JP4790470B2 - Substrate processing equipment - Google Patents

Description

  The present invention relates to a substrate processing apparatus that performs a process such as a drying process on a substrate such as a semiconductor wafer, a glass substrate for a liquid crystal display device, or a glass substrate for a PDP by a processing gas supplied into a processing chamber together with a carrier gas.

  2. Description of the Related Art Conventionally, in a substrate manufacturing process, a substrate processing apparatus that processes a substrate by supplying a processing gas around the substrate is known. For example, a substrate processing apparatus is known that performs a drying process on a substrate by supplying an IPA (isopropyl alcohol) gas around the substrate after the cleaning process. A processing gas such as IPA gas is fed into the processing chamber using an inert gas such as nitrogen gas as a carrier gas.

  In such a substrate processing apparatus, processing effects such as a drying process on the substrate vary greatly depending on the concentration of the processing gas. For this reason, it is necessary to accurately measure the concentration of the processing gas contained in the gas supplied around the substrate. In the conventional substrate processing apparatus, a concentration meter is installed in the processing chamber to measure the concentration of the processing gas, or a part of the gas supplied to the periphery of the substrate is collected to measure the concentration of the processing gas. A technique for measuring the concentration of a processing gas in a conventional substrate processing apparatus is disclosed in Patent Document 1, for example.

Japanese Patent Laid-Open No. 9-190997

  When performing the drying process of the substrate with the IPA gas, it is desirable to rapidly advance the drying process of the substrate so as not to cause a drying defect such as a watermark on the surface of the substrate. For this reason, in recent substrate processing apparatuses, an IPA gas having a very high concentration may be supplied into the processing chamber. As described above, when a high-concentration processing gas is used, the concentration of the processing gas may not be accurately measured because the processing gas concentration exceeds the measurable range of the concentration meter.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a substrate processing apparatus capable of accurately measuring the concentration of a processing gas even when a high concentration processing gas is used. .

  In order to solve the above-mentioned problem, the invention according to claim 1 is a substrate processing apparatus for processing a substrate with a processing gas, and supplies a processing gas together with a carrier gas to a processing chamber for accommodating the substrate inside the processing chamber. A processing gas supply unit, a sampling unit for collecting a part of the gas supplied from the processing gas supply unit to the processing chamber as a sample gas, and a dilution gas supply unit for supplying a dilution gas for diluting the sample gas Included in the sample gas diluted by the dilution unit and the dilution unit that dilutes the sample gas by mixing the sample gas collected by the collection unit and the dilution gas supplied by the dilution gas supply unit Concentration meter for measuring the concentration of the processing gas to be obtained, and the flow rate of the sample gas before dilution flowing through the pipe from the sampling section to the dilution section or the dilution flowing through the pipe from the dilution section A first flow meter for measuring the flow rate of the sample gas, a second flow meter for measuring a flow rate of the dilution gas flowing through a pipe from the dilution gas supply unit to the dilution unit, the concentration meter, and the first flow meter And a calculation unit that calculates the concentration of the processing gas contained in the sample gas before dilution based on each measurement value of the second flow meter.

  The invention according to claim 2 is the substrate processing apparatus according to claim 1, wherein the calculation unit is based on a measurement value of the densitometer and measurement values of the first flow meter and the second flow meter. The concentration of the processing gas contained in the sample gas before dilution is calculated by multiplying the reciprocal of the dilution rate obtained in this way.

  A third aspect of the present invention is the substrate processing apparatus according to the first or second aspect, wherein the flow rate of the sample gas flowing through the pipe from the sampling unit to the dilution unit is adjusted. A flow rate adjusting unit is further provided.

  The invention according to claim 4 is the substrate processing apparatus according to any one of claims 1 to 3, wherein after the dilution for adjusting the flow rate of the sample gas flowing through the pipe from the dilution section to the concentration meter A flow rate adjusting unit for sample gas is further provided.

  The invention according to claim 5 is the substrate processing apparatus according to any one of claims 1 to 4, wherein the flow rate of the dilution gas flowing through the pipe from the dilution gas supply unit to the dilution unit is adjusted. It further has a flow rate adjusting unit for dilution gas.

  The invention according to claim 6 is the substrate processing apparatus according to any one of claims 1 to 5, wherein the temperature of the sample gas flowing through the pipe from the collection unit to the dilution unit is controlled. The temperature control part is further provided.

  A seventh aspect of the present invention is the substrate processing apparatus according to any one of the first to sixth aspects, wherein the dilution gas for adjusting the temperature of the dilution gas flowing through the pipe from the dilution gas supply unit to the dilution unit is controlled. A temperature control unit for gas is further provided.

  The invention according to claim 8 is the substrate processing apparatus according to claim 7, wherein a container that houses a gas piping system including the concentration meter, the first flow meter, and the second flow meter; And a jetting unit for jetting the dilution gas temperature-controlled by the temperature control unit for the dilution gas into the container.

