JP6586394B2 - How to get data representing capacitance - Google Patents

Description

  Embodiments of the present invention relate to a method for obtaining data representing capacitance between a measuring instrument and a focus ring that are transported into a chamber by a transport device of a processing system.

  In the manufacture of an electronic device such as a semiconductor device, a processing system having a process module for processing a work piece is used. The process module generally has a chamber body and a mounting table. Further, the processing system includes a transfer device. The workpiece is carried into the chamber provided by the chamber body by the transfer device and placed on the placing table. The workpiece is then processed in the chamber.

  The position of the workpiece on the mounting table is an important factor in order to satisfy various requirements such as in-plane uniformity of processing of the workpiece. Therefore, the transport device needs to transport the workpiece to an appropriate position on the mounting table. If the workpiece is not transported to an appropriate position, the coordinate information specifying the transport destination position of the transport device must be corrected.

  In order to correct the coordinate information, it is necessary to detect the position of the workpiece on the mounting table. Conventionally, a measuring instrument for measuring capacitance is used for detecting such a position. The position detection using such a measuring device is described in, for example, Patent Document 1 below. Note that the measuring instrument described in Patent Document 1 wirelessly transmits the measured capacitance to a control unit provided outside the chamber.

  Patent Document 2 describes a wireless sensor that is arranged in a chamber of a process module and wirelessly transmits data measured during the process to a receiver provided outside the chamber.

Japanese Patent No. 4956328 Japanese Patent No. 4251814

  By the way, since the chamber main body is generally made of metal, a measuring instrument placed in the chamber and a device placed outside the chamber cannot perform wireless communication. Therefore, the measuring instrument needs to autonomously acquire measurement data and store the measurement data while in the chamber. In order to operate autonomously in such a measuring device, the measuring device needs to have a power source such as a battery. It is necessary to suppress the power consumption of this power source.

  In one aspect, a method for obtaining data representing capacitance is provided. In this method, the capacitance between the measuring instrument and the focus ring that are transferred into the chamber by the transfer device of the processing system is acquired. The processing system includes a process module, a transfer device, and a control unit. The process module includes a chamber body and a mounting table. The chamber body provides a chamber. The mounting table is provided in the chamber, and a measuring device is mounted thereon. The control unit controls the transport device.

  The measuring instrument includes a base substrate, a plurality of sensor units, and a circuit board. The base substrate has a disk shape. The plurality of sensor units are arranged along the edge of the base substrate. The circuit board is mounted on the base board. Each of the plurality of sensor units has a front surface extending along the edge of the base substrate. The circuit board includes a high-frequency oscillator, a plurality of C / V conversion circuits, an A / D converter, a processor, a storage device, a communication device, and a power source. The high-frequency oscillator is configured to generate a high-frequency signal, and is electrically connected to each sensor electrode of the plurality of sensor units. Each of the plurality of C / V conversion circuits is configured to convert the voltage amplitude at the sensor electrode of the corresponding sensor unit among the plurality of sensor units into a voltage signal representing capacitance. The A / D converter is configured to convert a voltage signal output from each of the plurality of C / V conversion circuits into a digital value. The processor is connected to the A / D converter. The storage device is connected to the processor. The communication device is configured to wirelessly transmit data stored in the storage device. The power source is configured to supply power to the processor, the high frequency oscillator, and the communication device.

  A method according to an aspect is a step in which (i) a processor acquires one or more first data sets at a preset time interval, and each of the one or more data sets includes a plurality of sensor units. Including a plurality of digital values obtained by acquiring a digital value representing the capacitance of the corresponding sensor unit among the one or more sensor units included in the first sampling period; and (ii) (Iii) one or more or one or more of a plurality of digital values included in each of the one or more first data sets; and (iii) a step of transporting the measuring device to a region surrounded by the focus ring on the table In response to the average value of the plurality of digital values included in each of the first data sets being equal to or greater than the first threshold, the processor acquires the plurality of second data sets during the measurement period. Each of the plurality of second data sets is obtained by acquiring a digital value representing a capacitance of a corresponding sensor unit among the plurality of sensor units at a second sampling period within a measurement period. The step of including a plurality of digital values obtained; and (iv) a step of storing the measurement data in a storage device, wherein the measurement data is stored in a plurality of second data sets or a plurality of second values. Including a plurality of average values obtained by calculating an average value of a plurality of digital values included in each of the data sets, and (v) unloading the measuring device from the chamber by the transfer device. Including.

  In a method according to an aspect, a measuring instrument including a plurality of sensor electrodes arranged along an edge of a disk-shaped base substrate is used, and a circumferential direction of a distance between an inner edge of a focus ring and an edge of the measuring instrument is used. Measurement data reflecting the distribution at is obtained. Further, the digital value representing the capacitance of each of the plurality of sensor electrodes becomes large when the measuring instrument is in the area surrounded by the focus ring. In this method, measurement data is not always acquired, but one or more first data sets are acquired at a preset time interval in a period before the measurement period. An average value of one or more of the plurality of digital values included in each of the one or more first data sets or the plurality of digital values included in each of the one or more first data sets is equal to or greater than the first threshold value. In the measurement period, the second data set is acquired and the measurement data is stored. Thus, in this method, since the intermittent operation is performed in the measuring instrument in the period before the measuring period, the power consumption of the power source of the measuring instrument can be suppressed.

  In one embodiment, the method is (vi) after the end of the measurement period, the processor acquiring one or more third data sets at a preset time interval, wherein the one or more third data sets Each includes a plurality of digital values obtained by acquiring a digital value representing a capacitance of a corresponding sensor unit among the one or more sensor units included in the plurality of sensor units in a third sampling period, And (vii) an average value of a plurality of digital values included in each of one or more or one or more third data sets among a plurality of digital values included in each of the one or more third data sets. And a step of causing the communication device to wirelessly transmit the measurement data in response to the threshold value of 2 being exceeded.

  The measuring instrument carried out of the chamber is accommodated in a container called a FOUP. When in the container, the capacitance of the sensor electrodes of the plurality of sensor units increases. Therefore, one or more of the plurality of digital values included in each of the one or more third data sets, or an average value of the plurality of digital values included in each of the one or more third data sets is equal to or greater than the second threshold value. In response to this, by causing the communication device to wirelessly transmit the measurement data, the measurement device can wirelessly transmit the measurement data autonomously when it is outside the chamber. In addition, according to this embodiment, even after the measurement period, the measurement device performs intermittent operation, so that the power consumption of the power source of the measurement device can be further suppressed.

  In one embodiment, the power supply from the power source to the high-frequency oscillator between a period during which one or more first data sets are acquired and a period during which one or more first data sets are then acquired. May be stopped. Further, in one embodiment, the power supply from the power source to the high frequency oscillator is between a period during which one or more third data sets are acquired and a period during which one or more third data sets are acquired. The power supply may be stopped.

  In one embodiment, in the step of transporting the measuring device, the control unit controls the transporting device so as to transport the measuring device to the transport destination position using preset coordinate information. The method of this embodiment further includes a step in which the control unit corrects the coordinate information so that the difference in the circumferential direction of the distance between the focus ring and the edge of the measuring device specified from the measurement data is reduced. .

  As described above, it is possible to suppress the power consumption of the power source of the measuring instrument in obtaining measurement data representing the capacitance between the measuring instrument and the focus ring.

3 is a flow diagram illustrating a method for measuring capacitance according to one embodiment. It is a figure which illustrates a processing system. It is sectional drawing which illustrates a container. It is a perspective view which illustrates an aligner. It is a figure which shows an example of a plasma processing apparatus. It is a perspective view which illustrates a measuring device. It is a perspective view which shows an example of a sensor part. It is sectional drawing taken along the VIII-VIII line of FIG. It is sectional drawing taken along the IX-IX line of FIG. It is a figure which illustrates the structure of the circuit board of a measuring device. It is a timing chart relevant to the method shown in FIG. It is a longitudinal cross-sectional view which shows another example of a sensor part. It is a longitudinal cross-sectional view which shows another example of a sensor part. It is a figure which illustrates the structure of the circuit board of the measuring device which concerns on another embodiment.

