Position derivation method and position derivation system

Abstract

A position derivation method according to an exemplary embodiment includes a step for measuring a first capacitance with a plurality of first sensors in a state in which a measuring instrument is disposed on an electrostatic chuck and surrounded by a ring member. The method includes a step for determining that the measuring instrument is disposed at a center position of the ring member on the basis of the first capacitance. The method includes a step for deriving, as a reference position, the position of the measuring instrument with respect to the center position of the electrostatic chuck on the basis of a second capacitance measured by a plurality of second sensors in a state in which the measuring instrument is disposed at the center position of the ring member.

Description

Position Derivation Method and Position Derivation System

[0001] Exemplary embodiments of the present disclosure relate to a position derivation method and a position derivation system.

[0002] Patent Document 1 describes a measuring instrument for capacitance measurement. This measuring instrument includes a base substrate having a disk shape, a plurality of first sensors each providing a plurality of side electrodes arranged along the edge of the base substrate, one or more second sensors each having a bottom electrode provided along the bottom surface of the base substrate, and a circuit board.

[0003] Japanese Patent Application Laid-Open No. 2017-228754

[0004] The present disclosure provides a technique capable of stably measuring the position of a measuring instrument regardless of the change over time of parts within a chamber.

[0005] In one exemplary embodiment, a method is provided for determining the position of a measuring instrument placed within a chamber of a processing system. The processing system comprises a process module having a chamber body providing the chamber, and a transport device for transporting the measuring instrument into the chamber. The process module includes at least an electrostatic chuck provided within the chamber on which the measuring instrument is placed, and a ring member disposed to surround the periphery of the electrostatic chuck. The measuring instrument comprises a base substrate, a plurality of first sensors, and a plurality of second sensors. The plurality of first sensors are provided along the periphery of the base substrate and measure a first capacitance between them and the ring member. The plurality of second sensors are provided along the periphery of the base substrate and measure a second capacitance between them and the electrostatic chuck. The method includes the step of measuring the first capacitance by the plurality of first sensors with the measuring instrument placed on the electrostatic chuck and surrounded by the ring member. The method includes the step of determining, based on the measured first capacitance, that the measuring instrument is positioned at the center of the ring member. The method includes the step of deriving the position of the measuring instrument relative to the center position of the electrostatic chuck as a reference position based on a second capacitance measured by a plurality of second sensors, while the measuring instrument is positioned at the center position of the ring member. The method also includes the step of comparing the position of the measuring instrument relative to the center position of the electrostatic chuck, which is derived based on the second capacitance measured by a plurality of second sensors, with the reference position when the measuring instrument is placed on the electrostatic chuck by a conveying device.

[0006] According to one exemplary embodiment of the position derivation method, the position of the measuring instrument can be measured stably regardless of changes in the parts within the chamber over time.

[0007] This is a diagram illustrating a processing system. This is a perspective view illustrating an aligner. This is a diagram illustrating an example of a plasma processing apparatus. This is a plan view showing an example of a measuring instrument as seen from above. This is a plan view showing an example of a measuring instrument as seen from below. This is a perspective view showing an example of a first sensor. This is a cross-sectional view taken along line VII-VII in Figure 6. This is an enlarged view of the second sensor in Figure 5. This is a diagram illustrating the configuration of the circuit board of the measuring instrument. This is a schematic diagram illustrating the measurement state of the first sensor. This is a schematic diagram illustrating the measurement state of the second sensor. This is a flow chart showing an example of operation including the position derivation process by the measuring instrument. This is a schematic diagram illustrating the change over time of parts in the chamber.

[0008] Various exemplary embodiments will be described below.

[0009] In one exemplary embodiment, a position derivation method is provided for deriving the position of a measuring instrument placed in a chamber of a processing system. The processing system comprises a process module having a chamber body providing the chamber, and a transport device for transporting the measuring instrument into the chamber. The process module includes at least an electrostatic chuck provided in the chamber on which the measuring instrument is placed, and a ring member disposed to surround the periphery of the electrostatic chuck. The measuring instrument comprises a base substrate, a plurality of first sensors, and a plurality of second sensors. The plurality of first sensors are provided along the periphery of the base substrate and measure a first capacitance with respect to the ring member. The plurality of second sensors are provided along the periphery of the base substrate and measure a second capacitance with respect to the electrostatic chuck. The method includes the step of measuring the first capacitance by the plurality of first sensors with the measuring instrument placed on the electrostatic chuck and surrounded by the ring member. The method includes the step of determining, based on the measured first capacitance, that the measuring instrument is positioned at the center of the ring member. The method includes the step of deriving the position of the measuring instrument relative to the center position of the electrostatic chuck as a reference position based on a second capacitance measured by a plurality of second sensors, while the measuring instrument is positioned at the center position of the ring member. The method also includes the step of comparing the position of the measuring instrument relative to the center position of the electrostatic chuck, which is derived based on the second capacitance measured by a plurality of second sensors, with the reference position when the measuring instrument is placed on the electrostatic chuck by a conveying device.

[0010] In one exemplary embodiment, a position derivation system is provided for deriving the position of a measuring instrument placed in a chamber of a processing system. The processing system comprises a process module having a chamber body providing the chamber, and a transport device for transporting the measuring instrument into the chamber. The process module includes at least an electrostatic chuck provided in the chamber on which the measuring instrument is placed, and a ring member arranged to surround the periphery of the electrostatic chuck. The measuring instrument includes a base substrate, a plurality of first sensors, a plurality of second sensors, and a circuit board. The plurality of first sensors are provided along the periphery of the base substrate and measure a first capacitance with respect to the ring member. The plurality of second sensors are provided along the periphery of the base substrate and measure a second capacitance with respect to the electrostatic chuck. The circuit board is fixed on the base substrate and includes a computing unit that controls the plurality of first sensors and the plurality of second sensors. The computing unit measures the first capacitance using the plurality of first sensors with the measuring instrument placed on the electrostatic chuck and surrounded by the ring member. The calculation unit determines, based on the measured first capacitance, that the measuring instrument is positioned at the center of the ring member. With the measuring instrument positioned at the center of the ring member, the calculation unit derives the position of the measuring instrument relative to the center of the electrostatic chuck as the reference position, based on the second capacitance measured by the multiple second sensors. When the measuring instrument is placed on the electrostatic chuck by the transport device, the calculation unit compares the position of the measuring instrument relative to the center of the electrostatic chuck, which was derived based on the second capacitance measured by the multiple second sensors, with the reference position.

[0011] In the above position derivation method and system, with the first sensor confirming that the measuring instrument is positioned at the center of the ring member, the position of the measuring instrument relative to the center of the electrostatic chuck is set as the reference position. In this case, the position of the measuring instrument relative to the ring member can be derived by comparing the set reference position with the position of the measuring instrument measured by the second sensor. The measurement by the second sensor is based on the measurement of capacitance between it and the electrostatic chuck and is not affected by wear of the ring member. Furthermore, the electrostatic chuck is less susceptible to changes over time due to etching. Therefore, in the above position derivation method and system, the position of the measuring instrument can be measured stably regardless of changes over time in the parts inside the chamber.

[0012] In one exemplary embodiment, the electrostatic chuck has a body made of an insulator and an electrode provided inside the body, and the center position of the electrostatic chuck may be the center position of the electrode. Since the electrode provided inside the body does not wear down due to changes over time, measurements by the second sensor can be performed stably.

