the on-off valve 14.

The input pressure adjusting unit 11 includes, for example, a pressure sensor 20 and a piezo nozzle 21 using a piezo element. That is, when the pressure of the gas supplied from the gas pipe 7c (7d) is abnormally large at the time of gas supply, the control unit 16 outputs the control signal V ₀ so that the piezo nozzle 21 is throttled. The downstream pressure P ₀ is reduced to such a degree that the mass flow controller 12 can control the flow rate. When the gas supply is stopped, the control unit 16 outputs a control signal V ₀ for making the piezo nozzle 21 fully closed.

The mass flow controller 12 includes, for example, a piezo nozzle 22 using a piezo element, a primary pressure sensor 23, an orifice 24, and a secondary pressure sensor 25 arranged in this order. The control unit 16 measures the flow rate Fo of the gas flowing through the orifice 24 from the relationship between the pressures P ₁ and P ₂ measured by the pressure sensors 23 and 25 on the primary side and the secondary side of the orifice 24. A control signal V ₁ for adjusting the opening degree of the piezo nozzle 22 is output so that Fo becomes the set value Fs of the flow rate input via the interface 15.

The internal pressure adjusting unit 13 includes, for example, a pressure sensor 26 and a piezo nozzle 27 using a piezo element, an exhaust passage 28, and an on-off valve 29. In the state where the supply of gas is stopped, the control unit 16 is located downstream of the on-off valve 14 to which the internal pressure P ₃ of the gas upstream of the on-off valve 14 is input via the interface 15 (that is, the chamber 3 The control signal V ₂ is output to the piezo nozzle 27 so as to be the same as the inner pressure Pc. A vacuum pump (not shown) is provided downstream of the exhaust passage 28.

  In this example, the pressure sensor 26 that functions only as the internal pressure adjusting unit 13 and the piezo nozzle 27 are separately formed to perform more reliable operation. However, the internal pressure adjusting unit 13 is configured. The pressure sensor 25 (or pressure sensor 23) may be used instead of the pressure sensor 26, and the piezo nozzle 23 (or piezo nozzle 21) may be used instead of the piezo nozzle 27.

The on-off valve 14 is specifically a piezo nozzle in this example, and is provided in a portion as close as possible to the nozzle 6. The controller 16 outputs a control signal V ₃ for making the on-off valve 14 fully closed when the gas supply is stopped.

Next, an example of a flow rate control method using the flow rate control device 2 will be described using FIG. 4 together with FIG. In the example shown in FIG. 4, a signal indicating the set flow rate Fs is a square wave, the supply of gas is stopped to the time point t _1, supplying a gas flow rate F ₁ at time t _1, again the gas at time t ₂ Fig. 2 shows a part of a recipe for a gas introduction process set to stop the supply.

First, at time t ₁ , with the rise of the signal of the set flow rate Fs, the control unit 16 first switches the control signal V ₃ from the cutoff level CLS to the fully open level OPN, and the on-off valve 14 is opened. However, since the pressure P ₃ upstream of the release valve 14 is adjusted to the same pressure as the pressure in the chamber 3 (for example, 10 mTorr) until the time t _{1, the} gas does not flow even when the on-off valve 14 is opened. Absent. Following this, the control unit 16 switches the control signal V ₂ from the cutoff level CLS to the fully open level OPN, and then releases the control signal V ₀ from the cutoff state. That is, the piezo nozzle 21 is opened, and a gas having a predetermined pressure P ₀ is supplied to the mass flow controller 12.

Further, the control unit 16 uses the mass flow controller 12 to output a control signal V ₁ for adjusting the piezo nozzle 22 so that the flow rate Fo of the gas flowing through the orifice 24 becomes the set flow rate Fs.

  At this time, the flow rate F of the gas supplied from the flow rate control device 2 is extremely rapid although a delay due to a small volume in the flow path inside the channel and a slight response speed of the piezoelectric nozzles 21, 22, and 27 occur. Rises to approximately the set flow rate Fs. Further, since the rush flow Ca (see FIG. 7) does not occur as in the prior art, the gas supply is started statically, so that the particles in the chamber 3 can be prevented from rising.