  Hereinafter, various embodiments will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals.

  FIG. 1 is a flow diagram illustrating a method for measuring capacitance according to one embodiment. The method MT shown in FIG. 1 is a method for acquiring data representing the capacitance between the measuring instrument and the focus ring that are transferred into the chamber by the transfer device of the processing system. In one embodiment, in the method MT, the coordinate information of the transport destination position of the transport device is corrected using the acquired data.

  FIG. 2 is a diagram illustrating a processing system. A processing system 1 shown in FIG. 2 is a processing system to which the method MT can be applied. The processing system 1 includes tables 2a to 2d, containers 4a to 4d, a loader module LM, an aligner AN, load lock modules LL1 and LL2, process modules PM1 to PM6, a transfer module TF, and a control unit MC. Note that the number of the bases 2a to 2d, the number of the containers 4a to 4d, the number of the load lock modules LL1 and LL2, and the number of the process modules PM1 to PM6 are not limited, and may be any one or more. obtain.

  The bases 2a to 2d are arranged along one edge of the loader module LM. The containers 4a to 4d are mounted on the platforms 2a to 2d, respectively. Each of the containers 4a to 4d is, for example, a container called FOUP (Front Opening Unified Pod). Each of the containers 4a to 4d is configured to accommodate the workpiece W. The workpiece W has a substantially disk shape.

  FIG. 3 is a cross-sectional view illustrating a container. FIG. 3 shows a longitudinal sectional view of the container 4 that can be adopted as each of the containers 4a to 4d. As shown in FIG. 3, the container 4 includes a container body 4M and a pair of support members 4S. The container body 4M provides a space therein. The pair of support members 4S are provided along the pair of side walls of the container body 4M in the space provided by the container body 4M. The pair of support members 4S provide a plurality of slots 4L. The plurality of slots 4L are arranged in the vertical direction and extend in the depth direction of the space provided by the container body 4M. A workpiece W can be accommodated in each of the plurality of slots 4L. The workpiece W accommodated in any of the plurality of slots 4L is supported by a pair of support members 4S.

  Returning to FIG. 2, the loader module LM has a chamber wall that defines a transfer space in an atmospheric pressure state therein. A transport device TU1 is provided in the transport space. The transport device TU1 is, for example, an articulated robot, and is controlled by the control unit MC. The transport device TU1 transports the workpiece W between the containers 4a to 4d and the aligner AN, between the aligner AN and the load lock modules LL1 to LL2, and between the load lock modules LL1 to LL2 and the containers 4a to 4d. It is configured.

  The aligner AN is connected to the loader module LM. The aligner AN is configured to adjust the position of the workpiece W (position calibration). FIG. 4 is a perspective view illustrating an aligner. The aligner AN has a support base 6T, a driving device 6D, and a sensor 6S. The support table 6T is a table that can rotate about the axis extending in the vertical direction, and is configured to support the workpiece W thereon. The support base 6T is rotated by the driving device 6D. The driving device 6D is controlled by the control unit MC. When the support base 6T is rotated by the power from the driving device 6D, the workpiece W placed on the support base 6T is also rotated.

  The sensor 6S is an optical sensor and detects the edge of the workpiece W while the workpiece W is rotated. The sensor 6S determines the amount of deviation of the angular position of the notch WN (or another marker) of the workpiece W from the reference angular position and the amount of deviation of the center position of the workpiece W from the reference position based on the edge detection result. Is detected. The sensor 6S outputs the deviation amount of the angular position of the notch WN and the deviation amount of the center position of the workpiece W to the control unit MC. The controller MC calculates the amount of rotation of the support base 6T for correcting the angular position of the notch WN to the reference angular position based on the deviation amount of the angular position of the notch WN. The controller MC controls the driving device 6D so as to rotate the support base 6T by this amount of rotation. As a result, the angular position of the notch WN can be corrected to the reference angular position. In addition, the control unit MC receives the workpiece W from the aligner AN so that the center position of the workpiece W coincides with a predetermined position on the end effector (end effector) of the transport device TU1. The position of the effector is controlled based on the shift amount of the center position of the workpiece W.

  Returning to FIG. 2, each of the load lock module LL1 and the load lock module LL2 is provided between the loader module LM and the transfer module TF. Each of the load lock module LL1 and the load lock module LL2 provides a preliminary decompression chamber. A gate valve is provided between the load lock module LL1 and the loader module LM. The preliminary decompression chamber of the load lock module LL1 and the transfer space of the loader module LM are communicated by opening the gate valve, and are separated from each other by closing the gate valve. Further, another gate valve is provided between the load lock module LL2 and the loader module LM. The preliminary decompression chamber of the load lock module LL2 and the transfer space of the loader module LM are communicated by opening the gate valve, and separated from each other by closing the gate valve.

  The transfer module TF is connected to the load lock module LL1 and the load lock module LL2 via a gate valve. The transfer module TF provides a decompression chamber that can be decompressed. In the decompression chamber, a transfer device TU2 is provided. The transport device TU2 is, for example, an articulated robot, and is controlled by the control unit MC. The transfer device TU2 is configured to transfer the workpiece W between the load lock modules LL1 to LL2 and the process modules PM1 to PM6 and between any two process modules among the process modules PM1 to PM6. ing.

  Each of the process modules PM1 to PM6 is connected to the transfer module TF via a gate valve. Each of the process modules PM1 to PM6 is a processing apparatus configured to perform a dedicated process such as a plasma process on the workpiece W. The chambers of the process modules PM1 to PM6 and the decompression chamber of the transfer module TF are communicated by opening the gate valve, and separated from each other by closing the gate valve.

  A series of operations when the workpiece W is processed in the processing system 1 is exemplified as follows. The transfer device TU1 of the loader module LM takes out the workpiece W from any of the containers 4a to 4d and transfers the workpiece W to the aligner AN. Next, the transport device TU1 takes out the workpiece W whose position is adjusted from the aligner AN, and transports the workpiece W to one of the load lock modules LL1 and LL2. Next, one of the load lock modules reduces the pressure in the preliminary decompression chamber to a predetermined pressure. Next, the transfer device TU2 of the transfer module TF takes out the workpiece W from one load lock module, and transfers the workpiece W to any one of the process modules PM1 to PM6. Then, one or more process modules among the process modules PM1 to PM6 process the workpiece W. Then, the transport apparatus TU2 transports the processed workpiece W from the process module to one of the load lock modules LL1 and LL2. Next, the transport device TU1 transports the workpiece W from one load lock module to any of the containers 4a to 4d.

  The processing system 1 includes the control unit MC as described above. The control unit MC can be a computer including a storage device such as a processor and a memory, a display device, an input / output device, a communication device, and the like. The series of operations of the processing system 1 described above is realized by control of each unit of the processing system 1 by the control unit MC according to a program stored in the storage device.

  FIG. 5 is a diagram illustrating an example of a plasma processing apparatus that can be employed as any one of the process modules PM1 to PM6. The plasma processing apparatus 10 shown in FIG. 5 is a capacitively coupled plasma etching apparatus. The plasma processing apparatus 10 includes a chamber body 12 having a substantially cylindrical shape. The chamber body 12 is made of, for example, aluminum, and an anodizing process can be performed on the inner wall surface thereof. The chamber body 12 is grounded for safety.

  A substantially cylindrical support portion 14 is provided on the bottom of the chamber body 12. The support part 14 is comprised from the insulating material, for example. The support portion 14 is provided in the chamber main body 12 and extends upward from the bottom of the chamber main body 12. In addition, a mounting table PD is provided in the chamber S provided by the chamber body 12. The mounting table PD is supported by the support unit 14.

  The mounting table PD includes a lower electrode LE and an electrostatic chuck ESC. The lower electrode LE includes a first plate 18a and a second plate 18b. The first plate 18a and the second plate 18b are made of a metal such as aluminum, for example, and have a substantially disk shape. The second plate 18b is provided on the first plate 18a and is electrically connected to the first plate 18a.

