SUBSTRATE PROCESSING APPARATUS, ABNORMALITY DETECTION METHOD AND NON-TRANSITORY COMPUTER READABLE MEDIUM STORING ABNORMALITY DETECTION PROGRAM

In a substrate processing apparatus, a substrate is processed with use of a processing liquid. A first operation component and a second operation component are used in the substrate process. A first operation value of the first operation component and a second operation value of the second operation component are acquired by an operation value acquirer. Whether an abnormality has occurred is determined by an abnormality determiner based on the correlation between the first operation value and the second operation value that are acquired by the operation value acquirer.

BACKGROUND

Technical Field

The present invention relates to a substrate processing apparatus that processes a substrate, an abnormality detection method and a non-transitory computer readable medium storing an abnormality detection program.

Description of Related Art

A substrate processing apparatus is used to perform various processes such as film formation, development and cleaning on a substrate such as a semiconductor substrate, a glass substrate for a liquid crystal display device, a glass substrate for a photomask or a glass substrate for an optical disc. In a case in which the substrate processing apparatus is operated for a long period of time, an abnormality such as damage or deterioration of an operation component of the substrate processing apparatus may occur.

JP 2018-77764 A describes an abnormality detection device that can predict an abnormality in a semiconductor manufacturing apparatus. In this abnormality detection apparatus, state information representing the state of each component of the semiconductor manufacturing apparatus is collected in a predetermined period. The state information includes a temperature, a pressure, a gas flow rate, electric power or the like of each component of the semiconductor manufacturing apparatus. The collected state information is stored as a log for each predetermined unit.

A monitoring band for monitoring the state of each component of the semiconductor manufacturing apparatus is generated based on a stored log. The monitoring band is a waveform used when it is determined whether the collected state information is normal, and is generated by interpolation based on an upper limit value and a lower limit value set for each predetermined period, for example. Whether the state of each component of the semiconductor manufacturing apparatus is abnormal is determined based on the state information and the monitoring band.

SUMMARY

As in the abnormality detection apparatus described in JP 2018-77464 A, it is desired to detect an abnormality before a substrate processing apparatus fails.

An object of the present invention is to provide a substrate processing apparatus and an abnormality detection method that enable detection of an abnormality at an early stage, and a computer-readable medium storing an abnormality detection program.

(1) A substrate processing apparatus according to one aspect of the present invention that includes a first operating component and a second operating component that are used in a substrate process with use of a processing liquid, includes an operation value acquirer that acquires a first operation value of the first operation component and a second operation value of the second operation component, and an abnormality determiner that determines whether an abnormality has occurred based on a correlation between the first operation value and the second operation value that are acquired by the operation value acquirer.

In this substrate processing apparatus, a substrate is processed with use of a processing liquid. Further, it is determined whether an abnormality has occurred based on the correlation between the first operation value of the first operation component and the second operation value of the second operation component. Therefore, it is possible to detect an abnormality in the substrate processing apparatus at an early stage before the substrate processing apparatus fails.

(2) The abnormality determiner may determine whether an abnormality has occurred based on a ratio of datapoints exceeding an allowable range defined based on a correlation between the first operation value and the second operation value to datapoints defined by sets of the first operation value and the second operation value that are acquired by the operation value acquirer. In this case, it is possible to detect an abnormality in the substrate processing apparatus in a simple process.

(3) The allowable range may be defined so as to include a predetermined ratio of datapoints out of datapoints defined by sets of the first operation value and the second operation value that are acquired in advance by the operation value acquirer before a substrate process. In this case, it is possible to easily determine the allowable range used for determination in regard to an abnormality.

(4) The abnormality determiner may determine whether an abnormality has occurred each time a predetermined number of substrates are processed or a predetermined period of time elapses. With this configuration, an abnormality in the substrate processing apparatus is detected at an early stage easily.

(5) The first operation component may include a first regulating valve that regulates a flow rate of a processing liquid to be supplied to the substrate based on a first pulse value, the second operation component may include a second regulating valve that regulates a flow rate of a processing liquid to be supplied to the substrate based on a second pulse value, the first operation value may be the first pulse value supplied to the first regulating valve, and the second operation value may be the second pulse value supplied to the second regulating valve.

In this case, it is possible to detect an abnormality in the substrate processing apparatus at an early stage based on the correlation between a pulse value supplied to the first regulating valve and a pulse value supplied to the second regulating valve.

(6) The first operation component may include a regulating valve that regulates a flow rate of a processing liquid to be supplied to the substrate based on a pulse value, the second operation component may include a manometer that detects a pressure of a processing liquid to be guided to the regulating valve, the first operation value may be the pulse value supplied to the regulating valve, and the second operation value may be a pressure detected by the manometer.

In this case, it is possible to detect an abnormality in the substrate processing apparatus at an early stage based on the correlation between a pulse value supplied to the regulating valve and a pressure detected by the manometer.

(7) The first operation component may include a first flowmeter and a second flowmeter that respectively detect flow rates of a first processing liquid and a second processing liquid, the second operation component may include a concentration meter that detects a concentration of a processing liquid mixture generated by mixing of the first processing liquid and the second processing liquid, the first operation value may be a theoretical value of concentration of the processing liquid mixture calculated based on a ratio between a flow rate of the first processing liquid and a flow rate of the second processing liquid that are respectively detected by the first flowmeter and the second flowmeter, and the second operation value may be an actual measured value of concentration of the processing liquid mixture detected by the concentration meter.

In this case, it is possible to detect an abnormality in the substrate processing apparatus at an early stage based on the correlation between a theoretical value of concentration of the processing liquid mixture calculated based on the ratio between the flow rate of the first processing liquid and the flow rate of the second processing liquid, and an actual measured value of concentration of the processing liquid mixture detected by the concentration meter.

(8) The substrate processing apparatus may further include a storage into which a processing liquid mixture in which a first processing liquid and a second processing liquid are mixed flows, the first operation component may include a first flowmeter and a second flowmeter that respectively detect flow rates of the first processing liquid and the second processing liquid, the second operation component may include a concentration meter that detects a concentration of the processing liquid mixture that flows out from the storage, the processing liquid mixture that has flowed into the storage may arrive at the concentration meter in a first period of time, the first operation value may be a theoretical value of concentration of the processing liquid mixture that is calculated based on an integrated value of flow rates of the first processing liquid and an integrated value of flow rates of the second processing liquid, the flow rates being respectively detected by the first flowmeter and the second flowmeter in a period from a first point in time to a second point in time at which a second period of time has elapsed from the first point in time, and the second operation value may be a statistical value of concentrations of the processing liquid mixture detected by the concentration meter in a period from a third point in time at which the first period of time has elapsed from the first point in time to a fourth point in time at which the first period of time has elapsed from the second point in time.

In this case, it is determined whether an abnormality has occurred in the substrate processing apparatus based on the correlation between a theoretical value of concentration of the processing liquid mixture calculated based on an integrated value of the flow rate of the first processing liquid and an integrated value of the flow rate of the second processing liquid, and a statistical value of concentration of the processing liquid mixture. Here, because there is the strong correlation between a theoretical value of concentration of the processing liquid mixture and a statistical value of concentration of the processing liquid mixture, described above, it is possible to detect an abnormality in the substrate processing apparatus more reliably.

(9) The first operation component may include a first flowmeter and a second flowmeter that respectively detect flow rates of a first processing liquid and a second processing liquid, the second operation component may include a concentration meter that detects a concentration of a processing liquid mixture generated by mixing of the first processing liquid and the second processing liquid, a concentration predictive model, which is obtained by machine learning of a relationship between flow rates of the first processing liquid, flow rates of the second processing liquid and concentrations of the processing liquid mixture in a period from a first point in time to a second point in time at which a first period of time has elapsed from the first point in time, and a concentration of the processing liquid mixture at a third point in time at which a second period of time has elapsed from the second point in time, may be prepared, the first operation value may be a predicted value of concentration of the processing liquid mixture at a sixth point in time at which the second period of time has elapsed from a fifth point in time, the predicted value being acquired by application of flow rates of the first processing liquid detected by the first flowmeter, flow rates of the second processing liquid detected by the second flowmeter and concentrations of the processing liquid mixture detected by the concentration meter in a period from a fourth point in time to the fifth point in time at which the first period of time has elapsed from the fourth point in time to the concentration predictive model, and the second operation value may be an actual measured value of concentration of the processing liquid mixture that is detected by the concentration meter at the sixth point in time.

In this case, it is possible to detect a single abnormality that occurs in the substrate processing apparatus in a relatively short period of time based on the correlation between a predicted value of concentration of the processing liquid mixture acquired based on the concentration predictive model and an actual measured value of concentration of the processing liquid mixture detected by the concentration meter.

(10) The substrate processing apparatus may further include a storage that stores a processing liquid mixture in which a first processing liquid and a second processing liquid are mixed, a substrate processor that processes a substrate using the processing liquid mixture, a first flow path portion that guides the processing liquid mixture while mixing the first processing liquid and the second processing liquid to generate the processing liquid mixture, a second flow path portion that guides the processing liquid mixture stored in the storage to the substrate processor, and a third flow path portion that guides the processing liquid mixture that has not been used in the substrate processor to the storage, the first operation component may include a first flowmeter and a second flowmeter that respectively detect flow rates of the first processing liquid and the second processing liquid, the second operation component may include a concentration meter that detects a concentration of the processing liquid mixture that flows out from the storage, the processing liquid mixture that has flowed into the storage through the first flow path portion may arrive at the concentration meter in a first period of time, the first operation value may be a theoretical value of concentration of the processing liquid mixture stored in the storage at each point in time, the theoretical value being calculated based on a volume of the processing liquid mixture that flows into the storage through the first flow path portion, a volume of the processing liquid mixture that flows out from the storage through the second flow path portion and a volume of the processing liquid mixture that flows into the storage through the third flow path portion, per unit time, and a flow rate of the first processing liquid and a flow rate of the second processing liquid that are respectively detected by the first flowmeter and the second flowmeter, and the second operation value may be an actual measured value of concentration of the processing liquid mixture detected by the concentration meter at a point in time at which the first period of time has elapsed from a point in time at which the processing liquid mixture flows into the storage through the first flow path portion.