[0013] In one exemplary embodiment of the position derivation method, if the position of the measuring instrument deviates from the reference position during the comparison process, the method may further include a step of changing the transport position of the measuring instrument by the transport device so that the amount of deviation from the reference position is offset. In this embodiment, deviations in the transport position of the measuring instrument can be appropriately corrected.

[0014] Various embodiments will be described in detail below with reference to the drawings. In each drawing, the same or corresponding parts will be denoted by the same reference numerals.

[0015] A position derivation system according to one exemplary embodiment may include a processing system 1 having the function of a transport system S1 and a measuring instrument 100. First, a processing system having a processing device for processing a workpiece and a transport device for transporting the workpiece to the processing device will be described. Figure 1 is a diagram illustrating a processing system. 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, a control unit MC, and a storage device 5. The number of tables 2a to 2d, the number of containers 4a to 4d, the number of load lock modules LL1 and LL2, and the number of process modules PM1 to PM6 are not limited and may be one or more arbitrary numbers.

[0016] The bases 2a to 2d are arranged along one edge of the loader module LM. The containers 4a to 4d are each mounted on the bases 2a to 2d. Each of the containers 4a to 4d is, for example, a container called a FOUP (Front Opening Unified Pod). Each of the containers 4a to 4d may be configured to contain a workpiece W. The workpiece W has a substantially disc shape, such as a wafer.

[0017] The loader module LM has a chamber wall that defines a transport space under atmospheric pressure within it. A transport device TU1 is provided within this transport space. The transport device TU1 is, for example, an articulated robot and is controlled by the control unit MC. The transport device TU1 is configured to transport the workpiece W between 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.

[0018] The aligner AN is connected to the loader module LM. The aligner AN is configured to adjust (calibrate) the position of the workpiece W. Figure 2 is a perspective view illustrating the aligner. The aligner AN has a support base 6T, a drive unit 6D, and a sensor 6S. The support base 6T is a rotatable base about an axis extending in the vertical direction. The support base 6T is configured to support the workpiece W on it. The support base 6T is rotated by the drive unit 6D. The drive unit 6D is controlled by the control unit MC. When the support base 6T rotates due to the power from the drive unit 6D, the workpiece W placed on the support base 6T also rotates.

[0019] Sensor 6S is an optical sensor. Sensor 6S detects the edges of the workpiece W while the workpiece W is rotating. From the edge detection results, Sensor 6S detects the amount of deviation of the angular position of the notch WN (or another marker) on the workpiece W relative to the reference angular position, and the amount of deviation of the center position of the workpiece W relative to the reference position. Sensor 6S outputs the amount of deviation of the angular position of the notch WN and the amount of deviation of the center position of the workpiece W to the control unit MC. Based on the amount of deviation of the angular position of the notch WN, the control unit MC calculates the amount of rotation of the support base 6T to correct the angular position of the notch WN to the reference angular position. The control unit MC controls the drive unit 6D to rotate the support base 6T by this amount of rotation. This corrects the angular position of the notch WN to the reference angular position. Furthermore, the control unit MC controls the position of the end effector of the transport device TU1 when receiving the workpiece W from the aligner AN, based on the amount of displacement of the center position of the workpiece W. As a result, the center position of the workpiece W coincides with a predetermined position on the end effector of the transport device TU1.

[0020] Returning to Figure 1, load lock module LL1 and load lock module LL2 are each located between loader module LM and transfer module TF. Load lock module LL1 and load lock module LL2 each provide a pre-pressure chamber.

[0021] The transfer module TF is hermetically connected to the load lock modules LL1 and LL2 via gate valves. The transfer module TF provides a depressurized chamber. A conveying device TU2 is provided in this depressurized chamber. The conveying device TU2 is, for example, an articulated robot having a conveying arm TUa. The conveying device TU2 is controlled by the control unit MC. The conveying device TU2 is configured to convey 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.

[0022] Process modules PM1 to PM6 are hermetically connected to the transfer module TF via gate valves. Each of the process modules PM1 to PM6 is a processing unit configured to perform a specific treatment, such as plasma treatment, on the workpiece W.

[0023] The storage device 5 can store the measuring instrument 100, described later, in a dehumidified environment. As shown in Figure 1, the storage device 5 includes a chamber 5a that provides a sealable internal space, a gas supply device 5b connected to the chamber 5a via a valve, and an exhaust device 5c connected to the chamber 5a. One example of the storage device 5 may be installed adjacent to a loader module LM. In this case, the chamber 5a may be connected to the transport space of the loader module LM via a gate through which the measuring instrument 100 can pass. When the gate is open, the space inside the chamber 5a is connected to the transport space inside the loader module LM. When the gate is closed, the space inside the chamber 5a can be sealed. The measuring instrument 100 can be transported by the transport device TU1 when the gate of the chamber 5a is open. For example, the transport device TU1 can transport the measuring instrument 100 between the load lock modules LL1 to LL2 and the chamber 5a via the loader module LM.

[0024] The gas supply device 5b can supply a moisture-free purge gas into the chamber 5a. The purge gas may be an inert gas such as nitrogen gas. The exhaust device 5c is a device for exhausting the gas inside the chamber 5a to the outside. As an example, the exhaust device 5c may be a vacuum pump that can reduce the pressure inside the chamber 5a to a desired vacuum level.

[0025] For example, the internal space of the chamber 5a can become a dehumidified environment by supplying purge gas from the gas supply device 5b into the chamber 5a. Alternatively, the internal space of the chamber 5a can become a dehumidified environment by evacuating it using the exhaust device 5c. As an example, the internal space of the chamber 5a may be adjusted to a vacuum dehumidified environment with a achievable vacuum level of approximately 10 mTorr. A dehumidified environment means that the humidity in the space is 10% or less. Furthermore, a dehumidifying agent such as silica gel may be placed inside the chamber 5a to achieve a dehumidified environment within the chamber 5a.

[0026] The following is an example of the sequence of operations when processing the workpiece W in this processing system 1. The transport device TU1 of the loader module LM takes the workpiece W from one of the containers 4a to 4d and transports the workpiece W to the aligner AN. Next, the transport device TU1 takes the workpiece W, whose position has been adjusted, from the aligner AN and transports the workpiece W to one of the load lock modules LL1 and LL2. Next, the load lock module reduces the pressure in the pre-pressure chamber to a predetermined pressure. Next, the transport device TU2 of the transfer module TF takes the workpiece W from the load lock module and transports the workpiece W to one of the process modules PM1 to PM6. Then, one or more of the process modules PM1 to PM6 process the workpiece W. Then, the conveying device TU2 conveys the processed workpiece W from the process module to one of the load lock modules LL1 and LL2. Next, the conveying device TU1 conveys the workpiece W from one of the load lock modules to one of the containers 4a to 4d.

[0027] As described above, this processing system 1 includes a control unit MC. The control unit MC may be a computer equipped with a processor, memory and other storage devices, a display device, input / output devices, communication devices, etc. The series of operations of the processing system 1 described above are realized by the control unit MC controlling each part of the processing system 1 according to a program stored in the storage device.

