CN215933545U

CN215933545U - Substrate processing apparatus

Info

Publication number: CN215933545U
Application number: CN201990001313.5U
Authority: CN
Inventors: 大石护
Original assignee: Kokusai Electric Corp
Current assignee: Kokusai Electric Corp
Priority date: 2019-02-01
Filing date: 2019-02-01
Publication date: 2022-03-01
Anticipated expiration: 2029-02-01
Also published as: WO2020157967A1; JP7055226B2; JPWO2020157967A1

Abstract

The present invention is provided with: a substrate holder for holding a substrate; a substrate transfer machine which is provided with an end effector for directly handling the substrate and a driving mechanism for moving the end effector, and transfers the substrate to or from the substrate holder; a vibration sensor that detects vibration of the end effector; a control part for controlling the substrate transfer machine; and an analysis device connected to the control unit and capable of receiving signals indicating the start and end of a predetermined transfer operation, and connected to the vibration sensor and capable of receiving time domain data of the vibration of the end effector, wherein in the predetermined transfer operation, it is determined whether or not the end effector or the substrate on the end effector and the substrate holder or the substrate on the substrate holder are in contact with each other, and the control unit outputs the signals indicating the start and end of the predetermined transfer operation to the analysis device.

Description

Substrate processing apparatus

Technical Field

The present disclosure relates to a substrate processing apparatus.

Background

The substrate processing apparatus is configured to transport wafers from a storage container (hereinafter also referred to as a wafer cassette) for storing substrates (hereinafter also referred to as wafers) to a boat as a substrate holder by a substrate transfer unit, load the boat holding the wafers into a reaction furnace, and perform a predetermined process on the wafers in the reaction furnace.

The substrate transfer machine transfers wafers between the wafer cassette and the wafer boat, and has the functions of advancing and retreating, lifting and rotating in a state where the wafers are placed on the clamp of the substrate transfer machine. The teaching task is performed so that the wafer can be placed at a proper position when the wafer is placed from the wafer cassette on the clamp by the substrate transfer machine, or when the wafer placed on the clamp is loaded on the boat.

However, the wafer may be loaded at a position different from the teaching task due to deformation of the wafer, vibration caused by a pump or the like provided in the substrate processing apparatus, secular change of the clamp, or the like, and positional deviation of the wafer may occur. If the positional deviation of the wafer becomes large, the clamp or the wafer on the clamp comes into contact with the wafer boat or the wafers on the wafer boat, and the wafer boat may be damaged or may fall over.

Conventionally, in order to prevent such a rollover accident, vibration at the time of collision has been detected by a collision sensor provided in a substrate transfer machine (for example, see patent document 1). Further, vibration generated by the lift pins is detected on a support table supporting the wafer, and the mounting state is determined based on a total value of periods in which the intensity of the detected vibration is greater than a threshold value (see, for example, patent document 2).

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2003-109999

Patent document 2: japanese patent No. 6244317

SUMMERY OF THE UTILITY MODEL

Problem to be solved by utility model

However, according to the conventional technique, many erroneous determinations are caused, which causes interruption of the transfer operation. Further, since the change in the analog quantity is detected by the threshold value, it is difficult to detect an abnormality such as a slight contact.

An object of the present disclosure is to provide a structure capable of detecting a contact between a substrate on a substrate transfer machine or a substrate transfer machine and a substrate on a substrate holder or a substrate holder with high accuracy, and detecting a slight abnormality before a failure state.

Means for solving the problems

According to one aspect of the present disclosure, there is provided a technique including:

a substrate holder that holds a substrate;

a substrate transfer unit which includes an end effector for directly handling a substrate and a drive mechanism for moving the end effector, and which transfers the substrate to or from the substrate holder;

a vibration sensor that detects vibration of the end effector;

a control unit for controlling the substrate transfer machine;

and an analysis device connected to the control unit and capable of receiving signals indicating the start and end of a predetermined transfer operation, and connected to the vibration sensor and capable of receiving time domain data of the vibration of the end effector, wherein during the predetermined transfer operation, it is determined whether or not the end effector or the substrate on the end effector and the substrate on the substrate holder or the substrate on the substrate holder are in contact with each other.

Effect of the utility model

According to the present disclosure, it is possible to detect with high accuracy that a substrate on a substrate transfer machine or a substrate transfer machine and a substrate on a substrate holder or a substrate holder are in contact with each other, and to detect a slight abnormality before a failure state.

Drawings

Fig. 1 is a perspective view of a receiving chamber preferably used in a first embodiment of the present disclosure.

Fig. 2 is a cross-sectional view of a substrate processing apparatus preferably used in the first embodiment of the present disclosure.

Fig. 3 is a perspective view of a substrate transfer machine preferably used in an embodiment of the present disclosure.

Fig. 4 is a schematic configuration diagram of a controller of a substrate processing apparatus preferably used in an embodiment of the present disclosure, and is a diagram showing a control system of the controller in a block diagram.

Fig. 5 (a) is a diagram showing time domain data for explaining the MT method, and fig. 5 (B) is a diagram showing the amount of change and the amount of existence per sample line extracted from the time domain data of fig. 5 (a).

Fig. 6 is a diagram for explaining multivariate data used when generating a normal space.

Fig. 7 is a diagram for explaining an operation of a substrate transfer machine preferably used in an embodiment of the present disclosure.

Fig. 8 (a) is a flowchart for explaining the operation of an analysis device preferably used in an embodiment of the present disclosure, and fig. 8 (B) is a diagram showing the calculation result of the mahalanobis distance (MD value) of the analysis device in real time.

Fig. 9 (a) is a diagram showing an example of time domain data of the output value of the vibration sensor in the normal transfer operation, and fig. 9 (B) is a diagram showing a feature extracted by using the time domain data of fig. 9 (a).

Fig. 10 (a) is a diagram showing an example of time domain data of the output value of the vibration sensor in the abnormal transfer operation, and fig. 10 (B) is a diagram showing a feature extracted by using the time domain data of fig. 10 (a).