In a case in which the concentration of the processing liquid mixture supplied to the substrate processor changes, an unused processing liquid mixture in the substrate processor is returned to the storage. Thus, the concentration of the processing liquid mixture stored in the storage changes. Even in this case, with the above-mentioned configuration, whether an abnormality has occurred in the substrate processing apparatus is determined based on the correlation between a theoretical value of concentration of the processing liquid mixture stored in the storage calculated based on a volume of the processing liquid mixture flowing into or out of the storage, the flow rate of the first processing liquid and the flow rate of the second processing liquid, and an actual measured value of concentration of the processing liquid mixture detected by the concentration meter. In this case, it is possible to strengthen the correlation between a theoretical value of concentration of the processing liquid mixture and a statistical value of concentration of the processing liquid mixture. Therefore, it is possible to detect an abnormality in the substrate processing apparatus more reliably.

(11) The first operation component may include a first chuck pin that transitions between a first close state in which the first operation component holds the substrate and a first open state in which the first operation component does not hold the substrate, the second operation component may include a second chuck pin that transitions between a second close state in which the second operation component holds the substrate and a second open state in which the second operation component does not hold the substrate, the first operation value may be a transition period of time in which the first chuck pin transitions between the first close state and the first open state, and the second operation value may be a transition period of time in which the second chuck pin transitions between the second close state and the second open state.

In this case, it is possible to detect an abnormality in the substrate processing apparatus at an early stage based on the correlation between a transition period of time of the first chuck pin and a transition period of time of the second chuck pin.

(12) The first operation component may include a chuck pin that transitions between a first close state in which the first operation component holds the substrate and a first open state in which the first operation component does not hold the substrate, the second operation component may include a chuck driver that transitions between a second close state in which the chuck pin transitions to the first close state and a second open state in which the chuck pin transitions to the first open state, the first operation value may be a transition period of time between the first close state and the first open state for the chuck pin, and the second operation value may be a transition period of time between the second close state and the second open state for the chuck driver.

In this case, it is possible to detect an abnormality in the substrate processing apparatus at an early stage based on the correlation between a transition period of time of the chuck pin and a transition period of time of the chuck driver.

(13) The first operation component may include a first processor that moves between a first waiting position at which the first operation component does not process the substrate and a first processing position at which the first operation component processes the substrate, the second operation component may include a second processor that moves between a second waiting position at which the second operation component does not process the substrate and a second processing position at which the second operation component processes the substrate, the first operation value may be a movement period of time in which the first processor moves between the first waiting position and the first processing position, and the second operation value may be a movement period of time in which the second processor moves between the second waiting position and the second processing position.

In this case, it is possible to detect an abnormality in the substrate processing apparatus at an early stage based on the correlation between a moving period of time of the first processor and a moving period of time of the second processor.

(14) The substrate processing apparatus may further include an operation value selector that selects a second operation value that satisfies a predetermined standard out of the second operation values acquired by the operation value acquirer and selects a first operation value corresponding to the second operation value selected out of the first operation values acquired by the operation value acquirer, wherein the abnormality determiner may determine whether an abnormality has occurred based on a change of a time series of a first operation value selected by the operation value selector.

In this case, it is determined whether an abnormality has occurred based on the change of a time-series of the first operation value satisfying a predetermined standard out of the acquired first operation values. Therefore, it is possible to detect an abnormality in the substrate processing apparatus reliably.

(15) The first operation component may include a torque sensor that detects a torque of a spin driver, the second operation component may include a temperature sensor that detects a temperature of the spin driver, the first operation value may be a torque of the spin driver detected by the torque sensor, and the second operation value may be a temperature of the spin driver detected by the temperature sensor.

In this case, it is possible to easily select a torque satisfying a predetermined standard out of the torques of the spin driver detected by the torque sensor based on a temperature of the spin driver detected by the temperature sensor. Therefore, it is possible to detect an abnormality in the substrate processing apparatus easily.

(16) The first operation value may be a torque acquired when the spin driver is rotating at a predetermined constant rotation speed out of torques of the spin driver detected by the torque sensor, and the second operation value may be a temperature acquired when the spin driver is rotating at the constant rotation speed out of temperatures of the spin driver detected by the temperature sensor. In this case, it is possible to detect an abnormality in the substrate processing apparatus more accurately.

(17) An abnormality detection method according to another aspect of the present invention of detecting an abnormality in a substrate processing apparatus that includes a first operation component and a second operation component that are used in a substrate process with use of a processing liquid, includes acquiring a first operation value of the first operation component and a second operation value of the second operation component that are correlated with each other, and determining whether an abnormality has occurred based on the acquired first operation value and the acquired second operation value.

With this abnormality detection method, it is determined whether an abnormality has occurred based on the correlation between the first operation value of the first operation component and the second operation value of the second operation component in a substrate process with use of a processing liquid. Therefore, it is possible to detect an abnormality in the substrate processing apparatus at an early stage before the substrate processing apparatus fails.

(18) A non-transitory computer readable medium according to yet another aspect of the present invention storing an abnormality detection program that is executed by a processing device and detects an abnormality in a substrate processing apparatus includes a first operation component and a second operation component that are used in a substrate process with use of a processing liquid, the abnormality detection program causes the processing device to perform the processes of acquiring a first operation value of the first operation component and a second operation value of the second operation component that are correlated with each other, and determining whether an abnormality has occurred based on the acquired first operation value and the acquired second operation value.

With this abnormality detection program, whether an abnormality has occurred is determined based on the correlation between the first operation value of the first operation component and the second operation value of the second operation component in a substrate process with use of a processing liquid. Therefore, it is possible to detect an abnormality in the substrate processing apparatus at an early stage before the substrate processing apparatus fails.

Other features, elements, characteristics, and advantages of the present disclosure will become more apparent from the following description of preferred embodiments of the present disclosure with reference to the attached drawings.

DETAILED DESCRIPTION

<1> Configuration of Substrate Processing Apparatus

A substrate processing apparatus, an abnormality detection method and a non-transitory computer readable medium storing an abnormality detection program according to embodiments of the present invention will be described below with reference to the drawings. In the following description, a substrate refers to a semiconductor substrate, a substrate for an FPD (Flat Panel Display) such as a liquid crystal display device or an organic EL (Electro Luminescence) display device, a substrate for an optical disc, a substrate for a magnetic disc, a substrate for a magneto-optical disc, a substrate for a photomask, a ceramic substrate, a substrate for a solar cell, or the like.

FIG.1is a block diagram showing the schematic configuration of the substrate processing apparatus according to one embodiment of the present invention. As shown inFIG.1, the substrate processing apparatus1includes a substrate processor100and a controller200. The substrate processor100includes one or a plurality of processing units110that performs various processes on a substrate using a processing liquid.

Specifically, each processing unit110may be a cleaning unit that supplies a cleaning liquid to a substrate, a coating unit that supplies a coating liquid to a substrate or a developing unit that supplies a developing liquid to a substrate. Each processing unit110is provided with a rotation holder that holds and rotates a substrate, a processing liquid supplier that supplies a processing liquid to a substrate or the like.

Further, in a case in which the processing unit110is an etching unit that supplies an etching liquid to a substrate, the substrate processor100may be provided with a chemical liquid generator300. The chemical liquid generator300generates a diluted chemical liquid obtained by dilution of an undiluted liquid of a chemical liquid as an etching liquid and supplies the etching liquid to each substrate processor100.

The controller200includes a CPU (Central Processing Unit) and a memory, a microcomputer or the like. The CPU of the controller200controls the operations of various operation components in the substrate processor100or the chemical liquid generator300. The memory of the controller200stores the abnormality detection program for detecting an abnormality of an operation component of the substrate processing apparatus1.

Further, the CPU of the controller200collects predetermined information from various operation components in the substrate processor100or the chemical liquid generator300during execution of substrate processing and detects an abnormality in the substrate processing apparatus1based on a result of processing of the collected information. An example of detection of an abnormality in the substrate processing apparatus1relating to various operation components of the substrate processor100or the chemical liquid generator300will be described below.

<2> First Embodiment

(1) Processing Liquid Supplier

In a first embodiment, an abnormality in a processing liquid supplier included in each processing unit110as an operation component of the substrate processor100is detected.FIG.2is a diagram showing the configuration of a processing liquid supplier in the first embodiment. As shown inFIG.2, a plurality of processing liquid suppliers400are connected to a circulation pipe401through which a processing liquid circulates. Further, a manometer402for detecting the pressure of a processing liquid is provided in the circulation pipe401.

A processing liquid supplier400includes an upper surface supplier410and a lower surface supplier420. The upper surface supplier410includes a pipe411, a flowmeter412, an on-off valve413, a regulating valve414and a nozzle415. The pipe411is connected to the circulation pipe401. Thus, a processing liquid flowing from the circulation pipe401flows through the pipe411. In the pipe411, the flowmeter412, the on-off valve413, the regulating valve414and the nozzle415are provided in this order from an upstream position to a downstream position.

The flowmeter412detects the flow rate of a processing liquid flowing through the pipe411and provides a result of detection to the controller200. The on-off valve413opens or closes the flow path of the pipe411. The regulating valve414includes a motor needle valve, for example, and adjusts the flow rate of a processing liquid flowing through the pipe411based on the pulse control performed by the controller200. The nozzle415is arranged above a substrate W and supplies a processing liquid to the upper surface of the substrate W.

The lower surface supplier420includes a pipe421, a flowmeter422, an on-off valve423, a regulating valve424and a nozzle425. The upstream end of the pipe421is connected to the pipe411at a position farther upstream than the flowmeter412. Thus, a processing liquid flowing from the circulation pipe401flows through the pipe421. In the pipe421, the flowmeter422, the on-off valve423, the regulating valve424and the nozzle425are provided in this order from an upstream position to a downstream position.

The flowmeter422detects the flow rate of a processing liquid flowing through the pipe421and provides a result of detection to the controller200. The on-off valve423opens or closes the flow path of the pipe421. The regulating valve424includes a motor needle valve, for example, and adjusts the flow rate of a processing liquid flowing through the pipe421based on the pulse control performed by the controller200. The nozzle425is arranged below a substrate W and supplies a processing liquid to the lower surface of the substrate W.

In the present example, the nozzles415,425supply a processing liquid to the upper surface and the lower surface of a substrate W to be processed at substantially the same frequency and at substantially the same flow rate. Thus, the upper surface and the lower surface of the substrate W are processed. The substrate W to be processed may be processed while being held and rotated by a rotation holder700ofFIG.19, described below, for example.