[0028] Figure 3 shows an example of a plasma processing apparatus that can be adopted as one of the process modules PM1 to PM6. The plasma processing apparatus 10 shown in Figure 3 is a capacitively coupled plasma etching apparatus. The plasma processing apparatus 10 comprises a substantially cylindrical chamber body 12. The chamber body 12 is formed from, for example, aluminum, and its inner wall surface may be subjected to anodizing treatment. This chamber body 12 is grounded for safety.

[0029] A substantially cylindrical support portion 14 is provided on the bottom of the chamber body 12. The support portion 14 is made of, for example, an insulating material. The support portion 14 is located inside the chamber body 12. The support portion 14 extends upward from the bottom of the chamber body 12. A stage ST is provided inside the chamber S provided by the chamber body 12. The stage ST is supported by the support portion 14.

[0030] The stage ST has 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 and are substantially disc-shaped. The second plate 18b is provided on the first plate 18a and is electrically connected to the first plate 18a.

[0031] An electrostatic chuck ESC is provided on the second plate 18b. The electrostatic chuck ESC has a structure in which electrodes, which are conductive films, are arranged between a pair of insulating layers or insulating sheets, and has a substantially disc shape. A DC power supply 22 is electrically connected to the electrodes of the electrostatic chuck ESC via a switch 23. This electrostatic chuck ESC attracts the workpiece W by electrostatic force such as Coulomb force generated by the DC voltage from the DC power supply 22. In this way, the electrostatic chuck ESC can hold the workpiece W.

[0032] An edge ring ER is provided on the periphery of the second plate 18b. This edge ring ER is provided so as to surround the edge of the workpiece W and the electrostatic chuck ESC. The edge ring ER has an annular plate shape. The workpiece W is conveyed onto the electrostatic chuck ESC by the conveying devices TU1 and TU2 so that the center position of the workpiece W coincides with the center position of the edge ring ER. This edge ring ER can be formed from any of various materials such as silicon, silicon carbide, or silicon oxide.

[0033] A refrigerant flow path 24 is provided inside the second plate 18b. The refrigerant flow path 24 constitutes a temperature control mechanism. Refrigerant is supplied to the refrigerant flow path 24 from a chiller unit located outside the chamber body 12 via piping 26a. The refrigerant supplied to the refrigerant flow path 24 is returned to the chiller unit via piping 26b. In this way, refrigerant circulates between the refrigerant flow path 24 and the chiller unit. By controlling the temperature of this refrigerant, the temperature of the workpiece W supported by the electrostatic chuck ESC is controlled.

[0034] The stage ST has multiple (for example, three) through holes 25 that penetrate the stage ST. The multiple through holes 25 are formed on the inside of the electrostatic chuck ESC in a plan view. A lift pin 25a is inserted into each of these through holes 25. In Figure 3, one through hole 25 with one lift pin 25a inserted is depicted. The lift pin 25a is provided to be vertically movable within the through hole 25. The workpiece W supported on the electrostatic chuck ESC is raised by the rise of the lift pin 25a. For example, the lift pin 25a can receive the workpiece W transported by the transport device TU2 based on transport position data and place the workpiece W on the electrostatic chuck ESC. The lift pin 25a can also transfer the workpiece W placed on the electrostatic chuck ESC to the transport device TU2.

[0035] The stage ST has multiple (for example, three) through-holes 27 that penetrate the stage ST (lower electrode LE) at a position outside the electrostatic chuck ESC in a plan view. A lift pin 27a is inserted into each of these through-holes 27. In Figure 3, one through-hole 27 with one lift pin 27a inserted is depicted. The lift pin 27a is provided to be vertically movable within the through-hole 27. The rise of the lift pin 27a causes the edge ring ER supported on the second plate 18b to rise. For example, the lift pin 27a can transfer a worn edge ring ER to the transport device TU2. The lift pin 27a can also receive a replacement edge ring ER transported by the transport device TU2 based on transport position data and place the edge ring ER in the designated position. The replacement edge ring ER may be an unused edge ring or a used edge ring with minimal wear.

[0036] Furthermore, the plasma processing apparatus 10 is provided with a gas supply line 28. The gas supply line 28 supplies heat transfer gas, such as He gas, from the heat transfer gas supply mechanism between the upper surface of the electrostatic chuck ESC and the back surface of the workpiece W.

[0037] The plasma processing apparatus 10 also includes an upper electrode 30. The upper electrode 30 is positioned above the stage ST and opposite to the stage ST. The upper electrode 30 is supported on the upper part of the chamber body 12 via an insulating shielding member 32. The upper electrode 30 may include a top plate 34 and a support 36. The top plate 34 faces the chamber S. The top plate 34 is provided with a plurality of gas discharge holes 34a. The top plate 34 may be formed from silicon or quartz. Alternatively, the top plate 34 may be constructed by forming a plasma-resistant film, such as yttrium oxide, on the surface of an aluminum base material.

[0038] The support 36 detachably supports the top plate 34. The support 36 may be made of a conductive material such as aluminum. The support 36 may have a water-cooling structure. A gas diffusion chamber 36a is provided inside the support 36. Multiple gas passage holes 36b that communicate with the gas discharge hole 34a extend downward from this gas diffusion chamber 36a. The support 36 also has a gas inlet 36c that guides the processed gas into the gas diffusion chamber 36a. A gas supply pipe 38 is connected to this gas inlet 36c.

[0039] A gas source group 40 is connected to the gas supply pipe 38 via a valve group 42 and a flow controller group 44. The gas source group 40 includes multiple gas sources for multiple types of gas. The valve group 42 includes multiple valves, and the flow controller group 44 includes multiple flow controllers such as mass flow controllers. Each of the multiple gas sources in the gas source group 40 is connected to the gas supply pipe 38 via a corresponding valve in the valve group 42 and a corresponding flow controller in the flow controller group 44.

[0040] Furthermore, in the plasma processing apparatus 10, a deposit shield 46 is detachably provided along the inner wall of the chamber body 12. The deposit shield 46 is also provided on the outer circumference of the support portion 14. The deposit shield 46 prevents etching by-products (deposits) from adhering to the chamber body 12. The deposit shield 46 can be constructed by coating an aluminum material with ceramics such as yttrium oxide.

[0041] On the bottom side of the chamber body 12 and between the support portion 14 and the side wall of the chamber body 12, an exhaust plate 48 is provided. The exhaust plate 48 can be formed, for example, by coating a ceramic such as yttrium oxide on an aluminum material. A plurality of holes penetrating in the plate thickness direction are formed in the exhaust plate 48. Below the exhaust plate 48 and in the chamber body 12, an exhaust port 12e is provided. 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 regulating valve and a turbo molecular pump. The exhaust device 50 can reduce the pressure in the space inside the chamber body 12 to a desired degree of vacuum. Further, a carry-in / carry-out port 12g for the workpiece W is provided on the side wall of the chamber body 12. This carry-in / carry-out port 12g can be opened and closed by a gate valve 54.

[0042] Further, 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 source 62 is a power source that generates a first high-frequency for plasma generation. The first high-frequency power source 62 generates a high-frequency having a frequency of, for example, 27 to 100 MHz. The first high-frequency power source 62 is connected to the upper electrode 30 via a matching unit 66. The matching unit 66 has a circuit for matching the output impedance of the first high-frequency power source 62 and the input impedance on the load side (upper electrode 30 side). Incidentally, the first high-frequency power source 62 may be connected to the lower electrode LE via the matching unit 66.