Detailed Description

Hereinafter, one embodiment of the present disclosure will be described.

(1) Structure of substrate processing apparatus

As shown in fig. 1, in the present embodiment, the substrate processing apparatus 4 is configured as a vertical heat processing apparatus (batch-type vertical heat processing apparatus) that performs a heat processing step in the IC manufacturing method. In the vertical heat processing apparatus, a FOUP (Front Opening unified Pod) 20 is used as a carrier for transporting a wafer W as a substrate. The substrate processing apparatus 4 includes a processing furnace 8, a storage chamber 12, and a transfer chamber 16, which will be described later.

(accommodation room)

A housing chamber 12 for loading and storing the wafer cassette 20 into the apparatus is disposed on the front side in the housing of the substrate processing apparatus 4. A loading/unloading port 22A, which is an opening for loading/unloading the wafer cassette 20 into/from the housing chamber 12, is opened in the front side of the housing chamber 12 so as to communicate the inside and the outside of the housing chamber 12. The carrying-in/out port 22A may be opened and closed by a front shutter. An AGV port (I/O stage) 22 as a load port (wafer cassette loading device) is provided inside the housing of the loading/unloading port 22A. A transfer port 42 is provided in a wall surface between the storage chamber 12 and the transfer chamber 16. The wafer cassette 20 is carried into the substrate processing apparatus 4 by an intra-process transport device (inter-process transport device) located outside the substrate processing apparatus 4 at the AGV port 22, and is carried out from the AGV port 22.

Storage shelves (wafer cassette shelves) 30A for storing wafer cassettes 20 are provided in upper and lower 2 stages above an AGV port 22 in front of the housing of the storage chamber 12. Further, a storage rack (wafer cassette rack) 30B for storing the wafer cassettes 20 is provided in a matrix shape at the rear side in the housing of the storage chamber 12.

OHT ports 32 as load ports are provided in a left-right array on the same horizontal line as the storage rack 30A on the upper stage in front of the housing. The wafer cassette 20 is carried into the OHT port 32 from above the substrate processing apparatus 4 by an intra-process conveying device (inter-process conveying device) located outside the substrate processing apparatus 4, or carried out from the OHT port 32. The AGV port 22, the storage rack 30A, and the OHT port 32 are configured to be able to slide the wafer cassette 20 in the front-rear direction at the loading position and the delivery position by the horizontal drive mechanism 26. Hereinafter, the AGV port 22 is sometimes referred to as a first load port, and the OHT port 32 is sometimes referred to as a second load port.

As shown in fig. 2, a space between the front storage rack 30A and the rear storage rack 30B in the frame of the storage chamber 12 forms a cassette transfer area 14, and the wafer cassette 20 is transferred and transferred in the cassette transfer area 14. A track mechanism 40A as a traveling path of the cassette conveying mechanism 40 as a cassette conveying device is formed at the top of the cassette conveying area 14 (the top of the housing chamber 12). Here, the delivery position is located in the cassette conveying area 14, for example, a position directly below the cassette conveying mechanism 40.

The cassette conveyance mechanism 40 that conveys the cassettes 20 includes a traveling section 40B that travels on a traveling path, a holding section 40C that holds the cassettes 24, and an elevating section 40D that is coupled to the traveling section 40B and elevates the holding section 40C in the vertical direction. By detecting the encoder of the motor that drives the traveling unit 40B, the position in the traveling unit 40B can be detected, and the traveling unit 40B can be moved to an arbitrary position.

(transport chamber)

A conveyance chamber 16 is formed adjacent to the rear of the storage chamber 12. A plurality of wafer loading/unloading ports for loading/unloading the wafers W into/from the transfer chamber 16 are opened in parallel in the horizontal direction on the transfer chamber 16 side of the storage chamber 12, and transfer ports 42 are provided for the wafer loading/unloading ports, respectively. In the transfer port 42, the mounting table 42B on which the wafer cassette 20 is mounted is horizontally moved and pressed against the wafer loading/unloading port, and the lid of the wafer cassette 20 is opened by a FIMS (Front-Opening Interface Standard) opener as a lid Opening/closing mechanism (lid Opening/closing device), not shown. When the lid of the pod 20 is opened, the wafer W is transferred to the inside and outside of the pod 20 by the substrate transfer unit 86 serving as a substrate transfer device. The substrate transfer unit 86 is fixedly installed in the transfer chamber 16, and transfers wafers W between the wafer boat 58 and the wafer cassette 20, which will be described later.

(treatment furnace)

A processing furnace 8 is provided above the transfer chamber 16. The processing furnace 8 is provided with a reaction tube 50 constituting a reaction container (processing container). The reaction tube 50 is formed in a cylindrical shape having a closed upper end and an open lower end. A processing chamber 54 is formed in the hollow portion of the reaction tube 50. The processing chambers 54 are configured to be accommodated in a state in which wafers W as substrates are held by boat 58 as a substrate holder in a horizontal posture and arranged in a plurality of stages in the vertical direction.

In the processing chamber 54, a plurality of nozzles are provided so as to penetrate through the lower portion of the reaction tube 50, and a plurality of types of processing gases are supplied to the processing chamber 54.

A seal cap 78 as a furnace opening lid body capable of hermetically closing the lower end opening of the reaction tube 50 is provided below the reaction tube 50. An O-ring as a sealing member is provided on the upper surface of the seal cap 78 to abut against the lower end of the reaction tube 50. The seal cap 78 is configured to abut against the lower end of the reaction tube 50 from the lower side in the vertical direction.

The wafer boat 58 is configured such that a plurality of, for example, 25 to 200 wafers W are arranged in a vertical direction in a horizontal posture with their centers aligned with each other, and are supported in multiple stages, that is, arranged at intervals.

