JP2013019685A - Flowmeter and method for detecting gas flow rate in deposition apparatus using the flowmeter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure precise deposition and safety in a deposition apparatus using corrosive gas, by detecting a gas flow rate and outputting the flow rate as an electric signal.SOLUTION: A flowmeter for detecting a flow rate of gas exhausted from a deposition apparatus which forms a film on a substrate by using corrosive gas, includes: a closed vessel 2 which has a gas supply port 3 and a gas discharge port 4 and which is filled up inside with an inert liquid when being used; a float 5 which is movably supported inside the closed vessel 2; a stopper 13 for controlling movement of the float 5; and a sensor 14 for counting the number of movements of the float 5 and outputting the number as an electric signal. The float 5 has a receiving space 8, which uses a partition plate 9 to be divided into a first chamber 8a and a second chamber 8b of which inner walls are treated with a corrosion resistant material, and is movably supported like a pendulum inside the closed vessel 2, and thereby detects the float mobility while taking in the gas alternately into the first chamber 8a and the second chamber 8b to output the float mobility as an electric signal.

Description

  The present invention relates to a flow meter and a gas flow rate detection method in a film forming apparatus using the same, and more particularly, in a film forming apparatus using a corrosive gas such as chlorine gas such as a CVD apparatus, exhausting the gas used. The present invention relates to a flow meter capable of ensuring the safety of the apparatus by detecting the amount and ensuring accurate film formation, and a gas flow rate detection method in a film forming apparatus using the same.

  As is well known, among film forming apparatuses for forming a thin film on the surface of a substrate such as silicon or glass, there is an apparatus using a corrosive gas such as a chlorine gas such as CVD.

For example, CVD employs a chemical film formation method, and in a state of atmospheric pressure to medium vacuum (100 to 10 ⁻¹ pa), a gas as a gas raw material is fed, and heat, plasma, light, This is a method of synthesizing thin films and fine particles by energizing and accelerating chemical reactions by applying energy, and adsorbing and depositing them on the surface of substrates and substrates to form thin films. In an apparatus or method for forming a thin film by using it, it is extremely important to detect whether an appropriate amount of gas is flowing properly.

  That is, in the film forming apparatus, it is necessary to exhaust the gas used for film formation from the inside of the apparatus. At this time, if the exhaust side is clogged for some reason, the pressure in the processing pipe on the exhaust side will increase. As a result, gas leakage due to breakage of the processing tube occurs, which is extremely dangerous.

  In addition, in a film forming apparatus, when the amount or size of a substrate to be formed changes, the amount of gas consumed for film formation also changes. For example, when the number of substrates is large or the substrates are large. Since a large amount of gas is taken by the substrate for film formation, it is necessary to increase the amount of gas to be supplied according to the amount and size of the substrate in order to prevent the film thickness from being reduced. is there.

  Therefore, as described above, in an apparatus or method for forming a thin film using a gas such as CVD, it is extremely important to detect whether or not an appropriate amount of gas is flowing properly.

  However, since the flowmeter conventionally used in the film forming apparatus is arranged on the gas supply side and detects the amount of gas supplied thereby, the gas flow rate on the exhaust side can be known. In addition, even when the exhaust side processing tube is clogged, it has been difficult to detect it quickly and reliably.

  In addition, when a conventional flow meter that detects the gas supply amount is used, it is impossible to know the gas flow rate on the exhaust side. Accordingly, even when it is necessary to increase the gas supply amount in order to ensure the uniformity of the film thickness, it is impossible to grasp and supply an accurate gas amount according to the amount and size of the substrate. And had to rely on the worker's experience based on the experience and data accumulation.

  Furthermore, since there is no conventional flow meter that has resistance to corrosive gases such as chlorine gas, in a film forming apparatus using a corrosive gas such as CVD, supply the flow meter. It was difficult to directly detect the amount of gas present and grasp the detected flow rate as an electrical signal.

JP 2009-44106 A JP 2008-7826 A JP 2006-261318 A JP-A-2005-45158 JP 2001-185492 A Japanese Patent Laid-Open No. 10-242133

  Therefore, the present invention can ensure the safety of the film forming apparatus by detecting the gas flow rate and outputting the detected flow rate as an electric signal in the film forming apparatus using corrosive gas such as chlorine gas. In addition, an object of the present invention is to provide a flow meter capable of ensuring accurate film formation and a gas flow rate detection method in a film formation apparatus using the flow meter.