[0043] The second high-frequency power source 64 is a power source that generates a second high-frequency for attracting ions to the workpiece W. The second high-frequency power source 64 generates a high-frequency having a frequency within a range of, for example, 400 kHz to 13.56 MHz. The second high-frequency power source 64 is connected to the lower electrode LE via a matching unit 68. The matching unit 68 has a circuit for matching the output impedance of the second high-frequency power source 64 and the input impedance on the load side (lower electrode LE side).

[0044] In the plasma processing apparatus 10, gas from one or more selected gas sources among a plurality of gas sources is supplied to the chamber S. Further, the pressure in the chamber S is set to a predetermined pressure by the exhaust device 50. Furthermore, the gas in the chamber S is excited by the first high-frequency wave from the first high-frequency power source 62. Thereby, plasma is generated. Then, the workpiece W is processed by the generated active species. Note that, if necessary, ions may be drawn into the workpiece W by the bias based on the second high-frequency wave of the second high-frequency power source 64.

[0045] Hereinafter, the measuring instrument will be described. FIG. 4 is a plan view showing the measuring instrument as viewed from the upper surface side. FIG. 5 is a plan view showing the measuring instrument as viewed from the bottom surface side. The measuring instrument 100 shown in FIGS. 4 and 5 includes a base substrate 102. The base substrate 102 is formed of, for example, silicon 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 the diameter of the workpiece W, for example, 300 mm. The shape and dimensions of the measuring instrument 100 are defined by the shape and dimensions of this base substrate 102. Therefore, the measuring instrument 100 has a shape similar to the shape of the workpiece W and dimensions similar to the dimensions of the workpiece W. Further, a notch 102N (or another marker) is formed at the edge of the base substrate 102.

[0046] A plurality of first sensors 104A to 104C for capacitance measurement are provided on the base substrate 102. The plurality of first sensors 104A to 104C are arranged at equal intervals along the edge of the base substrate 102, for example, over the entire circumference of the edge. Specifically, each of the plurality of first sensors 104A to 104C is provided along the edge on the upper surface side of the base substrate 102. The front end surface of each of the plurality of first sensors 104A to 104C is along the side surface of the base substrate 102.

[0047] Furthermore, the base substrate 102 is provided with a plurality of second sensors 105A to 105C for capacitance measurement. The plurality of second sensors 105A to 105C are arranged at equal intervals along the edge of the base substrate 102, for example, around the entire circumference of the edge. Specifically, each of the plurality of second sensors 105A to 105C is provided along the bottom edge of the base substrate. The sensor electrode 161 of each of the plurality of second sensors 105A to 105C is along the bottom surface of the base substrate 102. In addition, the second sensors 105A to 105C and the first sensors 104A to 104C are arranged alternately at 60° intervals in the circumferential direction.

[0048] A circuit board 106 is provided in the center of the upper surface of the base board 102. Wiring groups 108A to 108C are provided between the circuit board 106 and the multiple first sensors 104A to 104C for electrical connection between them. Wiring groups 208A to 208C are also provided between the circuit board 106 and the multiple second sensors 105A to 105C for electrical connection between them. The circuit board 106, the wiring groups 108A to 108C, and the wiring groups 208A to 208C are covered by a cover 103.

[0049] The first sensor will now be described in detail. Figure 6 is a perspective view showing an example of the sensor. Figure 7 is a cross-sectional view taken along the line VII-VII in Figure 6. The first sensor 104 shown in Figures 6 and 7 is a sensor used as one of several first sensors 104A to 104C of the measuring instrument 100, and in one example, it is configured as a chip-shaped component. In the following description, the XYZ Cartesian coordinate system will be referred to as appropriate. The X direction indicates the forward direction of the first sensor 104, the Y direction is one direction perpendicular to the X direction and indicates the width direction of the first sensor 104, and the Z direction is a direction perpendicular to both the X and Y directions and indicates the upward direction of the first sensor 104.

[0050] The first sensor 104 has an electrode 141, a guard electrode 142, a sensor electrode 143, a substrate portion 144, and an insulating region 147.

[0051] The substrate portion 144 is formed from, for example, borosilicate glass or quartz. The substrate portion 144 has an upper surface 144a, a lower surface 144b, and a front end surface 144c. The guard electrode 142 is provided below the lower surface 144b of the substrate portion 144 and extends in the X and Y directions. The electrode 141 is provided below the guard electrode 142 via an insulating region 147 and extends in the X and Y directions. The insulating region 147 is, for example, SiO ２ SiN, Al ２ O ３ , or formed from polyimide.

[0052] The front end face 144c of the substrate portion 144 is formed in a stepped shape. The lower portion 144d of the front end face 144c protrudes toward the edge ring ER than the upper portion 144u of the front end face 144c. The sensor electrode 143 extends along the upper portion 144u of the front end face 144c. In one exemplary embodiment, the upper portion 144u and the lower portion 144d of the front end face 144c are curved surfaces having a predetermined curvature. That is, the upper portion 144u of the front end face 144c has a constant curvature at any position on the upper portion 144u, and the curvature of the upper portion 144u is the reciprocal of the distance between the central axis AX100 of the measuring instrument 100 and the upper portion 144u of the front end face 144c. Furthermore, the lower portion 144d of the front end face 144c has a constant curvature at any point on the lower portion 144d, and the curvature of the lower portion 144d is the reciprocal of the distance between the central axis AX100 of the measuring instrument 100 and the lower portion 144d of the front end face 144c.

[0053] The sensor electrode 143 is provided along the upper portion 144u of the front end face 144c. In one exemplary embodiment, the front surface 143f of the sensor electrode 143 is also curved. That is, the front surface 143f of the sensor electrode 143 has a constant curvature at any point on the front surface 143f, and this curvature is the reciprocal of the distance between the central axis AX100 of the measuring instrument 100 and the front surface 143f.

[0054] When this first sensor 104 is used as a sensor for the measuring instrument 100, the electrode 141 is connected to the wiring 181, the guard electrode 142 is connected to the wiring 182, and the sensor electrode 143 is connected to the wiring 183, as will be described later.

[0055] In the first sensor 104, the sensor electrode 143 is shielded from the downward direction by the electrode 141 and the guard electrode 142. Therefore, with this first sensor 104, it is possible to measure capacitance with high directivity in a specific direction, that is, in the direction (X direction) in which the front surface 143f of the sensor electrode 143 is facing.

[0056] The second sensor will now be described in detail. Figure 8 is a partially enlarged view of Figure 5 and shows one of the second sensors. The second sensor 105 has a sensor electrode 161. The edge of the sensor electrode 161 is partially arc-shaped. That is, the sensor electrode 161 has a planar shape defined by an inner edge 161a and an outer edge 161b, which are two arcs with different radii centered on the central axis AX100. The radially outer edge 161b of each sensor electrode 161 of the multiple second sensors 105A to 105C extends on a common circle. Also, the radially inner edge 161a of each sensor electrode 161 of the multiple second sensors 105A to 105C extends on another common circle. The curvature of a part of the edge of the sensor electrode 161 matches the curvature of the edge of the electrostatic chuck ESC. In one exemplary embodiment, the curvature of the outer edge 161b forming the radially outer edge of the sensor electrode 161 matches the curvature of the edge of the electrostatic chuck ESC. The center of curvature of the outer edge 161b, that is, the center of the circle on which the outer edge 161b extends, shares the central axis AX100.