A rotation mechanism 80 as a boat rotating device for rotating the boat 58 is provided on the side of the seal cover 78 opposite to the processing chamber 54. The rotation shaft 80A of the rotation mechanism 80 is connected to the boat 58 through the seal cover 78. The rotation mechanism 80 is configured to rotate the wafer W by rotating the boat 58. An auxiliary sensor 301 as an auxiliary vibration sensor for detecting vibration of the wafer boat 58 is attached to the rotary shaft 80A.

(2) Structure of substrate transfer machine

Next, the structure of the substrate transfer unit 86 will be described in detail with reference to fig. 3.

The substrate transfer machine 86 mainly includes: a gripper 86a as an end effector for directly handling the wafer W; a drive mechanism 308 that moves the clamp 86 a; a vibration sensor 300 that is acoustically coupled to the clamp 86a and detects vibration of the clamp 86 a; and a rotation mechanism 310 for rotating the drive mechanism 308 about the vertical axis.

The clamp 86a has a U-shaped thin plate shape, for example, and a plurality of pieces (5 pieces in the present embodiment) are horizontally provided at equal intervals in the vertical direction. The clamp 86a is of a scooping type, and has a guide or a step provided on the upper surface at a position slightly outside the end of the wafer W to regulate the position of the wafer W, and the wafer W is placed only in the guide. Alternatively, the clamp 86a can be selected from an edge grip type, a drop-in (friction) edge grip type, an adsorption type, and the like. The suction type is vacuum suction, bernoulli chuck, or Johnsen-Rahbek type electrostatic chuck, and the wafer W can be processed in a non-contact manner.

The driving mechanism 308 is of a linear (linear) type, and mainly includes a fixing portion 304 and a guide portion 302. The fixing portion 304 holds the base portions of the clamps 86a and fixes them at equal intervals. A driving mechanism for the edge handle, a variable interval mechanism, a horizontal/vertical fine movement mechanism, and the like may be provided in the fixing portion 304.

The guide portion 302 holds the fixing portion 304 from below, and performs a retreating movement on the 1-axis in the horizontal direction. The guide portion 302 has, for example, 2 guide rails 302a (not shown) formed substantially in parallel to guide the clamp 86a in one axial direction. Then, the fixing portion 304 slides along the guide rail 302a, and the clamp 86a moves forward and backward relative to the guide portion 302.

The rotation mechanism 310 holds the guide portion 302 near the center of the lower surface and rotates the guide portion 302 in the left-right direction.

The substrate transfer device 86 is attached to a substrate transfer device elevator 306 described later. The substrate transfer machine elevator 306 holds the rotating mechanism 310 of the substrate transfer machine 86, and moves the substrate transfer machine 86 up and down.

That is, the gripper 86a of the substrate transfer unit 86 advances and retreats in the front-rear direction along the guide rail 302a by the driving mechanism 308, rotates in the left-right direction by the rotation of the driving mechanism 308 by the rotating mechanism 310, and moves in the vertical direction by the elevation of the substrate transfer unit elevator 306.

The vibration sensor 300 is a 3-axis acceleration sensor. The vibration sensor 300 is provided at a fixing portion 304 at the root of the laminated clamp 86 a. The vibration sensor 300 sometimes requires an amplifier (not shown). The amplifier is preferably located in the vicinity of the vibration sensor 300, for example, may be located within the drive mechanism 308.

(3) Structure of controller

As shown in fig. 4, the controller 210 as a control Unit (control means) is a computer including a CPU (Central Processing Unit) 212, a RAM (Random Access Memory) 214, a storage device 216, and an I/O port 218. The RAM214, the storage device 216, and the I/O port 218 are configured to be able to exchange data with the CPU212 via an internal bus 220. An input/output device 222 configured as a touch panel or the like, for example, is connected to the controller 210. The controller 210 is connected to an analyzer 400 for detecting an abnormality in the transfer operation of the wafer W.

The storage device 216 is configured by, for example, a flash memory, an HDD (Hard Disk Drive), or the like. The storage device 216 stores a control program for controlling the operation of the substrate processing apparatus, a process including steps, conditions, and the like of substrate processing described later, so as to be readable. The process steps are combined so that the controller 210 can execute each step in the substrate processing step described later to obtain a predetermined result, and function as a program. Hereinafter, the process, control program, and the like are also collectively referred to as a program. When a term such as a program is used in the present specification, there are cases where only a process step alone is included, only a control program alone is included, or both of them are included. The RAM214 is configured as a memory area (work area) for temporarily storing programs, data, and the like read by the CPU 212.

The I/O port 218 is connected to the wafer cassette conveyance mechanism 40, the horizontal drive mechanism 26, the sensors 25B and 28A, the drive mechanism 308, the substrate transfer elevator 306, the rotation mechanism 310, the rotation mechanism 80, the boat elevator 82, and the like.

The CPU212 is configured to read out and execute a control program from the storage device 216, and read out a process recipe from the storage device 216 in accordance with input of an operation command from the input/output device 222, or the like. The CPU212 is configured to control the wafer cassette 20 transfer operation by the cassette transfer mechanism 40, the wafer W loading and unloading operation by the substrate transfer machine 86 by the drive mechanism 308, the rotation mechanism 310, and the substrate transfer machine lifter 306, the wafer boat 58 lifting operation by the boat lifter 82, and the like so as to follow the contents of the read process recipe.

The controller 210 can configure the program stored in the external storage device (for example, a magnetic disk such as a hard disk, an optical disk such as a CD, or a semiconductor memory such as a USB memory) 224 by installing the program in the computer. The storage device 216 or the external storage device 224 is configured as a computer-readable recording medium. Hereinafter, they are also collectively referred to as recording media. When the term "recording medium" is used in this specification, there are cases where only the storage device 216 is included, only the external storage device 224 is included, or both of them are included. Further, the program may be provided to the computer by using a communication means such as the internet or a dedicated line without using the external storage device 224.

(4) Operation of substrate processing apparatus

Next, a series of operations using the substrate processing apparatus 4 will be described.

