Gasification device, material state determination device, material state determination method for gasification device, and storage medium

Abstract

The invention provides a gasification device, a material state determination device, a material state determination method of the gasification device, and a storage medium. The gasification device includes: a gasifier that gasifies a material; a flow rate control device having a flow rate sensor that measures the flow rate of the material gas generated by the gasifier; and a determination unit that determines whether or not the material gas returns to the state before gasification on the basis of the transient response of the flow rate measured by the flow rate sensor.

Description

Technical Field

[0001] The present invention relates to a gasification device, a material state judgment device, a material state judgment method for a gasification device, and a material state judgment program for a gasification device. Background Art

[0002] As such a vaporization device, for example, there is a vaporization device that heats and vaporizes a liquid material or a solid material used in semiconductor manufacturing to generate a material gas, and supplies the material gas to a semiconductor manufacturing chamber, etc. For example, as shown in Patent Document 1, the vaporization device includes: a vaporizer that heats and vaporizes a liquid material or a solid material; and a flow control device (so-called a mass flow controller) that controls the flow rate of the material gas generated by the vaporizer.

[0003] In this vaporization device, if poor vaporization occurs, such as the generated material gas returning to the state before vaporization, it will become a cause of product defects in semiconductor manufacturing. Therefore, a flow control device and piping from the vaporizer to the flow control device are heated by a heater or the like.

[0004] However, in this gasification device, although the flow control device and the piping thereto are heated, the material gas may return to the state before gasification. Therefore, in the past, when the deviation between the set flow rate of the flow control device and the measured flow rate measured by the flow control device continued for a predetermined time, it was determined that there was a possibility of gasification failure, such as the material gas returning to the state before gasification.

[0005] However, in the above detection method, since other reasons such as poor control of the flow control device are also taken into account, it is not possible to judge only the possibility of poor gasification. Moreover, the deviation needs to be continued for a predetermined time, so the detection of the situation of returning to the state before gasification is delayed. In addition, in thin film forming technologies such as atomic layer deposition (ALD), since a purge process is added between film forming processes, the measured flow rate has a deviation, and the detection of the situation of returning to the state before gasification becomes difficult.

[0006] Patent Document 1: Japanese Patent No. 5548292 Summary of the invention

[0007] Therefore, the present invention has been made to solve the above-mentioned problems, and an object of the present invention is to accurately determine whether the material gas has returned to the state before being vaporized.

[0008] That is, the gasification device of the present invention includes: a gasifier that gasifies the material; a flow control device having a flow sensor that measures the flow rate of the material gas generated by the gasifier; and a judgment unit that judges whether the material gas has returned to the state before gasification based on transient response data of the flow rate measured by the flow sensor as transient response.

[0009] In such a gasification device, it is determined whether the material gas has returned to the state before gasification based on the transient response data measured by the flow sensor, so it is possible to accurately determine whether the material gas has returned to the state before gasification. Specifically, the transient response data easily shows the behavior (e.g., waveform change) caused by the material gas returning to the state before gasification, and by using this behavior, it is possible to accurately determine whether the material gas has returned to the state before gasification. In addition, in the present invention, an additional sensor for detecting the state before gasification is not necessary, and the device can be miniaturized.

[0010] Preferably, the determination unit determines whether the material gas has returned to a state before gasification based on differential data obtained by differentiating the transient response data. With this structure, by differentiating the transient response data, the behavior (eg, waveform change) caused by the return to the state before vaporization contained in the transient response data can be easily captured, and the return of the material gas to the state before vaporization can be determined with high accuracy.

[0011] The behavior (e.g., waveform change) caused by the return to the state before gasification contained in the transient response data can be considered to appear as an inflection point in the transient response data. Therefore, it is preferred that the judgment unit judges whether the material gas has returned to the state before gasification based on whether there is an inflection point in the transient response data.

[0012] Since the change caused by the rise or the change caused by the fall in the transient response appears as an inflection point, in order to capture the inflection point representing the behavior caused by liquefaction other than the change caused by the rise or the change caused by the fall, it is preferred that, when there are two or more of the inflection points, the judgment unit judges that the material gas returns to the state before gasification.

[0013] As a specific embodiment of determining whether the material gas has returned to the state before gasification, it is preferable that the determination unit determines whether the material gas has returned to the state before gasification based on the transient response data during the descent.