FIG.3is the functional block diagram showing the configuration of the controller200. As shown inFIG.3, the controller200includes an operation value acquirer210, an abnormality determiner220and a notifier230as functions. The functions of the controller200are implemented by execution of the abnormality detection program stored in the memory by the CPU of the controller200. Part or all of the functions of the controller200may be implemented by hardware such as an electronic circuit.

The operation value acquirer210performs the pulse control of the regulating valve414by supplying a predetermined number of pulses to the regulating valve414such that the flow rate of a processing liquid flowing through the flow path of the upper surface supplier410is regulated to a predetermined value based on a result of detection supplied from the flowmeter412. Thus, the operation value acquirer210acquires a pulse value supplied to the regulating valve414as a first operation value.

Similarly, the operation value acquirer210performs the pulse control of the regulating valve424by supplying a predetermined number of pulses to the regulating valve424such that the flow rate of a processing liquid flowing through the flow path of the lower surface supplier420is regulated to a predetermined value based on a result of detection supplied from the flowmeter422. Thus, the operation value acquirer210acquires a pulse value supplied to the regulating valve424as a second operation value.

The flow rate of a processing liquid may not be stable immediately after the start and end of the supply of the processing liquid. As such, a pulse value does not have to be acquired immediately after the start and the end of the supply of a processing liquid. In this case, pulse values are acquired as first and second operation values in a period which is from a predetermined point in time after the start of supply to a predetermined point in time before the end of supply and during which the flow rate of a processing liquid is stabilized.

Each time the pulse control of the regulating valves414,424is performed, the abnormality determiner220plots a datapoint determined by a set of a pulse value supplied to the regulating valve414and a pulse value supplied to the regulating valve424on a correlation graph.FIG.4is a diagram showing a correlation graph. As shown inFIG.4, the correlation graph is a two-dimensional graph having first and second operation values as axes. Specifically, in the correlation graph ofFIG.4, the abscissa indicates a pulse value supplied to the regulating valve414, and the ordinate indicates a pulse value supplied to the regulating valve424.

In the correlation graph, an allowable range R is defined in advance based on the correlation between a pulse value supplied to the regulating valve414and a pulse value supplied to the regulating valve424. In the present example, the allowable range R has an elliptical shape, and is defined so as to include a predetermined ratio (95%, for example) of datapoints out of the datapoints defined by sets of a pulse value supplied to the regulating valve414and a pulse value supplied to the regulating valve424that are acquired in advance before a substrate is processed. The allowable range R may be defined based on a regression curve obtained by distribution of datapoints. The allowable range R is preferably defined based on datapoints acquired before the processing liquid supplier400deteriorates over time such as a time when the processing liquid supplier400is installed.

The abnormality determiner220determines whether an abnormality has occurred based on the ratio of datapoints exceeding the allowable range R to the plotted datapoints at a predetermined point in time. Determination in regard to an abnormality may be made each time a predetermined number of substrates W are processed or each time a predetermined period of time elapses. In this case, an abnormality in the substrate processing apparatus1is detected easily at an early stage.

In the present example, in a case in which the ratio of the datapoints exceeding the allowable range R to the plotted datapoints exceeds a predetermined threshold value, it is determined that an abnormality has occurred. In this case, it is assumed that an abnormality has occurred in an operation component relating to the regulating valve414or the regulating valve424. An operation component relating to the regulating valve414or the regulating valve424may include a needle, a diaphragm, a bearing, a motor coil or the like.

As another example of determination in regard to an abnormality, an allowable range may be updated so as to include a predetermined ratio of plotted datapoints at a point in time at which determination in regard to an abnormality is made. Further, it may be determined that an abnormality has occurred based on the change rate of an updated allowable range with respect to a predetermined allowable range R. The change rate of an allowable range includes the change rate of a major axis of the allowable range, the change rate of a minor axis of the allowable range or the change rate of an area of the allowable range.

In a case in which the abnormality determiner220determines that an abnormality has occurred, the notifier230notifies a user of an occurrence of the abnormality. As an example of notification made by the notifier230, in a case in which the substrate processing apparatus1includes a display device, a character string indicating that an abnormality has occurred may be displayed. In a case in which the substrate processing apparatus1includes a sound output device, a sound indicating the similar content may be output, or a warning sound such as a buzzer may be output. In a case in which the substrate processing apparatus1includes an indicator light such as a lamp, the indicator light may be turned on, turned off or blinked in a manner corresponding to the content of warning.

(3) Abnormality Detection Process

FIG.5is a flowchart showing an abnormality detection process performed by the controller200ofFIG.3. The abnormality detection process ofFIG.5is performed by execution of the abnormality detection program stored in the memory by the CPU of the controller200. The abnormality detection process is performed in parallel with a substrate process. The abnormality detection process will be described with reference to the controller200ofFIG.3and the flowchart ofFIG.5.

First, the operation value acquirer210acquires a pulse value supplied to the regulating valve414(step S1). Further, the operation value acquirer210acquires a pulse value supplied to the regulating valve424(step S2). The step S1is performed when the upper surface of a substrate W is processed, and the step S2is performed when the lower surface of a substrate W is processed. The execution order of the steps S1and S2is defined by the recipe of a substrate process. Therefore, either of the steps S1and S2may be performed first, or the steps S1and S2may be performed at the same time.

Next, the abnormality determiner220plots a datapoint defined by a set of pulse values acquired in the steps S1and S2on a correlation graph (step S3). Subsequently, the abnormality determiner220determines whether a current point in time is a point in time at which determination in regard to an abnormality is to be determined (step S4). Each time a predetermined number of substrates W are processed, it may be determined that a current point in time is a point in time at which determination in regard to an abnormality is to be determined. Alternatively, it may be determined that a current point in time is a point in time at which determination in regard to an abnormality is to be made each time a predetermined period of time elapses. In a case in which a current point in time is not a point in time at which determination in regard to an abnormality is to be made, the abnormality determiner220returns to the step S1. The steps S1to S4are repeated until a current point in time is a point in time at which determination in regard to an abnormality is to be made.

In a case in which a current point in time is a point in time at which determination in regard to an abnormality is to be made, the abnormality determiner220evaluates the ratio of datapoints exceeding the allowable range R to the datapoints plotted on the correlation graph (step S5). Thereafter, the abnormality determiner220determines whether the ratio evaluated in the step S5exceeds a predetermined threshold value (step S6). In a case in which the ratio is equal to or smaller than the threshold value, the abnormality determiner220does not determine that an abnormality has occurred and returns to the step S1. In a case in which the ratio exceeds the threshold value, the abnormality determiner220determines that an abnormality has occurred. In this case, the notifier230makes notification of an occurrence of an abnormality (step S7) and returns to the step S1.

When the process of all of substrates W to be processed by the substrate processing apparatus1ends, it may be determined in the step S4that a current point in time is a point in time at which determination in regard to an abnormality is to be made. With this configuration, in a case in which the ratio is equal to or smaller than a threshold value in the step S6, the abnormality detection process ends. Alternatively, after the notification is made in the step S7, the abnormality detection process ends.

In the substrate processing apparatus1according to the present embodiment, pulse values supplied to the regulating valves414,424are respectively acquired by the operation value acquirer210as the first and second operation values. The abnormality determiner220determines whether an abnormality has occurred based on the correlation between a pulse value supplied to the regulating valve414and a pulse value supplied to the regulating valve424, the pulse values being acquired by the operation value acquirer210. In this case, it is possible to detect an abnormality in the substrate processing apparatus1at an early stage based on the correlation between a pulse value supplied to the regulating valve414and a pulse value supplied to the regulating valve424.

Whether an abnormality has occurred is determined based on the ratio of datapoints exceeding the allowable range R to the datapoints defined by sets of a pulse value supplied to the regulating valve414and a pulse value supplied to the regulating valve424, the pulse values being acquired by the operation value acquirer210. In this case, it is possible to detect an abnormality in the substrate processing apparatus1in a simple process.

Further, the allowable range R is defined so as to include a predetermined ratio of datapoints to the datapoints defined by sets of a pulse value supplied to the regulating valve414and a pulse value supplied to the regulating valve424, the pulse values being acquired in advance by the operation value acquirer210before a substrate is processed.

Therefore, the allowable range R to be used for determination in regard to an abnormality can be defined easily.

(5) Modified Example

While a pulse value supplied to the regulating valve414is acquired as a first operation value and a pulse value supplied to the regulating valve424is acquired as a second operation value in the present embodiment, the embodiment is not limited to this. The pressure of a processing liquid flowing through the circulation pipe401detected by the manometer402is supplied to the operation value acquirer210. As such, a pulse value supplied to the regulating valve414may be acquired as a first operation value, and the pressure of a processing liquid flowing through the circulation pipe401may be acquired as a second operation value.

FIG.6is a diagram showing a correlation graph. In the correlation graph ofFIG.6, the abscissa indicates a pulse value supplied to the regulating valve414, and the ordinate indicates the pressure of a processing liquid. As shown inFIG.6, each time the pulse control of the regulating valve414is performed, a datapoint defined by a set of a pulse value supplied to the regulating valve414and a pressure of a processing liquid is plotted on the correlation graph. Whether an abnormality has occurred is determined based on the ratio of datapoints exceeding the allowable range R to the plotted datapoints.

With this configuration, in a case in which it is determined that an abnormality has occurred, it is assumed that an abnormality has occurred in an operation component relating to the regulating valve414or the circulation pipe401. In the modified example, a pulse value supplied to the regulating valve424may be acquired as a first operation value. With this configuration, in a case in which it is determined that an abnormality has occurred, it is assumed that an abnormality has occurred in an operation component relating to the regulating valve424or the circulation pipe401.

<3> Second Embodiment

(1) Chemical Liquid Generator

In a second embodiment, an abnormality in the chemical liquid generator300is detected.FIG.7is a diagram showing the configuration of the chemical liquid generator300in the second embodiment. As shown inFIG.7, the chemical liquid generator300includes an undiluted liquid supplier310, a dilution liquid supplier320, a mixing pipe330, a gas supplier340, a mixing tank350and a supply pipe360.

The undiluted liquid supplier310includes a pipe311, an on-off valve312, a flowmeter313and a regulating valve314. The upstream end of the pipe311is connected to an undiluted liquid supply source301that supplies an undiluted liquid of a chemical liquid. As a result, the undiluted liquid flowing from the undiluted liquid supply source301flows through the pipe311. In the present example, the undiluted liquid is hydrofluoric acid.

