Adjustment method of measuring instrument

Abstract

To provide a technique for increasing measurement precision of capacitance under environment in which process treatment is executed.SOLUTION: An adjustment method has a step of conveying a measuring instrument into a chamber of a process module. The adjustment method has a step of increasing temperature of the measuring instrument conveyed into the chamber by heating of the chamber. The adjustment method has a step of determining whether the measuring instrument in which temperature is raised is in a predetermined temperature state by a temperature sensor. The adjustment method has a step of supporting the measuring instrument in a treatment system such that an object in which capacitance can be acquired does not exist in an area that faces a sensor electrode in a state in which it is determined that the measuring instrument is in the predetermined temperature state. The adjustment method has a step of executing a reference point adjustment of the supported measuring instrument.SELECTED DRAWING: Figure 14

Description

[Technical Field]

[0001] An exemplary embodiment of the present disclosure relates to a method for adjusting a measuring device. [Background technology]

[0002] Patent Document 1 discloses a measuring instrument for measuring capacitance, which stores parameters for adjusting the admittance of each of a plurality of phase adjustment circuits at each of a plurality of temperatures, and adjusts the admittance using the parameters according to the temperature detected by a temperature sensor.

[0003] Patent Document 2 discloses a measurement method using a measuring device for measuring capacitance. In this measurement method, a reference point adjustment of the measuring device is performed. For example, the measuring device detects the ambient temperature while placed in a storage container, and performs reference point adjustment based on parameters acquired according to the detected temperature. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2020-190539 [Patent Document 2] Japanese Patent Application Publication No. 2023-121729 Summary of the Invention [Problem to be solved by the invention]

[0005] The present disclosure provides techniques for improving the accuracy of capacitance measurements in a process environment. [Means for solving the problem]

[0006] In one exemplary embodiment, a method for adjusting a measuring device in a processing system for performing a process is provided. The processing system includes a process module providing a heatable chamber and a transport device for transporting a measuring device into the chamber. The measuring device includes a base substrate, a sensor electrode provided on the base substrate for acquiring a measurement value representing a capacitance between the measuring device and an object facing the base substrate, and a temperature sensor provided on the base substrate. The adjustment method includes transporting the measuring device into the chamber of the process module. The adjustment method includes heating the chamber to raise the temperature of the measuring device transported into the chamber. The adjustment method includes determining, using the temperature sensor, whether the heated measuring device is in a predetermined temperature state. The adjustment method includes supporting the measuring device in the processing system so that, when it is determined that the measuring device is in the predetermined temperature state, there is no object from which capacitance can be acquired in an area facing the sensor electrode. The adjustment method includes performing a reference point adjustment of the measuring device supported in the processing system. [Effects of the Invention]

[0007] According to an adjustment method according to an exemplary embodiment, it is possible to improve the accuracy of measuring capacitance in an environment in which a process is performed. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 illustrates an example processing system. [Figure 2] FIG. 1 is a perspective view illustrating an aligner. [Figure 3] FIG. 2 is a cross-sectional view illustrating a load lock module. [Figure 4] FIG. 1 is a diagram illustrating an example of a plasma processing apparatus. [Figure 5] FIG. 1 is a plan view showing an example measuring device as viewed from the top side. [Figure 6] FIG. 1 is a plan view showing an example measuring device as viewed from the bottom side. [Figure 7] FIG. 2 is a perspective view showing an example of a first sensor. [Figure 8] FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 7. [Figure 9] FIG. 7 is an enlarged view of the second sensor of FIG. 6. [Figure 10] FIG. 2 is a diagram illustrating an example of the configuration of a circuit board of the measuring device. [Figure 11] FIG. 2 is a diagram illustrating an example of the detailed configuration of a circuit board of the measuring device. [Figure 12] 10 is a table showing an example of a reference parameter group. [Figure 13] 10 is a table showing an example of a correction parameter group. [Figure 14] 10 is a flowchart illustrating an example of a procedure for measuring capacitance by a measuring device. [Figure 15] 10 is a flowchart showing another example of the procedure for measuring capacitance by a measuring device. DETAILED DESCRIPTION OF THE INVENTION

[0009] Various exemplary embodiments are described below.

[0010] In one exemplary embodiment, a method for adjusting a measuring instrument that acquires a measurement value representing capacitance in a processing system for performing a process is provided. The processing system includes a process module providing a heatable chamber and a transport device that transports the measuring instrument into the chamber. The measuring instrument includes a base substrate, a sensor electrode provided on the base substrate for acquiring a measurement value representing capacitance between the base substrate and an object facing the measuring instrument, and a temperature sensor provided on the base substrate. The adjustment method includes transporting the measuring instrument into the chamber of the process module. The adjustment method includes heating the chamber to raise the temperature of the measuring instrument transported into the chamber. The adjustment method includes determining, using the temperature sensor, whether the heated measuring instrument is in a predetermined temperature state. The adjustment method includes supporting the measuring instrument in the processing system so that, when it is determined that the measuring instrument is in the predetermined temperature state, there is no object from which capacitance can be acquired in an area facing the sensor electrode. The adjustment method includes performing a reference point adjustment of the measuring instrument supported in the processing system.

[0011] In the above embodiment, the temperature of the measuring device is raised in the process module and managed to be in a predetermined temperature state. Then, when the predetermined temperature state is reached, the reference point adjustment of the measuring device is performed. In this case, it is possible to perform the reference point adjustment of the measuring device in a temperature state close to the temperature at which the process is performed, thereby improving the measurement accuracy of the capacitance in the environment in which the process is performed.

[0012] Various embodiments will be described in detail below with reference to the drawings, in which the same or equivalent parts are designated by the same reference numerals.

[0013] A measuring instrument, which is the subject of an adjustment method according to one exemplary embodiment, can be used in a processing system 1 that functions as a transfer system S1. First, a processing system including a processing device for processing a workpiece and a transfer device for transferring the workpiece to the processing device will be described. FIG. 1 is a diagram illustrating an example of the processing system. The processing system 1 includes tables 2a-2d, containers 4a-4d, a loader module LM, an aligner AN, load lock modules LL1 and LL2, process modules PM1-PM6, a transfer module TF, and a controller MC. Note that the numbers of tables 2a-2d, containers 4a-4d, load lock modules LL1 and LL2, and process modules PM1-PM6 are not limited and may be any number equal to or greater than one.