  An electrostatic chuck ESC is provided on the second plate 18b. The electrostatic chuck ESC has a structure in which an electrode which is a conductive film is disposed between a pair of insulating layers or insulating sheets, and has a substantially disk shape. A DC power source 22 is electrically connected to the electrode of the electrostatic chuck ESC via a switch 23. The electrostatic chuck ESC attracts the workpiece W with an electrostatic force such as a Coulomb force generated by a DC voltage from the DC power source 22. Thereby, the electrostatic chuck ESC can hold the workpiece W.

  A focus ring FR is provided on the peripheral edge of the second plate 18b. The focus ring FR is provided so as to surround the edge of the workpiece W and the electrostatic chuck ESC. The focus ring FR has a first portion P1 and a second portion P2 (see FIG. 8). The first part P1 and the second part P2 have an annular plate shape. The second part P2 is provided on the first part P1. The inner edge P2i of the second portion P2 has a diameter larger than the diameter of the inner edge P1i of the first portion P1. The workpiece W is placed on the electrostatic chuck ESC so that the edge region thereof is located on the first portion P1 of the focus ring FR. The focus ring FR can be formed from any of various materials such as silicon, silicon carbide, and silicon oxide.

  A coolant channel 24 is provided inside the second plate 18b. The refrigerant flow path 24 constitutes a temperature adjustment mechanism. Refrigerant is supplied to the refrigerant flow path 24 from a chiller unit provided outside the chamber body 12 via a pipe 26a. The refrigerant supplied to the refrigerant flow path 24 is returned to the chiller unit via the pipe 26b. In this way, the refrigerant is circulated between the refrigerant flow path 24 and the chiller unit. By controlling the temperature of the refrigerant, the temperature of the workpiece W supported by the electrostatic chuck ESC is controlled.

  The plasma processing apparatus 10 is provided with a gas supply line 28. The gas supply line 28 supplies the heat transfer gas from the heat transfer gas supply mechanism, for example, He gas, between the upper surface of the electrostatic chuck ESC and the back surface of the workpiece W.

  In addition, the plasma processing apparatus 10 includes an upper electrode 30. The upper electrode 30 is disposed above the mounting table PD so as to face the mounting table PD. The upper electrode 30 is supported on the upper portion of the chamber body 12 via an insulating shielding member 32. The upper electrode 30 can include a top plate 34 and a support 36. The top plate 34 faces the chamber S, and the top plate 34 is provided with a plurality of gas discharge holes 34a. The top plate 34 can be made of silicon or quartz. Alternatively, the top plate 34 can be configured by forming a plasma-resistant film such as yttrium oxide on the surface of an aluminum base material.

  The support 36 supports the top plate 34 in a detachable manner and can be made of a conductive material such as aluminum. The support 36 may have a water cooling structure. A gas diffusion chamber 36 a is provided inside the support 36. A plurality of gas flow holes 36b communicating with the gas discharge holes 34a extend downward from the gas diffusion chamber 36a. The support 36 is formed with a gas introduction port 36c that guides the processing gas to the gas diffusion chamber 36a, and a gas supply pipe 38 is connected to the gas introduction port 36c.

  A gas source group 40 is connected to the gas supply pipe 38 via a valve group 42 and a flow rate controller group 44. The gas source group 40 includes a plurality of gas sources for a plurality of types of gases. The valve group 42 includes a plurality of valves, and the flow rate controller group 44 includes a plurality of flow rate controllers such as a mass flow controller. The plurality of gas sources of the gas source group 40 are connected to the gas supply pipe 38 via the corresponding valve of the valve group 42 and the corresponding flow rate controller of the flow rate controller group 44, respectively.

In the plasma processing apparatus 10, a deposition shield 46 is detachably provided along the inner wall of the chamber body 12. The deposition shield 46 is also provided on the outer periphery of the support portion 14. The deposition shield 46 prevents etching by-products (deposition) from adhering to the chamber body 12 and can be configured by coating an aluminum material with ceramics such as Y ₂ O ₃ .

An exhaust plate 48 is provided on the bottom side of the chamber body 12 and between the support portion 14 and the side wall of the chamber body 12. The exhaust plate 48 can be configured by, for example, coating an aluminum material with ceramics such as Y ₂ O ₃ . The exhaust plate 48 is formed with a plurality of holes penetrating in the thickness direction. An exhaust port 12e is provided below the exhaust plate 48 and in the chamber body 12. An exhaust device 50 is connected to the exhaust port 12e via an exhaust pipe 52. The exhaust device 50 has a vacuum pump such as a pressure control valve and a turbo molecular pump, and can reduce the space in the chamber body 12 to a desired degree of vacuum. Further, a loading / unloading port 12 g for the workpiece W is provided on the side wall of the chamber body 12, and the loading / unloading port 12 g can be opened and closed by a gate valve 54.

  The plasma processing apparatus 10 further includes a first high frequency power source 62 and a second high frequency power source 64. The first high frequency power supply 62 is a power supply that generates a first high frequency for plasma generation, and generates a high frequency having a frequency of 27 to 100 MHz, for example. The first high frequency power supply 62 is connected to the upper electrode 30 via the matching unit 66. The matching unit 66 has a circuit for matching the output impedance of the first high-frequency power source 62 with the input impedance on the load side (upper electrode 30 side). Note that the first high-frequency power source 62 may be connected to the lower electrode LE via the matching unit 66.

  The second high-frequency power source 64 is a power source that generates a second high frequency for drawing ions into the workpiece W, and generates a high frequency having a frequency within a range of 400 kHz to 13.56 MHz, for example. The second high frequency power supply 64 is connected to the lower electrode LE via the matching unit 68. The matching unit 68 has a circuit for matching the output impedance of the second high-frequency power supply 64 with the input impedance on the load side (lower electrode LE side).

  In the plasma processing apparatus 10, gas from one or more gas sources selected from among a plurality of gas sources is supplied to the chamber S. The pressure in the chamber S is set to a predetermined pressure by the exhaust device 50. Further, the gas in the chamber S is excited by the first high frequency from the first high frequency power supply 62. Thereby, plasma is generated. Then, the workpiece W is processed by the generated active species. If necessary, ions may be drawn into the workpiece W by a bias based on the second high frequency of the second high frequency power supply 64.

  Hereinafter, a measuring instrument used in the method MT will be described. FIG. 6 is a perspective view illustrating a measuring instrument. A measuring instrument 100 shown in FIG. 6 includes a base substrate 102. The base substrate 102 is made of silicon, for example, and has a shape similar to the shape of the workpiece W, that is, a substantially disk shape. The diameter of the base substrate 102 is the same as that of the workpiece W, and is 300 mm, for example. The shape and size of the measuring instrument 100 are defined by the shape and size of the base substrate 102. Therefore, the measuring instrument 100 has the same shape as that of the workpiece W and has the same dimension as that of the workpiece W. A notch 102N (or another marker) is formed at the edge of the base substrate 102.

  The base substrate 102 has a lower part 102a and an upper part 102b. The lower portion 102a is a portion located closer to the electrostatic chuck ESC than the upper portion 102b when the measuring instrument 100 is disposed above the electrostatic chuck ESC. The lower portion 102a of the base substrate 102 is provided with a plurality of sensor units 104A to 104H for measuring capacitance. Note that the number of sensor units provided in the measuring instrument 100 may be an arbitrary number of three or more. The plurality of sensor units 104 </ b> A to 104 </ b> H are arranged along the edge of the base substrate 102, for example, at equal intervals along the entire circumference of the edge. Specifically, the front side end surface 104f of each of the plurality of sensor units 104A to 104H is provided along the edge of the lower portion 102a of the base substrate 102. In addition, in FIG. 6, sensor part 104A-104C is visible among several sensor part 104A-104H.

  The upper surface of the upper portion 102b of the base substrate 102 provides a recess 102r. The recess 102r includes a central region 102c and a plurality of radiation regions 102h. The central region 102c is a region that intersects the central axis AX100. The center axis AX100 is an axis that passes through the center of the base substrate 102 in the thickness direction. A circuit board 106 is provided in the central region 102c. The plurality of radiation regions 102h extend in the radial direction with respect to the central axis AX100 from the central region 102c to above the region where the plurality of sensor units 104A to 104H are disposed. The plurality of radiation regions 102h are provided with wiring groups 108A to 108H for electrically connecting the plurality of sensor units 104A to 104H and the circuit board 106, respectively. The plurality of sensor units 104 </ b> A to 104 </ b> H may be provided on the upper portion 102 b of the base substrate 102.