  The invention according to claim 9 is the substrate processing apparatus according to any one of claims 1 to 7, wherein the dilution gas supply unit supplies a carrier gas as a dilution gas.

  A tenth aspect of the present invention is the substrate processing apparatus according to any one of the first to ninth aspects, wherein the sampling unit uses a part of the gas supplied from the processing gas supply unit as a sample gas. And a second state in which a part of the gas in the processing chamber is sampled as a sample gas.

  According to invention of Claim 1-10, the substrate processing apparatus is a dilution part which mixes the sample gas extract | collected by the extraction | collection part, and the dilution gas supplied by the dilution gas supply part, and dilutes a sample gas And a concentration meter that measures the concentration of the processing gas contained in the sample gas diluted by the dilution unit, and the flow rate of the sample gas before dilution flowing through the pipe from the collection unit to the dilution unit or the pipe from the dilution unit A first flow meter that measures the flow rate of the diluted sample gas, a second flow meter that measures the flow rate of the dilution gas flowing through the pipe from the dilution gas supply unit to the dilution unit, a concentration meter, a first flow meter, and A calculation unit that calculates the concentration of the processing gas contained in the sample gas before dilution based on each measurement value of the second flow meter. For this reason, the concentration is measured after the sample gas is diluted, and the concentration of the processing gas before dilution can be calculated based on the measured value and the flow rates of the sample gas and the dilution gas. Accordingly, the concentration of the processing gas can be accurately measured even when a high concentration processing gas is used.

  In particular, according to the invention described in claim 2, the calculation unit multiplies the measurement value of the concentration meter by the reciprocal of the dilution rate obtained based on the measurement values of the first flow meter and the second flow meter. Thus, the concentration of the processing gas contained in the sample gas before dilution is calculated. For this reason, the concentration of the processing gas contained in the sample gas before dilution can be calculated easily and accurately.

  In particular, according to the invention described in claim 3, the substrate processing apparatus further includes a flow rate adjusting unit for the pre-dilution sample gas that adjusts the flow rate of the sample gas flowing through the pipe from the collection unit to the dilution unit. For this reason, the measured value of the first flow meter is stabilized, and the concentration of the processing gas can be calculated more accurately.

  In particular, according to the invention described in claim 4, the substrate processing apparatus further includes a flow rate adjusting unit for the diluted sample gas that adjusts the flow rate of the sample gas flowing through the pipe from the dilution unit to the concentration meter. For this reason, the measured value of the first flow meter is stabilized, and the concentration of the processing gas can be calculated more accurately.

  In particular, according to the fifth aspect of the present invention, the substrate processing apparatus further includes a dilution gas flow rate adjusting unit that adjusts the flow rate of the dilution gas flowing through the pipe from the dilution gas supply unit to the dilution unit. For this reason, the measured value of the second flow meter is stabilized, and the concentration of the processing gas can be calculated more accurately.

  In particular, according to the invention described in claim 6, the substrate processing apparatus further includes a temperature adjusting unit for the sample gas for adjusting the temperature of the sample gas flowing through the pipe from the collection unit to the dilution unit. For this reason, the temperature fall of the sample gas in a supply path | route is prevented, and condensation of the process gas contained in sample gas is suppressed. Therefore, the concentration of the processing gas can be calculated more accurately.

  In particular, according to the seventh aspect of the present invention, the substrate processing apparatus further includes a dilution gas temperature adjustment unit that adjusts the temperature of the dilution gas flowing through the pipe from the dilution gas supply unit to the dilution unit. For this reason, the temperature fall of the sample gas at the time of dilution is prevented, and condensation of the processing gas contained in the sample gas is suppressed. Therefore, the concentration of the processing gas can be calculated more accurately.

  In particular, according to the invention described in claim 8, the substrate processing apparatus includes a container for housing a gas piping system including a concentration meter, a first flow meter, and a second flow meter, and a temperature control unit for dilution gas. And a jetting part for jetting the dilution gas whose temperature is controlled by the above into the container. For this reason, the temperature fall of sample gas is prevented in the whole gas piping system contained in a container, and condensation of processing gas contained in sample gas is controlled. Therefore, the concentration of the processing gas can be calculated more accurately.

  Particularly, according to the invention described in claim 9, the dilution gas supply unit supplies the carrier gas as the dilution gas. For this reason, it is possible to accurately dilute the sample gas without increasing the types of gases contained in the sample gas. Further, since the carrier gas and the dilution gas can be supplied from the same gas supply source, the configuration of the substrate processing apparatus is simplified.