[0014] In order to determine with further high accuracy whether the material gas has returned to the state before gasification, it is preferred that the determination unit removes noise from the transient response data and determines whether the material gas has returned to the state before gasification based on the transient response data from which the noise has been removed.

[0015] As a specific embodiment of the case where it is determined that the material gas has returned to the state before gasification, it is preferred that the gasification device changes the heating temperature of the gasifier or stops the gasification operation when the determination unit determines that the material gas has returned to the state before gasification. In addition, the heating temperature of the piping in the gasification device may be changed or the temperature adjustment area in the gasification device may be changed by confirming whether there is a cold spot or the like.

[0016] If the flow sensor is a thermal flow sensor, the behavior caused by the material gas returning to the state before vaporization is easily expressed, and it can be determined with higher accuracy whether the material gas has returned to the state before vaporization.

[0017] In addition, the material state judgment device of the present invention is used for a gasification device, which has: a gasifier that gasifies the material; and a flow control device, which has a flow sensor that measures the flow rate of the material gas generated by the gasifier, wherein the material state judgment device includes a judgment unit that judges whether the material gas has returned to the state before gasification based on transient response data of the flow data measured by the flow sensor as a transient response.

[0018] In addition, in the material state judgment method of the gasification device of the present invention, the gasification device comprises: a gasifier that gasifies the material; and a flow control device, having a flow sensor that measures the flow rate of the material gas generated by the gasifier, wherein the material state judgment method of the gasification device judges whether the material gas returns to the state before gasification based on transient response data of the flow data measured by the flow sensor as a transient response.

[0019] In addition, the storage medium of the present invention stores a material state judgment program of a gasification device, wherein the gasification device comprises: a gasifier for gasifying materials; and a flow control device having a flow sensor for measuring the flow rate of the material gas generated by the gasifier. The material state judgment program of the gasification device enables a computer to function as a judgment unit, and the judgment unit judges whether the material gas has returned to the state before gasification based on transient response data of the flow data measured by the flow sensor as a transient response.

[0020] As described above, according to the present invention, since it is determined based on the transient response data of the flow rate sensor whether the material gas has returned to the state before being vaporized, it is possible to accurately determine whether the material gas has returned to the state before being vaporized. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a diagram schematically showing the structure of a gasification device according to one embodiment of the present invention. Figure 2(a) is the transient response data and its differential data in a normal state without liquefaction, and (b) is the transient response data and its differential data in an abnormal state with liquefaction. DETAILED DESCRIPTION

[0022] Hereinafter, one embodiment of the gasification device of the present invention will be described with reference to the drawings. In order to facilitate understanding, each of the following drawings is schematically depicted with appropriate omissions or exaggerations. The same components are given the same reference numerals, and the description thereof is appropriately omitted.

[0023] <Structure of Gasification Device> The vaporization device 100 of the present embodiment heats and vaporizes a liquid material used in semiconductor manufacturing to generate a material gas, and supplies the material gas to a semiconductor manufacturing chamber, etc. In addition, the vaporization device 100 of the present embodiment is a vaporization device that vaporizes a liquid material, but it may also be a vaporization device that vaporizes a solid material.

[0024] Specifically, if Figure 1 As shown, the vaporization device 100 includes: a vaporizer 2 for vaporizing a liquid material; and a flow control device 3 for controlling the flow rate of the material gas generated by the vaporizer 2 .

[0025] The vaporizer 2 is a baking type (heating type) vaporizer, comprising: a container 2a for storing liquid material; a heater 2b for heating the container 2a; an inlet pipe 2c for supplying liquid material to the container 2a; and an outlet pipe 2d for outlet generated material gas from the container 2a.

[0026] The container 2a contains a predetermined amount of liquid material, and is formed of a corrosion-resistant metal such as stainless steel. In addition, in order to maintain the amount of the liquid material within a predetermined range, a liquid amount sensor 2e such as a liquid level sensor is provided in the container 2a. In addition, a pressure sensor 2f for measuring the pressure inside the container 2a is sometimes provided in the container 2a.

[0027] The heater 2b is, for example, a heater, and is disposed inside the container 2a, or is disposed so as to surround the outer peripheral side surface and / or bottom surface of the container 2a. In the container 2a heated by the heater 2b, the liquid material reaches the saturated vapor pressure and vaporizes to generate material gas. In addition, the heating temperature of the heater 2b can be appropriately set according to the liquid material.