[0014] The stages 2a to 2d are arranged along one edge of the loader module LM. The containers 4a to 4d are mounted on the stages 2a to 2d, respectively. 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 can be configured to accommodate a workpiece W. The workpiece W has a substantially disk shape, such as a wafer.

[0015] The loader module LM has a chamber wall that defines a transfer space therein under atmospheric pressure. A transfer device TU1 is provided within this transfer space. The transfer device TU1 is, for example, an articulated robot, and is controlled by a control unit MC. The transfer device TU1 is configured to transfer workpieces 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.

[0016] The aligner AN is connected to the loader module LM. The aligner AN is configured to adjust (calibrate) the position of the workpiece W. FIG. 2 is a perspective view illustrating the aligner. The aligner AN has a support table 6T, a drive unit 6D, and a sensor 6S. The support table 6T is a table that can rotate around an axis extending in the vertical direction and is configured to support the workpiece W thereon. The support table 6T is rotated by the drive unit 6D. The drive unit 6D is controlled by the control unit MC. When the support table 6T rotates due to the power from the drive unit 6D, the workpiece W placed on the support table 6T also rotates.

[0017] The sensor 6S is an optical sensor that detects the edge of the workpiece W while it is being rotated. Based on the edge detection results, the sensor 6S detects the amount of deviation of the angular position of the notch WN (or another marker) of the workpiece W relative to a reference angular position and the amount of deviation of the center position of the workpiece W relative to the reference position. The 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 table 6T required 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 table 6T by this amount. This allows the angular position of the notch WN to be corrected to the reference angular position. The control unit MC also controls the position of the end effector of the transport unit TU1 when receiving the workpiece W from the aligner AN, based on the amount of deviation 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.

[0018] Returning to FIG. 1, each of the load lock modules LL1 and LL2 is provided between the loader module LM and the transfer module TF. Each of the load lock modules LL1 and LL2 provides a preliminary decompression chamber. Each of the load lock modules LL1 and LL2 and the loader module LM are connected to each other via a gate valve G1. Each of the load lock modules LL1 and LL2 and the transfer module TF are connected to each other via a gate valve G2.

[0019] FIG. 3 is a schematic diagram illustrating the interior of a load lock module. Each of the load lock modules LL1 and LL2 includes a mounting table 7 for transferring the workpiece W between the loader module LM and the transfer module TF. The mounting table 7 may be cylindrical, for example. The mounting table 7 has multiple (e.g., three) through-holes (not shown) that penetrate the mounting table 7 vertically, and a lift pin 7a is inserted into each through-hole. The lift pins 7a are arranged to be vertically movable within the through-holes. The multiple lift pins 7a are arranged on a circumference with a diameter smaller than that of the workpiece W so as to support the workpiece W from its underside. For example, while the workpiece W is being transported above the mounting table 7 by a transport device, the tips of the multiple lift pins 7a move above the mounting table 7, allowing the lift pins 7a to receive the workpiece W from the transport device. In addition, when a conveying device is waiting below the workpiece W supported by the lift pins 7a, the lift pins 7a can move downward, allowing the conveying device to receive the workpiece W from the lift pins 7a.

[0020] The transfer module TF provides a decompression chamber that can be decompressed. A transfer device TU2 is provided in this decompression chamber. The transfer device TU2 is, for example, an articulated robot having a transfer arm TUa, and is controlled by a control unit MC. The transfer device TU2 is configured to transfer workpieces W between the load lock modules LL1-LL2 and the process modules PM1-PM6, and between any two of the process modules PM1-PM6.

[0021] The process modules PM1 to PM6 are airtightly connected to the transfer module TF via gate valves. Each of the process modules PM1 to PM6 is a processing device configured to perform a dedicated process such as plasma processing on the workpiece W.

[0022] The gas supply device 5b can supply a moisture-free purge gas into the chamber 5a. The purge gas can be, for example, 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. For example, the exhaust device 5c can be a vacuum pump that can reduce the pressure inside the chamber 5a to a desired vacuum level.

[0023] For example, the internal space of the chamber 5a can be made into a dehumidified environment by supplying a purge gas from the gas supply device 5b into the chamber 5a. The internal space of the chamber 5a can also be made into a dehumidified environment by evacuating the internal space of the chamber 5a using the exhaust device 5c. For example, the internal space of the chamber 5a can be adjusted to a vacuum dehumidified environment with an ultimate vacuum of about 10 mTorr. A dehumidified environment means that the humidity in the space is 10% or less. A dehumidified environment in the chamber 5a can also be realized by placing a dehumidifying agent such as silica gel in the chamber 5a.

[0024] The series of operations when processing the workpiece W in this processing system 1 is exemplified as follows: The transfer device TU1 of the loader module LM takes the workpiece W from one of the containers 4a to 4d and transfers it to the aligner AN. Next, the transfer device TU1 takes the workpiece W, whose position has been adjusted, from the aligner AN and transfers it 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 the workpiece W from one of the load lock modules and transfers it to one of the process modules PM1 to PM6. Then, one or more of the process modules PM1 to PM6 processes the workpiece W. Then, the transfer device TU2 transfers the processed workpiece W from the process module to one of the load lock modules LL1 and LL2. Next, the transfer device TU1 transfers the workpiece W from one of the load lock modules to one of the containers 4a to 4d.

[0025] As described above, this processing system 1 includes a control unit MC. The control unit MC may be a computer including a processor, a storage device such as a memory, a display device, an input / output device, a communication device, 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 in accordance with a program stored in the storage device.

[0026] FIG. 4 is a diagram showing an example of a plasma processing apparatus that can be employed as any of the process modules PM1 to PM6. The plasma processing apparatus 10 shown in FIG. 4 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 its inner wall surface can be anodized. The chamber body 12 is protectively grounded.

[0027] A substantially cylindrical support 14 is provided on the bottom of the chamber body 12. The support 14 is made of, for example, an insulating material. The support 14 is provided within the chamber body 12 and extends upward from the bottom of the chamber body 12. A stage ST is provided within a chamber S provided by the chamber body 12. The stage ST is supported by the support 14. The chamber body 12 has a temperature sensor and a heater, and can maintain the interior of the chamber S at a set temperature.

[0028] 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 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.

[0029] 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 supply 22 is electrically connected to the electrode of the electrostatic chuck ESC via a switch 23. The electrostatic chuck ESC attracts the workpiece W by electrostatic force such as Coulomb force generated by a DC voltage from the DC power supply 22. This allows the electrostatic chuck ESC to hold the workpiece W.