  In particular, according to the invention described in claim 10, a first state in which a part of the gas supplied from the processing gas supply unit is sampled as a sample gas, and a part of the gas in the processing chamber is sampled as a sample gas. Switching to the second state is possible. For this reason, the substrate processing apparatus is capable of measuring either the concentration of the processing gas contained in the gas supplied from the processing gas supply unit or the concentration of the processing gas contained in the gas in the processing chamber. Yes.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

<1. Configuration of substrate processing apparatus and substrate processing operation>
FIG. 1 is a block diagram showing a configuration of a substrate processing apparatus 1 according to an embodiment of the present invention. The substrate processing apparatus 1 performs a cleaning process on a substrate W by immersing a plurality of substrates W (hereinafter simply referred to as “substrates W”) in pure water, and then cleaning the substrate W lifted from the pure water. This is an apparatus for drying the substrate W by supplying IPA gas to the surroundings. As shown in FIG. 1, the substrate processing apparatus 1 mainly includes a processing chamber 10, a nitrogen gas supply source 20, a first piping unit 30, an IPA gas generating unit 40, a second piping unit 50, and concentration measurement. Unit 60 and a control unit 80.

  The processing chamber 10 is a housing having a processing space for performing cleaning processing and drying processing of the substrate W inside. Inside the processing chamber 10, a processing tank 11, a lifter 12, and an IPA gas discharge unit 13 are arranged. The processing tank 11 is a container that stores pure water for cleaning the substrate W. The treatment tank 11 is connected with a pure water supply unit and a drainage unit (not shown). When the substrate W is immersed in the pure water stored in the processing tank 11, contaminants such as particles adhering to the surface of the substrate W are removed from the surface of the substrate by the pure water.

  The lifter 12 is a transport mechanism for transporting the substrate W up and down in the processing chamber 10. The lifter 12 includes three holding bars 12a in the horizontal direction, and the substrate W is held in a standing posture on a plurality of holding grooves carved in each holding bar 12a. The lifter 12 includes a drive unit (not shown) having a servo motor, a timing belt, and the like. When the driving unit is operated, the lifter 12 holding the substrate W moves up and down, and the substrate W is transported between the immersion position in the processing tank 11 and the pulling position above the processing tank 11.

  The IPA gas discharge unit 13 includes two discharge pipes 13a. The two discharge pipes 13a are respectively arranged along the row of the substrates W in the upper position of the processing tank 11, and a plurality of discharge ports 13b are formed in each discharge pipe 13a. Further, each discharge pipe 13a is connected to a pipe 13c that communicates with a pipe 52 of a second pipe section 50 described later. For this reason, the IPA gas supplied from the second piping unit 50 is introduced into the discharge pipe 13a via the pipe 13c and discharged into the processing chamber 10 from each discharge port 13b. Further, when measuring the concentration of IPA gas contained in the gas in the processing chamber 10, a part of the gas in the processing chamber 10 is taken into the discharge pipe 13a from the discharge port 13b, and the taken-in gas passes through the pipe 13c. Then, it is led out to the pipe 52 of the second pipe section 50. That is, the IPA gas discharge unit 13 has a function of collecting a part of the gas in the processing chamber 10 as a sample gas.

  The first piping unit 30 includes a plurality of pipings 31 to 33, and supplies nitrogen gas supplied from the nitrogen gas supply source 20 to the IPA gas generation unit 40 and the concentration measurement unit 60. The pipe 31 has an upstream end connected to the nitrogen gas supply source 20 and a downstream end branched into a pipe 32 and a pipe 33. An on-off valve 34, a mass flow controller 35, and a heater 36 are inserted in the middle of the path of the pipe 32 from the upstream side, and the downstream side of the pipe 32 is connected to the IPA gas generator 40. For this reason, when the on-off valve 34 is opened, nitrogen gas is supplied from the nitrogen gas supply source 20 to the IPA gas generator 40 via the pipes 31 and 32. The mass flow controller 35 has a function of adjusting the flow rate of nitrogen gas flowing in the pipe 32. Further, when the heater 36 is operated, the nitrogen gas flowing in the pipe 32 is heated. On the other hand, an on-off valve 37 and a heater 38 are inserted in the middle of the path of the pipe 33 from the upstream side, and the downstream side of the pipe 33 is connected to the concentration measuring unit 60. For this reason, when the on-off valve 37 is opened, nitrogen gas is supplied from the nitrogen gas supply source 20 to the concentration measuring unit 60 via the pipes 31 and 33. Further, when the heater 38 is operated, the nitrogen gas flowing in the pipe 33 is heated.

  The IPA gas generator 40 includes a tank 41 for storing liquid IPA, and a heater 42 attached to the bottom of the tank 41. When the heater 42 is operated, the liquid IPA stored in the tank 41 is heated and the liquid IPA is vaporized to generate IPA gas. The IPA gas generated in the tank 41 uses the nitrogen gas supplied from the pipes 31 and 32 of the first pipe part 30 as a carrier gas, and is sent to the second pipe part 50 together with the nitrogen gas.