(Carrier Loading step: S10)

When the pod 20 is supplied to the AGV port 22 or the OHT port 32, the pod 20 on the AGV port 22 or the OHT port 32 is carried into the substrate processing apparatus 4. The loaded wafer cassette 20 is automatically transferred to and received from a predetermined mounting table 25 of the storage rack 30 by the cassette transfer mechanism 40, and after being temporarily stored, is transferred from the storage rack 30 to another transfer port 42 and received or directly transferred to the transfer port 42.

(Cap unfolding step: S11)

When the pod 20 is placed on the placing portion of the transfer port 42, the lid of the pod 20 is opened by the FIMS opener.

(wafer filling step S12)

When the lid of the cassette 20 is opened, a plurality of wafers W in the wafer cassette 20 are loaded (supplied) to the boat 58 by the substrate transfer 86. Before that, a map for checking the storage state of the wafers W in the wafer cassette 20 can be performed.

(Crystal boat Loading step S13)

When a plurality of wafers W are loaded onto the boat 58, the boat 58 is carried in (boat loaded) to the processing chamber 54 by the boat elevator 82. At this time, the seal cap 78 hermetically seals the lower end of the reaction tube 50 via an O-ring.

(film Forming Process: S14)

Then, a film is formed on the wafer W by supplying a process gas to the wafer W in the process chamber 54.

After the film formation process is completed, the process chamber 54 is purged to remove the gas and reaction by-products remaining in the process chamber 54 from the process chamber 54. Thereafter, the atmosphere in the processing chamber 54 is replaced with an inert gas, and the pressure in the processing chamber 54 is returned to the normal pressure.

(boat unloading step: S15)

After the atmospheric pressure is restored, the seal cap 78 is lowered by the boat elevator 82 to open the lower end of the reaction tube 50. Then, the processed wafers W are carried out from the lower end of the reaction tube 50 to the outside of the reaction tube 50 (boat unloading) while being supported by the boat 58.

(wafer Release step: S16)

The processed wafer W is taken out from the boat 58 by the substrate transfer 86 (wafer unloading).

(Carrier off-load Process: S17)

The processed wafers W are stored in the pod 20 by the substrate transfer 86, and the pod 20 storing the processed wafers W is returned to the load port (the AGV port 22 or the OHT port 32) by the reverse operation of the carrier loading, and is collected by the external transport device.

(5) Analysis device

Next, the analysis device 400 in the present embodiment will be explained.

The analyzer 400 according to the present embodiment detects an abnormality in the transfer operation of the wafer W in the wafer loading step (S12) and the wafer unloading step (S16) by using the MT (Mahalanobis-Taguchi) method.

The MT method is a multivariate analysis method in quality engineering, and is an idea of determining a normal/abnormal state by calculating a distance (also referred to as mahalanobis distance or MD value) from a normal state.

The analyzer 400 in the present embodiment is configured to extract feature values from time domain data of output values detected by the vibration sensor 300, thereby generating multivariate data, and detect an abnormality in the transfer operation of the wafer W by the MT method. As shown in fig. 4, the analysis device 400 is connected to the vibration sensor 300 and the auxiliary sensor 301, and is configured to be able to acquire output values thereof.

First, a specific method of extracting the variation and the existence amount as the feature amount from the time domain data of the output value of the vibration sensor 300 will be described with reference to fig. 5 (a) and 5 (B). Fig. 5 (a) is data obtained by acquiring acceleration of a certain axis at a sampling rate of 100sps during 19.5 seconds in the transfer operation. Fig. 5 (B) is a diagram showing the amount of change and the amount of existence per sample line extracted from the time domain data shown in fig. 5 (a).

Here, the variation is a differential characteristic of the time domain data, and is the number of times each sample line set in the time domain data crosses the sample line. The presence amount is integral characteristics of time domain data, and is the number of data for each sampling line set in the time domain data that is larger than the value of the sampling line.

As shown in fig. 5 a, a plurality of (7 in fig. 5 a) sample lines (y-40, -20, 10, 20, 25, 50, and 75) are set in advance in the time domain data of the output value (analog value) of the vibration sensor 300 in the time domain direction. Each sample line is set to a plurality of thresholds, and a value to be monitored or a value characteristically representing a change in the environment is set.

Then, for each sample line, the number of times the waveform crosses the sample line is counted as a variation. In addition, for each sample line, the number of values larger than the sample line is calculated as the existence amount. That is, for 1 sample line, feature amounts of 2 items of the variation amount and the existence amount are extracted. Further, as the feature amount, in addition to the variation amount and the existence amount, a maximum value, a minimum value, an average value, and the like of the waveform may be used.

Then, as shown in fig. 5 (B), sample data, which is 14-dimensional multivariable data extracted by using the amount of change and the amount of existence in the normal transfer operation as feature quantities, is calculated.

Then, as shown in fig. 6, N pieces of sampling data calculated using a common sample line are calculated from time domain data in a plurality of transfer operations (N pieces in fig. 6) in a normal state, and a normal space is generated using the N pieces of sampling data. Specifically, the average vector and the covariance matrix are calculated using N sample data at the normal time. The normal space is a space stretched by the eigenvectors of the covariance matrix.

The mahalanobis distance MD in the normal space is expressed as follows using a data vector (column vector) which is multivariate data generated based on time domain data of the output value detected by the vibration sensor 300 during the transfer operation, and an inverse matrix of the calculated mean vector and covariance matrix of the multivariate data in the normal space.

[ mathematical formula 1]

Data vector

Average vector (Normal space)

Sigma covariance matrix (Normal space)

When the mahalanobis distance (MD value) exceeds a preset threshold value, it is determined that an abnormal situation has occurred during the transfer operation. The time domain data that is the basis of the multivariate data is preferably the same number of samples (1950 samples), but the multivariate data may be normalized by dividing the multivariate data by the number of samples. The mahalanobis distance may be determined as a 2-power value of the mahalanobis distance.

Next, the operation of the analysis device 400 according to the present embodiment will be described with reference to fig. 7, fig. 8 (a), and fig. 8 (B).