  In addition, since the flow rate control device 2 can start statically supplying a gas having a flow rate F equal to the set flow rate Fs, the flow channel 6a in the nozzle 6 does not require a flow channel resistance such as a venturi, and its inner diameter is reduced. Can be bigger. Therefore, the gas supply unit 1 a can supply a gas having an arbitrary set flow rate Fs from a small flow rate to a large flow rate into the chamber 3.

Even if the control signal V ₃ for opening the on-off valve 14 and the control signals V ₀ , V ₁ for opening the piezo nozzles 21 and 22 are switched at the same timing, the gas flow rate is adjusted after the on-off valve 14 is opened. Is possible. However, the control signals V ₃ , V ₀ , and V ₁ at the start of gas supply may be provided with a slight time difference in this order.

Next, at the time t ₂ , the signal of the set flow rate Fs falls, and the control unit 16 first outputs a control signal V ₀ of the cutoff level CLS for fully closing it to the piezo nozzle 21 to supply the gas to the mass flow meter 12. Shut off the supply. The control unit 16 outputs a control signal V ₃ for fully closed this opening and closing valve 14, completely stopping the gas supply.

  Further, the control unit 16 outputs an open level OPN control signal D for opening the on-off valve 29 in a state in which the on-off valve 14 is closed, lowers the pressure in the flow path to the lower limit, and then opens and closes again. The control signal D of the cutoff level CLS which closes the valve 29 is output.

Here, the control unit 16 again releases the control signal V ₀ to the piezo nozzle 21 from the cutoff level CLS, and outputs an appropriate control signal V ₂ to the piezo nozzle 27 to adjust the internal pressure P ₃ . That is, the internal pressure adjustment unit 13 is used to adjust the internal pressure P ₃ to be the same as the pressure Pc in the chamber 3. Next, control signals V ₁ and V ₂ of the closing level CLS are output so that the piezo nozzles 22 and 27 are fully closed.

Therefore, since the internal pressure P ₃ is controlled so as to be the same pressure as the pressure Pc downstream of the on / off valve 14 in a state where the on / off valve 14 is closed, a problem that causes a leak in the on / off valve 14 occurs. Even if the internal pressure P ₃ is the same as the pressure Pc on the downstream side of the on-off valve 14, the gas will not leak through the on-off valve 14, and the reliability of the flow control device 2 can be improved. it can.

  In the above-described example, the internal configuration of the flow control device 2 is simplified by controlling the input pressure adjusting unit 11, the mass flow controller 12, the internal pressure adjusting unit 13, and the on-off valve 14 by the same control unit 16. However, the present invention is not limited to this point, and each may be controlled independently. Further, not only electrical control but also mechanical control may be performed.

In the above example, the internal pressure adjusting unit 13 includes the exhaust flow path 28 and the opening / closing valve 29. Therefore, the response speed is increased by immediately closing the opening / closing valve 14 in response to the fall of the setting signal Fs. It is possible to control the internal pressure P ₃ on the upstream side of the on-off valve 14 to be the same as the pressure Pc on the downstream side after raising the valve as much as possible and closing the on-off valve 14.

However, the present invention is not limited to the internal pressure adjusting unit 13 including the exhaust passage 28 and the on-off valve 29. That is, by slightly delaying the control signal V ₃ for closing the on-off valve 14 with respect to the control signal V ₀ for closing the piezo nozzle 21, the pressure P ₃ is not exhausted upstream of the on-off valve 14. You may make it pull down.

  FIG. 5 is a diagram showing the configuration of the flow control device 30 of the second embodiment. In FIG. 5, since the part which attached | subjected the same code | symbol as FIGS. 1-3 is the same or equivalent part, the detailed description is abbreviate | omitted. In FIG. 5, reference numeral 31 denotes an internal pressure adjusting unit, and the internal pressure adjusting unit 31 includes a relief valve 32 and an exhaust passage 33. A vacuum pump (not shown) is connected to the exhaust passage 33.