In the pipe311, the on-off valve312, the flowmeter313and the regulating valve314are provided in this order from an upstream position to a downstream position. The on-off valve312opens or closes the flow path of the pipe311. The flowmeter313detects the flow rate of an undiluted liquid flowing through the pipe311and supplies a result of detection to the controller200. The regulating valve314includes a motor needle valve, for example, and regulates the flow rate of an undiluted liquid flowing through the pipe311based on the pulse control performed by the controller200.

The dilution liquid supplier320includes a pipe321, an on-off valve322, a flowmeter323and a regulating valve324. The upstream end of the pipe321is connected to a dilution liquid supply source302that supplies a dilution liquid. Thus, a dilution liquid flowing from the dilution liquid supply source302flows through the pipe321. In the present example, the dilution liquid is DIW (De-ionized water).

In the pipe321, the on-off valve322, the flowmeter323and the regulating valve324are provided in this order from an upstream position to a downstream position. The on-off valve322opens or closes the flow path of the pipe321. The flowmeter323detects the flow rate of a dilution liquid flowing through the pipe321and supplies a result of detection to the controller200. The regulating valve324includes an electric pressure regulator, for example, and regulates the flow rate of a dilution liquid flowing through the pipe321based on pulse control performed by the controller200.

The mixing pipe330has one main pipe331and two branch pipes332,333. The upstream end of the main pipe331is connected to the downstream end of the pipe311of the undiluted liquid supplier310and the downstream end of the pipe321of the dilution liquid supplier320. The branch pipe332is connected between the downstream end of the main pipe331and the mixing tank350. The branch pipe333is connected between the downstream end of the main pipe331and a waste liquid tank303. On-off valves334,335are respectively provided in the branch pipes332,333.

In the main pipe331, an undiluted liquid supplied from the undiluted liquid supplier310and a dilution liquid supplied from the dilution liquid supplier320are mixed, so that a diluted chemical liquid is generated. In the present example, the diluted chemical liquid is dilute hydrofluoric acid. A diluted chemical liquid generated in the main pipe331is supplied to the mixing tank350through the branch pipe332.

The gas supplier340includes a pipe341and an on-off valve342. The upstream end of the pipe341is connected to a gas supply source304that supplies gas. Thus, gas supplied from the gas supply source304flows through the pipe341. In the present example, gas is an inert gas such as nitrogen. The downstream end of the pipe341is connected to the mixing tank350. The on-off valve342is provided in the pipe341and opens or closes the flow path of the pipe341.

The mixing tank350stores a liquid mixture of an undiluted liquid and a dilution liquid as a diluted chemical liquid. The mixing tank350is provided with four liquid level sensors351,352,353,354. The liquid level sensors351to354respectively detect first to fourth liquid levels of a diluted chemical liquid stored in the mixing tank350and provide results of detection to the controller200.

The first, second, third and fourth liquid levels are located in this order from below toward above. Specifically, the first liquid level is slightly higher than the bottom surface of the mixing tank350. The second liquid level is higher than the first liquid level by a predetermined height. The third liquid level is lower than the fourth liquid level by a predetermined height. The fourth liquid level is slightly lower than the upper surface of the mixing tank350.

The supply pipe360has one main pipe361and two branch pipes362,363. The upstream end of the main pipe361is connected to the mixing tank350. The branch pipe362is a circulation pipe used for circulation of a diluted chemical liquid and is connected between the downstream end of the main pipe361and the mixing tank350. The branch pipe363is a processing pipe used for processing of a substrate W and is connected between the downstream end of the main pipe361and a substrate processor100.

A concentration meter364and a heater365are provided in the main pipe361. A pump366, a filter367and an on-off valve368are provided in the branch pipe362. An on-off valve369is provided in the branch pipe363. The concentration meter364measures the concentration of a diluted chemical liquid flowing through the main pipe361and supplies a result of measurement to the controller200.

The pump366is driven, and the on-off valve368is opened, so that a diluted chemical liquid flowing from the mixing tank350is heated by the heater365and circulates back to the mixing tank350through the filter367. In the present example, a diluted chemical liquid stored in the mixing tank350constantly circulates through the branch pipe362.

Further, the on-off valve342and the on-off valve369are opened, so that the diluted chemical liquid stored in the mixing tank350is pressurized by gas. Thus, the diluted chemical liquid stored in the mixing tank350is guided downstream through the main pipe361, heated by the heater365and then supplied to the substrate processor100through the branch pipe363.

As indicated by the one-dot and dash lines inFIG.7, the chemical liquid generator300may further include a circulation pipe370similar to the circulation pipe401ofFIG.2. In this case, the substrate processor100and the mixing tank350are connected to each other by the circulation pipe370. In the substrate processor100, part of a diluted chemical liquid supplied from the mixing tank350is used for a substrate process such as cleaning. The volume of a diluted chemical solution to be used is defined by the recipe of a substrate process. Another part of the diluted chemical liquid supplied to the substrate processor100is returned to the mixing tank350through the circulation pipe370without being used for a substrate process.

Since the configuration of a controller200in the present embodiment is basically similar to the configuration of the controller200ofFIG.3in the first embodiment, the operation of the controller200will be briefly described with reference toFIG.3. The same also applies to the controller200in third to seventh embodiments, described below.

In the substrate processor100, a diluted chemical liquid supplied from the chemical liquid generator300is used, so that the liquid level of the diluted chemical liquid stored in the mixing tank350is lowered. As such, in a case in which a second liquid level is detected by the liquid level sensor352, replenishment of a diluted chemical liquid is started.

Specifically, the operation value acquirer210ofFIG.3opens the on-off valves312,322. Further, the operation value acquirer210performs the pulse control of the regulating valve314such that an undiluted liquid is supplied at a constant flow rate from the undiluted liquid supplier310. Similarly, the operation value acquirer210performs the pulse control of the regulating valve324such that a diluted liquid is supplied at a constant flow rate from the dilution liquid supplier320. Thus, an undiluted liquid and a dilution liquid are respectively supplied at constant flow rates from the undiluted liquid supplier310and the dilution liquid supplier320.

The supplied undiluted liquid and the supplied dilution liquid are mixed in the main pipe331of the mixing pipe330, so that a diluted chemical liquid is generated. The operation value acquirer210calculates a theoretical value of concentration of a diluted chemical liquid to be generated based on the ratio between the flow rate of an undiluted liquid and the flow rate of a dilution liquid that are respectively detected by the flowmeters313,323, and acquires the calculated theoretical value of concentration as a first operation value.

A generated diluted chemical liquid is stored in the mixing tank350through the branch pipe332, so that the liquid level of the diluted chemical liquid stored in the mixing tank350rises. In a case in which a third liquid level is detected by the liquid level sensor353, the operation value acquirer210closes the on-off valves312,322. Thus, replenishment of a diluted chemical liquid is stopped. The operation value acquirer210acquires an actual measured value of concentration of a diluted chemical liquid after replenishment detected by the concentration meter364as a second operation value.

Since the flow rate of a dilution liquid or an undiluted liquid is not stable immediately after the start and end of generation of a diluted chemical liquid, the concentration of a generated diluted chemical liquid may be unstable. As such, immediately after the start of generation of a diluted chemical liquid, the on-off valve335is opened and the on-off valve334is closed for a predetermined period of time. Thus, a diluted chemical liquid having an unstable concentration is discarded into the waste liquid tank303. Further, also immediately after the end of generation of a diluted chemical liquid, the on-off valve335is opened and the on-off valve334is closed for a predetermined period of time. Thus, a diluted chemical liquid having an unstable concentration is discarded into the waste liquid tank303. Thus, a diluted chemical liquid having a stable concentration is stored in the mixing tank350.

FIG.8is a diagram showing a correlation graph. In the correlation graph ofFIG.8, the abscissa indicates a theoretical value of concentration, and the ordinate indicates an actual measured value of concentration. As shown inFIG.8, each time a diluted chemical liquid is replenished, the abnormality determiner220plots a datapoint defined by a set of a theoretical value and an actual measured value of concentration of a replenished diluted chemical liquid on the correlation graph. Further, the abnormality determiner220determines whether an abnormality has occurred based on the ratio of datapoints exceeding an allowable range R to the plotted datapoints. In a case in which it is determined that an abnormality has occurred, it is presumed that an abnormality has occurred in an operation component relating to the regulating valves314,324or the concentration meter364.

In a case in which the abnormality determiner220determines that an abnormality has occurred, the notifier230notifies a user of an occurrence of the abnormality. In the present embodiment, in a case in which a first liquid level is detected by the liquid level sensor351or a case in which a fourth liquid level is detected by the liquid level sensor354, the control of the chemical liquid generator300is stopped. Also in this case, the notifier230may notify a user that control of the chemical liquid generator300has been stopped.

The abnormality detection process in the present example is similar to the abnormality detection process ofFIG.5except that a theoretical value and an actual measured value of concentration of a diluted chemical liquid are respectively acquired in the steps S1and S2. The step S1is performed in a period during which a diluted chemical liquid is replenished, for example. The step S2is performed after replenishment of a diluted chemical liquid is stopped, for example.

In the substrate processing apparatus1according to the present embodiment, a theoretical value of concentration of a diluted chemical liquid calculated based on the ratio between the flow rate of an undiluted liquid and the flow rate of a dilution liquid that are respectively detected by the flowmeters313,323is acquired by the operation value acquirer210as a first operation value. Further, an actual measured value of concentration of a diluted chemical liquid detected by the concentration meter364is acquired by the operation value acquirer210as a second operation value.

The abnormality determiner220determines whether an abnormality has occurred based on the correlation between a theoretical value of concentration of a diluted chemical liquid and an actual measured value of concentration of a diluted chemical liquid that are acquired by the operation value acquirer210. In this case, it is possible to detect an abnormality in the substrate processing apparatus1at an early stage based on the correlation between a theoretical value of concentration of a diluted chemical liquid and an actual measured value of concentration of a diluted chemical liquid.

In the present embodiment, the abnormality determiner220may determine whether an abnormality has occurred using the Hotelling method, a cumulative sum or the like based on the difference between a first operation value and a second operation value. The same applies to the following third to fifth embodiments.

(1) Operation Value

In the second embodiment, a theoretical value of concentration of a diluted chemical liquid is calculated as a first operation value based on the ratio between an instantaneous value of the flow rate of an undiluted liquid detected by the flowmeter313and an instantaneous value of the flow rate of a dilution liquid detected by the flowmeter323. Further, an instantaneous value of concentration of a diluted chemical liquid is detected by the concentration meter364as a second operation value. However, the embodiment is not limited to this. As for operation values in a third embodiment, differences from the operation values in the second embodiment will be described below with suitable reference to the chemical liquid generator300ofFIG.7.