  Hereinafter, the sensor unit will be described in detail. FIG. 7 is a perspective view illustrating an example of a sensor unit. FIG. 8 is a cross-sectional view taken along the line VIII-VIII in FIG. 7 and shows the base substrate and the focus ring of the measuring device together with the sensor unit. 9 is a cross-sectional view taken along line IX-IX in FIG. The sensor unit 104 shown in FIGS. 7 to 9 is a sensor unit that is used as the plurality of sensor units 104A to 104H of the measuring instrument 100, and is configured as a chip-like component in one example. In the following description, an XYZ orthogonal coordinate system is referred to as appropriate. The X direction indicates the front direction of the sensor unit 104, the Y direction indicates one direction orthogonal to the X direction and the width direction of the sensor unit 104, and the Z direction indicates the X direction and the Y direction. The direction perpendicular to the sensor unit 104 is shown.

  As shown in FIGS. 7 to 9, the sensor unit 104 has a front end face 104f, an upper face 104t, a lower face 104b, a pair of side faces 104s, and a rear end face 104r. The front end face 104f constitutes a front surface of the sensor unit 104 in the X direction. The sensor unit 104 is mounted on the base substrate 102 of the measuring instrument 100 so that the front side end face 104f faces the radial direction with respect to the central axis AX100 (see FIG. 6). Further, in a state where the sensor unit 104 is mounted on the base substrate 102, the front end surface 104 f extends along the edge of the base substrate 102. Therefore, when the measuring instrument 100 is disposed on the electrostatic chuck ESC, the front end face 104f faces the inner edge of the focus ring FR.

  The rear side end face 104r constitutes the rear side surface of the sensor unit 104 in the X direction. In a state where the sensor unit 104 is mounted on the base substrate 102, the rear end face 104r is located closer to the central axis AX100 than the front end face 104f. The upper surface 104t constitutes the upper surface of the sensor unit 104 in the Z direction, and the lower surface 104b constitutes the lower surface of the sensor unit 104 in the Z direction. The pair of side surfaces 104s constitutes the surface of the sensor unit 104 in the Y direction.

  The sensor unit 104 has an electrode 143. The sensor unit 104 may further include an electrode 141 and an electrode 142. The electrode 141 is formed from a conductor. The electrode 141 has a first portion 141a. As shown in FIGS. 7 and 8, the first portion 141a extends in the X direction and the Y direction.

  The electrode 142 is made of a conductor. The electrode 142 has a second portion 142a. The second portion 142a extends on the first portion 141a. In the sensor unit 104, the electrode 142 is insulated from the electrode 141. As shown in FIGS. 7 and 8, the second portion 142a extends in the X direction and the Y direction on the first portion 141a.

  The electrode 143 is a sensor electrode formed from a conductor. The electrode 143 is provided on the first portion 141 a of the electrode 141 and the second portion 142 a of the electrode 142. The electrode 143 is insulated from the electrode 141 and the electrode 142 in the sensor unit 104. The electrode 143 has a front surface 143f. The front surface 143f extends in a direction intersecting the first portion 141a and the second portion 142a. Further, the front surface 143f extends along the front end surface 104f of the sensor unit 104. In one embodiment, the front surface 143f constitutes a part of the front end surface 104f of the sensor unit 104. Alternatively, the sensor unit 104 may have an insulating film that covers the front surface 143f on the front side of the front surface 143f of the electrode 143.

  As shown in FIGS. 7 to 9, the electrode 141 and the electrode 142 open on the side (X direction) of the region where the front surface 143 f of the electrode 143 is disposed and extend so as to surround the periphery of the electrode 143. You may do it. That is, the electrode 141 and the electrode 142 may extend so as to surround the electrode 143 above, behind, and on the side of the electrode 143.

  The front end surface 104f of the sensor unit 104 may be a curved surface having a predetermined curvature. In this case, the front end face 104f has a constant curvature at an arbitrary position of the front end face, and the curvature of the front end face 104f is between the center axis AX100 of the measuring instrument 100 and the front end face 104f. It can be the reciprocal of the distance. The sensor unit 104 is mounted on the base substrate 102 so that the center of curvature of the front side end face 104f coincides with the central axis AX100.

  The sensor unit 104 may further include a substrate unit 144, insulating regions 146 to 148, pads 151 to 153, and via wirings 154. The substrate part 144 has a main body part 144m and a surface layer part 144f. The main body portion 144m is made of, for example, silicon. The surface layer portion 144f covers the surface of the main body portion 144m. The surface layer portion 144f is made of an insulating material. The surface layer portion 144f is, for example, a silicon thermal oxide film.

The second portion 142 a of the electrode 142 extends below the substrate portion 144, and an insulating region 146 is provided between the substrate portion 144 and the electrode 142. Insulating region 146, for _{example, SiO 2, SiN, Al 2} O 3, or are formed of polyimide.

The first portion 141 a of the electrode 141 extends below the substrate portion 144 and the second portion 142 a of the electrode 142. An insulating region 147 is provided between the electrode 141 and the electrode 142. Insulating region 147, for _{example, SiO 2, SiN, Al 2} O 3, or are formed of polyimide.

The insulating region 148 constitutes the upper surface 104 t of the sensor unit 104. Insulating region 148, for _{example, SiO 2, SiN, Al 2} O 3, or are formed of polyimide. Pads 151 to 153 are formed in the insulating region 148. The pad 153 is made of a conductor and connected to the electrode 143. Specifically, the electrode 143 and the pad 153 are connected to each other by the insulating region 146, the electrode 142, the insulating region 147, and the via wiring 154 that penetrates the electrode 141. An insulator is provided around the via wiring 154, and the via wiring 154 is insulated from the electrode 141 and the electrode 142. The pad 153 is connected to the circuit board 106 via a via wiring 123 provided in the base substrate 102 and a wiring 183 provided in the radiation region 102h of the recess 102r. Similarly, the pad 151 and the pad 152 are formed of a conductor. The pad 151 and the pad 152 are connected to the electrode 141 and the electrode 142 through corresponding via wirings, respectively. Further, the pad 151 and the pad 152 are connected to the circuit board 106 through corresponding via wiring provided in the base substrate 102 and corresponding wiring provided in the radiation region 102h of the recess 102r.

  Hereinafter, the configuration of the circuit board 106 will be described. FIG. 10 is a diagram illustrating the configuration of the circuit board of the measuring instrument. As shown in FIG. 10, the circuit board 106 includes a high-frequency oscillator 161, a plurality of C / V conversion circuits 162A to 162H, an A / D converter 163, a processor 164, a storage device 165, a communication device 166, and a power source 167. Have.

  Each of the plurality of sensor units 104A to 104H is connected to the circuit board 106 via a corresponding wiring group among the plurality of wiring groups 108A to 108H. In addition, each of the plurality of sensor units 104A to 104H is connected to a corresponding C / V conversion circuit among the plurality of C / V conversion circuits 162A to 162H via some wirings included in the corresponding wiring group. ing. Hereinafter, one sensor unit 104 having the same configuration as each of the plurality of sensor units 104A to 104H, one wiring group 108 having the same configuration as each of the plurality of wiring groups 108A to 108H, and a plurality of C / V conversion circuits 162A to 162A. One C / V conversion circuit 162 having the same configuration as each of 162H will be described.

  The wiring group 108 includes wirings 181 to 183. One end of the wiring 181 is connected to a pad 151 connected to the electrode 141. The wiring 181 is connected to a ground potential line GL connected to the ground GC of the circuit board 106. Note that the wiring 181 may be connected to the ground potential line GL via the switch SWG. One end of the wiring 182 is connected to the pad 152 connected to the electrode 142, and the other end of the wiring 182 is connected to the C / V conversion circuit 162. One end of the wiring 183 is connected to the pad 153 connected to the electrode 143, and the other end of the wiring 183 is connected to the C / V conversion circuit 162.