Fig. 7 is a diagram showing a state in which wafers W are transferred between the wafer cassette 20 and the boat 58 in the transfer port 42 in the transfer chamber 16 by the substrate transfer machine 86. The transfer chamber 16 is provided with a camera 226, and images of the wafer W being transferred and the wafer boat 58 being moved up and down are captured and recorded in accordance with a command from the controller 210.

The analysis device 400 detects that the wafer W on the clamp 86a or the clamp 86a and the wafer W on the boat 58 or the wafer boat 58 are in contact with each other or the like during the transfer operation of the wafer W to the boat 58 in the wafer loading step (S12) and the wafer release step (S16) which are transfer steps.

For example, in the wafer loading step (S12), the controller 210 controls the substrate transfer device 86, the rotation mechanism 310, and the substrate transfer device lift 306 to transfer the wafer W to be transferred, but detects an abnormality in all or a part of the transfer operation. Specifically, in a state where the clamp 86a is opposed to the wafer W to be transferred in the pod 20, the transfer unit 86 moves the clamp 86a forward to a position below the wafer W, raises the clamp 86a to place the wafer W, and then moves the clamp 86a backward. Then, the substrate transfer elevator 306 is vertically moved up and down to a position where the wafers W are placed on the boat 58. The rotation mechanism 310 rotates the transfer unit 86 in the left-right direction to face the boat 58. Then, the gripper 86a is moved forward by the transfer unit 86 to the wafer placement position of the wafer boat 58, and then moved in the vertical direction, so that the wafer W is transferred to the wafer boat 58 and retreated in the backward direction. Thereafter, the transfer machine 86 moves in the vertical direction to the height of the next wafer W to be transferred, and rotates so as to face the wafer W to be transferred. The controller 210 repeats this series of operations until all the wafers W are transferred. In this case, the abnormality can be detected in a section where the possibility of contact is high in a series of operations, that is, in the operation of advancing to retracting the clamp 86a toward the boat 58. In this example, the operation of the abnormality detection section is the same every time, and the required time is constant.

Similarly, in the wafer release step, the processed wafers W are discharged to the wafer cassette 20 by the reverse operation of the wafer loading step.

The analyzer 400 generates a normal space for the transfer operation of the wafers W to the boat 58 in advance during adjustment after the installation of the apparatus, and records the space therein. Specifically, when the operator is present, time domain data of the output value of the vibration sensor 300 when the substrate transfer machine 86 normally performs the transfer operation of the wafers W onto the boat 58 is acquired a plurality of times, a sample line is set, and the acquired plurality of time domain data are analyzed by the MT method, thereby generating a normal space.

Fig. 8 (a) is a flowchart for explaining the operation of the analysis device 400. In operation, the controller 210 transmits signals indicating the start and end of the abnormality detection section during transfer to the analysis device 400. Upon receiving the start signal, the analysis device 400 starts the operation of fig. 8 and continues until receiving the end signal. In this example, in the abnormality detection section, time domain data is acquired at 100sps to 100ksps (samples/second), and feature amount extraction (multivariate datamation) and mahalanobis distance calculation are performed in units of time domain data smaller than 2048 samples. In this case, it is preferable to calculate the mahalanobis distance within 3 seconds from the occurrence of the contact phenomenon. More preferably, the cycle of calculating the mahalanobis distance is 0.5 seconds or less or the time from the acquisition of the time domain data to the calculation of the mahalanobis distance is 1 second or less.

First, while the substrate transfer operation by the substrate transfer device 86 is being performed, the analysis device 400 acquires time domain data of the output value obtained by the vibration sensor 300 as M samples (step S100). Here, M is the same number as the number of samples of the time domain data used in the generation of the normal space, and in this example, 1950. M may be set such that the time of M sampling is an integral multiple of the period of a specific noise (e.g., power supply noise). The acquired M samples may also be repeated with a portion of the data already acquired. For example, the time domain data can be acquired using a sliding window that is set while shifting the M/d samples every time. Here, d is the number of divisions, and is selected so that d is not less than 2 and not more than M and M/d is an integer.

Next, based on the time domain data acquired in step S100, the amount of change, the amount of existence, of each sample line is extracted as a feature amount (step S101), thereby generating multivariate data. When a sliding window is used, the processing is performed and held in units of M/d samples, and the latest d quantities may be added.

Next, from the multivariate data generated in step S101 and the mean value and covariance matrix of the multivariate data in the normal space, the mahalanobis distance in the normal space is calculated for each transfer operation (step S102). When a sliding window is used, the 2 nd power of the mahalanobis distance may be calculated and held in units of M/d samples in the time domain data, and the nearest d quantities may be added.

Next, it is determined whether or not the calculated mahalanobis distance exceeds a preset threshold value (step S103). If the mahalanobis distance does not exceed the predetermined threshold (no in step S103), the analysis operation is continued while the wafer W is being transported to the boat 58 (no in step S104), and if the transport of the wafer W to the boat 58 (abnormality detection section) is completed (yes in step S104), the analysis operation is stopped. The threshold determination is not limited to 1 time, and may be performed, for example, based on the number of times the threshold is continuously exceeded.

When the mahalanobis distance exceeds the preset threshold value (yes in step S103), it is determined that an abnormal situation has occurred (step S105), and the substrate transfer machine 86 is stopped urgently. That is, it is determined that an abnormal situation in which the wafer W on the clamp 86a or the clamp 86a and the wafer W on the boat 58 or the wafer boat 58 are in contact with each other has occurred, and an emergency stop signal is transmitted from the analyzer 400 to the controller 210, so that the substrate transfer machine 86 is brought to an emergency stop.