  The second piping unit 50 includes a plurality of pipings 51 to 53, functions as an IPA gas supply path from the IPA gas generation unit 40 to the processing chamber 10, and has a concentration from the IPA gas generation unit 40 or the processing chamber 10. It functions as a sample gas supply path to the measurement unit 60. The upstream end of the pipe 51 is connected to the IPA gas generator 40, and a heater 54 and an opening / closing valve 55 are inserted in the middle of the pipe 51 from the upstream side. Further, the downstream end of the pipe 51 is branched into a pipe 52 and a pipe 53. An on-off valve 56 is inserted in the middle of the route of the pipe 52, and the downstream side of the pipe 52 is connected to the pipe 13 c in the processing chamber 10. For this reason, when the on-off valve 55 and the on-off valve 56 are opened, IPA gas is fed together with nitrogen gas from the IPA gas generator 40 into the processing chamber 10 via the pipes 51 and 52. Further, when the heater 54 is operated, the nitrogen gas and the IPA gas flowing through the pipe 51 are heated. On the other hand, an on-off valve 57 and a heater 58 are inserted in the middle of the path of the pipe 53 from the upstream side, and the downstream side of the pipe 53 is connected to the concentration measuring unit 60. For this reason, when the on-off valve 55 and the on-off valve 57 are opened, a part of the gas supplied from the IPA gas generating unit 40 is supplied to the concentration measuring unit 60 through the pipes 51 and 53 as the sample gas. When the on-off valve 55 is closed and the on-off valve 56 and the on-off valve 57 are opened, the gas in the processing chamber 10 collected from the IPA gas discharge unit 13 passes through the pipe 52 and the pipe 53 to the concentration measurement unit 60. Be sent. Further, when the heater 58 is operated, the sample gas flowing in the pipe 53 is heated.

  The concentration measuring unit 60 is a measuring unit for diluting the sample gas supplied from the pipe 53 and measuring the concentration of the processing gas contained in the diluted sample gas. The concentration measuring unit 60 includes a container 61 and pipes 62 to 64 configured inside the container 61. An upstream end of the pipe 62 is connected to the pipe 33 of the first pipe section 30, and a variable flow valve 65 and a flow meter 66 are inserted from the upstream side in the course of the pipe 62. . Further, the downstream side of the pipe 62 merges with the pipe 63 at a junction point 67. For this reason, the nitrogen gas fed as the dilution gas from the pipes 31 and 32 of the first pipe section 30 is introduced to the junction 67 through the pipe 62. The variable flow valve 65 has a function of adjusting the flow rate of nitrogen gas flowing in the pipe 62, and the flow meter 66 has a function of measuring the flow rate of nitrogen gas flowing in the pipe 62. Further, an ejection part 68 for ejecting a part of the nitrogen gas in the pipe 62 is provided at an upstream position of the variable flow valve 65 in the course of the pipe 62. For this reason, a part of the nitrogen gas heated by the heater 38 is ejected from the ejection part 68 toward the internal space of the container 61, thereby preventing the temperature inside the container 61 from being lowered. A variable flow valve 68 a for adjusting the amount of nitrogen gas jetted is attached to the jetting portion 68.

  On the other hand, the upstream end of the pipe 63 is connected to the pipe 53 of the second pipe section 50, and a variable flow valve 69 and a flow meter 70 are inserted from the upstream side along the path of the pipe 63. ing. Further, the downstream side of the pipe 63 merges with the pipe 62 at a junction point 67. For this reason, the sample gas supplied from the pipes 52 and 53 of the second pipe section 50 is introduced into the junction 67 through the pipe 63. At the junction 67, the sample gas introduced from the pipe 63 and the nitrogen gas introduced from the pipe 62 are mixed to dilute the sample gas. The variable flow valve 69 has a function of adjusting the flow rate of the sample gas flowing through the pipe 63, and the flow meter 70 has a function of measuring the flow rate of the sample gas flowing through the pipe 63.

  The upstream end of the pipe 64 is connected to the junction 67, and a variable flow valve 71, a flow meter 72, and a concentration meter 73 are inserted from the upstream side in the course of the pipe 64. In addition, the downstream end of the pipe 64 is connected to an exhaust line outside the container 61. For this reason, the sample gas diluted at the junction 67 is discharged to the exhaust line through the pipe 64. The variable flow valve 71 has a function of adjusting the flow rate of the sample gas flowing through the pipe 64, and the flow meter 72 has a function of measuring the flow rate of the sample gas flowing through the pipe 64. The concentration meter 73 has a function of measuring the concentration of the IPA gas contained in the sample gas flowing in the pipe 64.