[0030] An edge ring ER is provided on the peripheral edge of the second plate 18b. This edge ring ER is provided to surround the edge of the workpiece W and the electrostatic chuck ESC. The edge ring ER has a first portion P1 and a second portion P2 (see FIG. 8). The first portion P1 and the second portion P2 have an annular plate shape. The second portion P2 is located outside the first portion P1. The second portion P2 has a greater thickness in the height direction than the first portion P1. The inner edge P2i of the second portion P2 has a larger diameter than the inner edge P1i of the first portion P1. The workpiece W is placed on the electrostatic chuck ESC so that its edge region is located on the first portion P1 of the edge ring ER. The edge ring ER can be formed from any of a variety of materials, such as silicon, silicon carbide, or silicon oxide.

[0031] A coolant flow path 24 is provided inside the second plate 18b. The coolant flow path 24 constitutes a temperature control mechanism. A coolant is supplied to the coolant flow path 24 from a chiller unit provided outside the chamber body 12 via a pipe 26a. The coolant supplied to the coolant flow path 24 is returned to the chiller unit via a pipe 26b. In this manner, the coolant circulates between the coolant flow path 24 and the chiller unit. By controlling the temperature of this coolant, the temperature of the workpiece W supported by the electrostatic chuck ESC is controlled.

[0032] The stage ST has a plurality of (e.g., three) through holes 25 formed therethrough. The through holes 25 are formed inside the electrostatic chuck ESC in a plan view. A lift pin 25a is inserted into each of the through holes 25. Note that FIG. 4 illustrates one through hole 25 into which one lift pin 25a is inserted. The lift pin 25a is provided to be movable up and down within the through hole 25. As the lift pin 25a rises, the workpiece W supported on the electrostatic chuck ESC rises. For example, the lift pin 25a can receive the workpiece W transferred by the transfer device TU2 based on the transfer 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 transfer device TU2.

[0033] The stage ST has a plurality of (e.g., three) through-holes 27 formed therein, penetrating the stage ST (lower electrode LE), at positions outside the electrostatic chuck ESC in a plan view. A lift pin 27a is inserted into each of the through-holes 27. Note that FIG. 4 illustrates one through-hole 27 into which one lift pin 27a is inserted. The lift pin 27a is provided to be movable up and down within the through-hole 27. The edge ring ER supported on the second plate 18b is raised by the lift pin 27a rising. For example, the lift pin 27a can transfer an edge ring ER worn due to use 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 the transport position data and place the edge ring ER at the placement position. The replacement edge ring ER may be an unused edge ring or a used edge ring with little wear.

[0034] The plasma processing apparatus 10 is also provided with a gas supply line 28. The gas supply line 28 supplies a heat transfer gas, for example, He gas, from a heat transfer gas supply mechanism to between the upper surface of the electrostatic chuck ESC and the back surface of the workpiece W.

[0035] The plasma processing apparatus 10 also includes an upper electrode 30. The upper electrode 30 is disposed above the stage ST and faces 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 and has a plurality of gas ejection holes 34a formed therein. The top plate 34 may be made of silicon or quartz. Alternatively, the top plate 34 may be formed by forming a plasma-resistant film such as yttrium oxide on the surface of an aluminum base material.

[0036] The support 36 detachably supports the top plate 34 and may be made of a conductive material such as aluminum. The support 36 may have a water-cooled structure. A gas diffusion chamber 36a is provided inside the support 36. A plurality of gas flow holes 36b extend downward from the gas diffusion chamber 36a and communicate with the gas discharge holes 34a. The support 36 also has a gas inlet 36c formed therein for introducing a process gas into the gas diffusion chamber 36a, and a gas supply pipe 38 is connected to the gas inlet 36c.

[0037] 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 gas. 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 mass flow controllers. The plurality of gas sources in the gas source group 40 are connected to the gas supply pipe 38 via the corresponding valves in the valve group 42 and the corresponding flow rate controllers in the flow rate controller group 44.

[0038] 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 periphery of the support portion 14. The deposit shield 46 prevents etching by-products (deposits) from adhering to the chamber body 12, and can be formed by coating an aluminum material with a ceramic such as yttrium oxide.

[0039] An exhaust plate 48 is provided on the bottom side of the chamber body 12, between the support member 14 and the sidewall of the chamber body 12. The exhaust plate 48 can be made, for example, of aluminum coated with a ceramic such as yttrium oxide. A plurality of holes are formed through the exhaust plate 48 in its 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 pressure adjustment valve and a vacuum pump such as a turbomolecular pump, and can reduce the pressure inside the chamber body 12 to a desired vacuum level. A load / unload port 12g for the workpiece W is provided on the sidewall of the chamber body 12, and this load / unload port 12g can be opened and closed by a gate valve 54.

[0040] The plasma processing apparatus 10 further includes a first high frequency power supply 62 and a second high frequency power supply 64. The first high frequency power supply 62 is a power supply that generates a first high frequency power supply for plasma generation, and generates a high frequency power supply having a frequency of, for example, 27 to 100 MHz. The first high frequency power supply 62 is connected to the upper electrode 30 via a matching box 66. The matching box 66 has a circuit for matching the output impedance of the first high frequency power supply 62 with the input impedance on the load side (upper electrode 30 side). The first high frequency power supply 62 may also be connected to the lower electrode LE via the matching box 66.

[0041] The second high frequency power supply 64 is a power supply that generates a second high frequency for attracting ions into the workpiece W, and generates a high frequency with a frequency within a range of, for example, 400 kHz to 13.56 MHz. The second high frequency power supply 64 is connected to the lower electrode LE via a matching box 68. The matching box 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).

[0042] In this plasma processing apparatus 10, gas is supplied to a chamber S from one or more selected gas sources among a plurality of gas sources. The pressure in the chamber S is set to a predetermined pressure by an exhaust device 50. The gas in the chamber S is excited by a first high frequency wave from a first high frequency power supply 62. This generates plasma. The workpiece W is then processed by the generated activated species. If necessary, ions may be attracted to the workpiece W by a bias based on a second high frequency wave from a second high frequency power supply 64.