The flow meter of the present invention is
A flow meter for detecting a flow rate of gas exhausted from a film forming apparatus for forming a film on an object such as silicon or glass using a corrosive gas,
It is equipped with a gas supply port for receiving the gas exhausted from the film forming apparatus, and a gas exhaust port for discharging the gas after detecting the flow rate of the received gas. A sealed container,
A float movably supported in the sealed container;
A stopper for controlling the movement of the float;
A sensor for counting the number of movements of the float and outputting the number of counts as an electrical signal;
The float is
A lower portion having a top plate and a pair of side plates continuously provided at both end portions of the top plate, and a receiving space in which a side wall portion orthogonal to the side plate is opened;
A partition plate that is arranged to partition the receiving space into a first chamber and a second chamber that are cut off from each other and have the same capacity, and that is continuously provided on the lower surface of the top plate toward a lower side perpendicular to the top plate. And comprising
At least the inner walls of the first chamber and the second chamber are processed with a corrosion-resistant material,
The first chamber and the second chamber are supported in the sealed container so as to be movable in a pendulum shape so as to move in opposite directions.

And, using this flow meter, the gas flow rate detection method of the present invention for detecting the flow rate of the gas exhausted from the film forming apparatus,
The gas exhausted from the film forming apparatus is received into the sealed container from the gas supply port,
The gas received in the sealed container is received in one of the first chamber and the second chamber of the receiving space,
Move the float in one direction in a pendulum shape by moving the one room that received the gas upward by the buoyancy of the received gas,
The movement of the float is detected by a sensor and output as an electrical signal.
The gas received in the one room is taken out of the room from an open part of the one room, and the gas received in the sealed container from the gas supply port is received in the other room,
Move the float in the other direction in a pendulum shape by moving the other room that received the gas upward by the buoyancy of the received gas,
The movement of the float is detected by a sensor and output as an electrical signal.
The gas received in the other room is discharged from the open part of the other room to the outside of the room, and the gas received in the sealed container from the gas supply port is received inside the one room,
Thereafter, the process can be repeated.

  In the present invention, since the flow rate of the gas exhausted from the film forming apparatus after being used for film formation is detected, the processing on the exhaust side is different from the conventional flow meter for detecting the gas supply amount. If the pipe is clogged, it can be detected quickly and reliably, and therefore, clogging on the exhaust side increases the pressure in the processing pipe on the exhaust side, thereby causing gas leakage due to breakage of the processing pipe. It is possible to effectively prevent the possibility of occurrence.

  Further, in the present invention in which the flow rate of the gas exhausted from the film formation apparatus after being used for film formation is detected, the amount and size of the substrate to be formed changes, and the film formation is performed accordingly. Therefore, if the amount of gas consumed is changed and the amount of exhausted gas is changed, it can be detected, so that a change in the amount of gas consumed can be detected quickly, Accurate gas amount according to the amount and size of the substrate can be grasped, and the amount and size of the substrate to be deposited changes, and accordingly, gas supply to ensure film thickness uniformity When it is necessary to increase the amount, an accurate gas amount corresponding to the amount and size of the substrate can be grasped and supplied without being based on the experience and data accumulation of the operator.

  And at this time, in the flowmeter of the present invention, the float is movably supported in the sealed container, the float is moved by the gas received in the sealed container, and the number of times the float is moved is counted. Since the sensor for outputting the number of times as an electrical signal is provided, it is possible to reliably grasp the exhaust flow rate of the gas.

  In the flowmeter of the present invention, at least the inner walls of the first chamber and the second chamber that are in contact with the exhaust gas from the film forming apparatus are processed with a corrosion-resistant material. Even when it is used in a film forming apparatus such as a CVD that uses the material, it can have durability.

It is a figure which shows the front structure of the Example of the flowmeter of this invention. It is a figure which shows the side surface structure of the Example of the flowmeter of this invention. It is a figure which shows the plane structure of the Example of the flowmeter of this invention. It is a figure for demonstrating the float in the Example of the flowmeter of this invention. It is a figure for demonstrating the float in the Example of the flowmeter of this invention. It is a figure which shows the other form of the float in the Example of the flowmeter of this invention. It is a figure which shows the effect | action of the float in the Example of the flowmeter of this invention. It is a block diagram for demonstrating the Example of the gas flow rate detection method of this invention. It is a flowchart for demonstrating the Example of the gas flow rate detection method of this invention.