FIG.9is a diagram for explaining an operation value in the third embodiment. InFIG.9, the time series of the flow rate of an undiluted liquid, the flow rate of a dilution liquid and the concentration of a diluted chemical liquid respectively detected by the flowmeter313, the flowmeter323and the concentration meter364are shown. As shown inFIG.9, at a point T1in time at which a predetermined period of time has elapsed from the time when the on-off valves312,322are opened, an undiluted liquid and a dilution liquid are mixed in the mixing pipe330. Thus, generation of a diluted chemical liquid is started.

As described above, the flow rates of an undiluted liquid and a dilution liquid are not stable immediately after the start of generation of a diluted chemical liquid. As such, in a period from the point T1in time to a point T2in time at which a predetermined period of time has elapsed from the point T1in time, the on-off valve335is opened, and the on-off valve334is closed. Therefore, the generated diluted chemical liquid is discarded to the waste liquid tank303. At the point T2in time, the on-off valve335is closed, and the on-off valve334is opened. Thus, the supply of a diluted chemical liquid to the mixing tank350is started.

At a point T4at which a predetermined period of time ΔT1has elapsed from the point T2in time, the on-off valve335is opened, and the on-off valve334is closed. Thus, the supply of a diluted chemical liquid to the mixing tank350ends. The operation value acquirer210of the controller200ofFIG.3calculates a theoretical value of concentration of a diluted chemical liquid to be generated based on an integrated value of the flow rates of an undiluted liquid detected by the flowmeter313and an integrated value of the flow rates of a dilution liquid detected by the flowmeter323in the period from the point T2to the point T4in time. Further, the operation value acquirer210acquires the calculated theoretical value of concentration of a diluted chemical liquid as a first operation value.

At a point T3in time at which a period ΔT2of time smaller than the period ΔT1of time has elapsed from the point T2in time, a diluted chemical liquid the supply of which to the mixing tank350is started at the point T2arrives at the concentration meter364. At a point T5in time at which the period ΔT1of time has elapsed from the point T3in time, that is, the point T5in time at which the period ΔT2of time has elapsed from a point T4in time, a diluted chemical liquid the supply of which to the mixing tank350ends at the point T4in time arrives at the concentration meter364. In the period from the point T3to the point T5in time, the operation value acquirer210calculates a statistical value of concentrations of a diluted chemical liquid detected by the concentration meter364. Further, the operation value acquirer210acquires the calculated statistical value of concentration of a diluted chemical liquid as a second operation value.

In the present embodiment, the above-mentioned statistical value is a mean value and is specifically a value obtained when the sum of concentrations detected at respective points in time in the period from the point T3to the point T5in time is divided by the number of times concentrations are detected. A statistical value may be another calculation value such as a weighted average value. Further, the period ΔT2of time may be determined by measurement or may be determined by calculation based on the length of a flow path, the cross-sectional area of a flow path and the flow rate of a diluted chemical liquid.

The abnormality detection process in the present embodiment is similar to the abnormality detection process ofFIG.5except that a theoretical value and a statistical value of concentration of a diluted chemical liquid are respectively acquired in the steps S1and S2. The steps S1and S2are performed in a period during which a diluted chemical liquid is replenished, for example. Although the step S1can be performed at a point in time earlier than a point in time at which the step S2is performed by the period ΔT2of time, the step S2may be started before the step S1ends.

In the present embodiment, the abnormality determiner220of the controller200determines whether an abnormality has occurred based on the correlation between a theoretical value of concentration of a diluted chemical liquid and a statistical value of concentration of a diluted chemical liquid. Here, the correlation between a theoretical value of concentration of a diluted chemical liquid and a statistical value of concentration of a diluted chemical liquid that is acquired in the present embodiment is stronger than the correlation between a theoretical value of concentration of a diluted chemical liquid and an actual measured value of concentration of a diluted chemical liquid acquired in the second embodiment. Therefore, it is possible to detect an abnormality in the substrate processing apparatus1more reliably.

(1) Operation Value

As for operation values in a fourth embodiment, differences from the operation values in the second embodiment will be described below with suitable reference to the chemical liquid generator300ofFIG.7. In the present embodiment, a concentration predictive model for predicting the concentration of a diluted chemical liquid is constructed in advance. The constructed concentration predictive model is stored in the memory or the like of the controller200inFIG.1.

When the concentration predictive model is constructed, the control similar to the control performed during a substrate process is performed on each component of the chemical liquid generator300. A concentration predictive model is preferably constructed before the chemical liquid generator300deteriorates over time such as the time when the chemical liquid generator300is installed.FIG.10is a diagram for explaining one example of the procedure for constructing a concentration predictive model. InFIG.10, the time series of the flow rate of an undiluted liquid, the flow rate of a dilution liquid, a discharge amount of a diluted chemical liquid to a substrate W in the substrate processor100and the concentration of a diluted chemical liquid are shown.

As shown inFIG.10, when a concentration predictive model is constructed, the flow rate of an undiluted liquid, the flow rate of a dilution liquid, the discharge amount of a diluted chemical liquid and the concentration of a diluted chemical liquid at a plurality of points in time are sequentially detected. The flow rate of an undiluted liquid, the flow rate of a dilution liquid and the concentration of a diluted chemical liquid are respectively detected by the flowmeter313, the flowmeter323and the concentration meter364. The discharge amount of a diluted chemical liquid may be detected by a flowmeter (not shown) or may be detected by calculation based on the capacity of a flow path, a discharge period of time and the like.

A dataset including the flow rate of an undiluted liquid, the flow rate of a dilution liquid, the discharge amount of a diluted chemical liquid and the concentration of a diluted chemical liquid that are detected in a period from each point in time to a point in time earlier than the point in time by a predetermined period ΔT11of time is acquired as an explanatory variable corresponding to each point in time. Further, the concentration of a diluted chemical liquid detected at a point in time later than each point in time by a predetermined period ΔT12of time is acquired as an objective variable corresponding to each point in time. Based on an acquired explanatory variable and an acquired objective variable corresponding to each point in time, training data representing the relationship between the explanatory variable and the objective variable corresponding to the point in time is generated.

In the example ofFIG.10, a dataset detected between a point T11in time and a point T12in time at which the period ΔT11of time has elapsed from the point T11in time is an explanatory variable corresponding to the point T12in time. Further, the concentration of a diluted chemical liquid detected at a point T13in time at which a period ΔT12of time has elapsed from the point T12in time is an objective variable corresponding to the point T12in time. Also in regard to a point in time later than the point T12in time, an explanatory variable and an objective variable are sequentially acquired, so that a plurality of training data pieces are generated.

A LightGBM (Gradient Boosting Machine) is prepared in advance as a machine learning model. A concentration predictive model is constructed when the LightGBM learns the plurality of generated training data pieces. While the machine learning model is the LightGBM in the present embodiment, the embodiment is not limited to this. The machine learning model may be linear regression, Lasso regression, LSTM (Long Short Term Memory) or the like.

During a substrate process, the flow rate of an undiluted liquid, the flow rate of a dilution liquid, a discharge amount of a diluted chemical liquid and the concentration of a diluted chemical liquid at a plurality of points in time are detected by the flowmeters313,323, the concentration meter364or the like. The operation value acquirer210of the controller200inFIG.3acquires the flow rate of an undiluted liquid, the flow rate of a dilution liquid, the discharge amount of a diluted chemical liquid and the concentration of a diluted chemical liquid that are detected between each point in time and a point in time that is earlier than the point in time by the period ΔT11of time as a dataset corresponding to each point in time.

Here, the operation value acquirer210predicts the concentration of a diluted chemical liquid at a point in time later than each point in time by the period ΔT12of time based on the acquired dataset corresponding to each point in time and a concentration predictive model that is constructed in advance. The operation value acquirer210acquires a predicted value of concentration of a diluted chemical liquid as a first operation value. Further, the operation value acquirer210acquires an actual measured value of concentration of a diluted chemical liquid that is detected at a point in time later than each point in time by the period ΔT12of time as a second operation value. In this case, a correlation graph in which the abscissa indicates a predicted value of concentration and the ordinate indicates an actual measured value of concentration is created.

An abnormality detection process in the present example is similar to the abnormality detection process ofFIG.5except that a predicted value and an actual measured value of concentration of a diluted chemical liquid are respectively acquired in the steps S1and S2. The steps S1and S2are performed in a period during which a diluted chemical liquid is replenished, for example.

In the present embodiment, the abnormality determiner220determines whether an abnormality has occurred based on the correlation between a predicted value of concentration of a diluted chemical liquid and an actual measured value of concentration of a diluted chemical liquid. Here, the correlation between a predicted value of concentration of a diluted chemical liquid and an actual measured value of concentration of a diluted chemical liquid that are acquired in the present embodiment is stronger than the correlation between a theoretical value of concentration of a diluted chemical liquid and an actual measured value of concentration of a diluted chemical liquid that are acquired in the second embodiment. Therefore, it is possible to detect a single abnormality that occurs in the substrate processing apparatus1in a relatively short period of time more reliably.

While the explanatory variables of the training data include the flow rate of an undiluted liquid, the flow rate of a dilution liquid, the discharge amount of a diluted chemical liquid and the concentration of a diluted chemical liquid in the present embodiment, the embodiment is not limited to this. In a case in which contribution of the discharge amount of a diluted chemical liquid to an objective variable is relatively small, the explanatory variables of training data do not have to include the discharge amount of a diluted chemical liquid. On the other hand, the explanatory variables of the training data may include a feature amount other than the flow rate of an undiluted liquid, the flow rate of a dilution liquid, the discharge amount of a diluted chemical liquid and the concentration of a diluted chemical liquid. In this case, the concentration of a diluted chemical liquid can be predicted more accurately.

(3) Reference Example

In the present embodiment, the flow rates of an undiluted liquid and a dilution liquid are respectively controlled to be constant by the regulating valves314,324. Further, a dilution liquid and an undiluted liquid present in a period during which the flow rate is not stable are discarded to the waste liquid tank303without being supplied to the mixing tank350. With this configuration, because contribution of the flow rates of an undiluted liquid and a dilution liquid to an objective variable is relatively small, explanatory variables of training data do not have to include the flow rate of an undiluted liquid or a dilution liquid. Even in this case, it is possible to acquire a predicted value of concentration of a diluted chemical liquid having the strong correlation with an actually measured value of concentration of a diluted chemical liquid.