[0043] The measuring instrument will be described below. FIG. 5 is a plan view showing the measuring instrument from the top side. FIG. 6 is a plan view showing the measuring instrument from the bottom side. The measuring instrument 100 shown in FIGS. 5 and 6 includes a base substrate 102. The base substrate 102 is made of, for example, silicon and has a shape similar to that of the workpiece W, i.e., a substantially disk shape. The diameter of the base substrate 102 is the same as that of the workpiece W, e.g., 300 mm. The shape and dimensions of the measuring instrument 100 are determined by the shape and dimensions of the base substrate 102. Therefore, the measuring instrument 100 has a shape similar to that of the workpiece W and dimensions similar to those of the workpiece W. In addition, a notch 102N (or another marker) is formed on the edge of the base substrate 102. The measuring instrument 100, like the workpiece W, is transported by a transport system S1 including transport devices TU1, TU2, etc.

[0044] A plurality of first sensors 104A to 104C for measuring capacitance 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, around 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 aligned along the side surface of the base substrate 102.

[0045] The base substrate 102 is also provided with a plurality of second sensors 105A to 105C for measuring capacitance. The 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 second sensors 105A to 105C is provided along the edge on the bottom surface side of the base substrate. The sensor electrode 161 of each of the second sensors 105A to 105C is arranged along the bottom surface of the base substrate 102. The second sensors 105A to 105C and the first sensors 104A to 104C are arranged alternately at 60° intervals in the circumferential direction.

[0046] A circuit board 106 is provided in the center of the upper surface of the base substrate 102. Wiring groups 108A to 108C are provided between the circuit board 106 and the plurality of first sensors 104A to 104C to electrically connect them to each other. Furthermore, wiring groups 208A to 208C are provided between the circuit board 106 and the plurality of second sensors 105A to 105C to electrically connect them to each other. The circuit board 106, the wiring groups 108A to 108C, and the wiring groups 208A to 208C are covered by a cover 103.

[0047] The first sensor will be described in detail below. FIG. 7 is a perspective view showing an example of a sensor. FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 7. The first sensor 104 shown in FIGS. 7 and 8 is a sensor used as multiple first sensors 104A to 104C of the measuring device 100, and in one example, is configured as a chip-like component. In the following description, an XYZ Cartesian coordinate system will be referred to as appropriate. The X direction indicates the front direction of the first sensor 104, the Y direction is a 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 the X and Y directions and indicates the upward direction of the first sensor 104. FIG. 8 shows the edge ring ER together with the first sensor 104.

[0048] The first sensor 104 includes an electrode 141 , a guard electrode 142 , a sensor electrode 143 , a substrate portion 144 , and an insulating region 147 .

[0049] The substrate 144 is made of, for example, borosilicate glass or quartz. The substrate 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 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 made of, for example, SiO2, SiN, Al2O3, or polyimide.

[0050] The front end surface 144c of the substrate portion 144 is formed in a stepped shape. A lower portion 144d of the front end surface 144c protrudes toward the edge ring ER more than an upper portion 144u of the front end surface 144c. The sensor electrode 143 extends along the upper portion 144u of the front end surface 144c. In one exemplary embodiment, the upper portion 144u and the lower portion 144d of the front end surface 144c are curved surfaces each having a predetermined curvature. That is, the upper portion 144u of the front end surface 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 surface 144c. Furthermore, the lower portion 144d of the front end face 144c has a constant curvature at any position 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.

[0051] Sensor electrode 143 is provided along upper portion 144u of front end surface 144c. In one exemplary embodiment, front surface 143f of sensor electrode 143 is also curved. That is, front surface 143f of sensor electrode 143 has a constant curvature at any position on front surface 143f, and this curvature is the reciprocal of the distance between central axis AX100 of measuring device 100 and front surface 143f.

[0052] When first sensor 104 is used as a sensor of measuring device 100, electrode 141 is connected to wiring 181, guard electrode 142 is connected to wiring 182, and sensor electrode 143 is connected to wiring 183, as described below.

[0053] In the first sensor 104, the sensor electrode 143 is shielded from below the first sensor 104 by the electrode 141 and the guard electrode 142. Therefore, with this first sensor 104, it is possible to measure the capacitance with high directivity in a specific direction, that is, in the direction in which the front surface 143f of the sensor electrode 143 faces (X direction).

[0054] The second sensors will be described in detail below. FIG. 9 is a partially enlarged view of FIG. 6, showing one second sensor. 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 having different radii and centered on the central axis AX100. The outer edges 161b on the radially outer side of the sensor electrodes 161 of each of the second sensors 105A to 105C extend on a common circle. Furthermore, the inner edges 161a on the radially inner side of the sensor electrodes 161 of each of the second sensors 105A to 105C extend on another common circle. The curvature of a portion 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 an outer edge 161b forming the radially outer edge of the sensor electrode 161 matches the curvature of the edge of the electrostatic chuck ESC. Note that the center of curvature of the outer edge 161b, i.e., the center of the circle on which the outer edge 161b extends, shares the central axis line AX100.

[0055] In one exemplary embodiment, the second sensor 105 further includes a guard electrode 162 that surrounds the sensor electrode 161. The guard electrode 162 has a frame shape and surrounds the sensor electrode 161 over its entire periphery. The guard electrode 162 and the sensor electrode 161 are spaced apart such that an insulating region 164 is interposed between them. In one exemplary embodiment, the second sensor 105 further includes an electrode 163 that surrounds the guard electrode 162 on the outside thereof. The electrode 163 has a frame shape and surrounds the guard electrode 162 over its entire periphery. The guard electrode 162 and the electrode 163 are spaced apart such that an insulating region 165 is interposed between them.

[0056] The configuration of circuit board 106 will be described below. FIG. 10 is a diagram illustrating the configuration of a circuit board of a measuring device. Circuit board 106 has high-frequency oscillator 171, multiple C / V conversion circuits 172A-172C, multiple C / V conversion circuits 272A-272C, A / D converter 173, processor 174, storage device 175, communication device 176, and power supply 177. In one example, processor 174, storage device 175, etc. form a computing device. Circuit board 106 also has temperature sensor 179. Temperature sensor 179 outputs a signal corresponding to the detected temperature to processor 174. For example, temperature sensor 179 can acquire the temperature of the environment surrounding measuring device 100.