[0057] In one exemplary embodiment, the second sensor 105 further includes a guard electrode 162 surrounding the sensor electrode 161. The guard electrode 162 is frame-shaped and surrounds the sensor electrode 161 around its entire circumference. The guard electrode 162 and the sensor electrode 161 are spaced apart from each other so that an insulating region 164 is interposed between them. In another exemplary embodiment, the second sensor 105 further includes an electrode 163 surrounding the guard electrode 162 on the outside. The electrode 163 is frame-shaped and surrounds the guard electrode 162 around its entire circumference. The guard electrode 162 and the electrode 163 are spaced apart from each other so that an insulating region 165 is interposed between them.

[0058] The configuration of the circuit board 106 will be described below. Figure 9 is a diagram illustrating the configuration of the circuit board of a measuring instrument. The circuit board 106 includes a high-frequency oscillator 171, multiple C / V conversion circuits 172A to 172C, multiple C / V conversion circuits 272A to 272C, an A / D converter 173, a processor 174, a storage device 175, a communication device 176, and a power supply 177. In one example, the arithmetic unit is composed of the processor 174, the storage device 175, etc.

[0059] Each of the multiple first sensors 104A to 104C is connected to the circuit board 106 via the corresponding wiring group from among the multiple wiring groups 108A to 108C. Each of the multiple first sensors 104A to 104C is also connected to the corresponding C / V conversion circuit from among the multiple C / V conversion circuits 172A to 172C via several wires included in the corresponding wiring group. Each of the multiple second sensors 105A to 105C is connected to the circuit board 106 via the corresponding wiring group from among the multiple wiring groups 208A to 208C. Each of the multiple second sensors 105A to 105C is also connected to the corresponding C / V conversion circuit from among the multiple C / V conversion circuits 272A to 272C via several wires included in the corresponding wiring group. The following describes a first sensor 104 with the same configuration as each of the first sensors 104A to 104C, a wiring group 108 with the same configuration as each of the wiring groups 108A to 108C, and a C / V conversion circuit 172 with the same configuration as each of the C / V conversion circuits 172A to 172C. Furthermore, the second sensor 105 with the same configuration as each of the second sensors 105A to 105C, a wiring group 208 with the same configuration as each of the wiring groups 208A to 208C, and a C / V conversion circuit 272 with the same configuration as each of the C / V conversion circuits 272A to 272C will be described.

[0060] The wiring group 108 includes wirings 181 to 183. One end of wiring 181 is connected to a pad 151 connected to electrode 141. This wiring 181 is connected to a ground potential line GL connected to the ground G of the circuit board 106. Wiring 181 may also be connected to the ground potential line GL via a switch SWG. One end of wiring 182 is connected to a pad 152 connected to guard electrode 142, and the other end of wiring 182 is connected to a C / V conversion circuit 172. One end of wiring 183 is connected to a pad 153 connected to sensor electrode 143, and the other end of wiring 183 is connected to a C / V conversion circuit 172.

[0061] The wiring group 208 includes wirings 281 to 283. One end of wiring 281 is connected to electrode 163. This wiring 281 is connected to the ground potential line GL, which is connected to the ground G of the circuit board 106. Wiring 281 may also be connected to the ground potential line GL via a switch SWG. One end of wiring 282 is connected to guard electrode 162, and the other end of wiring 282 is connected to C / V conversion circuit 272. One end of wiring 283 is connected to sensor electrode 161, and the other end of wiring 283 is connected to C / V conversion circuit 272.

[0062] The high-frequency oscillator 171 is connected to a power source 177, such as a battery, and is configured to generate a high-frequency signal by receiving power from the power source 177. The power source 177 is also connected to the processor 174, the storage device 175, and the communication device 176. The high-frequency oscillator 171 has multiple output lines. The high-frequency oscillator 171 supplies the generated high-frequency signal to wiring 182 and 183, and wiring 282 and 283, via the multiple output lines. Therefore, the high-frequency oscillator 171 is electrically connected to the guard electrode 142 and the sensor electrode 143 of the first sensor 104, and the high-frequency signal from the high-frequency oscillator 171 is supplied to the guard electrode 142 and the sensor electrode 143. In addition, the high-frequency oscillator 171 is electrically connected to the sensor electrode 161 and the guard electrode 162 of the second sensor 105, and the high-frequency signal from the high-frequency oscillator 171 is supplied to the sensor electrode 161 and the guard electrode 162.

[0063] The inputs of the C / V conversion circuit 172 are the wiring 182 connected to pad 152 and the wiring 183 connected to pad 153. Specifically, the inputs of the C / V conversion circuit 172 are the guard electrode 142 and the sensor electrode 143 of the first sensor 104. The inputs of the C / V conversion circuit 272 are the sensor electrode 161 and the guard electrode 162, respectively. The C / V conversion circuits 172 and 272 are configured to generate a voltage signal having an amplitude corresponding to the potential difference at their inputs and to output the said voltage signal. The C / V conversion circuit 172 generates a voltage signal corresponding to the capacitance formed by the corresponding first sensor 104. Specifically, the larger the capacitance of the sensor electrode connected to the C / V conversion circuit 172, the larger the voltage of the voltage signal output by the C / V conversion circuit 172. Similarly, the larger the capacitance of the sensor electrode connected to the C / V conversion circuit 272, the larger the voltage of the voltage signal output by the C / V conversion circuit 272.

[0064] The outputs of the C / V conversion circuit 172 and C / V conversion circuit 272 are connected to the input of the A / D converter 173. The A / D converter 173 is also connected to the processor 174. The A / D converter 173 is controlled by a control signal from the processor 174, and converts the output signals (voltage signals) of the C / V conversion circuit 172 and the C / V conversion circuit 272 (voltage signals) into digital values, which are then output to the processor 174 as detected values.

[0065] A storage device 175 is connected to the processor 174. The storage device 175 is a volatile memory and is configured to store, for example, measurement data. Another storage device 178 is also connected to the processor 174. The storage device 178 is a non-volatile memory and stores, for example, a program that is read and executed by the processor 174.

[0066] The communication device 176 is a communication device compliant with any wireless communication standard. For example, the communication device 176 is compliant with Bluetooth®. The communication device 176 is configured to wirelessly transmit measurement data stored in the storage device 175.

[0067] The processor 174 is configured to control various parts of the measuring instrument 100 by executing the program described above. For example, the processor 174 controls the supply of high-frequency signals from the high-frequency oscillator 171 to the guard electrode 142, sensor electrode 143, sensor electrode 161, and guard electrode 162. The processor 174 also controls the power supply from the power supply 177 to the storage device 175, the power supply from the power supply 177 to the communication device 176, and so on. Furthermore, by executing the program described above, the processor 174 acquires the measured values ​​of the first sensor 104 and the second sensor 105 based on the detected values ​​input from the A / D converter 173. In one embodiment, if the detected value output from the A / D converter 173 is X, the processor 174 acquires the measured values ​​based on the detected value such that the measured values ​​are proportional to (a・X+b). Here, a and b are constants that change depending on the circuit state, etc. The processor 174 may have, for example, a predetermined arithmetic formula (function) such that the measured value is proportional to (a・X+b).