Fig. 8 (B) is a diagram showing a time transition of the mahalanobis distance (MD value) calculated by the analysis device 400. The threshold is set to about 3.8, showing the case where the MD value eventually exceeds the threshold and an emergency stop occurs. Even if the sampling rate of the time domain data is 100sps, the mahalanobis distance can be calculated at an interval of about 0.4 second by setting d to 50, and thus an abnormality can be detected substantially in real time. The abnormality detectable from the MD value may include a collision contact that means that the wafer cannot be used as a product, a scratch (scratch) of the wafer by the clamp 86a, and friction between the end face of the wafer W held by the clamp 86a and the groove of the wafer boat 58. Such friction can be understood as a sign of more serious contact, but in a situation where it is not desirable to cause an emergency stop due to slight friction many times, it is possible to suppress the emergency stop by generating a normal space or adjusting the threshold value of the MD value by data including friction.

Fig. 9 (a) is a diagram showing an example of time domain data of the output value of the vibration sensor 300 in the normal transfer operation, and fig. 9 (B) is a diagram showing a feature extracted by using the time domain data of fig. 9 (a). Fig. 10 (a) is a diagram showing an example of time domain data of the output value of the vibration sensor during the transfer operation in the abnormal state, and fig. 10 (B) is a diagram showing the feature amount extracted by using the time domain data of fig. 10 (a).

Based on the feature quantity extracted from the time domain data shown in (B) of fig. 9, the mahalanobis distance (MD value) on the normal space is 0.9. In the present transfer operation, since the MD value is lower than the threshold value of 3.8, it is determined that the transfer operation is in the normal state, and the conveyance operation is continued.

On the other hand, the mahalanobis distance (MD value) in the normal space is 33.1 based on the feature amount extracted from the time domain data shown in fig. 10 (B). In this transfer operation, the MD value greatly exceeds the threshold value, and therefore it is determined that the transfer operation is in an abnormal state.

The transfer chamber 16 is provided with a camera 226 for capturing images of the transfer operation by the substrate transfer device 86, and images captured by the camera 226 are recorded in the storage device 216 or the external storage device 224 as a recording device in association with time. That is, the transfer operation of the substrate transfer device 86 is recorded in the storage device 216 or the external storage device 224 as an operation log in association with the time, and when an abnormal situation is detected by the analysis device 400, the user can grasp the time of the conveyance error, the position of the conveyance error, the content of the conveyance error, and the like in the input/output device 222 remotely connected to and displaying the operation screen. In addition, when a conveyance error occurs, the input/output device 222 can display a reproduced video and a live video before and after the conveyance error of the camera 226.

Furthermore, the analysis device 400 generates a normal space using a plurality of multivariate data generated by extracting, as feature quantities, the time domain data of each axis of the front-back, left-right, top-bottom, and upper-bottom of the vibration sensor 300, and the amount of change and presence of the time domain data of the auxiliary sensor 301, selects a corresponding normal space from the plurality of normal spaces, and calculates the mahalanobis distance in the selected normal space, thereby improving the accuracy of the abnormality detection. For example, 1 normal space is generated from the data of 3 axes of the vibration sensor 300 by combining their feature quantities, and an independent normal space is generated from the data of the auxiliary sensor 301. Further, an abnormality due to contact can be determined in consideration of the co-occurrence of mahalanobis distances in each normal space. That is, when 2 mahalanobis distances exceed the threshold at the same time, contact will be more firmly presumed, and if not, other abnormalities will be presumed.

The analysis device 400 may be configured to generate a plurality of normal spaces in accordance with the number of wafers W being transferred, the moving speed and acceleration of the grippers 86a, the amount of air blown around the boat 58, the temperature of the boat 58, or the temperature of the processing chamber in which the boat 58 is stored, and select a normal space that matches the state when the transfer operation of the substrate transfer device 86 is performed from among the plurality of normal spaces, and calculate the mahalanobis distance in the selected normal space to detect an abnormality. This improves the accuracy of detecting the abnormality. Alternatively, in the case of a section (for example, the vicinity of the start point, the end point, the switching point of the operation, and the like of acceleration and deceleration) in which the value tends to increase constantly in the time domain data during the transfer operation, a second normal space may be generated from data not including a large-value section in addition to the first normal space generated from data including the large-value section, and an abnormality may be detected in the second normal space in the section. In this case, the time domain data becomes temporally discontinuous before and after the time domain data by excluding the large value section, but the analysis device 400 can treat them as continuous data without any problem.

(6) Effects of the present embodiment

According to the present embodiment, at least one or more of the following effects (a) to (d) are obtained.

(a) According to the present embodiment, it is possible to detect with high accuracy that the wafers W on the substrate transfer machine 86 and the substrate transfer machine 86, the wafer boat 58, and the wafers W on the wafer boat 58 are in contact with each other, and further, it is possible to detect a slight abnormality before the contact. That is, there is a possibility that abnormal vibration before a failure occurs may be detected from vibration generated from the substrate transfer device 86 or the like itself due to aging or the like.

(b) According to the present embodiment, the accuracy of detecting contact can be improved by providing the auxiliary sensor 301 for detecting the vibration of the boat 58.

(c) According to the present embodiment, it is possible to detect an abnormality and to stop the abnormality in an emergency within 3 seconds from the occurrence of contact. Since the time for 1 advance and retreat of the clamp 86a is about 3 seconds, it is expected that the clamp is stopped suddenly in the middle of the advance and retreat, and the wafer breakage is prevented from being enlarged. Furthermore, since the analysis device 400 acquires time domain data through a sliding window, it is possible to shorten the detection cycle of an abnormality with a small calculation load. Therefore, even if the analysis device 400 is configured by a commercially available industrial sequence analyzer, emergency stop can be performed at a sufficient speed. On the other hand, in spectrum analysis using FFT, a predetermined (for example, 512 points) or more resolution is required, but even if a sliding window is used, the past calculation result cannot be used, and the calculation load is large. That is, the calculation period is limited by the amount of calculation, and even if the sampling rate is increased, the calculation period cannot be shortened.