  The control unit 80 is electrically connected to the flow meters 66, 70, 72 and the concentration meter 73, and acquires these measurement values. The control unit 80 includes the lifter 12, the on-off valves 34, 37, 55, 56, and 57, the mass flow controller 35, the heaters 36, 38, 42, 54, and 58, the variable flow valves 65, 68a, 69, and 72. They are electrically connected to control these operations. The control part 80 is comprised by the computer provided with CPU and memory, and performs said control, when CPU operate | moves based on a predetermined program. The control unit 80 is connected to a display unit 81 configured by a liquid crystal display or a CRT. The control unit 80 performs predetermined calculation processing (steps S23 to S24 and S33 to S34 described later) based on the measurement values acquired from the flow meters 65, 70, 71 and the concentration meter 73, and displays the calculated concentration values. Displayed on the part 81.

  FIG. 2 is a flowchart showing the flow of substrate processing in such a substrate processing apparatus 1. When processing the substrate W in the substrate processing apparatus 1, first, the substrate W is carried into the processing chamber 10, and the substrate W is placed on the lifter 12 waiting in the processing chamber 10 (step S11). The substrate processing apparatus 1 immerses the substrate W in the pure water stored in the processing tank 11 by lowering the lifter 12 holding the substrate W (step S12). Contaminants such as particles adhering to the surface of the substrate W are removed with pure water, and the surface of the substrate W is cleaned. When the dipping process for a predetermined time is completed, the substrate processing apparatus 1 raises the lifter 12 and pulls up the substrate W above the processing tank 11 (step S13). Then, the substrate processing apparatus 1 opens the on-off valves 34, 55, and 56, operates the heater 42 of the IPA gas generation unit 40, and supplies IPA gas together with nitrogen gas into the processing chamber 10 (step S14). At this time, the substrate processing apparatus 1 operates the heater 36 of the first piping unit 30 and the heater 54 of the second piping unit 50 to prevent the IPA gas being supplied from condensing due to a temperature drop. The IPA gas supplied into the processing chamber 10 is discharged toward the substrate W from the discharge port 13b of the discharge pipe 13a. The IPA gas is condensed on the surface of the substrate W and replaced with pure water attached to the surface of the substrate W. Then, the IPA droplets are vaporized from the surface of the substrate W, whereby the surface of the substrate W is dried. When the drying process of the substrate W is completed, the substrate W is carried out of the processing chamber 10 (step S15), and the processing of the substrate W in the substrate processing apparatus 1 is completed.

<2. Concentration measurement processing (when the gas in the processing chamber is the sample gas)>
Subsequently, in the substrate processing apparatus 1 described above, processing when measuring the concentration of the IPA gas using the gas in the processing chamber 10 as a sample gas will be described with reference to the flowchart of FIG. First, the substrate processing apparatus 1 closes the opening / closing valve 55 and opens the opening / closing valves 37, 56, 57. Thereby, sampling of the gas in the processing chamber 10 and supply of dilution gas are started (step S21). A part of the gas in the processing chamber 10 is taken into the discharge pipe 13a as a sample gas, and is sent to the junction 67 through the pipes 13c, 52, 53, and 63. Further, the nitrogen gas serving as the dilution gas is supplied from the nitrogen gas supply source 20 to the junction 67 through the pipes 31, 33 and 62. Thereby, sample gas and nitrogen gas are mixed in the junction point 67, and sample gas is diluted. Then, the diluted sample gas is discharged to the exhaust line through the pipe 64.

  At this time, the substrate processing apparatus 1 operates the heater 58 to heat the sample gas in the pipe 53. Thereby, temperature fall of sample gas is prevented and condensation of IPA gas contained in sample gas is controlled. Further, the substrate processing apparatus 1 operates the heater 38 to heat the nitrogen gas in the pipe 33. Thereby, the temperature fall of the sample gas at the time of dilution is prevented, and condensation of the IPA gas contained in the sample gas is suppressed. Further, part of the nitrogen gas heated by the heater 38 is ejected from the ejection portion 68 into the container 61. For this reason, the temperature drop of sample gas is prevented in the whole piping system contained in the container 61, and condensation of IPA gas contained in sample gas is suppressed.

  Next, the substrate processing apparatus 1 acquires the measurement values of the flow meters 66, 70, 72 and the concentration meter 73 (step S22). The flow rate of the dilution gas flowing in the pipe 62 is measured by the flow meter 66, and the measured value is transmitted to the control unit 80. The substrate processing apparatus 1 adjusts the opening of the variable flow valve 65 to adjust the flow rate of the dilution gas, and stabilizes the measurement result of the flow meter 66. This improves the accuracy of subsequent calculation processing. Further, the flow rate of the sample gas before dilution is measured by the flow meter 70, and the measured value is transmitted to the control unit 80. The substrate processing apparatus 1 adjusts the opening of the variable flow valve 65 to adjust the flow rate of the sample gas, and stabilizes the measurement result of the flow meter 70. This improves the accuracy of subsequent calculation processing. Further, the flow rate of the diluted sample gas is measured by the flow meter 72, and the measured value is transmitted to the control unit 80. The substrate processing apparatus 1 adjusts the opening of the variable flow valve 71 to adjust the flow rate of the sample gas, and stabilizes the measurement result of the flow meter 72. This improves the accuracy of subsequent calculation processing. Further, the concentration of the IPA gas contained in the diluted sample gas is measured by the densitometer 73, and the measured value is transmitted to the control unit 80.