  The high frequency oscillator 161 is connected to a power source 167 such as a battery, and is configured to receive a power from the power source 167 and generate a high frequency signal. The power source 167 is also connected to the processor 164, the storage device 165, and the communication device 166. The high frequency oscillator 161 has a plurality of output lines. The high-frequency oscillator 161 supplies the generated high-frequency signal to the wiring 182 and the wiring 183 via a plurality of output lines. Therefore, the high frequency oscillator 161 is electrically connected to the electrode 142 and the electrode 143 of the sensor unit 104, and the high frequency signal from the high frequency oscillator 161 is supplied to the electrode 142 and the electrode 143.

  A wiring 182 and a wiring 183 are connected to the input of the C / V conversion circuit 162. That is, the electrode 142 and the electrode 143 of the sensor unit 104 are connected to the input of the C / V conversion circuit 162. The C / V conversion circuit 162 is configured to generate a voltage signal representing the capacitance of the electrode (electrode 143) connected to the input from the voltage amplitude at the input, and output the voltage signal. Note that the larger the electrostatic capacitance of the electrode connected to the C / V conversion circuit 162, the greater the magnitude of the voltage signal output from the C / V conversion circuit 162.

  To the input of the A / D converter 163, the outputs of the plurality of C / V conversion circuits 162A to 162H are connected. The A / D converter 163 is connected to the processor 164. The A / D converter 163 is controlled by a control signal from the processor 164, and converts output signals (voltage signals) from the plurality of C / V conversion circuits 162A to 162H into digital values. That is, the A / D converter 163 generates a digital value representing the capacitance of the electrode 143 and outputs the digital value to the processor 164.

  A storage device 165 is connected to the processor 164. The storage device 165 is a storage device such as a volatile memory, and is configured to store measurement data described later. Further, another storage device 168 is connected to the processor 164. The storage device 168 is a storage device such as a non-volatile memory, and stores a program that is read and executed by the processor 164. The storage device 168 can also store parameters to be described later.

  The communication device 166 is a communication device that complies with an arbitrary wireless communication standard. For example, the communication device 166 is compliant with Bluetooth (registered trademark). The communication device 166 is configured to wirelessly transmit measurement data stored in the storage device 165.

  The processor 164 is configured to control each unit of the measuring instrument 100 in the method MT by executing the above-described program. For example, the processor 164 controls supply of a high-frequency signal from the power source 167 to the electrode 142 and the electrode 143, power supply from the power source 167 to the storage device 165, power supply from the power source 167 to the communication device 166, and the like. Yes. Further, the processor 164 executes the above-described program to acquire a digital value in the method MT, store the measurement data in the storage device 165, transmit the measurement data, and the like.

  In this measuring instrument 100, sensor units 104 </ b> A to 104 </ b> H are arranged along the edge of the base substrate 102. Therefore, when this measuring device 100 is arranged on the electrostatic chuck ESC, a digital value representing the capacitance between the focus ring FR and each of the sensor units 104A to 104H can be acquired. The capacitance C is represented by C = εS / d. ε is the dielectric constant of the medium between the front surface 143f of the electrode 143 and the inner edge of the focus ring FR, S is the area of the front surface 143f of the electrode 143, d is the front surface 143f of the electrode 143 and the inner edge of the focus ring FR Can be regarded as the distance between. Therefore, the plurality of digital values acquired by the measuring instrument 100 decreases as the distance between the front surface 143f of the electrode 143 and the inner edge of the focus ring FR increases.

  In addition, as described above, in the sensor unit 104 mounted on the measuring instrument 100, the electrode 143 (sensor electrode) is provided on the electrode 141, and the electrode 142 is provided between the electrode 141 and the electrode 143. A second part is interposed. When the sensor unit 104 is used, the switch SWG is closed, the potential of the electrode 141 is set to the ground potential, and a high frequency signal is supplied to the electrode 142 and the electrode 143. At this time, the voltage amplitude of the electrode 143 is not affected by the capacitance from the direction in which the electrode 141 is provided with respect to the electrode 143, that is, the lower side of the sensor unit 104, and is in a specific direction, that is, the electrode 143. The voltage amplitude reflects the electrostatic capacitance in the direction (X direction) in which the front surface 143f faces. Therefore, according to the sensor unit 104, the capacitance can be measured with high directivity in a specific direction. When the switch SWG is opened when the sensor unit 104 is used, the C / V conversion circuit 162 has a voltage corresponding to the size of the combined capacitance of the capacitance of the electrode 143 and the capacitance of the electrode 142. A voltage signal having the following is output.

  Further, the electrode 141 and the electrode 142 are opened on the side (X direction) of the region where the front surface of the electrode 143 is disposed, and extend so as to surround the periphery of the electrode 143. Therefore, the electrode 141 and the electrode 142 shield the electrode 143 from directions other than the specific direction. Therefore, the directivity of the sensor unit 104 with respect to a specific direction is further improved in the capacitance measurement.

  The front end face 104f of the sensor unit 104 is configured as a curved surface having a predetermined curvature, and the front face 143f of the electrode 143 extends along the front end face 104f. Therefore, the radial distance between each position of the front surface 143f of the electrode 143 and the inner edge of the focus ring FR can be set to be approximately equal. Therefore, the accuracy of capacitance measurement is further improved.

  Hereinafter, the method MT will be described in detail with reference to FIG. 1 again. In the following description, FIG. 11 is referred to together with FIG. FIG. 11 is a timing chart related to the method shown in FIG. As shown in FIG. 1, in the method MT, first, the process ST1 is performed. In step ST1, the power source 167 of the measuring instrument 100 is set to ON. Then, the processor 164 starts executing the program stored in the storage device 168. In the subsequent step ST2, the measuring device 100 is accommodated in any one of the containers 4a to 4d.

  In the subsequent step ST3, parameters are input to the measuring device 100. The parameter may be wirelessly transmitted from the control unit MC to the measuring device 100. The measuring instrument 100 stores the received parameter in the storage device 168. The parameters are: the time length TA of the first monitoring period, the time interval IA, the first sampling period, the time length TM of the measurement period, the second sampling period, the time length TB of the second monitoring period, the time interval IB, It includes a third sampling period, a first threshold Th1, and a second threshold Th2. The time length TA, the time interval IA, and the first sampling period may be common to the time length TB, the time interval IB, and the third sampling period, respectively. In this case, the parameters do not include the time length TB, the time interval IB, and the third sampling period. Thereafter, in the method MT, processing proceeds in parallel. Note that the two processing flows drawn between two double lines in FIG. 1 are the processing flows executed in parallel.

  In step ST4 following step ST3, the measuring device 100 is transported to the aligner AN by the transport device TU1 under the control of the control unit MC. In the aligner AN, under the control of the control unit MC, the position of the measuring instrument 100 is adjusted, that is, the position is calibrated, similarly to the adjustment of the position of the workpiece W described above.

  In the subsequent process ST5, the measuring instrument 100 is transported into an area surrounded by the focus ring FR on the mounting table PD. Specifically, the measuring device 100 is transported from the aligner AN to one of the load lock modules LL1 and LL2 by the transport device TU1 under the control of the control unit MC. Subsequently, it is transferred from one load lock module into the chamber of one of the process modules PM1 to PM6 by the transfer device TU2. In the chamber, measuring instrument 100 is arranged in a region surrounded by focus ring FR on mounting table PD. The transport destination position (position on the mounting table PD) of the measuring instrument 100 by the transport apparatus TU2 is specified by preset coordinate information. Thereafter, the gate valve between the one process module and the transfer module TF is closed.

  In step ST6 following step ST5, measuring instrument 100 is unloaded from the chamber. Specifically, under the control of the control unit MC, the gate valve between the one process module and the transfer module TF is then opened, and then the measuring device 100 is taken out of the chamber by the transfer device TU2. Then, it is conveyed to one of the load lock modules LL1 and LL2. In the subsequent step ST7, the measuring device 100 is accommodated in the slot of one of the containers 4a to 4d. Specifically, under the control of the control unit MC, the measuring device 100 is transported from one load lock module to a slot of one container by the transport device TU1.