[0068] Figure 10 is a schematic diagram illustrating the measurement state of the first sensor 104. As shown in Figure 10, when the measuring instrument 100 is positioned in the area enclosed by the edge ring ER, the first sensor 104 faces the inner edge of the edge ring ER. The measurement value generated by the first sensor 104 represents the capacitance that reflects the distance between the first sensor 104 and the edge ring ER. The capacitance C is expressed as C = εS / d, where ε is the dielectric constant of the medium between the first sensor 104 and the inner edge of the edge ring ER, S is the area of ​​the first sensor 104 (front surface 143f), and d is the distance between the first sensor 104 (front surface 143f) and the inner edge of the edge ring ER.

[0069] Therefore, the measuring instrument 100 provides measurement data that reflects the relative positional relationship between the measuring instrument 100, which simulates the workpiece W, and the edge ring ER. For example, the multiple measurement values ​​acquired by the measuring instrument 100 decrease as the distance between the first sensor 104 and the inner edge of the edge ring ER increases. Therefore, based on the measurement values ​​representing the capacitance of each of the first sensors 104A to 104C, the amount of displacement of each first sensor 104 in each radial direction of the edge ring ER can be determined. Then, from the amount of displacement of each of the first sensors 104A to 104C in each radial direction, the amount of displacement of the center position of the measuring instrument 100 relative to the center position of the edge ring ER can be determined.

[0070] Figure 11 is a schematic diagram illustrating the measurement state of the second sensor 105. As shown in Figure 11, when the measuring instrument 100 is placed on the electrostatic chuck ESC, the second sensor 105 faces the electrostatic chuck ESC. As described above, capacitance C is expressed as C = εS / d. ε is the dielectric constant of the medium between the sensor electrode 161 and the electrostatic chuck ESC. d is the distance between the second sensor 105 (sensor electrode 161) and the electrostatic chuck ESC. S can be considered as the area where the second sensor 105 (sensor electrode 161) and the electrostatic chuck ESC overlap each other in a plan view. The area S changes depending on the relative positional relationship between the measuring instrument 100 and the electrostatic chuck ESC. Therefore, the measuring instrument 100 provides measurement data that reflects the relative positional relationship between the measuring instrument 100, which simulates the workpiece W, and the electrostatic chuck ESC.

[0071] In one exemplary embodiment, the electrostatic chuck ESC has a disc-shaped body EM made of an insulator such as ceramics, and a disc-shaped HV (High Voltage) electrode E provided inside the body EM. The diameter of the HV electrode E is smaller than the diameter of the body EM. When the measuring instrument 100 is placed on such an electrostatic chuck ESC, the measurement value of the second sensor 105 reflects the capacitance between it and the HV electrode E. In one example, when the center of the measuring instrument 100 and the center of the HV electrode E coincide, the inner edge 161a of the sensor electrode 161 (see Figure 8) and the outer edge of the HV electrode E coincide.

[0072] In this case, S in the above-mentioned C = εS / d reflects the area of ​​the portion where the sensor electrode 161 and the HV electrode E face each other. This area changes depending on the relationship between the center position of the HV electrode E and the center position of the measuring instrument 100. That is, the measured value of the second sensor 105 changes depending on the relationship (amount of displacement) between the center position of the HV electrode E and the center position of the measuring instrument 100. For example, if the second sensor 105 is shifted radially outward relative to the HV electrode E, the measured value measured by the second sensor 105 will be smaller than when the center of the measuring instrument 100 and the center of the HV electrode E coincide. Also, if the second sensor 105 is shifted toward the center of the HV electrode E, the measured value measured by the second sensor 105 will be larger than when the center of the measuring instrument 100 and the center of the HV electrode E coincide. Therefore, by referring to the measured value representing the capacitance of the second sensor 105, the amount of displacement between the center of the HV electrode E and the center of the measuring instrument 100 can be determined.

[0073] As described above, in one exemplary embodiment, the position of the measuring instrument 100 relative to the center of the edge ring ER is derived by the first sensor 104, and the position of the measuring instrument 100 relative to the center of the electrostatic chuck ESC (HV electrode E) is derived by the second sensor 105. Therefore, the measuring instrument 100 can correlate the position of the measuring instrument 100 relative to the edge ring ER with the position of the measuring instrument 100 relative to the electrostatic chuck ESC based on the measurements obtained simultaneously by the first sensor 104 and the second sensor 105.

[0074] Next, an example of the operation of the position derivation system including the measuring instrument 100 will be described. Figure 12 is a flowchart showing an example of operation including the position derivation process by the measuring instrument. The operation in this flowchart is controlled by one or more control devices (in one example, the processor 174 of the measuring instrument 100 and the control unit MC of the processing system 1).

[0075] In the operation flow shown in Figure 12, first, the target chamber is selected (step ST1). In one exemplary embodiment, the target chamber S may be selected by the user by selecting any of the process modules PM1 to PM6.

[0076] In the subsequent step ST2, the measuring instrument 100 is transported into the chamber S selected in step ST1. For example, the measuring instrument 100 is stored in chamber 5a of the storage device 5. In this case, the transport devices TU1 and TU2 transport the measuring instrument 100 from the storage device 5 into the target chamber S under the control of the control unit MC. The measuring instrument 100 transported into the chamber S is then transported onto the electrostatic chuck ESC based on the transport position data stored in the control unit MC. The transport position data may be, for example, coordinate data of a position where the center of the measuring instrument 100 and the center of the electrostatic chuck ESC coincide with each other.

[0077] Next, measurement is performed by the measuring instrument 100 (step ST3). That is, the measurement in step ST3 is performed with the measuring instrument 100 placed on the electrostatic chuck ESC and surrounded by the edge ring ER. For example, in the above state, the measuring instrument 100 acquires the measurement values ​​of the first sensors 104A to 104C and the second sensors 105A to 105C.

[0078] Next, the position of the measuring instrument 100 is derived (step ST4). That is, based on the measurements from the first sensors 104A to 104C, the amount of deviation of the center position of the measuring instrument 100 relative to the center position of the edge ring ER (first deviation) is derived. For example, the deviation of the measuring instrument 100 may be derived as the coordinates of the center position of the measuring instrument 100 with the center position of the edge ring ER as the origin. Also, based on the measurements from the second sensors 105A to 105C, the amount of deviation of the center position of the measuring instrument 100 relative to the center position of the HV electrode E of the electrostatic chuck ESC (second deviation) is derived. For example, the deviation of the measuring instrument 100 may be derived as the coordinates of the center position of the measuring instrument 100 with the center position of the HV electrode E as the origin.

[0079] Next, it is determined whether the center position of the measuring instrument 100 coincides with the center position of the edge ring ER (step ST5). That is, based on the first amount of deviation derived in step ST4, it is determined whether the measuring instrument 100 is positioned at the center of the edge ring ER. For example, if the first amount of deviation is less than a predetermined threshold, it is determined that the measuring instrument 100 is positioned at the center of the edge ring ER. This determination may be performed by the processor 174 of the measuring instrument 100. The measuring instrument 100 may be returned to the storage device 5 by the transport devices TU1 and TU2 at a predetermined timing after the measurement in step ST3 described above is completed. In this case, the measurement result in step ST4 and the determination result in step ST5 are transmitted from the measuring instrument 100 to the control unit MC.