  Subsequently, the substrate processing apparatus 1 calculates the dilution rate of the sample gas based on each acquired measurement result (step S23). As shown in FIGS. 4 and 5, the dilution rate can be calculated by two calculation formulas, and any calculation formula may be used. According to the calculation formula of FIG. 4, the sample gas dilution rate (P) is set to P = R1 / (R1 + R2) using the measurement value (R1) of the flow meter 70 and the measurement value (R2) of the flow meter 66. calculate. Further, according to the calculation formula of FIG. 5, the dilution rate (P) of the sample gas is set to P = (R3−R2) using the measurement value (R2) of the flow meter 65 and the measurement value (R3) of the flow meter 72. ) / R3.

  Thereafter, the control unit 80 multiplies the measurement value (C1) of the densitometer 73 and the reciprocal (1 / P) of the above dilution rate to obtain the concentration (C0) of the IPA gas contained in the sample gas before dilution. Calculation is performed as C0 = C1 × (1 / P) (step S24). Then, the substrate processing apparatus 1 displays the calculated IPA gas concentration (C0) on the display unit 81 (step S25).

<3. Concentration measurement processing (when the gas supplied to the processing chamber is the sample gas)>
Next, in the substrate processing apparatus 1 described above, a process when measuring the concentration of the IPA gas using the gas supplied from the IPA gas generator 40 to the processing chamber 10 as a sample gas will be described with reference to the flowchart of FIG. To do. First, the substrate processing apparatus 1 opens the on-off valves 37, 55, and 57. Thereby, collection of the gas supplied from the IPA gas generation unit 40 and supply of the dilution gas are started (step S31). A part of the gas supplied from the IPA gas generator 40 to the processing chamber 10 is introduced into the pipe 53 as a sample gas, and is supplied to the junction 67 through the pipe 53 and the pipe 63. Further, the nitrogen gas serving as the dilution gas is supplied from the nitrogen gas supply source 20 to the junction 67 through the pipes 31, 33 and 62. Thereby, sample gas and nitrogen gas are mixed in the junction point 67, and sample gas is diluted. Then, the diluted sample gas is discharged to the exhaust line through the pipe 64.

  At this time, the substrate processing apparatus 1 operates the heater 58 to heat the sample gas in the pipe 53. Thereby, temperature fall of sample gas is prevented and condensation of IPA gas contained in sample gas is controlled. Further, the substrate processing apparatus 1 operates the heater 38 to heat the nitrogen gas in the pipe 33. Thereby, the temperature fall of the sample gas at the time of dilution is prevented, and condensation of the IPA gas contained in the sample gas is suppressed. Further, part of the nitrogen gas heated by the heater 38 is ejected from the ejection portion 68 into the container 61. For this reason, the temperature drop of sample gas is prevented in the whole piping system contained in the container 61, and condensation of IPA gas contained in sample gas is suppressed.

  Next, the substrate processing apparatus 1 acquires the measurement values of the flow meters 66, 70, 72 and the concentration meter 73 (step S32). The flow rate of the dilution gas flowing in the pipe 62 is measured by the flow meter 66, and the measured value is transmitted to the control unit 80. The substrate processing apparatus 1 adjusts the opening of the variable flow valve 65 to adjust the flow rate of the dilution gas, and stabilizes the measurement result of the flow meter 66. This improves the accuracy of subsequent calculation processing. Further, the flow rate of the sample gas before dilution is measured by the flow meter 70, and the measured value is transmitted to the control unit 80. The substrate processing apparatus 1 adjusts the opening of the variable flow valve 65 to adjust the flow rate of the sample gas, and stabilizes the measurement result of the flow meter 65. This improves the accuracy of subsequent calculation processing. Further, the flow rate of the diluted sample gas is measured by the flow meter 72, and the measured value is transmitted to the control unit 80. The substrate processing apparatus 1 adjusts the opening of the variable flow valve 71 to adjust the flow rate of the sample gas, and stabilizes the measurement result of the flow meter 72. This improves the accuracy of subsequent calculation processing. Further, the concentration of the IPA gas contained in the diluted sample gas is measured by the densitometer 73, and the measured value is transmitted to the control unit 80.