The relief valve 32 causes gas to flow toward the exhaust pipe 33 when the internal pressure P ₂ upstream of the on-off valve 14 becomes higher than the pressure P ₄ in the exhaust passage 33 by, for example, a differential pressure ΔP. The passage 33 is sucked so that the pressure P ₄ is the same as the pressure Pc in the chamber 3. Accordingly, when the internal pressure P ₂ upstream of the on-off valve 14 is higher than the pressure Pc downstream of the on-off valve 14 by the differential pressure ΔP, the pressure P ₂ is decreased. Here, the differential pressure ΔP is set to such an extent that the gas inflow Ca from the nozzle 6 does not occur when the on-off valve 14 is fully opened.

In the present embodiment, the mass flow controller 12 functions as the internal pressure adjusting unit 31 when the flow control device 2 stops supplying gas. That is, the control unit 16 outputs the control signal V ₁ to the piezo nozzle 22 so that the internal pressure P ₂ measured by the pressure sensor 25 is approximately the same as the pressure Pc downstream of the on-off valve 14.

That is, the flow control devices 2 and 30 of the present invention start gas supply by adjusting the internal pressures P ₃ , P ₂ ... Upstream of the on-off valve 14 to the same level as the pressure Pc downstream of the on-off valve 14. Therefore, the internal pressure adjusting unit 31 only needs to be able to adjust the internal pressures P ₃ , P ₂ ... That is, various modifications can be considered in the configuration of the internal pressure adjusting units 2 and 31.

It is a figure explaining the structure of the thin film deposition apparatus which concerns on 1st Example of this invention. It is a block diagram which shows the structure of the said thin film deposition apparatus. It is a figure explaining the structure of the flow control apparatus used for the said thin film deposition apparatus. It is a figure explaining the example of the flow control method using the said flow control apparatus. It is a figure explaining the 2nd example of a flow control device. It is a figure explaining the structure of the conventional thin film deposition apparatus. It is a figure explaining the example of the flow control method in the conventional thin film deposition apparatus.

Explanation of symbols

1 thin film deposition apparatus 2,30 flow control device 3 chamber 6 nozzles 12 flow rate control unit 13 inside the pressure adjusting unit 14 off valves P _2, P ₃ internal pressure Pc-off valve downstream of the pressure t ₁ the gas supply start time t ₂ gas When supply is cut off

Claims (5)

An on-off valve that interrupts the flow of gas,
A flow rate adjusting unit arranged upstream of the on-off valve to adjust the flow rate of gas;
And an internal pressure adjusting unit that adjusts the internal pressure so that the internal pressure on the upstream side of the on-off valve becomes equal to the pressure on the downstream side of the on-off valve with the on-off valve closed. Flow control device.   At the start of gas supply, first, the flow rate of the gas is adjusted using the flow rate adjusting unit after opening the on-off valve, and at the time of shutting off the gas supply, first, the flow rate of the gas is set to 0 using the flow rate adjusting unit. The flow control device according to claim 1, further comprising a control unit that controls the on-off valve and the flow rate adjusting unit so as to close the on-off valve.   A plurality of gas supply units each including the flow rate control device according to claim 1 and a nozzle connected to the flow rate control device are provided in the upper part of the chamber. A thin film deposition apparatus configured to deposit a predetermined thin film on a substrate provided in the chamber by blowing a gas whose flow rate is adjusted to an arbitrary value into the chamber.   A method for controlling a state in which a gas having a flow rate set arbitrarily and a state in which a gas flow is interrupted are controlled by intermittently controlling the gas flow using an on-off valve and stopping the gas flow. The flow rate control method characterized by adjusting the internal pressure of the gas upstream of the on-off valve in the state so as to be equal to the external pressure downstream of the on-off valve. When flowing a gas with a set flow rate from a state where the gas is shut off, first, the gas flow rate is adjusted after opening the on-off valve, and when shutting off the gas from a state where the gas with the set flow rate is flowing, The flow rate control method according to claim 4, wherein the on-off valve is closed after the flow rate of the gas to be supplied is adjusted to 0 and the flow rate is adjusted.

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