  On the other hand, after step ST3, in step ST11, the processor 164 of the measuring instrument 100 acquires one or more first data sets. This step ST11 is executed in the first monitoring period of the time length TA. The time length TA is not limited, but is, for example, 1 second. In each of the one or more first data sets acquired in step ST11, the processor 164 has a capacitance of the electrode 143 of the corresponding sensor unit among the one or more sensor units included in the plurality of sensor units 104A to 104H. Is obtained by acquiring a digital value representing the first sampling period. The first sampling period is not limited, but is 0.1 second, for example. Note that the sensor units used in step ST11 may be all of the plurality of sensor units 104A to 104H, or may be one or more sensor units specified in the parameters described above.

  In the subsequent step ST12, the processor 164 determines whether or not an average value of a plurality of digital values included in each of the one or more first data sets acquired in the step ST11 is equal to or greater than a first threshold Th1. . Note that when the measuring instrument 100 is disposed in a region surrounded by the focus ring FR, the capacitance of the electrode 143 of the one or more sensor units described above increases. Therefore, by comparing the first threshold value Th1 with the average value of a plurality of digital values included in each of the one or more data sets, it is determined whether or not the measuring device 100 is arranged in the region surrounded by the focus ring FR. Can be determined. If the processor 164 determines in step ST12 that the average value is not greater than or equal to the first threshold value Th1, the processor 164 determines in step ST13 whether the time interval IA has elapsed since the end of step ST11. The time interval IA is not limited, but is 29 seconds, for example. When the time interval IA has not elapsed since the end of the process ST11, the processor 164 performs the determination of the process ST13 again. On the other hand, if the time interval IA has elapsed since the end of the process ST11, the processor 164 again acquires one or more first data sets in the process ST11. Note that the processor 164 may stop supplying power from the power source 167 to the high-frequency oscillator 161 in the time interval IA.

  In step ST12, when the processor 164 determines that the average value is equal to or greater than the first threshold Th1, the process proceeds to the process of step ST14. In step ST12, not the average value but one or more digital values included in each of the one or more first data sets may be compared with the first threshold value Th1.

  In step ST14, the processor 164 acquires a plurality of second data sets. This step ST14 is executed in the measurement period of the time length TM. The time length TM is not limited, but is, for example, 1 second. Each of the plurality of second data sets acquired in step ST14 is a second sampling of a digital value representing the capacitance of the electrode 143 of the corresponding sensor unit among the plurality of sensor units 104A to 104H within the measurement period. It includes a plurality of digital values obtained by acquiring in a cycle. The second sampling period is not limited, for example, 0.1 second.

  In the subsequent step ST15, the processor stores the measurement data in the storage device 165. The measurement data may be a plurality of second data sets. Alternatively, the measurement data may be a plurality of average values obtained by calculating an average value of a plurality of digital values included in each of the plurality of second data sets.

  In the subsequent step ST16, the processor 164 acquires one or more third data sets. This step ST16 is executed in the second monitoring period of time length TB. The time length TB of the second monitoring period may be common to the time length TA as described above. In each of the one or more third data sets acquired in step ST16, the processor 164 has a capacitance of the electrode 143 of the corresponding sensor unit among the one or more sensor units included in the plurality of sensor units 104A to 104H. Is obtained at a third sampling period. Note that the sensor units used in step ST16 may be all of the plurality of sensor units 104A to 104H, or may be one or more sensor units specified in the parameters described above. Further, the third sampling period may be common with the first sampling period.

  In the subsequent step ST17, the processor 164 determines whether or not the average value of the plurality of digital values included in each of the one or more third data sets acquired in the step ST16 is equal to or greater than the second threshold Th2. . Note that when the measuring instrument 100 is accommodated in the slot of any one of the containers 4a to 4d, the capacitance of the electrode 143 of the one or more sensor units described above increases. Therefore, by comparing the second threshold Th2 and the average value of a plurality of digital values included in each of the one or more data sets, the measuring device 100 is accommodated in any one of the containers 4a to 4d. It can be determined whether or not. Note that the capacitance of the electrode 143 when the measuring device 100 is accommodated in the container slot is larger than the capacitance of the electrode 143 when the measuring device 100 is disposed in the region surrounded by the focus ring FR. small. Therefore, the second threshold Th2 is a value smaller than the first threshold Th1.

  If the processor 164 determines in step ST17 that the average value is not greater than or equal to the second threshold Th2, the processor 164 determines in step ST18 whether the time interval IB has elapsed since the end of step ST16. When the time interval IB has not elapsed since the end of the process ST11, the processor 164 performs the determination of the process ST18 again. On the other hand, when the time interval IB has elapsed since the end of the process ST16, the processor 164 acquires one or more third data sets in the process ST16 again. Note that in the time interval IB, the processor 164 may stop supplying power from the power source 167 to the high-frequency oscillator 161. Further, the time interval between the second monitoring period and the next second monitoring period may be the time interval IA instead of the time interval IB.

  In step ST17, when the processor 164 determines that the average value is equal to or greater than the second threshold Th2, the process proceeds to step ST19. In step ST17, not the average value but one or more digital values included in each of the one or more third data sets may be compared with the second threshold Th2.

  In step ST19, the processor 164 wirelessly transmits the measurement data stored in the storage device 165 to the reception unit connected to the control unit MC. When the control unit MC receives the measurement data, in step ST8, the control unit MC corrects the coordinate information of the transport destination position of the transport device TU2. Specifically, the coordinate information is corrected so that the difference in the circumferential direction between the focus ring FR specified from the measurement data and the edge of the measuring instrument 100 is reduced. When the execution of this step ST19 is completed, the method MT ends.

  As described above, in the method MT, the measuring instrument 100 including the plurality of electrodes 143 (sensor electrodes) arranged along the edge of the disk-shaped base substrate 102 is used, and the inner edge of the focus ring FR and the measuring instrument are measured. Measurement data reflecting the distribution in the circumferential direction of the spacing between 100 edges is obtained. In addition, the digital value representing the capacitance of each of the plurality of electrodes 143 increases when the measuring instrument 100 is in the region surrounded by the focus ring FR. In the method MT, measurement data is not always acquired, but one or more first data sets are acquired at a time interval IA in a period before the measurement period. The average value of the plurality of digital values included in each of the one or more first data sets among the plurality of digital values included in each of the one or more first data sets is the first threshold Th1. When this is the case, the second data set is acquired in the measurement period, and the measurement data is stored. Thus, in the method MT, since the intermittent operation is performed in the measuring instrument 100 in the period before the measuring period, the power consumption of the power source 167 of the measuring instrument 100 can be suppressed.

  The average value of the plurality of digital values included in each of the one or more third data sets among the plurality of digital values included in each of the one or more third data sets is the second threshold Th2. In response to the above, the measurement device 100 can wirelessly transmit measurement data autonomously when it is outside the chamber of the process module by causing the communication device 166 to wirelessly transmit measurement data. Therefore, even after the measurement period, intermittent operation is performed in the measuring instrument 100, so that the power consumption of the power source 167 of the measuring instrument 100 is further suppressed.

  Hereinafter, another example of the sensor unit that can be mounted on the measuring instrument 100 will be described. FIG. 12 is a longitudinal sectional view showing another example of the sensor unit. A sensor unit 104 </ b> A illustrated in FIG. 12 is a modification of the sensor unit 104 and is different from the sensor unit 104 in that the substrate unit 144 </ b> A is provided instead of the substrate unit 144. The substrate portion 144A is made of an insulating material. For example, the substrate portion 144A is made of borosilicate glass. Note that the substrate portion 144A may be formed of silicon nitride.