[0080] If it is determined in step ST5 that the center position of the measuring instrument 100 does not coincide with the center position of the edge ring ER, the process proceeds to step ST6. In step ST6, the transport position data from the transport devices TU1 and TU2 is modified. Specifically, the transport position data in the transport device TU2 is corrected by the control unit MC so that the first misalignment is canceled out. The process then returns to step ST2, and the measuring instrument 100 is transported again onto the electrostatic chuck ESC based on the corrected transport position data.

[0081] On the other hand, if it is determined in step ST5 that the center position of the measuring instrument 100 coincides with the center position of the edge ring ER, the process proceeds to step ST7. In step ST7, a reference position is set. That is, the processor 174 of the measuring instrument 100 acquires the reference position. The reference position should be an indicator that allows confirmation that the measuring instrument 100 is at the center of the edge ring ER based on the measurement value of the second sensor 105. For example, the reference position may be the position of the measuring instrument 100 relative to the center position of the HV electrode E, derived based on the capacitance measured by the second sensors 105A to 105C when the measuring instrument 100 is positioned at the center of the edge ring ER. The reference position may also be the second displacement amount derived in step ST4. Furthermore, the processor 174 of the measuring instrument 100 may acquire not only the reference position but also the first displacement amount.

[0082] Through the steps up to this point, the transport position data from the transport devices TU1 and TU2 has been calibrated so that the measuring instrument 100 is transported to the center of the edge ring ER. Then, in the following step ST8, the workpiece W is subjected to dry etching. That is, based on the calibrated transport position data, the workpiece W is transported onto the electrostatic chuck ESC, and etching is performed by the plasma processing device 10.

[0083] Next, the process moves to a quality control check at a predetermined timing (step ST9). Upon moving to the quality control check, the target chamber is first selected (step ST10). In the following step ST11, the measuring instrument 100 is transported into the chamber S selected in step ST10. The measuring instrument 100 has acquired a reference position in step ST7 and is stored in the chamber 5a of the storage device 5. In step ST11, the transport devices TU1 and TU2 transport the measuring instrument 100 from the storage device 5 into the target chamber S under the control of the control unit MC. The measuring instrument 100 transported into the chamber S is then transported onto the electrostatic chuck ESC based on the transport position data stored in the control unit MC. The transport position data may be, for example, the calibrated coordinate data used in the dry etching process in step ST8.

[0084] Next, measurements are taken using the measuring instrument 100 (step ST12). Specifically, the measurement in step ST12 is performed with the measuring instrument 100 placed on the electrostatic chuck ESC and surrounded by the edge ring ER. For example, in the above state, the measuring instrument 100 acquires the measurement values ​​of the first sensors 104A to 104C and the second sensors 105A to 105C.

[0085] Next, the position of the measuring instrument 100 is derived (step ST13). That is, based on the measurements from the second sensors 105A to 105C, the amount of deviation of the center position of the measuring instrument 100 relative to the center position of the HV electrode E of the electrostatic chuck ESC (third deviation amount) is derived. In addition, along with the derivation of the third deviation amount, the amount of deviation of the center position of the measuring instrument 100 relative to the center position of the edge ring ER (fourth deviation amount) may also be derived based on the measurements from the first sensors 104A to 104C.

[0086] Next, it is determined whether the measuring instrument 100 is positioned at the reference position set in step ST7 (step ST14). In one example, since the second displacement amount derived in step ST4 is acquired as the reference position, it is determined whether the second displacement amount and the third displacement amount match each other. For example, it may be determined whether the difference between the second displacement amount and the third displacement amount is less than a predetermined threshold. If the second displacement amount and the third displacement amount match each other, it is considered that the measuring instrument 100 is positioned at the center of the edge ring ER. In this case, it can be confirmed that there is no problem with the transport position by the transport devices TU1 and TU2, so the process returns to step ST8 and proceeds to the dry etching process. The measuring instrument 100 may be returned to the storage device 5 by the transport devices TU1 and TU2 at a predetermined timing after the measurement in step ST12 described above is completed. In this case, the measurement result in step ST13 and the determination result in step ST14 are transmitted from the measuring instrument 100 to the control unit MC.

[0087] If it is determined in step ST14 that the measuring instrument 100 is not located at the reference position, the process proceeds to step ST15. In step ST15, the transport position data from the transport devices TU1 and TU2 is modified. Specifically, the transport position data from the transport devices TU1 and TU2 is corrected by the control unit MC so that the third deviation from the reference position is offset. Then, the process returns to step ST11.

[0088] As described above, in one exemplary embodiment, a position derivation method is provided for deriving the position of a measuring instrument 100 placed in a chamber S of a processing system 1. The processing system 1 comprises a process module having a chamber body 12 that provides the chamber S, and transport devices TU1 and TU2 for transporting the measuring instrument 100 into the chamber S. The process module includes at least an electrostatic chuck ESC provided in the chamber S on which the measuring instrument 100 is placed, and an edge ring ER arranged to surround the periphery of the electrostatic chuck ESC. The measuring instrument 100 comprises a base substrate 102, a plurality of first sensors 104, and a plurality of second sensors 105. The plurality of first sensors 104 are provided along the periphery of the base substrate 102 and measure a first capacitance with respect to the edge ring ER. The plurality of second sensors 105 are provided along the periphery of the base substrate 102 and measure a second capacitance with respect to the electrostatic chuck ESC.

[0089] The position derivation method includes the step of measuring a first capacitance using a plurality of first sensors 104 while the measuring instrument 100 is placed on the electrostatic chuck ESC and surrounded by the edge ring ER. The method includes the step of determining that the measuring instrument 100 is positioned at the center of the edge ring ER based on the measured first capacitance. The method includes the step of deriving the position of the measuring instrument 100 relative to the center of the electrostatic chuck ESC as a reference position based on a second capacitance measured by a plurality of second sensors 105 while the measuring instrument 100 is positioned at the center of the edge ring ER. The method includes the step of comparing the position of the measuring instrument 100 relative to the center of the electrostatic chuck ESC, which is derived based on a second capacitance measured by a plurality of second sensors 105, with the reference position when the measuring instrument 100 is placed on the electrostatic chuck ESC by a transport device.

[0090] In one exemplary embodiment, the processor 174 measures a first capacitance using a plurality of first sensors 104 while the measuring instrument 100 is placed on the electrostatic chuck ESC and surrounded by the edge ring ER. Based on the measured first capacitance, the processor 174 determines that the measuring instrument 100 is positioned at the center of the edge ring ER. With the measuring instrument 100 positioned at the center of the edge ring ER, the processor 174 derives a reference position for the position of the measuring instrument 100 relative to the center of the electrostatic chuck ESC based on a second capacitance measured by a plurality of second sensors 105. When the measuring instrument 100 is placed on the electrostatic chuck ESC by the transport device, the processor 174 compares the position of the measuring instrument 100 relative to the center of the electrostatic chuck ESC, which was derived based on a second capacitance measured by a plurality of second sensors 105, with the reference position.