[0057] Each of the plurality of first sensors 104A-104C is connected to the circuit board 106 via a corresponding one of the plurality of wiring groups 108A-108C. Also, each of the plurality of first sensors 104A-104C is connected to a corresponding one of the plurality of C / V conversion circuits 172A-172C via some wires included in the corresponding wiring group. Each of the plurality of second sensors 105A-105C is connected to the circuit board 106 via a corresponding one of the plurality of wiring groups 208A-208C. Also, each of the plurality of second sensors 105A-105C is connected to a corresponding one of the plurality of C / V conversion circuits 272A-272C via some wires included in the corresponding wiring group. Below, we will explain one first sensor 104 with the same configuration as each of first sensors 104A to 104C, one wiring group 108 with the same configuration as each of wiring groups 108A to 108C, and one C / V conversion circuit 172 with the same configuration as each of C / V conversion circuits 172A to 172C. We will also explain one second sensor 105 with the same configuration as each of second sensors 105A to 105C, one wiring group 208 with the same configuration as each of wiring groups 208A to 208C, and C / V conversion circuit 272 with the same configuration as each of C / V conversion circuits 272A to 272C.

[0058] 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 that is connected to the ground G of the circuit board 106. The wiring 181 may be connected to the ground potential line GL via a switch SWG. One end of the wiring 182 is connected to a pad 152 that is connected to the guard electrode 142, and the other end of the wiring 182 is connected to the C / V conversion circuit 172. One end of the wiring 183 is connected to a pad 153 that is connected to the sensor electrode 143, and the other end of the wiring 183 is connected to the C / V conversion circuit 172.

[0059] The wiring group 208 includes wirings 281 to 283. One end of the wiring 281 is connected to the electrode 163. The wiring 281 is connected to a ground potential line GL that is connected to the ground G of the circuit board 106. The wiring 281 may be connected to the ground potential line GL via a switch SWG. One end of the wiring 282 is connected to the guard electrode 162, and the other end of the wiring 282 is connected to the C / V conversion circuit 272. One end of the wiring 283 is connected to the sensor electrode 161, and the other end of the wiring 283 is connected to the C / V conversion circuit 272.

[0060] 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 upon 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 provides the generated high-frequency signal to wiring 182, wiring 183, wiring 282, and wiring 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 provided to the guard electrode 142 and the sensor electrode 143. The high-frequency oscillator 171 is also 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 provided to the sensor electrode 161 and the guard electrode 162.

[0061] The input of the C / V conversion circuit 172 is connected to a wiring 182 connected to the pad 152 and a wiring 183 connected to the pad 153. That is, the guard electrode 142 and the sensor electrode 143 of the first sensor 104 are connected to the input of the C / V conversion circuit 172. Furthermore, the sensor electrode 161 and the guard electrode 162 are connected to the input of the C / V conversion circuit 272, respectively. The C / V conversion circuit 172 and the C / V conversion circuit 272 are configured to generate voltage signals having amplitudes corresponding to the potential difference at their inputs and output the voltage signals. The C / V conversion circuit 172 generates a voltage signal corresponding to the capacitance formed by the corresponding first sensor 104. That is, the larger the capacitance of the sensor electrode connected to the C / V conversion circuit 172, the larger the voltage magnitude 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 magnitude of the voltage signal output by the C / V conversion circuit 272.

[0062] The outputs of the C / V conversion circuit 172 and the 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 signal (voltage signal) of the C / V conversion circuit 172 and the output signal (voltage signal) of the C / V conversion circuit 272 into a digital value, which is output to the processor 174 as a detection value.

[0063] A storage device 175 is connected to the processor 174. The storage device 175 is a storage device such as 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 storage device such as a nonvolatile memory, and stores, for example, programs that are read and executed by the processor 174.

[0064] The communication device 176 is a communication device that complies with any wireless communication standard. For example, the communication device 176 complies with Bluetooth (registered trademark). The communication device 176 is configured to wirelessly transmit the measurement data stored in the storage device 175.

[0065] Processor 174 is configured to control each component of measuring instrument 100 by executing the above-described program. For example, processor 174 controls the supply of high-frequency signals from high-frequency oscillator 171 to guard electrode 142, sensor electrode 143, sensor electrode 161, and guard electrode 162. Processor 174 also controls the power supply from power supply 177 to storage device 175 and the power supply from power supply 177 to communication device 176. Furthermore, by executing the above-described program, processor 174 acquires the measurement values of first sensor 104 and second sensor 105 based on the detection values input from A / D converter 173. In one embodiment, when the detection value output from A / D converter 173 is X, processor 174 acquires the measurement values based on the detection values so that the measurement values are proportional to (a·X+b), where a and b are constants that vary depending on the circuit state, etc. The processor 174 may have, for example, a predetermined arithmetic expression (function) that causes the measured value to be proportional to (a·X+b).

[0066] In the measuring instrument 100 described above, when the measuring instrument 100 is placed in an area surrounded by the edge ring ER, the multiple sensor electrodes 143 and the guard electrode 142 face the inner edge of the edge ring ER. A measurement value generated based on the potential difference between the signal of the sensor electrode 143 and the signal of the guard electrode 142 represents a capacitance that reflects the distance between each of the multiple sensor electrodes 143 and the edge ring ER. Note that the capacitance C is expressed as C = εS / d. ε can be considered to be the permittivity of the medium between the front surface 143f of the sensor electrode 143 and the inner edge of the edge ring ER, S is the area of the front surface 143f of the sensor electrode 143, and d is the distance between the front surface 143f of the sensor electrode 143 and the inner edge of the edge ring ER.

[0067] Therefore, measuring instrument 100 can obtain measurement data that reflects the relative positional relationship between measuring instrument 100, which simulates workpiece W, and edge ring ER. For example, the multiple measurement values obtained by measuring instrument 100 become smaller as the distance between front surface 143f of sensor electrode 143 and the inner edge of edge ring ER increases. Therefore, the amount of deviation of each sensor electrode 143 in each radial direction of edge ring ER can be calculated based on the measurement value representing the capacitance of each sensor electrode 143 of first sensors 104A-104C. Then, the error in the transport position of measuring instrument 100 can be calculated from the amount of deviation of each sensor electrode 143 of first sensors 104A-104C in each radial direction.

[0068] Furthermore, when the measuring device 100 is placed on the electrostatic chuck ESC, the multiple sensor electrodes 161 and guard electrode 162 face the electrostatic chuck ESC. As described above, the 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 sensor electrode 161 and the electrostatic chuck ESC, and S can be considered to be the area where the sensor electrode 161 and the electrostatic chuck ESC overlap each other in a plan view. The area S varies depending on the relative positional relationship between the measuring device 100 and the electrostatic chuck ESC. Therefore, the measuring device 100 can obtain measurement data that reflects the relative positional relationship between the measuring device 100, which simulates the workpiece W, and the electrostatic chuck ESC.