(d) According to the present embodiment, the transfer operation of the substrate transfer device 86 is recorded in the storage device 216 or the external storage device 224 as an operation log in association with the time, and when an abnormal situation is detected by the analysis device 400, the user can grasp the timing of the conveyance error, the location of the conveyance error, the content of the conveyance error, and the like in the input/output device 222 remotely connected to display the operation screen. Further, it is possible to display a video image or live image screen of the camera 226, which is provided when the conveyance error has occurred, immediately before the conveyance error has occurred on the input/output device 222.

(7) Other embodiments

The present disclosure is not limited to the above embodiments, and various modifications can be made without departing from the scope of the present disclosure.

In the above embodiment, the normal space is created and the mahalanobis distance in the normal space is calculated in the operation of the substrate transfer machine 86 between the wafers 58 after the clamp 86a is aligned with the wafer boat 58 until the wafers W are transferred to the wafer boat 58 and retracted, but the present invention is not limited thereto, and the mahalanobis distance in the normal space may be calculated by creating the normal space for the operation of the substrate transfer machine 86 between the wafer cassettes 20. This makes it possible to detect with high accuracy that the wafer W on the substrate transfer device 86 or the substrate transfer device 86 and the wafer W in the wafer cassette 20 or the wafer cassette 20 are in contact with each other, and to detect a slight abnormality before the failure state.

In the above-described embodiment, the example in which the auxiliary sensor 301 is attached to the rotary shaft 80A as an auxiliary vibration sensor to detect the vibration of the boat 58 has been described, but the present invention is not limited thereto, and the auxiliary sensor 301 may be attached to the rotary mechanism 80 or an insulating unit provided between the boat 58 and the rotary shaft 80A, or may be attached to a table on which the boat 58 is placed. Further, as the auxiliary vibration sensor, a sound collecting microphone having directivity toward the tip of the clamp 86a and collecting vibration in the gas may be used. In this case, the sound collecting microphone is mounted on the substrate transfer unit 86 or installed in the transfer chamber 16. As the auxiliary vibration sensor, a laser doppler vibrometer that irradiates the wafer boat 58 with laser light and detects the vibration thereof may be used. At this time, the laser doppler vibrometer is disposed in the transfer chamber 16. Further, a plurality of auxiliary vibration sensors may also be used. By using a plurality of auxiliary vibration sensors, the accuracy of abnormality detection of the analysis device 400 can be improved.

In the above-described embodiment, the example in which the vibration sensor 300 is provided on the fixing portion 304 that laminates and fixes the root portions of the plurality of grippers 86a has been described, but the present invention is not limited thereto, and the vibration sensor may be provided on each of the plurality of grippers 86 a. In this case, a plurality of normal spaces are generated for each time domain data of the output value of the vibration sensor of each clamp 86a, and the mahalanobis distance in the corresponding normal space is calculated from the plurality of normal spaces. This enables the clamp 86a with the abnormality detected to be specified.

In the above-described embodiment, the case where the MT method is applied without performing any special preprocessing on the signals of the vibration sensor 300 and the like has been described, but the present invention is not limited thereto, and preprocessing such as a filter may be performed. The preprocessing may be configured as a filter for suppressing noise at a specific frequency, passing a frequency unique to the contact, or an equalizer for compensating for a frequency characteristic of a detection system including a clamp having a natural frequency. When the frequency generated by the scratches depends on the moving speed of the substrate transfer unit 86 or when the noise frequency fluctuates by using a variable speed vacuum pump, the center frequency and the cutoff frequency of the filter can be variably controlled in synchronization with the frequency.

In the above-described embodiments, the case of processing a wafer has been described, but the present disclosure can be applied to the entire substrate processing apparatus that processes a substrate such as a glass substrate of a liquid crystal panel, a magnetic disk, or an optical disk. In the above-described embodiments, an example of using a batch-type substrate processing apparatus that processes a plurality of substrates at a time is described. The present disclosure is not limited to the above-described embodiments, and can be suitably applied to a case where a single-wafer substrate processing apparatus that processes 1 or more substrates at a time is used, for example.

(8) Preferred mode of the present disclosure

Hereinafter, preferred embodiments of the present disclosure will be described.

(attached note 1)

According to one aspect of the present disclosure, there is provided a substrate processing apparatus including:

a substrate holder that holds a substrate;

a vibration sensor that detects vibration of the end effector;

a control unit for controlling the substrate transfer machine;

an analysis device that calculates a mahalanobis distance of the time domain data detected by the vibration sensor in the normal space while the substrate transfer machine carries out a predetermined transfer operation, using a normal space generated by analyzing the time domain data of the vibration of the end effector detected by the vibration sensor when the transfer operation of the substrate by the substrate transfer machine is normally performed by an MT method, and determines that the substrate on the end effector or the end effector and the substrate on the substrate holder or the substrate holder are in contact with each other when the calculated mahalanobis distance exceeds a predetermined threshold value,

the control unit outputs a signal indicating the start and end of the predetermined transfer operation to the analysis device.

(attached note 2)

The substrate processing apparatus according to supplementary note 1, preferably,

the analysis device extracts, as feature quantities, a variation amount, which is the number of times the time domain data crosses a sample line for each of a predetermined plurality of sample lines, and an existence amount, which is the number of data pieces larger than the value of the sample line, thereby generating multivariate data,

calculating an average value and a covariance matrix of multivariate data generated based on a plurality of time domain data of the vibration of the end effector detected by the vibration sensor when the transfer operation of the substrate by the substrate transfer machine is normally performed, and defining the normal space by using the covariance matrix,

the mahalanobis distance in the normal space is calculated during the transfer operation based on multivariate data generated from time domain data detected by the vibration sensor during the transfer operation of the substrate transfer machine.

(attached note 3)

The substrate processing apparatus according to supplementary note 2, preferably,

the analysis device stores a plurality of normal spaces in accordance with the number of substrates being transferred, the moving speed of the end effector, the amount of insertion of the end effector into the substrate holder, the amount of air flowing around the substrate holder, the temperature of the substrate holder, or the temperature of the processing chamber in which the substrate holder is accommodated,

selecting a normal space that matches the state of the substrate transfer machine when the transfer operation is performed from the plurality of normal spaces, and calculating the mahalanobis distance in the selected normal space.