[0028] The introduction pipe 2c is provided to penetrate, for example, the upper wall of the container 2a, and its lower end extends to the vicinity of the bottom surface of the container 2a. An introduction port P1 for introducing a liquid material is provided at the upstream end of the introduction pipe 2c. In addition, a flow rate regulating valve 2g for regulating the flow rate of the liquid material supplied to the container 2a is provided on the introduction pipe 2c and outside the container 2a. The valve opening of the flow rate regulating valve 2g is controlled based on the detection signal of the liquid amount sensor 2e.

[0029] The outlet pipe 2d is opened at, for example, the upper wall of the container 2a, and is connected to the internal space of the container 2a. Moreover, the material gas generated in the container 2a flows into the outlet pipe 2d and is discharged from the container 2a. A supply port P2 for supplying the material gas to a semiconductor manufacturing chamber or the like is provided at the downstream end of the outlet pipe 2d. In addition, an on-off valve 2h is provided at the outlet pipe 2d, and the on-off valve 2h is closed when the material gas is not discharged from the container 2a. The outlet pipe 2d is heated to a predetermined temperature by the heater 2i from the connection portion connected to the container 2a to the supply port P2 so as not to liquefy the material gas.

[0030] Furthermore, a purge gas supply pipe 2j for supplying purge gas is connected between the on-off valve 2h in the outlet pipe 2d and the flow control device 3 described later. A supply port P3 for supplying purge gas is provided at the upstream end of the purge gas supply pipe 2j. In addition, an on-off valve 2k is provided in the purge gas supply pipe 2j, and the on-off valve 2k is closed when the purge gas is not supplied.

[0031] The flow control device 3 is provided in the outlet pipe 2d to control the flow rate of the material gas flowing in the outlet pipe 2d. Specifically, the flow control device 3 comprises: a flow sensor 31 for measuring the flow rate of the material gas; a fluid control valve 32 provided on the upstream side or downstream side (here, the downstream side) of the flow sensor 31; and a valve control unit 33 for controlling the fluid control valve 32 based on the measured flow rate of the flow sensor 31.

[0032] The flow sensor 31 is a thermal flow sensor, comprising: a sensor piping 31a for the material gas to flow; a sensing part 31b for detecting physical quantities (such as current, voltage, resistance, etc.) associated with the temperature on the upstream and downstream sides of the sensor piping 31a; and a flow calculation part 31c for calculating the flow of the material gas based on the detection signal obtained by the sensing part 31b.

[0033] The upstream end and the downstream end of the sensor pipe 31 a are connected to the outlet pipe 2 d , and the sensor pipe 31 a bypasses a part of the material gas.

[0034] The sensing unit 31b uses a thermistor whose resistance value increases and decreases with temperature, and includes: an upstream sensor 31b2 wound in a coil shape on the upstream side of the sensor piping 31a; and a downstream sensor 31b1 wound in a coil shape on the downstream side of the sensor piping 31a.

[0035] The flow calculation unit 31c is composed of a circuit, and has: a control circuit that controls the temperature of the upstream sensor 31b2 and the downstream sensor 31b1 to be always equal and constant; an amplifier circuit that amplifies the electrical signal output by the control circuit; and a conversion circuit that converts the electrical signal amplified by the amplifier circuit into a flow rate. In addition, the flow calculation unit 31c can also make a constant current flow through the upstream sensor 31b2 and the downstream sensor 31b1 through a constant current circuit, and convert the temperature difference between the upstream sensor 31b2 and the downstream sensor 31b1 at this time into a flow rate.

[0036] The valve control unit 33 controls the fluid control valve 32 based on the measured flow rate of the material gas calculated by the flow rate calculation unit 31c. In addition, the valve control unit 33 is a so-called computer including a CPU, a memory, an A / D and D / A converter, and an input / output device, and controls the fluid control valve 32 by executing a program stored in the memory to make various devices cooperate.

[0037] Specifically, the valve control unit 33 performs feedback control on the opening of the fluid control valve 32 so as to reduce the deviation between the set flow rate set by the user and the measured flow rate calculated by the flow rate calculation unit 31c. The valve control unit 33 is a PID controller that receives the deviation between the set flow rate and the measured flow rate and outputs a voltage command to be applied to the fluid control valve 32 through PID calculation.

[0038] <Liquefaction judgment function> Furthermore, the gasification device 100 of the present embodiment has a function of judging whether the material gas has returned to the state before gasification, that is, a function of judging whether the material gas has been liquefied. Here, "judging whether the material gas has returned to the state before gasification" means: in the case of a solid material, judging whether the material gas has returned to a solid; in the case of a liquid material, judging whether the material gas has returned to a liquid.