  In use, the flowmeter of the present invention has a sealed container filled with an inert liquid. The sealed container includes a gas supply port for receiving gas exhausted from the film forming apparatus, A gas discharge port is provided for discharging the gas received in the sealed container through the gas supply port from the sealed container after detecting the flow rate.

  A float is movably supported in the sealed container, and a stopper for controlling the movement of the float and the number of times the float is moved are counted, and the counted number is output as an electrical signal. A sensor is provided.

  The float has a receiving space for receiving the gas received in the hermetic container. The receiving space includes a top plate and a pair of lower side plates connected downward to both ends of the top plate. The lower part and the side wall part orthogonal to the side plate are open.

  In addition, a partition plate is continuously provided on the lower surface of the top plate so as to divide the receiving space into two spaces, the first chamber and the second chamber, toward the lower side orthogonal to the top plate. Thus, the receiving space is divided into a first chamber and a second chamber.

  Furthermore, the first chamber and the second chamber are cut off from each other and have the same capacity, and the inner wall is constructed or processed with a corrosion-resistant material. Various resin plastic materials such as fluororesin, PVC, and PEEK are conceivable.

  The float is supported in an airtight container so as to be movable like a pendulum so that the first chamber and the second chamber move in opposite directions.

  Here, the sensor includes a first sensor that counts when one surface of the partition plate abuts when the float moves in one direction, and the other surface of the partition plate when the float moves in the other direction. In this case, the first sensor and the second sensor are each configured so that when the float is moved in one direction or the other direction, the partition plate A reed switch disposed at a position where one surface or the other surface abuts, and a magnet disposed at a position where the reed switch abuts when the float moves in one direction or the other direction in the partition plate. It may be provided and configured, and this makes it easy to output the number of float movements as an electrical signal.

  In the gas flow rate detection method of the present invention using the flow meter configured as described above, first, the gas exhausted from the film forming apparatus is received into the sealed container from the gas supply port of the sealed container, and the detection is performed. This reception is continued until the end, and the gas received in the sealed container is received in one of the first chamber and the second chamber of the receiving space.

  Next, the one room that has received the gas is moved upward by the buoyancy of the received gas, thereby moving the float in a pendulum shape in one direction.

  In both cases, the movement of the float is detected by a sensor and output as an electrical signal.

  At the same time, the gas received in one room is taken out of the room from the open part of one room, and the gas received in the sealed container from the gas supply port is introduced into the other room. accept.

  Then, the other chamber that has received the gas is moved upward by the buoyancy of the received gas, so that the float is moved in a pendulum shape in the other direction, and the movement of the float is detected by a sensor and electric. It outputs as a signal, Furthermore, the gas received in the other room is taken out of the room from the open part in the other room.

  At the same time, the gas received in the sealed container from the gas supply port is received in one of the chambers. Thereafter, this series of processing is performed until the exhaust gas from the film forming apparatus runs out, or the flow rate of the exhaust gas. The detection is repeated until the detection is completed, whereby the flow rate of the gas exhausted from the film forming apparatus is detected.

  An embodiment of a flow meter of the present invention will be described with reference to the drawings. FIGS. 1 to 3 are partial sectional views for explaining the configuration of the flow meter of the present embodiment. FIG. FIG. 2 is a diagram illustrating a front configuration of the flow meter of the example, FIG. 2 is a diagram illustrating a side configuration of the flow meter of the present embodiment, and FIG. 3 is a diagram illustrating a planar configuration of the flow meter of the present embodiment. Is the flow meter of the present embodiment.

  And the flowmeter of a present Example is equipped with the airtight container with which an inert liquid is filled inside, and the float arrange | positioned in this airtight container. That is, in the figure, 2 is a closed container, and in this embodiment, the closed container 2 is made of transparent PVC and has a bottomed box shape having a ceiling portion.

  In addition, a gas supply port 3 for supplying exhaust gas exhausted from the film forming apparatus into the sealed container 2 is provided at the bottom, and a gas supplied into the sealed container 2 is provided at the ceiling. It has a discharge port 4 for discharging.