  Subsequently, the substrate processing apparatus 1 calculates the dilution rate of the sample gas based on each acquired measurement result (step S33). As shown in FIGS. 4 and 5, the dilution rate can be calculated by two calculation formulas, and any calculation formula may be used. According to the calculation formula of FIG. 4, the sample gas dilution rate (P) is set to P = R1 / (R1 + R2) using the measurement value (R1) of the flow meter 70 and the measurement value (R2) of the flow meter 66. calculate. Further, according to the calculation formula of FIG. 5, the dilution rate (P) of the sample gas is set to P = (R3−R2) using the measurement value (R2) of the flow meter 65 and the measurement value (R3) of the flow meter 72. ) / R3.

  Thereafter, the control unit 80 multiplies the measurement value (C1) of the densitometer 73 and the reciprocal (1 / P) of the above dilution rate to obtain the concentration (C0) of the IPA gas contained in the sample gas before dilution. Calculation is performed as C0 = C1 × (1 / P) (step S24). Then, the substrate processing apparatus 1 displays the calculated IPA gas concentration (C0) on the display unit 81 (step S25).

<4. Summary>
As described above, the substrate processing apparatus 1 dilutes the sample gas by mixing the sample gas and the dilution gas, and measures the concentration of the IPA gas contained in the diluted sample gas. Then, the concentration of the IPA gas contained in the sample gas before dilution is calculated based on the measured concentration value and the flow rates of the sample gas and the dilution gas. For this reason, even when a high concentration IPA gas is used, the concentration of the IPA gas can be accurately measured.

  In particular, the substrate processing apparatus 1 is included in the sample gas before dilution by multiplying the measured value of the concentration meter 73 by the reciprocal of the dilution rate obtained based on the measured values of the flow meters 66, 70, and 72. The concentration of the processing gas is calculated. For this reason, the concentration of the processing gas contained in the sample gas before dilution can be calculated easily and accurately.

  In addition, the substrate processing apparatus 1 flows in the pipe 64, a variable flow valve 65 that adjusts the flow rate of nitrogen gas flowing in the pipe 62, a variable flow valve 69 that adjusts the flow rate of sample gas flowing in the pipe 63, and the pipe 64. And a variable flow valve 71 for adjusting the flow rate of the sample gas. For this reason, each measurement value of the flow meters 66, 70, 72 is stabilized, and the concentration of the IPA gas can be calculated more accurately.

  The substrate processing apparatus 1 also includes a heater 38 that controls the temperature of the nitrogen gas that flows through the pipe 33, and a heater 58 that controls the temperature of the sample gas that flows through the pipe 53. For this reason, the temperature fall of sample gas is prevented and condensation of IPA gas contained in sample gas is controlled. Therefore, the concentration of the IPA gas can be calculated more accurately.

  In addition, the substrate processing apparatus 1 includes a container 61 that houses a piping system including flow meters 66, 70, 72 and a concentration meter 73, and an ejection unit 68 that ejects temperature-controlled nitrogen gas into the container 61. Is provided. For this reason, the temperature fall of sample gas is prevented in the whole piping system contained in the container 61, and condensation of IPA gas contained in sample gas is suppressed. Therefore, the concentration of the IPA gas can be calculated more accurately.

  Further, the substrate processing apparatus 1 uses nitrogen gas as a carrier gas as a dilution gas. For this reason, it is possible to accurately dilute the sample gas without increasing the types of gases contained in the sample gas. In addition, since the carrier gas and the dilution gas can be supplied from the same nitrogen gas supply source 20, the configuration of the substrate processing apparatus 1 is simplified.

  Further, the substrate processing apparatus 1 switches the opening and closing of the on-off valves 55 to 57 to use the gas in the processing chamber 10 as the sample gas and the gas supplied from the IPA gas generator 40 as the sample gas. The state can be switched. For this reason, it is possible to cope with either the case where it is desired to measure the concentration of the IPA gas contained in the gas in the processing chamber 10 or the case where it is desired to measure the concentration of the IPA gas contained in the gas supplied to the processing chamber 10.

  As mentioned above, although one Embodiment of this invention was described, this invention is not limited to said example. For example, in the substrate processing apparatus 1 described above, the IPA gas discharge unit 13 is used to collect a part of the gas in the processing chamber 10, but a gas suction unit for collecting the gas in the processing chamber 10 is separately provided. It may be provided. The substrate processing apparatus 1 has the flow meter 70 for measuring the flow rate of the sample gas before dilution and the flow meter 72 for measuring the flow rate of the sample gas after dilution. It is only necessary to have at least one of them.