(1) Operation Value

As for operation values in a fifth embodiment, differences from the operation values in the third embodiment will be described below with suitable reference to the chemical liquid generator300ofFIG.7andFIG.11, described below.

FIG.11is a partially enlarged view of the chemical liquid generator300ofFIG.7. As shown inFIG.11, at a point t in time at which a diluted chemical liquid is replenished, a volume W1(t)of a diluted chemical liquid flows into the mixing tank350through the mixing pipe330per unit time. In the present example, the unit time is a period τ1in which flow rates are detected by the flowmeters313,323. Therefore, the volume W1(t)is the volume of a diluted chemical liquid flowing into the mixing tank350between the point t in time and a point in time earlier than the point t in time by the period τ1, and is calculated based on the flow rates of an undiluted liquid and a dilution liquid that are respectively detected by the flowmeters313,323. A concentration C0(t)of an inflowing dilution liquid is calculated based on the flow rates of an undiluted liquid and a dilution liquid, and the specific gravity of an undiluted liquid.

Further, a volume W2of a diluted chemical liquid flows out from the mixing tank350through the supply pipe360per unit time. The volume W2is a known constant value that is independent of time and is defined by an operating parameter of the pump366.

Further, at the point t in time, a volume W3(t)of a diluted chemical liquid flows into the mixing tank350through the circulation pipe370per unit time. Here, the diluted chemical liquid that has passed through the substrate processor100arrives at the mixing tank350after a predetermined period τ0of time has elapsed. Therefore, the volume W3(t)is calculated by subtraction of the volume of a diluted chemical liquid used in the substrate processor100at a point (t−τ0) in time that is earlier than the point t in time by the period τ0of time from the volume W2. Further, the period τ0of time may be determined by measurement or may be determined by calculation based on the length of a flow path, the cross sectional area of a flow path and the flow rate of a diluted chemical liquid.

Due to these inflow and outflow of a diluted chemical liquid, a volume W(t)of a diluted chemical liquid is stored in the mixing tank350at the point t in time. An update formula of the volume W(t)at the point t in time and the update formula of the concentration C(t)of a diluted chemical liquid stored in the mixing tank350are calculated with use of the following formulas (1) and (2).

In the formula (2), τ2is a period until a diluted chemical liquid that has flowed out from the mixing tank350through the supply pipe360flows into the mixing tank350through the circulation pipe370. The period τ2may be determined by measurement or may be determined by calculation based on the length of a flow path, the cross sectional area of a flow path and the flow rate of a diluted chemical liquid. A volume W(t−τ1)and the concentrations C(t−τ1)and C(t−τ2)as initial values may be appropriately determined so as to match actual measured values.

The operation value acquirer210of the controller200ofFIG.3calculates a concentration C(t)of a diluted chemical liquid stored in the mixing tank350at each point t in time based on the formula (2). The operation value acquirer210acquires a calculated theoretical value of concentration C(t)of a diluted chemical liquid as a first operation value. Further, the operation value acquirer210acquires an actual measured value of concentration (that is, a concentration C(t+≢T2)detected by the concentration meter364at a point in time at which the period ΔT2of time ofFIG.9has elapsed from each point t in time. The period ΔT2of time is a period of time until a diluted chemical liquid flowing out from the mixing tank350arrives at the concentration meter364. In this case, the correlation graph in which the abscissa indicates a theoretical value of concentration and the ordinate indicates a measured value of concentration is created.

An abnormality detection process in the present example is similar to the abnormality detection process ofFIG.5except that a predicted value and an actual measured value of concentration of a diluted chemical liquid are respectively acquired in the steps S1and S2. The steps S1and S2may be performed in a period during which a diluted chemical liquid is replenished, for example. On the other hand, the steps S1and S2may be performed in a period during which a diluted chemical liquid is not replenished. In this case, W1(t)and the concentration C0(t)may be set to 0 at a point in time other than the point in time at which a diluted chemical solution is replenished.

In the present embodiment, the abnormality determiner220of the controller200determines whether an abnormality has occurred based on the correlation between a theoretical value of concentration of a diluted chemical liquid and an actual measured value of concentration of a diluted chemical liquid stored in the mixing tank350. Here, in a case in which the concentration of a diluted chemical liquid supplied to the substrate processor100changes, an unused diluted chemical liquid in the substrate processor100is returned to the mixing tank350. Thus, the concentration of a diluted chemical liquid stored in the mixing tank350changes.

Even in this case, with the present embodiment, because a theoretical value of concentration of a diluted chemical liquid stored in the mixing tank350is calculated based on the volume of a diluted chemical liquid flowing into or out of the mixing tank350, the flow rate of an undiluted liquid and the flow rate of a dilution liquid, it is possible to strengthen the correlation between a theoretical value of concentration of a diluted chemical liquid and a statistical value of concentration of a diluted chemical liquid. Therefore, it is possible to detect an abnormality in the substrate processing apparatus1more reliably.

There may be a certain amount of deviation between a theoretical value of concentration of a diluted chemical liquid calculated based on the formula (2) and an actual measured value of concentration of a diluted chemical liquid detected by the concentration meter364. As such, an appropriately defined offset value may be added to the concentration C0(t)of a dilution liquid flowing into the mixing tank350so as to cancel the deviation. In this case, even in a period immediately after the start of calculation of concentration of a diluted chemical liquid, the correlation between a theoretical value of concentration of a diluted chemical liquid and an actual measured value of concentration of a diluted chemical liquid can be strengthened.

In a sixth embodiment, an abnormality in a rotation holder that is included in each processing unit110as an operation component of the substrate processor100is detected.FIG.12is a side view showing the configuration of a rotation holder in the sixth embodiment. As shown inFIG.12, a rotation holder500includes a spin chuck510, a plurality of chuck pins520and a chuck driver530. The spin chuck510is configured to horizontally hold and rotate a substrate W, and includes a spin driver511, a rotation shaft512, a plate support member513and a spin plate514.

The spin driver511is provided in an upper portion of the processing unit110ofFIG.1and is supported by a support member (not shown). The rotation shaft512is provided to extend downwardly from the spin driver511. The plate support member513is attached to the lower end of the rotation shaft512. The spin plate514has a disc shape and is horizontally supported by the plate support member513. The rotation shaft512is rotated by the spin driver511, so that the spin plate514is rotated about a vertical axis.

The plurality of chuck pins520are provided in the peripheral portion of the spin plate514at equal angular intervals with respect to the rotation shaft512. In the present example, eight chuck pins520are provided in the peripheral portion of the spin plate514at intervals of45degrees with respect to the rotation shaft512. Each chuck pin520includes a shaft portion521, a pin supporter522and a holder523. The shaft portion521is provided so as to penetrate the spin plate514in a vertical direction. The pin supporter522is provided so as to extend in a horizontal direction from the lower end of the shaft portion521. The holder523is provided so as to project downwardly from the tip of the pin supporter522.

Each chuck pin520is switched between a close state and an open state by rotating about the vertical axis and the shaft portion521. In a close state, each holder523abuts against the outer peripheral end (bevel portion) of a substrate W. In an open state, each holder523is spaced apart from the outer peripheral end of the substrate W.

The chuck driver530includes a rotary actuator, a magnet, a linear slide and a cam, for example, and switches between a close state and an open state.FIG.13is a functional block diagram showing the configuration of the rotation holder500. As shown inFIG.13, the controller200provides an instruction for causing the chuck driver530to be in a close state (hereinafter referred to as a closing instruction) to the chuck driver530. Further, the controller200provides an instruction for causing the chuck driver530to be in an open state (hereinafter referred to as an opening instruction) to the chuck driver530.

When a closing instruction is provided to the chuck driver530, air is supplied to the rotary actuator. Thus, the chuck driver530enters a close state. In this case, the linear slide moves linearly due to rotation of the magnet. The rectilinear movement of the linear slide is converted by the cam into rotation movement for rotating each chuck pin520. Thus, each chuck pin520enters a close state. On the other hand, when an opening instruction is provided to the chuck driver530, the supply of air to the rotary actuator is stopped. Thus, the chuck driver530enters an open state. In this case, each chuck pin520enters an open state.

Further, the rotation holder500includes a plurality of Hall sensors524and a Hall sensor531. The plurality of Hall sensors524respectively correspond to the plurality of chuck pins520. Each Hall sensor524detects the state of a corresponding chuck pin520based on a magnet (not shown) provided in the chuck pin520and provides a result of detection to the controller200. The Hall sensor531detects the state of the chuck driver530based on a magnet of the chuck driver530and provides a result of detection to the controller200.

In the following description, the eight chuck pins520are referred to as first to eighth chuck pins520, respectively. The first and second chuck pins520are paired, and the third and fourth chuck pins520are paired. The fifth and sixth chuck pins520are paired, and the seventh and eighth chuck pins520are paired. While the operation of the controller200in regard to the first and second chuck pins520will be described below, the same applies to the operation of the controller200in regard to the third to eighth chuck pins520.

The operation value acquirer210ofFIG.3provides a closing instruction or an opening instruction to the chuck driver530. Further, the operation value acquirer210acquires a transition period of time of the first chuck pin520as a first operation value based on a result of detection provided from the Hall sensor524corresponding to the first chuck pin520. Similarly, the operation value acquirer210acquires a transition period of time of the second chuck pin520as a second operation value based on a result of detection provided from the Hall sensor524corresponding to the second chuck pin520.

The transition period of time of the chuck pin520is a period of time from the time when a closing instruction is provided to the chuck driver530to the time when the chuck pin520enters a closed state, or a period of time from the time when an opening instruction is provided to the chuck driver530to the time when the chuck pin520enters an open state.

FIG.14is a diagram for explaining the transition period of time of the chuck pin520when a closing instruction is provided. As shown inFIG.14, a closing instruction is provided to the chuck driver530at a point t1in time. In this case, the chuck driver530switches from an open state to a close state. Thus, each chuck pin520switches from an open state to a close state, and the Hall sensor524detects that each chuck pin520is in a close state at a point t2in time. The operation value acquirer210acquires a transition period Δt1of time from the point t1in time at which a closing instruction is provided to the point t2in time at which a close state is detected in regard to each chuck pin520.