  In the present embodiment, the closed container 2 is filled with an inert liquid such as Florinart (registered trademark) or Galden (registered trademark) when used.

  Next, 5 in the figure is a float. That is, in the flow meter 1 of the present embodiment, the float 5 is disposed in the sealed container 2, and the amount of gas received in the sealed container 2 can be detected by the action of the float.

  Here, the float 5 will be described with reference to FIGS. 4 and 5. FIG. 4 is a diagram for explaining the float 5 in the present embodiment, and FIG. It is the figure shown from the side, and 5 is the said float in the figure.

  In this embodiment, the float 5 has a receiving space for receiving the gas received in the sealed container 2. That is, the float in the present embodiment has a rectangular flat top plate 6, and side plates in an inverted triangular shape facing downward at both end portions along the longitudinal direction of the top plate 6. 7, the receiving space 8 is constituted by the top plate 6 and the side plate 7.

  Therefore, the receiving space 8 has a lower portion integrated with a side wall portion orthogonal to the side plate 7, and a lower portion integrated with the side wall portion orthogonal to the side plate 7 is opened.

  The receiving space 8 in which the lower part and the side wall part are integrally opened is partitioned into a first chamber and a second chamber by a partition plate. That is, in the figure, 9 is a partition plate, and this partition plate 9 has a long plate shape in which the dimension in the longitudinal direction is longer than the dimension in the height direction of the side plate 7, and the upper end portion is the top plate 6. On the lower surface, it is connected to the central portion of the top plate 6 viewed in the longitudinal direction, and in the receiving space 8, both ends along the longitudinal direction are respectively connected to the inner surface of the side plate 7, whereby the partition plate 9, the receiving space 8 is partitioned into a first chamber 8a and a second chamber 8b.

  Further, the first chamber 8 a and the second chamber 8 b are partitioned by the partition plate 9, thereby being a space that is blocked from each other, and the upper end portion of the partition plate 9 is on the lower surface of the top plate 6. By connecting to the central portion of the top plate 6 viewed in the longitudinal direction, the rooms have the same capacity.

  Further, at least the inner walls of the first chamber 8a and the second chamber 8b, that is, the lower surface of the top plate 6, the inner side of the side plate 7, and the portion disposed in the receiving space 8 in the partition plate 9 are formed by CVD or the like. It is made of a corrosion-resistant material that is resistant to corrosive gases such as chlorine gas used. Specifically, it is made of or processed from various resin plastic materials such as fluororesin, PVC, and PEEK. . That is, in the flowmeter of the present embodiment, the location where the exhaust gas from the film forming apparatus contacts is made of a corrosion-resistant material that is resistant to corrosive gases such as chlorine gas used in CVD or the like. .

  In the present embodiment, the float 5 having the top plate 6, the side plate 7 and the partition plate 9 is movable in a pendulum shape so that the first chamber 8a and the second chamber 8b move in opposite directions. , And is supported in the sealed container 2.

  That is, a pair of plate-like support portions are disposed in the sealed container 2 at intervals, and the partition plate 9 is rotatably supported by the support portions.

  Here, in FIG. 4, 10 is a support part, and in the present embodiment, the support part 10 has a plate shape, and is provided at the bottom of the sealed container 2 with an interval in which the surfaces face each other. It is fixed to the mounting base 11.

  Further, the mounting base 11 has the gas supply port 3 penetrating through a central portion thereof, and accordingly, gas is supplied from the central portion between the support portions 10 into the sealed container 2.

  The support portion 10 is configured such that the surface of the support portion 10 is arranged to be orthogonal to the surface of the partition plate 9, and the base end portion is connected to the upper portion of the surface of each of the support portions 10. The rod 12 penetrates the side plate 7 and the partition plate 9 at the lower end portion of the side plate 7, and the float 5 is rotatable in a pendulum manner during the penetration.

  Accordingly, the float 5 is movable in a pendulum shape so that the first chamber 8a and the second chamber 8b move in opposite directions. That is, when the float 5 moves in a pendulum shape in one direction (A direction in FIG. 4), the first chamber 8a moves upward and the second chamber 8b moves downward, while the float 5 moves in the other direction (FIG. 4), the second chamber 8b moves upward and the first chamber 8a moves downward.