[0039] Specifically, the vaporizer 100 includes a liquefaction determination unit 4 that determines whether the material gas has been liquefied based on transient response data, which is flow rate data at the time of transient response measured by the flow sensor 31. The transient response data may be analog data or digital data.

[0040] Here, the transient response is the time of decrease, and the liquefaction determination unit 4 determines whether the material gas has been liquefied based on the transient response data of the decrease. In addition, for example, by setting the set flow rate (set value) of the flow control device 3 from a predetermined flow rate (for example, a flow rate greater than zero such as 500 [sccm]) to zero and fully closing the fluid control valve 32, a decrease in the measured flow rate (transient response) is generated.

[0041] For example, the function of the liquefaction judging unit 4 may be realized by storing the liquefaction judging program in the memory of the same computer as the valve control unit 33, or the function of the liquefaction judging unit 4 may be realized by storing the liquefaction judging program in the memory of a computer different from the valve control unit 33. In addition, the function of the liquefaction judging unit 4 may be provided to the flow control device 3, or the function of the liquefaction judging unit 4 may be provided to the semiconductor manufacturing apparatus.

[0042] Specifically, if Figure 2 Specifically, the liquefaction determination unit 4 detects whether the transient response data has an inflection point from the differential data, and determines whether the material gas has liquefied based on the presence or absence of the inflection point.

[0043] Here, if Figure 2 As shown in (b), when there are two or more inflection points, the liquefaction determination unit 4 determines that the material gas has been liquefied. This is because, in the case of no liquefaction, Figure 2 As shown in (a), in the transient response, an inflection point is shown due to the change caused by the drop, so in addition to the change caused by the drop, an inflection point representing the behavior caused by liquefaction is also captured.

[0044] Furthermore, the liquefaction determination unit 4 may remove flow noise and noise caused by interference from the transient response data, and determine whether the material gas has been liquefied based on the transient response data from which the noise has been removed. Here, as a method of removing noise, for example, moving average of the transient response data may be considered.

[0045] Furthermore, it is conceivable to configure such that, when the liquefaction determination unit 4 determines that the material gas has been liquefied, the user is notified of the liquefaction of the material gas. Specifically, it is conceivable to display the liquefaction determination on the display 5 of the computer, and it is conceivable to notify the user by sound or light by a notification device installed in the production line (site) where the gasification device 100 is assembled.

[0046] Furthermore, it is also possible to consider that, when the liquefaction determination unit 4 determines that the material gas has been liquefied, the vaporizer 100 performs control to change (specifically, increase) the heating temperature of the vaporizer 2 or to stop the vaporization operation. In addition, it is also possible to confirm whether there is a cold spot and change the heating temperature of the piping of the vaporizer 100 or change the temperature control area.

[0047] <Effects of the present embodiment> Thus, according to the vaporization device 100 of the present embodiment, whether the material gas has been liquefied can be determined with high accuracy based on the transient response data measured by the flow sensor 31. Specifically, the behavior (e.g., waveform change) caused by the liquefaction of the material gas is easily shown in the transient response data, and by using the behavior caused by the liquefaction, the liquefaction of the material gas can be determined with high accuracy.

[0048] Furthermore, the liquefaction determination unit 4 determines whether the material gas has been liquefied based on the differential data obtained by differentiating the transient response data, and thus can easily capture the behavior (such as waveform change) caused by liquefaction contained in the transient response data, and can accurately determine the liquefaction of the material gas.

[0049] Furthermore, in the present embodiment, since the thermal flow rate sensor 31 is used, the behavior due to the liquefaction of the material gas is easily revealed, and the liquefaction of the material gas can be determined with further high accuracy.

[0050] <Other Implementation Methods> For example, the determination method of liquefaction by the liquefaction determination unit 4 is not limited to the determination method based on the inflection point, and the determination of liquefaction may be performed based on the amount of change in differential data. For example, when the amount of change in differential data is greater than a predetermined value, or when the amount of change in differential data is less than a predetermined value and does not become zero within a predetermined time, the determination of liquefaction is performed.