FIG.15is a diagram for explaining a transition period of time of the chuck pin520when an opening instruction is provided. As shown inFIG.15, an opening instruction is provided to the chuck driver530at a point t11in time. In this case, the chuck driver530switches from a close state to an open state. Thus, each chuck pin520switches from a close state to an open state, and the Hall sensor524detects that each chuck pin520is in an open state at a point t12in time. The operation value acquirer210acquires a transition period Δt11of time from the point t11in time at which an opening instruction is provided to the point t12in time at which an open state is detected in regard to each chuck pin520.

Each time a closing instruction or an opening instruction is provided to the chuck driver530, the abnormality determiner220ofFIG.3plots a datapoint defined based on a set of a transition period of time of the first chuck pin520and a transition period of time of the second chuck pin520on a correlation graph. Datapoints may be plotted separately for a closing instruction and an opening instruction. In this case, allowable ranges R are defined separately for a closing instruction and an opening instruction.

The abnormality determiner220determines whether an abnormality has occurred based on the ratio of datapoints exceeding an allowable range R to plotted datapoints. In a case in which it is determined that an abnormality has occurred, it is presumed that an abnormality has occurred in an operation component relating to the first or second chuck pin520. An operation component relating to the first or second chuck pin520includes a rotary actuator, a magnet, a linear slide, a cam or the like of the chuck driver530. In a case in which the abnormality determiner220determines that an abnormality has occurred, the notifier230notifies a user of an occurrence of the abnormality.

An abnormality detection process in the present example is similar to the abnormality detection process ofFIG.5except that transition period of times of the first and second chucking pins520are respectively acquired in the steps S1and S2. The steps S1and S2are performed substantially at the same time in response to a closing instruction or an opening instruction provided to the chuck driver530. The steps S1and S2may be performed in response to only one of a closing instruction and an opening instruction.

In the substrate processing apparatus1according to the present embodiment, the transition periods of time of the first and second chuck pins520are respectively acquired by the operation value acquirer210as first and second operation values. The abnormality determiner220determines whether an abnormality has occurred based on the correlation between the transition period of time of the first chuck pin520and the transition period of time of the second chuck pin520that are acquired by the operation value acquirer210. In this case, it is possible to detect an abnormality in the substrate processing apparatus1at an early stage based on the correlation between the transition period of time of the first chuck pin520and the transition period of time of the second chuck pin520.

(4) Modified Example

While the transition period of time of the first chuck pin520is acquired as a first operation value and the transition period of time of the second chuck pin520is acquired as a second operation value in the present embodiment, the embodiment is not limited to this. There may be a time difference between the transition period of time of each chuck pin520and the transition period of time of the chuck driver530.

FIG.16is a diagram for explaining the transition periods of time of the chuck pin520and the chuck driver530. As shown inFIG.16, a closing instruction is provided to the chuck driver530at the point t1in time. In this case, similarly toFIG.14, a Hall sensor524detects that each chuck pin520is in a close state at the point t2in time. On the other hand, the Hall sensor531detects that the chuck driver530is in a close state at a point t3in time that is later than the point t2in time. There may be a similar time difference in regard to an opening instruction.

As such, the transition period Δt1of any chuck pin520may be acquired as a first operation value, and the transition period Δt2of time of the chuck driver530may be acquired as a second operation value. Alternatively, instead of the transition period Δt2of time, a period of time from the point t2to the point t3in time may be acquired as a second operation value. With this configuration, in a case in which it is determined that an abnormality has occurred, it is presumed that an abnormality has occurred in an operation component relating to any of the chuck pins520or the chuck driver530.

(5) Reference Example

As an abnormality detection process in a reference example, it is also possible to monitor the temporal change of the transition period of time of each chuck pin520or the chuck driver530, and determine that an abnormality has occurred in a case in which the transition period of time exceeds a predetermined allowable range. However, in the reference example, even in a case in which no abnormality has actually occurred, it may be determined that an abnormality has occurred when a transition period of time exceeds a predetermined allowable range. Therefore, in the reference example, it is difficult to accurately detect an abnormality.

(1) Processing Liquid Supplier

In a seventh embodiment, an abnormality in a processing liquid supplier that is included in each processing unit110as an operation component of the substrate processor100is detected.FIG.17is a diagram showing the configuration of a processing liquid supplier. As shown inFIG.17, the processing liquid supplier600includes scan drivers610,620and cleaners630,640.

Each of the scan drivers610,620includes a stepping motor and an encoder, for example. The scan driver610moves the cleaner630between a waiting position outwardly of a substrate W and a processing position below the center of the substrate W based on the pulse control performed by the controller200. Further, the scan driver610detects that the cleaner630has arrived at the processing position using the encoder, and provides a positioning completion signal indicating that positioning is completed to the controller200.

The scan driver620moves the cleaner640between a waiting position outwardly of a substrate W and a processing position below the center of the substrate W based on the pulse control performed by the controller200. Further, the scan driver620detects that the cleaner640has arrived at the processing position using the encoder, and provides a positioning completion signal indicating that positioning is completed to the controller200.

Each of the cleaners630,640is a nozzle, for example, and supplies a processing liquid to the vicinity of the center of the lower surface of a substrate W at the processing position. Thus, the substrate W is processed. The substrate W may be processed while being held by the rotation holder500ofFIG.12, for example. The cleaner630may be not a nozzle but a brush (a polishing brush is included) for cleaning a substrate W. Similarly, the cleaner640may be not a nozzle but a brush (a polishing brush is included) for cleaning a substrate W.

While the scan drivers610,620and the cleaners630,640are provided in the same processing unit110in the present example, the embodiment is not limited to this. As long as a substrate process with use of the cleaner630and a substrate process with use of the cleaner640are performed at substantially the same frequency, the scan driver610and the cleaner630may be provided in a processing unit110different from a processing unit110in which the scan driver620and the cleaner640are provided.

The operation value acquirer210ofFIG.3performs the pulse control on the scan driver610during a substrate process, thereby moving the cleaner630from the waiting position to the processing position. Further, the operation value acquirer210acquires the moving period of time of the cleaner630as a first operation value based on a positioning completion signal provided from the scan driver610. The moving period of time of the cleaner630is a period of time from the time when the pulse control of the scan driver610is started to the time when the positioning completion signal is supplied.

FIG.18is a diagram for explaining the moving period of time of the cleaner630.

InFIG.18, the abscissa indicates the time, and the ordinate indicates a pulse value supplied to the scan driver610. As shown inFIG.18, the pulse control of the scan driver610is started at a point t21in time. In this case, the cleaner630moves from the waiting position toward the processing position. At a point t22in time, a positioning complete signal is supplied. Thus, the operation value acquirer210ends the pulse control.

Further, the operation value acquirer210acquires a moving period Δt21of time from the point t21in time at which the pulse control is started to the point t22in time at which the positioning completion signal is supplied.

Similarly, the operation value acquirer210performs the pulse control on the scan driver620during a substrate process, thereby moving the cleaner640from the waiting position toward the processing position. Further, the operation value acquirer210acquires the moving period of time of the cleaner640as a second operation value based on the positioning completion signal provided from the scan driver620. The moving period of time of the cleaner640is a period of time from the time when the pulse control of the scan driver620is started to the time when the positioning completion signal is supplied.

Each of the cleaners630,640is returned from the processing position to the waiting position after the substrate process ends. While the moving periods of time of the cleaners630,640from the waiting position to the processing position are respectively the first and second operation values, the embodiment is not limited to this. The moving period of time of the cleaners630,640from the processing position to the waiting position may respectively be the first and second operating values.

The abnormality determiner220ofFIG.3plots a datapoint defined by a set of the moving period of time of the cleaner630and the moving period of time of the cleaner640on a correlation graph each time the pulse control is performed on the scan drivers610,620. Further, the abnormality determiner220determines whether an abnormality has occurred based on the ratio of datapoints exceeding an allowable range R to the plotted datapoints. In a case in which it is determined that an abnormality has occurred, it is presumed that an abnormality has occurred in an operation component relating to the scan drivers610,620. In a case in which the abnormality determiner220determines that an abnormality has occurred, the notifier230notifies a user of an occurrence of the abnormality.

The abnormality detection process in the present example is similar to the abnormality detection process ofFIG.5except that the moving period of times of the cleaners630,640are respectively acquired in the steps S1and S2. Either of the steps S1and S2may be performed first. In a case in which the scan driver610and the cleaner630are provided in a processing unit110different from a processing unit110in which the scan driver620and the cleaner640are provided, the steps S1and S2may be performed at substantially the same time.

In the substrate processing apparatus1according to the present embodiment, the moving periods of time of the cleaners630,640are respectively acquired by the operation value acquirer210as first and second operation values. The abnormality determiner220determines whether an abnormality has occurred based on the correlation between the moving period of time of the cleaner630and the moving period of time of the cleaner640acquired by the operation value acquirer210. In this case, it is possible to detect an abnormality in the substrate processing apparatus1at an early stage based on the correlation between the transition period of time of the cleaner630and the transition time of the cleaner640.

(4) Reference Example

As an abnormality detection process in a reference example, it is also possible to determine that an abnormality has occurred in a case in which the temporal change of the moving period of time of the cleaner630or the cleaner640is monitored and the moving period of time exceeds a predetermined allowable range. However, in the reference example, even in a case in which no abnormality has actually occurred, it may be determined that an abnormality has occurred when a moving period of time exceeds a predetermined allowable range. Therefore, in the reference example, it is difficult to detect an abnormality accurately.

In an eighth embodiment, an abnormality in a rotation holder included in each processing unit110is detected as an operation component of the substrate processor100.FIG.19is a side view showing the configuration of the rotation holder in the eighth embodiment. As shown inFIG.19, the rotation holder700includes a spin driver710, a rotation shaft720and a sucker730.

The spin driver710is provided in the bottom portion of the processing unit110ofFIG.1. The rotation shaft720is provided to extend upwardly from the spin driver710. The sucker730is attached to the upper end of the rotation shaft720and holds a substrate W horizontally by sucking the substrate W. The rotation shaft720is rotated by the spin driver710, so that the sucker730is rotated about a vertical axis.

The spin driver710is provided with a torque sensor711and a temperature sensor712. The torque sensor711detects a torque of the spin driver710and provides a result of detection to the controller200. The temperature sensor712detects a temperature of the spin driver710and provides a result of detection to the controller200. A torque detected in the present example is expressed as a percentage [%] with respect to a rated torque.