  Next, 13 is a stopper in the figure. That is, in the flowmeter 1 of the present embodiment, a pair of rod-like stoppers 13 are arranged so as to sandwich the partition plate 9 between the support portions 10 and to prevent the pendulum-like movement of the float 5. Thus, the movement of the float 5 is restricted.

  In this embodiment, when the partition plate 9 is tilted by about 45 degrees around the fulcrum to which the support rod 12 is connected, the lower part of the partition plate 9 comes into contact with it, thereby further The stopper 13 is disposed at a position where the float 5 does not tilt.

  Here, 14 is a sensor in the figure. That is, the flow meter 1 of the present embodiment includes a sensor 14 for counting the number of movable times of the float 5 and outputting the counted number as an electric signal.

  Here, the sensor 14 will be described. In the present embodiment, a magnet 14b is disposed at a position in contact with the stopper 13 at each of the tip portions on both surfaces of the partition plate 9, while the stopper 14 In FIG. 13, a reed switch 14a is disposed at a position where the magnet 14b abuts, and the reed switch 14a is connected to a counter 14c (see FIG. 8) disposed outside the sealed container 1.

  With this configuration, when the magnet 14b comes into contact with the reed switch 14a, the movement of the float 5 is output as an electric signal from the reed switch 14a to the counter 14c, and the counter 14c floats based on the signal. The number of movements is detected.

  Therefore, in this embodiment, the first sensor for detecting the movement of the float 5 in one direction and the second sensor for detecting the movement of the float 5 in the other direction are provided. In both cases of movement and movement in the other direction, the movement can be counted. Therefore, in this embodiment, the movement of the float can be detected more finely.

  FIG. 6 is a view showing another form of the float 5 according to the present invention. In the float 5 in the figure, both end portions facing the longitudinal direction of the top plate 6 are slightly inclined downward, and the side plate 7 The top plate 6 may be configured in such a form.

  Further, as described above, in the flow meter 1 of the present embodiment, the inner wall portions of the first chamber 8a and the second chamber 8b are made of a corrosion-resistant material that is resistant to corrosive gases such as chlorine gas. Although the case has been described, the present invention is not necessarily limited to this method, and the entire float 5 and all the parts that are considered to be in contact with the gas, such as the support portion 10, the mounting base 11, the support rod 12, the stopper 13, the sensor 14, and the like. It may be constructed or processed with a corrosion resistant material.

  Furthermore, in the present invention, the method of moving the float 5 is not particularly limited, as long as it is movable in a pendulum shape so that the first chamber 8a and the second chamber 8b move in opposite directions. There is no need to configure. Therefore, for example, the support rod 12 may be protruded from the inner wall of the sealed container 2 to support the partition plate 9, or other configurations may be employed.

  Further, the type and location of the sensor 14 are not necessarily limited to the above-described locations, and any location and method that can detect the movement of the float 5 may be used.

  Next, an embodiment of the gas flow rate detection method of the present invention for detecting the flow rate of gas exhausted from a film forming apparatus such as CVD using the flow meter of the present embodiment configured as described above will be described. 8 is a block diagram showing a film forming system to which the gas flow rate detection method of this embodiment is applied.

  In FIG. 8, 21 is a film forming apparatus such as CVD, 22 is a valve for supplying a corrosive gas to the film forming apparatus 21, and 24 is a gas exhausted from the film forming apparatus 21 to the sealed container 2. In addition to the control of the gas supply flow rate, reference numeral 23 denotes a control unit for controlling the operation of the entire system. FIG. 7 is a diagram showing the movement of the float 5. In FIG. 7, c12 is chlorine gas.

  FIG. 9 is a flowchart for explaining the gas flow rate detection method of this embodiment. When the flow rate of gas exhausted from the film forming apparatus 21 is detected using the flow meter 1 of this embodiment, Fluorinert is used. The inside of the sealed container 2 is filled with an inert liquid such as (Registered Trademark) or Galden (Registered Trademark). Thus, the corrosive gas exhausted from the film forming apparatus 21 can be received in the sealed container 2.

  Further, the reed switch 14a is connected to a counter 14c disposed outside the sealed container 2, and the counter 14c is connected to the control unit 23, and the number of float movements detected via the reed switch 14a is determined by the control unit. 23 is made possible to feed back.

  Furthermore, in this embodiment, as shown in FIG. 7A, the float 5 is moved in a pendulum shape in advance so that the first chamber 8a of the receiving space 8 of the float 5 is on the lower side. Keep it.