  The substrate portion 144A is a polyhedron and has a surface including a front surface 144a and a lower surface 144b. In one example, the surface of the substrate portion 144A further includes an upper surface 144c, a rear surface 144d, and a pair of side surfaces. The lower surface 144b and the upper surface 144c extend in the X direction and the Y direction, and face each other. The front surface 144a forms a front end surface in the X direction of the substrate portion 144A, and extends in a direction intersecting the lower surface 144b. The front surface 144a may have a predetermined curvature. This curvature is the reciprocal of the distance between the central axis AX100 and the front surface 144a when the sensor unit 104A is mounted on the base substrate 102. The rear surface 144d constitutes the rear end surface of the substrate portion 144A in the X direction, and faces the front surface 144a. Further, the pair of side surfaces are between one edge portion in the Y direction of the front surface 144a and one edge portion in the Y direction of the rear surface 144d, and in the Y direction of the other edge portion in the Y direction of the front surface 144a and the rear surface 144d. It extends between the other edge of the.

  The electrode 143 extends along the front surface 144a and the upper surface 144c of the substrate portion 144A. The insulating region 146 extends so as to cover the lower surface 144b, the upper surface 144c, the rear surface 144d, the pair of side surfaces, and the electrode 143 extending on the upper surface 144c of the substrate portion 144A. The electrode 142 is provided so as to cover the insulating region 146. In addition, the second portion 142a of the electrode 142 extends along the lower surface 144b of the substrate portion 144A via the insulating region 146. The insulating region 147 extends so as to cover the electrode 142. The electrode 141 is provided so as to cover the insulating region 147. Further, the first portion 141 a of the electrode 141 extends below the second portion 142 a of the electrode 142 via the insulating region 147.

  When the main body portion 144m of the substrate portion 144 of the sensor portion 104 described above is formed of silicon, the sensor portion 104 has an internal capacitance. Due to this internal capacitance, it is necessary to set the output of the high-frequency oscillator 161 to a large output. On the other hand, in the sensor unit 104A, since the substrate unit 144A is formed of an insulating material, the internal capacitance is extremely small. Therefore, in the measuring instrument 100 having the sensor unit 104A, the output of the high-frequency oscillator 161 can be reduced.

  In addition, since the measuring instrument 100 can be used in a temperature range including a high temperature (for example, 20 ° C. to 80 ° C.) and a reduced pressure environment (for example, 1 Torr (133.3 Pa) or less), the gas from the substrate unit 144A can be used. It is necessary to suppress the occurrence. Therefore, the substrate portion 144A can be formed from borosilicate glass, silicon nitride, quartz, or aluminum oxide. According to such a substrate part 144A, generation of gas can be suppressed.

  Moreover, since the measuring instrument 100 can be used in a temperature range including a high temperature (for example, 20 ° C. to 80 ° C.), the substrate portion 144A has a linear expansion coefficient close to the linear expansion coefficient of the constituent material of the base substrate 102. Is desirable. For this reason, when the base substrate 102 is formed of silicon, the substrate portion 144A can be formed of, for example, borosilicate glass or silicon nitride. The linear expansion coefficient of the substrate portion 144A is close to the linear expansion coefficient of the base substrate 102. Therefore, damage to the sensor unit 104A and peeling of the sensor unit 104A from the base substrate 102 due to the difference between the linear expansion coefficient of the substrate unit 144A and the linear expansion coefficient of the base substrate 102 can be suppressed.

  Moreover, it is desirable that the weight of the measuring instrument 100 is small. Therefore, it is desirable that the density (mass per unit volume) of the substrate portion 144A is close to the density of the base substrate 102 or smaller than the density of the base substrate 102. For this reason, when the base substrate 102 is made of silicon, the substrate portion 144A can be made of, for example, borosilicate glass.

  Hereinafter, still another example of the sensor unit that can be mounted on the measuring device 100 will be described. FIG. 13 is a longitudinal sectional view showing still another example of the sensor unit. FIG. 13 shows a longitudinal sectional view of the sensor unit 204, and a focus ring FR together with the sensor unit 204.

  The sensor unit 204 includes an electrode 241, an electrode 242, and an electrode 243. The sensor unit 204 may further include a substrate unit 244 and an insulating region 247. The substrate portion 244 has a main body portion 244m and a surface layer portion 244f. The main body 244m is made of, for example, silicon. The surface layer portion 244f covers the surface of the main body portion 244m. The surface layer portion 244f is made of an insulating material. The surface layer portion 244f is, for example, a silicon thermal oxide film.

  The substrate unit 244 has an upper surface 244a, a lower surface 244b, and a front end surface 244c. The electrode 242 is provided below the lower surface 244b of the substrate portion 244, and extends in the X direction and the Y direction. The electrode 241 is provided below the electrode 242 via the insulating region 247, and extends in the X direction and the Y direction.

  The front end surface 244c of the substrate portion 244 is formed in a step shape. The lower part 244d of the front end face 244c protrudes toward the focus ring FR side with respect to the upper part 244u of the front end face 244c. The electrode 243 extends along the upper portion 244u of the front end surface 244c.

  When the sensor unit 204 is used as the sensor unit of the measuring instrument 100, the electrode 241 is connected to the wiring 181, the electrode 242 is connected to the wiring 182, and the electrode 243 is connected to the wiring 183.

  In the sensor unit 204, an electrode 243 that is a sensor electrode is shielded from below the sensor unit 204 by the electrode 241 and the electrode 242. Therefore, according to the sensor unit 204, the capacitance can be measured with high directivity in a specific direction, that is, a direction in which the front surface 243f of the electrode 243 faces (X direction).

  Hereinafter, a measuring instrument according to another embodiment will be described. FIG. 14 is a diagram illustrating a configuration of a circuit board of a measuring instrument according to another embodiment. The measuring instrument 100A shown in FIG. 14 further includes an acceleration sensor 171, a temperature sensor 172, a humidity sensor 173, and a pressure sensor 174 in addition to the same constituent elements as the constituent elements of the measuring instrument 100. The acceleration sensor 171, the temperature sensor 172, the humidity sensor 173, and the pressure sensor 174 are connected to the processor 164. The acceleration sensor 171 outputs acceleration data representing the measured acceleration of the measuring instrument 100A to the processor 164. The temperature sensor 172 outputs temperature data representing the measured ambient temperature of the measuring instrument 100A to the processor 164. The humidity sensor 173 outputs humidity data representing the measured humidity around the measuring instrument 100 </ b> A to the processor 164. The pressure sensor 174 outputs pressure data representing the measured pressure around the measuring instrument 100A to the processor 164.

  The processor 164 performs an abnormality detection process based on the acceleration data, temperature data, humidity data, and pressure data. The processor 164 compares the acceleration of the measuring instrument 100A specified from the acceleration data with the threshold value of acceleration, and if the acceleration of the measuring instrument 100A is larger than the threshold value of the acceleration, an abnormality occurs during the conveyance of the measuring instrument 100A. It is determined that it has occurred, and the first signal is wirelessly transmitted to the control unit MC. Further, the processor 164 wirelessly transmits the second signal to the control unit MC when it is determined from the acceleration of the measuring instrument 100A that abnormal vibration is generated in the measuring instrument 100A. Control part MC will stop conveyance of measuring instrument 100A, if the 1st signal or the 2nd signal is received. The abnormality related to the first signal may occur when the transport device TU1 or the transport device TU2 comes into contact with another tool. Further, the abnormality related to the second signal may occur when an operation failure of the transport apparatus TU1 or the transport apparatus TU2 occurs.

  Further, the processor 164 wirelessly transmits the third signal to the control unit MC when the angle of the measuring instrument 100A specified from the acceleration data is larger than the threshold value of the angle. The angle of the measuring instrument 100A is a scale indicating the level of the measuring instrument 100A, and is calculated based on, for example, the acceleration of the measuring instrument 100A specified from the acceleration data. When the control unit MC receives the third signal, the control unit MC performs control for collection into any of the containers 4a to 4d of the measuring device 100A. Note that an abnormality related to the third signal may occur when a part of the measuring instrument 100A rides on the focus ring FR.

  The processor 164 wirelessly transmits the fourth signal to the control unit MC when the temperature around the measuring instrument 100A specified from the temperature data is higher than the temperature threshold. When receiving the fourth signal, the control unit MC performs control for collecting the measuring device 100A. Note that the abnormality related to the fourth signal may be caused by an abnormality of the process module that provides the chamber into which the measuring instrument 100A is loaded.