[0069] In one example, when the measuring device 100 is transported to a predetermined transfer position, i.e., a position on the electrostatic chuck ESC where the center of the electrostatic chuck ESC and the center of the measuring device 100 coincide, the outer edge 161b of the sensor electrode 161 may coincide with the edge of the electrostatic chuck ESC. In this case, for example, when the transfer position of the measuring device 100 deviates from the predetermined transfer position, causing the sensor electrode 161 to deviate radially outward relative to the electrostatic chuck ESC, the area S decreases. That is, the capacitance measured by the sensor electrode 161 becomes smaller than the capacitance when the measuring device 100 is transported to the predetermined transfer position. Therefore, the amount of deviation of each sensor electrode 161 in each radial direction of the electrostatic chuck ESC can be calculated based on the measured values representing the capacitance of each sensor electrode 161 of the second sensors 105A to 105C. Then, the error in the transfer position of the measuring device 100 can be calculated from the amount of deviation of each sensor electrode 161 of the second sensors 105A to 105C in each radial direction.

[0070] The connections between the high-frequency oscillator 171 and the wiring 182, and between the wiring 183 and the C / V conversion circuit 172 will be described in more detail. FIG. 11 is a circuit diagram showing the connections between the high-frequency oscillator 171 and the wiring 182, and between the wiring 183 and the C / V conversion circuit 172. As shown in FIG. 11, a resistor 171a is connected between the high-frequency oscillator 171 and the wiring 182. A phase adjustment circuit 171d including a variable resistor 171b and a variable capacitor 171c is connected between the high-frequency oscillator 171 and the wiring 183. The C / V conversion circuit 172 includes an amplifier circuit 172a including an operational amplifier and a resistor. In the amplifier circuit 172a, a wiring 183 is connected to the inverting input terminal of the operational amplifier, and a wiring 182 is connected to the non-inverting input terminal of the operational amplifier. The inverting input terminal and output terminal of the operational amplifier are also connected via a resistor. The amplifier circuit 172 a amplifies the potential difference between the signal from the sensor electrode 143 and the signal from the guard electrode 142 that are input to the C / V conversion circuit 172 .

[0071] The high-frequency oscillator 171 and wiring 282, and wiring 283 and C / V conversion circuit 272 are connected in the same manner as the high-frequency oscillator 171 and wiring 182, and wiring 183 and C / V conversion circuit 172. That is, a resistor is connected between the high-frequency oscillator 171 and wiring 282. A phase adjustment circuit including a variable resistor and a variable capacitor is connected between the high-frequency oscillator 171 and wiring 283. The C / V conversion circuit 272 includes an amplifier circuit including an operational amplifier and a resistor as part thereof. In the amplifier circuit, wiring 283 is connected to the inverting input terminal of the operational amplifier, and wiring 282 is connected to the non-inverting input terminal of the operational amplifier. Furthermore, the inverting input terminal and output terminal of the operational amplifier are connected via a resistor.

[0072] In the circuit configuration described above, the resistance value of the variable resistor 171b of the phase adjustment circuit 171d can be changed to change the amplitude of the signal from the sensor electrode 143. Furthermore, the capacitance value of the variable capacitor 171c of the phase adjustment circuit 171d can be changed to change the phase of the signal from the sensor electrode 143. In one exemplary embodiment, the resistance value of the variable resistor 171b and the capacitance value of the variable capacitor 171c are adjusted (controlled) by the processor 174, thereby adjusting the admittance of the phase adjustment circuit 171d.

[0073] 11, the output of a D / A converter 174a connected to a processor 174 is input to a variable resistor 171b. The processor 174 outputs a parameter for adjusting the resistance value of the variable resistor 171b as a digital signal to the D / A converter 174a. The D / A converter 174a converts the input digital signal into an analog signal and outputs it to the variable resistor 171b. As a result, the resistance value of the variable resistor 171b is controlled to a resistance value corresponding to the digital signal output from the processor 174.

[0074] Furthermore, the output of D / A converter 174b connected to processor 174 is input to variable capacitor 171c. Processor 174 outputs a parameter for adjusting the capacitance value of variable capacitor 171c as a digital signal to D / A converter 174b. D / A converter 174b converts the input digital signal into an analog signal and outputs it to variable capacitor 171c. As a result, the capacitance value of variable capacitor 171c is controlled to a capacitance value corresponding to the digital signal output from processor 174.

[0075] In one exemplary embodiment, processor 174 obtains a set of correction parameters according to the measurement environment based on a set of reference parameters (second set of parameters) that serve as a basis for adjusting the resistance value of variable resistor 171b and the capacitance value of variable capacitor 171c. The set of reference parameters includes a plurality of reference parameters obtained in advance in a dehumidified environment. For example, the set of reference parameters may be obtained during the manufacturing stage of measuring device 100.

[0076] The set of reference parameters for adjusting the resistance value of the variable resistor 171b and the set of reference parameters for adjusting the capacitance value of the variable capacitor 171c may be stored, for example, as a table in the storage device 178. The table includes reference parameters corresponding to each of a plurality of temperatures. The set of reference parameters is used to adjust the reference points of the output voltage signals of the plurality of C / V conversion circuits 172, 272 at each of a plurality of temperatures. As an example, the reference point adjustment may be a zero-point adjustment. That is, the reference parameters may be parameters for adjusting the resistance value of the variable resistor 171b and the capacitance value of the variable capacitor 171c so that the voltage signals output from the C / V conversion circuits 172, 272 become zero when the measuring instrument 100 is not present to detect an object. These parameters may correspond to digital signals output from the processor 174 to the D / A converters 174a, 174b to control the capacitance value of the variable capacitor 171c and the resistance value of the variable resistor 171b, respectively.

[0077] As an example, the storage device 178 has a table for each of the first sensors 104A to 104C, the table having as elements reference parameters for controlling the variable resistor 171b. The storage device 178 has a table for each of the second sensors 105A to 105C, the table having as elements reference parameters for controlling the variable resistor 171b. Each table for controlling the variable resistor 171b has reference parameters corresponding to each sensor for each of a plurality of temperatures.