[0051] Specifically, in order to prevent erroneous judgment due to the operation of the stop valve on the gasification device side during the down response, a threshold is set for the differential value of the transient response data during the down response, so that liquefaction is not judged in the case of a sharp response accompanied by the operation of the stop valve, etc. For example, it is conceivable to detect the down signal, and when an inflection point is confirmed in the differential data at a predetermined time after the detection and the differential data is within a predetermined range, it is judged that the material gas has been liquefied. Here, the predetermined range is set to an appropriate value according to the film forming conditions of the semiconductor manufacturing process.

[0052] In addition, the liquefaction determination unit 4 may be configured to determine liquefaction without differentiating the transient response data. In this case, for example, the transient response data obtained by the flow sensor 31 and the transient response data (standard data) in a state where liquefaction does not occur may be compared by fitting or the like, and liquefaction may be determined based on the comparison result.

[0053] Furthermore, the flow sensor in the above-described embodiment is a thermal flow sensor, but may be a pressure flow sensor or a flow sensor using other measurement principles.

[0054] In the above embodiment, the vaporizer 100 has the function of determining whether the material gas has been liquefied, but a device (liquefaction determination device) different from the vaporizer 100 may have the function of determining whether the material gas has been liquefied. That is, the liquefaction determination unit 4 may be provided in a device different from the vaporizer 100.

[0055] The vaporizer in the above embodiment is a baking type vaporizer, but it may also be a bubbling type vaporizer that introduces a carrier gas into a liquid material to cause bubbling to vaporize it, or a bubbling type vaporizer that blows a carrier gas into a solid material to cause it to sublime.

[0056] In addition, various modifications and combinations of the embodiments are possible within the scope not departing from the gist of the present invention. Description of Reference Numerals

[0057] 100 Gasification device 2 Vaporizer 3 Flow control equipment 31 Flow sensor 4. Liquefaction determination unit (determination unit).

Claims

1. A gasification device, characterized in that: include: A gasifier, which gasifies the material; a flow control device having a flow sensor for measuring the flow rate of the material gas generated by the gasifier; as well as The determination unit determines whether the material gas has returned to a state before gasification based on transient response data, which is flow rate data at the time of transient response, measured by the flow sensor.

2. The gasification device according to claim 1, characterized in that: The determination unit determines whether the material gas has returned to a state before gasification based on differential data obtained by differentiating the transient response data.

3. The gasification device according to claim 2, characterized in that: The determination unit determines whether the material gas has returned to a state before gasification based on whether there is an inflection point in the transient response data.

4. The gasification device according to claim 1, characterized in that: When there are two or more inflection points in the transient response data, the determination unit determines that the material gas has returned to a state before gasification.

5. The gasification device according to any one of claims 1 to 4, characterized in that: The determination unit determines whether the material gas has returned to a state before gasification based on the transient response data during the descent.

6. The gasification device according to any one of claims 1 to 5, characterized in that: The determination unit removes noise from the transient response data, and determines whether the material gas has returned to a state before gasification based on the transient response data from which the noise has been removed.

7. The gasification device according to any one of claims 1 to 6, characterized in that: When the determination unit determines that the material gas has returned to the state before vaporization, the heating temperature of the vaporizer or the pipe is changed, the temperature control region is changed, or the vaporization operation is stopped.

8. The gasification device according to any one of claims 1 to 7, characterized in that: The flow sensor is a thermal flow sensor.

9. A material state judgment device for a gasification device, the gasification device comprising: a gasifier for gasifying a material; and a flow control device having a flow sensor for measuring the flow rate of the material gas generated by the gasifier, The material state judgment device is characterized in that: A determination unit is included for determining whether the material gas has returned to a state before gasification based on transient response data as flow rate data at the time of transient response measured by the flow sensor.

10. A method for determining a material state of a gasification device, the gasification device comprising: a gasifier for gasifying a material; and a flow control device having a flow sensor for measuring a flow rate of a material gas generated by the gasifier, wherein the method for determining a material state of the gasification device is characterized in that: Based on transient response data, which is flow rate data at the time of transient response measured by the flow sensor, it is determined whether the material gas has returned to the state before gasification.

11. A storage medium, characterized in that: A material state judgment program of a gasification device is stored, wherein the gasification device comprises: a gasifier for gasifying a material; and a flow control device having a flow sensor for measuring a flow rate of a material gas generated by the gasifier, The material state judgment program of the vaporization device enables a computer to function as a judgment unit that judges whether the material gas has returned to the state before vaporization based on transient response data as flow rate data at the time of transient response measured by the flow sensor.

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