  In addition, the substrate processing apparatus 1 described above is an apparatus that performs a cleaning process and a drying process in the processing chamber 10. However, the substrate processing apparatus 1 may perform only a drying process in the processing chamber 10. In addition, the substrate processing apparatus of the present invention may perform processing different from the drying processing using a processing gas other than the IPA gas. Moreover, although the said substrate processing apparatus 1 processed the several board | substrate W collectively, the single-wafer | sheet-fed substrate processing apparatus which processes the board | substrate W one by one may be sufficient.

It is the block diagram which showed the structure of the substrate processing apparatus which concerns on one Embodiment of this invention. It is the flowchart which showed the flow of the substrate processing in a substrate processing apparatus. It is the flowchart which showed the flow of the density | concentration measurement process which uses the gas in a process chamber as sample gas. It is the figure which showed the content of the calculation process performed based on a measurement result. It is the figure which showed the content of the calculation process performed based on a measurement result. It is the flowchart which showed the flow of the density | concentration measurement process which uses the gas supplied from an IPA gas generation part as sample gas.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate processing apparatus 10 Processing chamber 11 Processing tank 12 Lifter 20 Nitrogen gas supply source 30 1st piping part 34, 37, 55, 56, 57 On-off valve 36, 38, 54, 58 Heater 40 IPA gas generation part 50 2nd piping Unit 60 Concentration measuring unit 61 Container 65, 69, 71 Variable flow valve 66, 70, 72 Flow meter 67 Junction point 68 Ejecting unit 73 Densitometer 80 Control unit 81 Display unit W substrate

Claims (10)

A substrate processing apparatus for processing a substrate with a processing gas,
A processing chamber for accommodating the substrate therein;
A processing gas supply unit for supplying a processing gas together with a carrier gas to the processing chamber;
A sampling unit for sampling a part of the gas supplied from the processing gas supply unit to the processing chamber as a sample gas;
A dilution gas supply unit for supplying a dilution gas for diluting the sample gas;
A dilution unit for diluting the sample gas by mixing the sample gas collected by the collection unit and the dilution gas supplied by the dilution gas supply unit;
A concentration meter that measures the concentration of the processing gas contained in the sample gas diluted by the dilution section;
A first flow meter for measuring a flow rate of the sample gas before dilution flowing through the pipe from the sampling unit to the dilution unit or a flow rate of the sample gas after dilution flowing through the pipe from the dilution unit;
A second flow meter for measuring a flow rate of the dilution gas flowing through a pipe from the dilution gas supply unit to the dilution unit;
Based on the measured values of the concentration meter, the first flow meter, and the second flow meter, a calculation unit that calculates the concentration of the processing gas contained in the sample gas before dilution;
A substrate processing apparatus comprising: The substrate processing apparatus according to claim 1,
The calculation unit includes the sample value before dilution by multiplying the measured value of the concentration meter by the reciprocal of the dilution rate obtained based on the measured values of the first flow meter and the second flow meter. A substrate processing apparatus for calculating a concentration of a processing gas to be obtained. The substrate processing apparatus according to claim 1 or 2, wherein
The substrate processing apparatus further comprising a flow rate adjusting unit for the pre-dilution sample gas that adjusts the flow rate of the sample gas flowing through the pipe from the collection unit to the dilution unit. A substrate processing apparatus according to any one of claims 1 to 3, wherein
A substrate processing apparatus, further comprising: a flow rate adjusting unit for the diluted sample gas that adjusts a flow rate of the sample gas flowing through a pipe from the dilution unit to the concentration meter. A substrate processing apparatus according to any one of claims 1 to 4, wherein
A substrate processing apparatus, further comprising a dilution gas flow rate adjusting unit for adjusting a flow rate of the dilution gas flowing through a pipe from the dilution gas supply unit to the dilution unit. A substrate processing apparatus according to any one of claims 1 to 5, wherein
A substrate processing apparatus, further comprising a temperature control unit for sample gas that controls the temperature of the sample gas flowing through the pipe from the collection unit to the dilution unit. A substrate processing apparatus according to any one of claims 1 to 6,
A substrate processing apparatus, further comprising a dilution gas temperature adjusting unit for adjusting the temperature of the dilution gas flowing through a pipe from the dilution gas supply unit to the dilution unit. The substrate processing apparatus according to claim 7,
A container containing a gas piping system including the concentration meter, the first flow meter, and the second flow meter;
An ejection part for ejecting the dilution gas temperature-controlled by the temperature adjustment part for the dilution gas into the container;
A substrate processing apparatus further comprising: A substrate processing apparatus according to any one of claims 1 to 7,
The dilution gas supply unit supplies a carrier gas as a dilution gas. A substrate processing apparatus according to any one of claims 1 to 9, wherein
The sampling unit is in a first state where a part of the gas supplied from the processing gas supply unit is sampled as a sample gas, and in a second state where a part of the gas in the processing chamber is sampled as a sample gas A substrate processing apparatus characterized by being switchable.

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