[0078] The storage device 178 has a table for each of the first sensors 104A to 104C, the table having as elements reference parameters for controlling the variable capacitor 171c. The storage device 178 has a table for each of the second sensors 105A to 105C, the table having as elements reference parameters for controlling the variable capacitor 171c. Each table for controlling the variable capacitor 171c has reference parameters corresponding to each sensor for each of a plurality of temperatures.

[0079] As an example, the reference parameter group may be acquired in a dehumidified environment at a temperature of 20° C. to 80° C. and with an ultimate vacuum of approximately 10 mTorr and humidity of 10% or less. In one exemplary embodiment, the reference parameter group is acquired by measuring instrument 100 that has been left in the dehumidified environment for one day or more.

[0080] To acquire the reference parameter set, under the above-described environment, variable resistor 171b and variable capacitor 171c are adjusted so that the voltage signal output from C / V conversion circuits 172, 272 becomes zero when there is no target to be detected by measuring device 100. A state in which there is no target to be detected by measuring device 100 may be, for example, a state in which a space is formed between measuring device 100 and the target to be detected, in which the detection value should be zero. The resistance value of variable resistor 171b and the capacitance value of variable capacitor 171c, adjusted in this manner, are acquired as the target reference parameters. A table can be created by acquiring reference parameters at each temperature while measuring device 100 is adjusted to a temperature range of 20°C to 80°C. Alternatively, reference parameters may be acquired at predetermined temperature increments within the range from 20°C to 80°C. For example, reference parameters may be acquired at approximately 3°C increments. In this case, temperature ranges for which no reference parameters have been acquired may be estimated based on the acquired reference parameters. As an example, the reference parameters for the temperature ranges for which no reference parameters have been obtained may be determined by linear interpolation between the obtained reference parameters.

[0081] As described above, the set of reference parameters is obtained during the manufacturing stage of measuring device 100 and may not be usable as is in the actual usage environment. For example, even if measuring device 100 is placed in a dehumidified environment before use, the state of measuring device 100 when the set of reference parameters was obtained may not be reproduced, and zero point adjustment may not be possible even if the set of reference parameters is used. Therefore, in one exemplary embodiment, measuring device 100 obtains a set of correction parameters appropriate for the usage environment based on the set of reference parameters.

[0082] In one example, processor 174 acquires parameters (first parameters) for adjusting the reference point at a given temperature in the environment during use, and acquires parameters for each temperature in the environment during use based on the acquired parameters and reference parameters. That is, in one example, processor 174 acquires parameters for adjusting the resistance value of variable resistor 171b and the capacitance value of variable capacitor 171c so that the voltage signal of C / V conversion circuits 172, 272 becomes zero when measuring device 100 is not present. Processor 174 acquires temperature data indicating the temperature at the time when this parameter was acquired (first time) as a correction temperature and stores it together with the parameters. Processor 174 corrects the reference parameters so that the parameters acquired at the correction temperature match the reference parameters. For example, processor 174 acquires a reference parameter corresponding to the correction temperature based on the reference parameter group, and acquires the difference between the reference parameter and the parameter (first parameter) acquired at the correction temperature. For example, if the reference parameters corresponding to the correction temperature are not stored in the table, the reference parameters corresponding to the correction temperature may be obtained by linearly interpolating a group of reference parameters previously obtained. Processor 174 obtains a group of correction parameters by expanding the obtained difference to all of the reference parameters in the group of reference parameters.

[0083] FIG. 12 is an example of a table storing a set of reference parameters. FIG. 13 is an example of a table storing a set of correction parameters. FIGS. 12 and 13 show resistance parameters and capacitance parameters for each temperature when reference points are adjusted at multiple temperatures. Suppose measuring instrument 100 has the set of reference parameters shown in FIG. 12 and newly acquires parameters (first parameters) for reference point adjustment in a temperature environment of 23.8°C. For example, assume that the newly acquired resistance parameter for reference point adjustment has a value of "11097" and the capacitance parameter has a value of "38892." In this case, processor 174 linearly interpolates between the reference parameters constituting the set of reference parameters to acquire a value of "11068" as the reference parameter for resistance at 23.8°C and a value of "38873" as the reference parameter for capacitance. Processor 174 obtains the differences between the parameters "11097" and "38892" obtained for the reference point adjustment and the reference parameters "11068" and "38873." Processor 174 applies the obtained differences to all reference parameters in the reference parameter group. That is, in the above example, processor 174 adds the differences "29" and "19" to the reference parameter for the resistance value and the reference parameter for the capacitance value, respectively, to obtain the correction parameter group shown in FIG. 13.

[0084] The processor 174 uses the acquired set of correction parameters to adjust the resistance value of the variable resistor 171b and the capacitance value of the variable capacitor 171c to adapt to temperature fluctuations. That is, the processor 174 acquires correction parameters corresponding to a temperature acquired by the temperature sensor 179 at a second time period that is later than the first time period, based on the set of correction parameters. Then, the processor 174 adjusts the resistance value of the variable resistor 171b and the capacitance value of the variable capacitor 171c based on the acquired correction parameters. If a correction parameter corresponding to the acquired temperature is not stored, the corresponding correction parameter may be acquired by linear interpolation between the correction parameters.

[0085] Furthermore, as described above, when the detection value output from the A / D converter 173 is X, the processor 174 acquires the measurement value so that the measurement value is proportional to (a·X+b). a and b are constants that change depending on the circuit state, etc., and may depend on the ambient temperature. In one embodiment, the constants a and b are adjusted corresponding to the C / V conversion circuits 172A-172C and the C / V conversion circuits 272A-272C, respectively, so that each detection value X output from the A / D converter 173 is converted into a measurement value indicating a calculated capacitance. The calculated capacitance can be calculated using the equation for determining the capacitance C described above.

[0086] In one exemplary embodiment, the constants a and b are adjusted by the processor 174. The constants a and b may be stored, for example, as a table in the storage device 178. The table has, as elements, constants a and b associated with a plurality of temperatures. As an example, the storage device 178 has a table corresponding to each of the C / V conversion circuits 172A to 172C and the C / V conversion circuits 272A to 272C. That is, the storage device 178 stores a plurality of constant groups associated with a plurality of temperatures in order to suppress the temperature dependence of a plurality of measurement values output from the A / D converter 173. Each constant group has a plurality of constants a and b corresponding to the C / V conversion circuits 172A to 172C and the C / V conversion circuits 272A to 272C, respectively. The processor 174 selects a constant group corresponding to the environmental temperature and uses the multiple constants a and b constituting the selected constant group as constants of the corresponding functions.