  That is, in the present embodiment, a weight is embedded in the top plate 6 or in a portion above the fulcrum to which the support rod 12 of the partition plate 9 is connected, and this weight causes the partition plate 9 to face in the vertical direction. When the float 5 is unstable, the float 5 is buried in a position where the float 5 is inclined so that the first chamber 8a is on the lower side.

  As a result, when the flow rate of the gas exhausted from the film forming apparatus 21 is detected using the flow meter 1 of this embodiment, the float 5 is set so that the first chamber 8a of the receiving space 8 of the float 5 is on the lower side. Can be moved like a pendulum.

  In this state, the gas exhausted from the film forming apparatus 21 is received into the sealed container 2 through the exhaust path 24 and the gas supply port 3, and this reception is continued until the detection of the gas flow rate is completed.

  Then, the gas c12 received in the sealed container 2 rises in the sealed container 2 in Step 1, and in the first chamber 8a located on the lower side, as shown in FIG. It is integrated with the side wall portion orthogonal to the side plate 7 and is received in the first chamber 8a through the opened lower portion, and accumulates in the upper portion of the first chamber 8a.

  The float 5 is gradually moved by the buoyancy of the received gas c12 so that the first chamber 8a goes upward. As shown in FIG. In Step 2, the first chamber 8a moves upward and the second chamber moves downward as shown in FIG. 7D due to the buoyancy of the received gas. It moves like a pendulum in one direction (A direction in FIG. 4) so as to move. That is, the first chamber 8a tries to move upward due to the buoyancy of the received gas, while the buoyancy does not work in the second chamber 8b filled with the inert liquid. After receiving the gas (“maximum value”) for the internal volume, the float 5 moves in one direction (direction A in FIG. 4) so that the first chamber 8a moves upward and the second chamber moves downward. ) Move like a pendulum.

  Therefore, in the flowmeter 1 of the present embodiment, the first chamber 8a is operated such that the float 5 operates in a pendulum shape when the maximum gas is received in the first chamber 8a and the second chamber 8b. In addition, it is necessary to set the capacity of the second chamber 8b, the shaft support portion between the partition plate 9 and the support rod 12, and the float 5 when the maximum gas is received in the first chamber 8a. It is necessary to adjust the weight and the location of the weight so that the first chamber 8a moves upward and the second chamber 8b moves downward while reliably operating in one direction like a pendulum. .

  Next, when the float 5 moves in one direction, the partition plate 9 is inclined by about 45 degrees and the lower part of the partition plate 9 comes into contact with the stopper 13, the magnet 14b comes into contact with the reed switch 14a. The sensor 14 is activated, that is, an electrical signal is output from the reed switch 14a to the counter 14c. The counter 14c counts the movement of the float 5, and outputs the count result to the control unit 23 ("feedback").

  Based on the fed back signal, the control unit 23 controls the valve 22 to adjust the gas supply amount, or when it is determined that the exhaust amount is small and the exhaust side processing tube is clogged. Activate an alarm.

  When the float 5 moves in one direction, the first chamber 8a moves upward, and the second chamber 8b moves downward, the gas received in the first chamber 8a is stored in the first chamber 8a in step 4. While going outside, the gas is discharged from the gas outlet 4 to the outside of the sealed container 2.

  On the other hand, when the float 5 moves in one direction, when the first chamber 8a moves upward and the second chamber 8b moves downward, the float 5 is received in the sealed container 2 and rises in the sealed container 2. In step 5, as shown in FIG. 7 (d), the gas is integrated with the side wall portion orthogonal to the side plate 7 and opened through the lower portion in the second chamber 8b located on the lower side. Then, it is received in the second chamber 8b and accumulates in the upper part of the second chamber 8b.

  In the same manner as described above, the float 5 receives the gas corresponding to the capacity in the second chamber 8b ("maximum value"), and then in step 6, the second chamber 8b is moved upward by the buoyancy of the received gas. It moves like a pendulum in the other direction (B direction in FIG. 4) so that the first chamber 8a moves downward.