(attached note 4)

The substrate processing apparatus according to supplementary note 2 or supplementary note 3, preferably,

the substrate transfer device is fixedly arranged in the substrate processing device and transfers the substrate between the substrate transfer device and the substrate holder which is moved out from the processing chamber,

the vibration sensor is a 3-axis acceleration sensor,

the substrate processing apparatus further includes: an auxiliary vibration sensor including at least 1 of an auxiliary sensor attached to a member holding the substrate holder, a sound collecting microphone facing a tip end of the end effector and having directivity to collect vibration in gas, and a laser doppler vibrometer irradiating laser light to the substrate holder to detect the vibration,

the analysis device generates the normal space using a plurality of multivariate data generated by extracting, as feature quantities, variation amounts and presence amounts of time domain data of respective axes of the vibration sensor and time domain data of the auxiliary vibration sensor, respectively.

(attached note 5)

the number of data of the time domain data in the normal space is 24576 samples or less, and the multivariate data is subjected to multivariate quantization at intervals of less than 1024 samples.

(attached note 6)

the substrate processing apparatus further includes: a camera for shooting the transfer operation; a recording device for recording the shot image in association with the time,

the control unit controls the transfer operation and the time to be associated and recorded as an operation log in the recording device.

(attached note 7)

According to another aspect of the present disclosure, there is provided a method of manufacturing a semiconductor device, including:

a transfer step of transferring a substrate to or from a substrate holder holding the substrate by a substrate transfer machine including an end effector for directly handling the substrate and a drive mechanism for moving the end effector;

an analyzing step of calculating, by an analyzing device, a normal space generated by analyzing, by an MT method, time-domain data of the vibration of the end effector detected by a vibration sensor that detects the vibration of the end effector when the transfer operation of the substrate by the substrate transfer machine is normally performed in the transfer step, a mahalanobis distance in the normal space of the time-domain data detected by the vibration sensor while the substrate transfer machine is carrying the substrate and performing the predetermined transfer operation in the transfer step, and determining that an abnormal situation in which the end effector or the substrate on the end effector and the substrate on the substrate holder or the substrate on the substrate holder contact each other has occurred when the calculated mahalanobis distance exceeds a predetermined threshold value;

and an output step of outputting a signal indicating the start and end of a predetermined transfer operation by the substrate transfer device to the analysis device.

Description of the reference numerals

4 a processing apparatus (substrate processing apparatus);

20 wafer cassettes (containers);

58 boat (substrate holder);

86a substrate transfer machine;

210 a controller;

300 a vibration sensor;

301 auxiliary sensors;

400 analytical device.

Claims

1. A substrate processing apparatus is characterized in that,

the substrate processing apparatus includes:

a substrate holder that holds a substrate;

a vibration sensor that detects vibration of the end effector;

a control unit for controlling the substrate transfer machine; and

2. The substrate processing apparatus according to claim 1,

the end effector has a plurality of U-shaped thin plate-like grippers arranged in the vertical direction.

3. The substrate processing apparatus according to claim 1,

the analysis device extracts, as feature quantities, a variation amount, which is the number of times a sample line is crossed for each of a predetermined plurality of sample lines, and an existence amount, which is the number of data pieces larger than the value of the sample line, of the time domain data, thereby generating multivariate data,

calculating a multivariate data average value and a covariance matrix generated based on a plurality of time domain data of the vibration of the end effector detected by the vibration sensor when the transfer operation of the substrate by the substrate transfer machine is normally performed, and defining a normal space by using the covariance matrix,

and calculating mahalanobis distance in the normal space during the transfer operation based on multivariate data generated based on time domain data detected by the vibration sensor during the transfer operation of the substrate transfer machine.

4. The substrate processing apparatus according to claim 3,

the analysis device stores a plurality of normal spaces in accordance with the number of substrates being transferred, the moving speed of the end effector, the state of insertion of the end effector into the substrate holder, the volume of air flowing around the substrate holder, the temperature of the substrate holder, or the temperature of the processing chamber in which the substrate holder is accommodated,

5. The substrate processing apparatus according to claim 1,

6. The substrate processing apparatus according to claim 3,

the vibration sensor is a 3-axis acceleration sensor,

the substrate processing apparatus further includes an auxiliary vibration sensor including at least 1 of an auxiliary sensor mounted on a member holding the substrate holder, a sound collecting microphone facing a tip end of the end effector and having directivity to collect vibration in gas, and a laser Doppler vibrometer irradiating the substrate holder with laser light to detect the vibration,

7. The substrate processing apparatus according to claim 3,

the parsing means is capable of computing a set of said multivariate data from said time domain data sampled less than 2048.

8. The substrate processing apparatus according to claim 3,

the analysis device calculates the mahalanobis distance that can determine the contact as abnormal within 3 seconds from the occurrence of the contact.

9. The substrate processing apparatus according to claim 3,

the analysis device acquires the time domain data through a sliding window, and calculates the mahalanobis distance in a period of 0.5 seconds or less.

10. The substrate processing apparatus according to claim 3,

the parsing means is capable of computing a set of said multivariate data from said time domain data sampled less than M, where M is a natural number less than 2048,

the sliding window can be set while shifting the M/d samples every time, using the division number d selected so that d is not less than 2 and not more than M and M/d becomes an integer.

11. The substrate processing apparatus according to claim 9,

the resolving means may be capable of calculating the mahalanobis distance at a period of M/d sampling.

12. The substrate processing apparatus according to claim 3,

the substrate processing apparatus further comprises a camera for capturing images of the transfer operation and a recording device for recording the captured images in association with the time,

the control unit may control the transfer operation to be recorded in the recording device as an operation log in association with a time.

13. The substrate processing apparatus according to claim 3,

the acquisition of the time domain data is performed by variable rate or unequal interval sampling.