[0091] Figure 13 is a schematic diagram illustrating the change over time of the edge ring ER, a part placed inside the chamber. When etching is repeated in the process module, the parts inside the chamber S may wear down due to the effects of the plasma. The etching is performed with the workpiece W placed on the electrostatic chuck ESC. Therefore, the electrostatic chuck ESC, covered by the workpiece W, is less affected by the plasma. On the other hand, the surface of the edge ring ER is easily worn down by the effects of the plasma. For example, the edge ring ER may deform as shown by the dashed line edge ring ER2 in Figure 13 due to wear. When the edge ring ER wears down in such a way that its height decreases, the measured value of the first sensor 104, which measures the capacitance between the inner edge of the edge ring ER and the sensor, will decrease. If the measured value fluctuates, it is considered that it will be difficult to derive the accurate position of the measuring instrument 100 using the first sensor 104.

[0092] Furthermore, the electrostatic chuck ESC has a structure in which the HV electrode is arranged inside a ceramic body EM. In this case, due to manufacturing variations, processing constraints, etc., the center of the body EM and the center of the HV electrode E do not necessarily coincide. Typically, the center position of the edge ring ER is positioned to coincide with the center position of the body EM that constitutes the outer shape of the electrostatic chuck. Therefore, even if the measuring instrument 100 is positioned so that the center position of the HV electrode E and the center position of the measuring instrument 100 coincide based on the measurement value of the second sensor 105, the center of the measuring instrument 100 and the center of the edge ring ER do not necessarily coincide.

[0093] In the above position derivation method and system, with the first sensor 104 confirming that the measuring instrument 100 is positioned at the center of the edge ring ER, the position of the measuring instrument 100 relative to the center of the electrostatic chuck ESC is set as the reference position. The center of the electrostatic chuck ESC may be the center of the HV electrode E. In this case, the position of the measuring instrument 100 relative to the edge ring ER can be derived by comparing the set reference position with the position of the measuring instrument 100 measured by the second sensor 105. The measurement by the second sensor 105 is based on the measurement of capacitance between it and the electrostatic chuck ESC and is not affected by wear of the edge ring ER. Furthermore, the electrostatic chuck ESC is less susceptible to changes over time due to etching. Therefore, in the above position derivation method and system, the position of the measuring instrument 100 can be measured stably regardless of changes over time in the parts in the chamber S. In particular, since the HV electrode E in the main body EM is not affected by plasma, the measurement by the second sensor 105 can be performed stably.

[0094] In one exemplary embodiment of the position derivation method, if the measured position of the measuring instrument 100 deviates from the reference position, the transport position data of the measuring instrument 100 by the transport device may be modified so as to cancel out the amount of deviation from the reference position. In this embodiment, deviations in the transport position of the measuring instrument 100 can be appropriately corrected.

[0095] Although various exemplary embodiments have been described above, the invention is not limited to the exemplary embodiments described above, and various omissions, substitutions, and modifications may be made. Furthermore, it is possible to combine elements from different embodiments to form other embodiments.

[0096] For example, although the example shown is that the measuring instrument 100 is stored in the storage device 5, one of the containers (FOUPs) that hold the workpiece W may also be used as the storage device.

[0097] Furthermore, in step ST14, it may be determined whether the center position of the measuring instrument 100 coincides with the center position of the edge ring ER, based on the fourth amount of displacement. For example, if it is determined that the measuring instrument 100 is in the reference position based on the third amount of displacement, it may be determined that the center position of the measuring instrument 100 does not coincide with the center position of the edge ring ER, based on the fourth amount of displacement. In this case, it may be determined that the degree of wear of the edge ring ER is high.

[0098] From the above description, it will be understood that the various embodiments of this disclosure are described herein for illustrative purposes and can be modified in various ways without departing from the scope and spirit of this disclosure. Accordingly, the various embodiments disclosed herein are not intended to limit the scope and spirit, and the true scope and spirit are shown by the appended claims.

[0099] 1...Processing system, 100...Measuring instrument, 102...Base substrate, 104...First sensor, 105...Second sensor, 174...Processor (arithmetic unit), E...HV electrode, EM...Main unit, ER...Edge ring (ring member), ESC...Electrostatic chuck, PM1 to PM6...Process module, S...Chamber, TU1, TU2...Transportation device.

Claims

1. A method for determining the position of a measuring instrument placed in a chamber of a processing system, wherein the processing system comprises a process module having a chamber body providing the chamber, and a transport device for transporting the measuring instrument into the chamber, the process module includes at least an electrostatic chuck provided in the chamber on which the measuring instrument is placed, and a ring member arranged to surround the periphery of the electrostatic chuck, the measuring instrument comprises a base substrate, a plurality of first sensors provided along the periphery of the base substrate for measuring a first capacitance between it and the ring member, and a plurality of second sensors provided along the periphery of the base substrate for measuring a second capacitance between it and the electrostatic chuck, the method comprising the steps of: measuring the first capacitance using the plurality of first sensors while the measuring instrument is placed on the electrostatic chuck and surrounded by the ring member; and determining, based on the measured first capacitance, that the measuring instrument is positioned at the center of the ring member. A position derivation method comprising: a step of deriving the position of the measuring instrument relative to the center position of the electrostatic chuck as a reference position based on the second capacitance measured by the plurality of second sensors while the measuring instrument is positioned at the center position of the ring member; and a step of comparing the position of the measuring instrument relative to the center position of the electrostatic chuck, which was derived based on the second capacitance measured by the plurality of second sensors, with the reference position when the measuring instrument is placed on the electrostatic chuck by the transport device.

2. The electrostatic chuck comprises a body made of an insulator and an electrode provided inside the body, wherein the center position of the electrostatic chuck is the center position of the electrode, the method for determining the position according to claim 1.

3. The position derivation method according to claim 1 or 2, further comprising the step of changing the transport position of the measuring instrument by the transport device so that the amount of deviation from the reference position is offset when the position of the measuring instrument is deviated from the reference position in the comparison step.

4. A position derivation system for deriving the position of a measuring instrument placed in a chamber of a processing system, comprising at least the measuring instrument, wherein the processing system comprises a process module having a chamber body providing the chamber, and a transport device for transporting the measuring instrument into the chamber, wherein the process module comprises at least an electrostatic chuck provided in the chamber on which the measuring instrument is placed, and a ring member arranged to surround the periphery of the electrostatic chuck, wherein the measuring instrument comprises a base substrate, a plurality of first sensors provided along the periphery of the base substrate for measuring a first capacitance between itself and the ring member, a plurality of second sensors provided along the periphery of the base substrate for measuring a second capacitance between itself and the electrostatic chuck, and a circuit board fixed on the base substrate and including a computing device for controlling the plurality of first sensors and the plurality of second sensors, wherein the computing device measures the first capacitance using the plurality of first sensors while the measuring instrument is placed on the electrostatic chuck and surrounded by the ring member. A position derivation system that determines, based on the measured first capacitance, that the measuring instrument is positioned at the center of the ring member; derives the position of the measuring instrument relative to the center of the electrostatic chuck as a reference position based on the second capacitance measured by the plurality of second sensors while the measuring instrument is positioned at the center of the ring member; and compares the position of the measuring instrument relative to the center of the electrostatic chuck, derived based on the second capacitance measured by the plurality of second sensors, with the reference position when the measuring instrument is placed on the electrostatic chuck by the transport device.

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