FIG.20is a functional block diagram showing the configuration of the controller200. As shown inFIG.20, the controller200in the present embodiment further includes an operation value selector240. Differences of the operation of the controller200in the present embodiment from that of the controller200ofFIG.3will be mainly described below.

FIG.21is a diagram showing the changes of a rotation speed and a torque of the spin driver710in a substrate process. In the upper field ofFIG.21, the temporal change of the rotation speed of the spin driver710when one substrate W is processed is shown. The temporal change of a rotation speed of the spin driver710is defined by the recipe of a substrate process. In the lower field ofFIG.21, the temporal change of a torque of the spin driver710when one substrate W is processed is shown so as to correspond to the rotation speed of the spin driver710.

As shown in the portion A ofFIG.21, when the rotation speed of the spin driver710rapidly changes, a torque of the spin driver710becomes extremely large. As such, the operation value acquirer210acquires a torque when the spin driver710is rotating at a predetermined constant rotation speed, as shown in the portion B ofFIG.21, as a first operation value from the torque sensor711based on the recipe of a substrate process. Further, the operation value acquirer210acquires a temperature when the spin driver710is rotating at the above-mentioned predetermined constant rotation speed as a second operation value from the temperature sensor712.

In a case in which the rotation speed of the spin driver710during a substrate process is substantially constant, all of the torques detected by the torque sensor711may be acquired as first operation values. Similarly, in a case in which the rotation speed of the spin driver710during a substrate process is substantially constant, all of the temperatures detected by the temperature sensor712may be acquired as second operation values.

FIG.22is a diagram showing the acquired torques and temperatures. In the upper field ofFIG.22, the temporal change of the acquired torques is shown. In the lower field ofFIG.22, the temporal change of the acquired temperatures is shown to correspond to the torques. InFIG.22, whether the acquired temperatures are equal to or higher than a predetermined reference temperature is shown. In a case in which the temperature is equal to or higher than the reference temperature, it is indicated as “high.” In a case in which the temperature is lower than the reference temperature, it is indicated as “low.”

As shown in the upper field ofFIG.22, because being acquired when the spin driver710is rotating at a constant rotation speed, a torque does not change extremely greatly but changes in a relatively limited range. On the other hand, as a result of various experiments and study, the inventors of the present invention have obtained the following knowledge in regard to a torque and a temperature of the spin driver710.

As shown in the portion C ofFIG.22, a torque is relatively large at a point in time immediately after the start of a substrate process. Similarly, as shown in the portion D ofFIG.22, a torque is relatively large also at a point in time at which a relatively long period of time has elapsed from the point in time at which a torque is previously acquired. Further, at a point in time immediately before the start of a substrate process or a point in time at which a relatively long period of time has elapsed from the point in time at which a torque is previously acquired, the temperature of the spin driver710is relatively low. That is, a torque and a temperature have a correlation. Further, even in a case in which the rotation speed of the spin driver710is constant, when the temperature of the spin driver710is relatively low, a torque is relatively large.

As such, the operation value selector240selects a temperature equal to or higher than a reference temperature out of the temperatures acquired by the operation value acquirer210. Further, the operation value selector240selects a torque corresponding to a selected temperature out of the torques acquired by the operation value acquirer210. The abnormality determiner220determines whether an abnormality has occurred based on the change of a torque selected by the operation value selector240.

FIG.23is a diagram for explaining one example of an abnormality determination method. InFIG.23, the abscissa indicates the date on which a torque is acquired, and the ordinate indicates an acquired torque. As shown inFIG.23, in the present example, a box-and-whisker diagram is created based on a torque acquired on each day, and the created box-and-whisker diagrams are arranged in a chronological order. Further, whether the straight line indicating a predetermined torque reference value (3% in the example ofFIG.23) passes through the box of a box-and-whisker diagram is determined. In a case in which the straight line indicating the torque reference value does not pass through the box portion of a box-and-whisker diagram a predetermined number of times (on a predetermined number of days in the present example) or more, it is determined that an abnormality has occurred.

The abnormality determination method is not limited to the above-mentioned example. In a case in which the temporal change of a torque selected by the operation value selector240is monitored, and a torque exceeds a predetermined allowable range a predetermined number of times or more, it may be determined that an abnormality has occurred. In a case in which the abnormality determiner220determines that an abnormality has occurred, the notifier230notifies a user of an occurrence of the abnormality.

(3) Abnormality Detection Process

FIG.24is a flowchart showing an abnormality detection process performed by the controller200ofFIG.20. The abnormality detection process ofFIG.24is performed by execution of the abnormality detection program stored in the memory by the CPU of the controller200. The abnormality detection process is performed in parallel with a substrate process on each day. The abnormality detection process will be explained with reference to the controller200ofFIG.20and the flowchart ofFIG.24.

First, the operation value acquirer210acquires a torque of the spin driver710when the spin driver710is rotating at a predetermined constant rotation speed from the torque sensor711(step S11). Further, the operation value acquirer210acquires a temperature corresponding to the torque acquired in the step S11from the temperature sensor712(step S12). The steps S11and S12are performed at substantially the same time as a rotating substrate W is processed based on the recipe of a substrate process.

Next, the operation value selector240selects a temperature equal to or higher than a reference temperature out of the temperatures acquired in the step S12(step S13). Subsequently, the operation value selector240selects a torque corresponding to the temperature selected in the step S13out of the torques acquired in the step S11(step S14).

Thereafter, the abnormality determiner220determines whether the process of all of the substrates W to be processed has ended (step S15). In a case in which the process of all of the substrates to be processed has not ended, the abnormality determiner220returns to the step S11. The steps S11to S15are repeated until the process of all of the substrates to be processed ends.

In a case in which the process of all of the substrates to be processed has ended, the abnormality determiner220creates a box-and-whisker diagrams using a torque selected in the step S14(step S16). Next, the abnormality determiner220arranges the box-and-whisker diagram created in the step S16and the box-and-whisker diagrams that have been created by the day before in a chronological order (step S17).

Subsequently, the abnormality determiner220determines whether the straight line indicating a torque reference value passes through the box portions of the box-and-whisker diagrams arranged in the step S17on a predetermined number of days or more (step S18). In a case in which the straight line passes through the box portions of the box-and-whisker diagrams on the predetermined number of days or more, the abnormality determiner220does not determine that an abnormality has occurred and ends the abnormality detection process. In a case in which the straight line does not pass through the box portions of the box-and-whisker diagrams on the predetermined number of days or more, the abnormality determiner220determines that an abnormality has occurred. In this case, the notifier230makes notification of an occurrence of the abnormality (step S19) and ends the abnormality detection process.

In the substrate processing apparatus1according to the present embodiment, a torque of the spin driver710is acquired by the operation value acquirer210as a first operation value. Further, the temperature of the spin driver710is acquired by the operation value acquirer210as a second operation value. Out of the temperatures acquired by the operation value acquirer210, a temperature equal to or higher than the reference temperature is selected by the operation value selector240. Further, a torque corresponding to the selected temperature out of the torques acquired by the operation value acquirer210is selected by the operation value selector240.

Whether an abnormality has occurred is determined by the abnormality determiner220based on the change of the time-series of a torque selected by the operation value selector240. In this case, because it is determined whether an abnormality has occurred based on the change of a time-series of a torque satisfying a predetermined standard out of the acquired torques, it is possible to easily and accurately detect an abnormality in the substrate processing apparatus1.

A torque acquired as a first operation value is a torque acquired when the spin driver710is rotating at a constant rotation speed. Similarly, the temperature acquired as a second operation value is a temperature acquired when the spin driver710is rotating at a constant rotation speed. Therefore, it is possible to detect an abnormality in the substrate processing apparatus1more accurately.

(5) Reference Example

As an abnormality detection process in a reference example, it is also possible to create the above-mentioned box-and-whisker diagrams using all of torques of the spin driver710acquired by the operation value acquirer210regardless of a temperature of the spin driver710. With this configuration, in a case in which the straight line indicating a torque reference value does not pass through a box-and-whisker diagram on a predetermined number of days or more, it is determined that an abnormality has occurred.

However, in the reference example, because the temperature of the spin driver710is low, the straight line indicating the torque reference value may not pass through the box portion of a box-and-whisker diagram. That is, even in a case in which no abnormality has actually occurred, it may be determined that an abnormality has occurred because the straight line indicating the torque reference value does not pass through the box portion of a box-and-whisker diagram on a predetermined number of days or more. Therefore, in the reference example, it is difficult to detect an abnormality accurately.

<10> Correspondences Between Constituent Elements in Claims and Parts in Preferred Embodiments

In the following paragraphs, non-limiting examples of correspondences between various elements recited in the claims below and those described above with respect to various preferred embodiments of the present disclosure are explained.

In the above-mentioned embodiment, the substrate W is an example of a substrate, the substrate processing apparatus1is an example of a substrate processing apparatus, the operation value acquirer210is an example of an operation value acquirer, and the abnormality determiner220is an example of an abnormality determiner. The allowable range R is an example of an allowable range, the operation value selector240is an example of an operation value selector, and the controller200is an example of a processing device.

In the first embodiment, the regulating valve414is an example of a first operation component or a first regulating valve, and the regulating valve424is an example of a second operation component or a second regulating valve. Alternatively, in the first embodiment, the regulating valve414or the regulating valve424is an example of a first operation component or a regulating valve, and the manometer402is an example of a second operation component or a manometer.

In the second to fifth embodiments, the flowmeter313is an example of a first operation component or a first flowmeter, the flowmeter323is an example of a first operation component or a second flowmeter, and the concentration meter364is an example of a second operation component or a concentration meter. The mixing tank350is an example of a storage, the substrate processor100is an example of a substrate processor, the mixing pipe330is an example of a first flow path portion, the supply pipe360is an example of a second flow path portion, and the circulation pipe370is an example of a third flow path portion.

In the sixth embodiment, the first chuck pin520is an example of a first operation component or a first chuck pin, and the second chuck pin520is an example of a second operation component or a second chuck pin. Alternatively, in the sixth embodiment, any one of the chuck pins520is an example of a first operation component or a chuck pin, and the chuck driver530is an example of a second operation component or a chuck driver.

In the seventh embodiment, the cleaner630is an example of a first operation component or a first processor, and the cleaner640is an example of a second operation component or a second processor. In the eighth embodiment, the spin driver710is an example of a spin driver, the torque sensor711is an example of a first operation component or a torque sensor, and the temperature sensor712is an example of a second operation component or a temperature sensor.