  Further, the processor 164 wirelessly transmits a fifth signal to the control unit MC when the humidity around the measuring instrument 100A specified from the humidity data is higher than the humidity threshold. When receiving the fifth signal, the controller MC executes the dehydration sequence. The dehydration sequence can be realized by exhaust, for example. Note that the abnormality related to the fifth signal may occur due to moisture absorption in the containers 4a to 4d, the loader module LM, the load lock module LL1, or the load lock module LL1.

  Further, the processor 164 wirelessly transmits a sixth signal to the control unit MC when the pressure around the measuring instrument 100A specified from the pressure data is higher than the pressure threshold. When receiving the sixth signal, the controller MC executes control for exhaust processing, purge processing, or collection of the measuring instrument 100A. The abnormality related to the sixth signal may occur due to insufficient decompression of the pre-decompression chamber of the load lock module LL1, the pre-decompression chamber of the load lock module LL2, the decompression chamber of the transfer module, or the chamber of the process module. . An anomaly associated with the sixth signal can also occur when gas remains in the chamber of the process module.

  In one embodiment, the method MT may further include the abnormality detection process described above. The abnormality detection process can be performed in parallel with the flow of the two processes between the double lines shown in FIG. 1 after the process ST3. In this abnormality detection process, the measuring device 100A and the control unit MC need to be in a state in which wireless communication is possible in order to transmit the first to sixth signals described above. For this reason, each of the containers 4a to 4d, the loader module LM, the load lock module LL1, the load lock module LL2, and the transfer module TF may have a window region that can transmit radio waves. Alternatively, each of the internal space of each of the containers 4a to 4d, the transfer space of the loader module LM, the preliminary decompression chamber of the load lock module LL1, the preliminary decompression chamber of the load lock module LL2, and the decompression chamber of the transfer module TF It communicates with a window area that is transmissive. The measuring instrument 100A is provided in any of the internal space of each of the containers 4a to 4d, the transfer space of the loader module LM, the preliminary decompression chamber of the load lock module LL1, the preliminary decompression chamber of the load lock module LL2, and the decompression chamber of the transfer module TF. Even if it is arranged, it is possible to wirelessly communicate with the control unit MC via the window area. If the gate valve between the process module and the transfer module TF is opened, the measuring instrument 100A can be connected to the control unit MC via the window region even if it is disposed in the chamber of the process module. Wireless communication is possible.

  In the abnormality detection process, it is only necessary to detect at least one abnormality among all the abnormalities described above. Therefore, measuring instrument 100A may have only the sensors necessary for detecting an abnormality among acceleration sensor 171, temperature sensor 172, humidity sensor 173, and pressure sensor 174.

  Although various embodiments have been described above, various modifications can be made without being limited to the above-described embodiments. For example, the plasma processing apparatus is illustrated as an example of the process modules PM1 to PM6. However, the process modules PM1 to PM6 may be any processing apparatuses as long as they use an electrostatic chuck and a focus ring. The plasma processing apparatus 10 described above is a capacitively coupled plasma processing apparatus. However, plasma processing apparatuses that can be used as the process modules PM1 to PM6 are inductively coupled plasma processing apparatuses and surface waves such as microwaves. It can be any plasma processing apparatus, such as a plasma processing apparatus to be used.

  DESCRIPTION OF SYMBOLS 1 ... Processing system, LM ... Loader module, AN ... Aligner, LL1, LL2 ... Load lock module, TF ... Transfer module, TU1, TU2 ... Conveyor, PM1-PM6 ... Process module, MC ... Control part, 10 ... Plasma processing Device: 12 ... Chamber body, 30 ... Upper electrode, 40 ... Gas source group, 50 ... Exhaust device, 62 ... First high frequency power source, 64 ... Second high frequency power source, PD ... Mounting table, LE ... Lower electrode, ESC ... electrostatic chuck, FR ... focus ring, P1 ... first part, P2 ... second part, 100 ... measuring instrument, 102 ... base substrate, 104 ... sensor part, 104A to 104H ... sensor part, 104f ... front end face, 141 ... Electrode, 141a ... First part, 142 ... Electrode, 142a ... Second part, 143 ... Electrode, 143f ... Front face, 106 Circuit board, 108, 108A to 108H ... wiring group, 161 ... high frequency oscillator, 162 ... C / V conversion circuit, 162A-162H ... C / V conversion circuit, 163 ... A / D converter, 164 ... processor, 165 ... memory Device, 167: power supply, GL: ground potential line.

Claims (5)

A method for obtaining data representing a capacitance between a measuring instrument and a focus ring which are transferred into a chamber by a transfer device of a processing system,
The processing system includes:
A chamber body that provides the chamber; and a process module that is provided in the chamber and has a mounting table on which the measuring device is mounted;
The transfer device;
A control unit for controlling the conveying device;
With
The measuring instrument is
A base substrate having a disk shape;
A plurality of sensor units arranged along an edge of the base substrate;
A circuit board mounted on the base substrate;
With
Each of the plurality of sensor units has a sensor electrode having a front surface extending along an edge of the base substrate,
The circuit board is
A high-frequency oscillator for generating a high-frequency signal, the high-frequency oscillator electrically connected to the sensor electrode of each of the plurality of sensor units;
A plurality of C / V conversion circuits each converting a voltage amplitude at the sensor electrode of the corresponding sensor unit among the plurality of sensor units into a voltage signal representing capacitance;
An A / D converter that converts the voltage signal output from each of the plurality of C / V conversion circuits into a digital value;
A processor connected to the A / D converter;
A storage device connected to the processor;
A communication device for wirelessly transmitting data stored in the storage device;
A power source for supplying power to the processor, the high-frequency oscillator, and the communication device;
Have
The method
The processor is a step of acquiring one or more first data sets at a preset time interval, each of the one or more data sets being one or more sensor units included in the plurality of sensor units Including a plurality of digital values obtained by acquiring a digital value representing the capacitance of the corresponding sensor unit in the first sampling period,
Transporting the measuring device by the transport device to a region surrounded by a focus ring on the mounting table;
An average value of one or more of the plurality of digital values included in each of the one or more first data sets or each of the plurality of digital values included in each of the one or more first data sets is a first value. In response to the threshold value being exceeded, the processor acquires a plurality of second data sets in a measurement period, and each of the plurality of second data sets includes the plurality of sensor units. Including a plurality of digital values obtained by acquiring a digital value representing the capacitance of the corresponding sensor unit in the second sampling period within the measurement period, and
The processor stores measurement data in the storage device, and the measurement data is the plurality of second data sets or the plurality of digital data included in each of the plurality of second data sets. Including a plurality of average values obtained by determining an average value of the values;
Unloading the measuring device from the chamber by the transport device;
Including methods. After the end of the measurement period, the processor obtains one or more third data sets at a preset time interval, and each of the one or more data sets is stored in the plurality of sensor units. Including a plurality of digital values obtained by acquiring a digital value representing a capacitance of a corresponding sensor unit among the one or more sensor units included in a third sampling period; and
An average value of one or more of the plurality of digital values included in each of the one or more third data sets or each of the plurality of digital values included in each of the one or more third data sets is a second value. In response to the threshold being exceeded, the processor causes the communication device to wirelessly transmit the measurement data;
The method of claim 1 further comprising:   Power supply from the power source to the high-frequency oscillator is stopped between a period in which the one or more first data sets are acquired and a period in which the one or more first data sets are acquired. The method according to claim 1 or 2, wherein:   The power supply from the power source to the high-frequency oscillator is stopped between a period in which the one or more third data sets are acquired and a period in which the one or more third data sets are acquired. The method according to any one of claims 1 to 3, wherein: In the step of transporting the measuring device, the control unit controls the transport device to transport the measuring device to a transport destination position specified by preset coordinate information,
The control unit further includes a step of correcting the coordinate information so that a difference in a circumferential direction of an interval between the focus ring and an edge of the measuring device specified from the measurement data is reduced.
The method according to any one of claims 1 to 4.

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