  Then, as described above, the magnet 14b comes into contact with the reed switch 14a, and in step 7, the sensor 14 is activated, that is, an electrical signal is output from the reed switch 14a to the counter 14c, and the movement of the float 5 is counted in the counter 14c. At the same time, the count result is output to the control unit 23 ("feedback"), and the gas received in the second chamber 8b goes out of the second chamber 8b in step 8, and the gas discharge port. 4 is discharged out of the sealed container 2.

  Further, when the float 5 moves in the other direction, when the second chamber 8b moves upward and the first chamber 8a moves downward, it is received in the sealed container 2 and rises in the sealed container 2. The gas returns to Step 1 and is received in the first chamber 8a through the lower portion which is integrated with the side wall portion orthogonal to the side plate 7 and opened in the first chamber 8a located on the lower side. Thereafter, the processing from step 1 to step 8 is repeated until the detection of the gas flow rate is completed.

  In the course of these processes, the control unit 23 that receives the number of movements of the float 5 as an electrical signal detects and analyzes the flow rate of the gas exhausted from the film forming apparatus 21 based on the fed back signal.

  Then, by converting the number of movements of the float 5 detected by the sensor 14 into an electric signal, the exhaust amount of the gas can be accurately detected, thereby clogging the processing pipe on the exhaust side, thereby causing the gas to flow. When the amount of exhaust gas decreases, it can be detected quickly and reliably to ensure safety, and the amount and size of the substrate to be deposited changes, and the film thickness is ensured accordingly. Therefore, even when it is necessary to increase the gas supply amount, the accurate gas amount can be grasped and supplied.

  As described above, in the flowmeter and the gas flow rate detection method of the present embodiment, the flow rate of the gas exhausted from the film forming apparatus after being used for film formation is detected, so the gas supply amount is detected. Unlike conventional flowmeters, if the exhaust side processing tube is clogged and the amount of exhausted gas is reduced, it can be detected quickly and reliably. It is possible to effectively prevent the risk of gas leakage due to the pressure in the tube rising and thereby damage to the processing tube.

  In addition, in the flowmeter and the gas flow rate detection method of this embodiment that detects the flow rate of the gas exhausted from the deposition apparatus after being used for deposition, the amount and size of the substrate to be deposited are increased. If the amount of gas consumed for film formation changes and the amount of gas exhausted changes accordingly, it can be detected, so the change in the amount of gas consumed can be detected quickly. It can be detected, so that the accurate gas amount according to the amount and size of the substrate can be grasped, so the amount and size of the substrate to be deposited changes, and the film thickness accordingly When it is necessary to increase the amount of gas supply to ensure uniformity, it is necessary to grasp and supply an accurate gas amount according to the amount and size of the substrate without relying on the experience and data accumulation of the operator. Can do.

  At this time, in the flowmeter of the present embodiment, the airtight container 2 is moved so that the float 5 having the first chamber 8a and the second chamber 8b moves in the opposite directions to each other. It is supported movably in a pendulum shape inside, and the exhaust gas is received in the sealed container 2, and the float 5 is formed in a pendulum shape while the received gas is alternately received in the first chamber 8a and the second chamber 8b. It is possible to move and convert the number of movements of the float into an electric signal, and the electric signal is fed back to the control unit. It is possible to adjust the amount of gas supplied to the membrane device.

  Further, in the flow meter of the present embodiment, at least the inner wall portions of the first chamber 8a and the second chamber 8b that are in contact with the exhaust gas from the film forming apparatus are resistant to corrosive gases such as chlorine gas. Even if it is used for film-forming equipment such as CVD using corrosive gas such as chlorine gas because it is composed or processed with corrosive materials (various plastic materials such as fluororesin, PVC, PEEK) It is possible to have durability.

  The present invention can ensure the safety of the apparatus by detecting the flow rate of gas exhausted from the film forming apparatus in a film forming apparatus using a corrosive gas such as chlorine gas, such as CVD. Therefore, it can be applied to all types of flow meters used in film forming apparatuses using corrosive gas such as chlorine gas.

DESCRIPTION OF SYMBOLS 1 Flowmeter 2 Sealed container 3 Gas supply port 4 Gas discharge port 5 Float 6 Top plate 7 Side plate 8 Receiving space 8a 1st chamber 8b 2nd chamber 9 Partition plate 10 Support part 11 Mounting base 12 Support rod 13 Stopper 14 Sensor 14a Lead Switch 14b Magnet 14c Counter 21 Deposition device 22 Valve 23 Control unit 24 Exhaust passage

Claims (5)

A flow meter for detecting a flow rate of gas exhausted from a film forming apparatus for forming a film on an object such as silicon or glass using a corrosive gas,
A gas supply port (3) for receiving the gas exhausted from the film forming apparatus and a gas exhaust port (4) for discharging the gas after detecting the flow rate of the received gas, A sealed container (2) filled with an inert liquid;
A float (5) movably supported in the sealed container (2);
A stopper (13) for controlling the movement of the float (5);
A sensor (14) for counting the number of movable times of the float (5) and outputting the counted number as an electric signal;
The float (5)
A receiving portion having a top portion (6) and a pair of side plates (7) connected downward to both end portions of the top plate (6), and a lower portion and a side wall portion orthogonal to the side plate (7) being opened. Space (8),
The receiving space (8) is divided into a first chamber (8a) and a second chamber (8b) which are blocked from each other and have the same capacity, and the top plate (6 And a partition plate (9) provided continuously downward toward the lower side perpendicular to
At least the inner walls of the first chamber (8a) and the second chamber (8b) are processed with a corrosion-resistant material,
The first chamber (8a) and the second chamber (8b) are supported in the hermetic container (2) so as to be movable like a pendulum so as to move in opposite directions,
The gas exhausted from the film forming apparatus is received into the sealed container (2) from the gas supply port (3),
The gas received in the sealed container (2) is received in one of the first chamber (8a) and the second chamber (8b) of the receiving space (8),
Move the float (5) in a pendulum shape in one direction by moving the one room that received the gas upward by the buoyancy of the received gas,
The movement of the float (5) is detected by a sensor and output as an electrical signal,
The gas received in the one room is taken out of the room from the open part of the one room, and the gas received from the gas supply port (3) into the sealed container (2) is supplied to the other room. Accepted inside,
The float (5) is moved in a pendulum shape in the other direction by moving the other chamber that has received the gas upward by the buoyancy of the received gas.
The movement of the float (5) is detected by a sensor and output as an electrical signal,
The gas received in the other room is taken out of the room from the open part of the other room, and the gas received in the sealed container (2) from the gas supply port (3) is supplied to the other room. Accepted inside,
Thereafter, it is possible to repeat the above-described process. The sensor (14)
A first sensor that counts when one surface of the partition plate (9) abuts when the float (5) moves in one direction;
The flowmeter according to claim 1, further comprising a second sensor that counts when the other surface of the partition plate (9) comes into contact with the float (5) when the float (5) moves in the other direction. . The first sensor and the second sensor are respectively
A reed switch (14a) disposed at a position where one surface or the other surface of the partition plate (9) contacts when the float (5) moves in one direction or the other direction in the stopper (13). When,
A magnet (14b) disposed at a position where the reed switch (14a) contacts when the float (5) is moved in one direction or the other direction in the partition plate (9). The flow meter according to claim 2, wherein the flow meter is characterized in that:   The inner wall of at least the first chamber (8a) and the second chamber (8b) is made of various resin plastic materials such as fluororesin, PVC, and PEEK. The flow meter described in 1. A flow rate of gas exhausted from a film forming apparatus for forming a film on an object such as silicon or glass using various gases using the flowmeter according to any one of claims 1 to 4. A gas flow rate detection method for detecting,
The gas exhausted from the film forming apparatus is received into the sealed container (2) from the gas supply port (3),
The gas received in the sealed container (2) is received in one of the first chamber (8a) and the second chamber (8b) of the receiving space (8),
Move the float (5) in a pendulum shape in one direction by moving the one room that received the gas upward by the buoyancy of the received gas,
The movement of the float (5) is detected by a sensor and output as an electrical signal,
The gas received in the one room is taken out of the room from the open part of the one room, and the gas received from the gas supply port (3) into the sealed container (2) is supplied to the other room. Accepted inside,
The float (5) is moved in a pendulum shape in the other direction by moving the other chamber that has received the gas upward by the buoyancy of the received gas.
The movement of the float (5) is detected by a sensor and output as an electrical signal,
The gas received in the other room is taken out of the room from the open part of the other room, and the gas received in the sealed container (2) from the gas supply port (3) is supplied to the other room. Accepted inside,
Thereafter, the gas flow rate detecting method characterized in that the process can be repeated.

Images