[0087] An example of a method for obtaining such a table will be described. The constants a and b are obtained in the environment in which the measuring device 100 is actually used. That is, for example, the constants a and b are obtained in a temperature environment of 20°C to 80°C and a dehumidified vacuum environment with an ultimate vacuum of approximately 10 mTorr. To obtain the constants a and b, the measuring device 100 is first placed inside the edge ring ER and on the electrostatic chuck ESC. Then, while the position of the measuring device 100 is changed horizontally, the relative position of the measuring device 100 and the detection value X at that position are obtained. The relative position of the measuring device 100 may be the distance of each of the first sensors 104A to 104C relative to the edge ring ER. In this case, the electrostatic capacitance of each of the first sensors 104A to 104C can be calculated. The relative position of the measuring device 100 may be the position of each of the second sensors 105A to 105C relative to the electrostatic chuck ESC. In this case, the area where the sensor electrode 161 and the electrostatic chuck ESC overlap each other in a plan view can be calculated. That is, the capacitance of each of the second sensors 105A to 105C can be calculated based on a calculated value. Then, constants a and b are calculated so that the acquired detection value X approximates the capacitance based on the calculated value. The calculated constants a and b are acquired as elements constituting a table. The table can be created by acquiring the constants a and b at each temperature while the temperature of the measuring device 100 is adjusted to 20°C to 80°C.

[0088] Next, an example of the operation of measuring device 100 will be described. FIG. 14 is a flow diagram showing the operation of a system including measuring device 100, from the step of adjusting the reference point to the step of measuring capacitance. The operation in this flow diagram is the operation of the measurement system in which measuring device 100 acquires a measurement value representing capacitance within chamber S of processing system 1. This operation is controlled by one or more control devices (for example, processor 174 of measuring device 100 and controller MC of processing system 1). Processor 174 and controller MC may cooperate while being able to communicate with each other. Furthermore, processor 174 and controller MC may control measuring device 100 and processing system 1 to cooperate with each other by counting the time required for each step. Note that, as a prerequisite, a table containing the above-mentioned constants a and b as elements has been obtained during the manufacturing process of measuring device 100. Furthermore, a reference parameter group has been obtained by measuring device 100 that has been left in a dehumidified environment for one day or more.

[0089] As a preliminary step of the operation flow shown in FIG. 14, the measuring instrument 100 may be stored in a storage container. In one example, the inside of the storage container is in a dehumidified environment. As shown in FIG. 14, the measuring instrument 100 is transferred to a process module PM (step ST1). In one example, the measuring instrument 100 is moved from the storage container to one of the containers 4a to 4d. The measuring instrument 100 may be carried from the storage container to the container 4a or the like by a user. Furthermore, the processing system 1 may have a device for transferring the measuring instrument 100 from the storage container to the container 4a or the like.

[0090] The measuring instrument 100 moved to one of the vessels 4a to 4d is then transferred into the chamber body 12 of the process module by the transfer apparatus TU1 and the transfer apparatus TU2. The measuring instrument 100 moved to the vessel may be controlled by a program for performing reference point adjustment and measurement. For example, in one exemplary embodiment, a computer or the like may be provided separately outside the processing system 1. The measuring instrument 100 may start the operation of the program based on a wireless instruction from the computer. The processing system 1 may also start the operation based on an instruction from the computer.

[0091] The measuring device 100 transferred to the chamber body 12 may be supported by lift pins 25a provided on the stage ST. That is, the measuring device 100 is not placed on the stage ST, but is supported by the lift pins 25a above the stage ST. The measuring device 100 supported in this manner is heated by heating the chamber body 12 (step ST2). The chamber body 12 may be in a preheated state before the measuring device 100 is transferred.

[0092] The measuring device 100, whose temperature is being increased, detects the temperature using the temperature sensor 179 and determines whether the detected temperature is suitable for adjusting the reference point (step ST3). In one example, it may be determined whether the temperature is the same as the set temperature of the chamber body 12 or a temperature within a certain range close to the set temperature of the chamber body 12. The set temperature of the chamber body 12 may be the temperature at which plasma processing is performed or the temperature at which capacitance measurement is performed by the measuring device 100. The interior of the chamber body 12 may be adjusted to a vacuum dehumidified environment with an ultimate vacuum of about 10 mTorr.

[0093] If it is determined in step ST3 that the temperature is suitable for reference point adjustment, the detected temperature data is stored in storage device 175, and reference point adjustment of the output voltage signal of C / V conversion circuits 172, 272 is performed (step ST4). As described above, the reference point adjustment may be a zero-point adjustment. That is, in a state where there is no target to be detected by measuring instrument 100, processor 174 adjusts the resistance value of variable resistor 171b and the capacitance value of variable capacitor 171c so that the voltage signal output from C / V conversion circuits 172, 272 becomes zero. In one example, the state where there is no target to be detected by measuring instrument 100 is realized by supporting measuring instrument 100 with lift pins 25a.

[0094] The processor 174 stores the digital values output to the D / A converters 174a and 174b to adjust the resistance value of the variable resistor 171b and the capacitance value of the variable capacitor 171c in, for example, the storage device 175. That is, the processor 174 acquires parameters for adjusting the reference point under the current environment. Next, the processor 174 acquires reference parameters corresponding to the acquired temperature data based on a pre-stored reference parameter group. The processor 174 acquires a correction parameter group based on the difference between the parameters for adjusting the reference point and the reference parameter corresponding to the temperature data. The acquired correction parameter group is saved in, for example, the storage device 175.

[0095] Subsequently, the lift pins 25a are lowered, so that the measuring device 100 is placed on the placement area of the electrostatic chuck ESC. The timing for the lift pins 25a to be lowered may be after a sufficient time has elapsed for the reference point adjustment of the measuring device 100 to be completed. The placement area may be an area surrounded by an edge ring ER. The transfer position data is coordinate data that is predetermined so that the position of the central axis AX100 of the measuring device 100 coincides with the center position of the edge ring ER. The transfer position data may also be coordinate data that is predetermined so that the position of the central axis AX100 of the measuring device 100 coincides with the center position of the electrostatic chuck ESC.

[0096] When the measuring instrument 100 is placed on the electrostatic chuck ESC, the temperature is detected by the temperature sensor 179, and the resistance value of the variable resistor 171b and the capacitance value of the variable capacitor 171c in the phase adjustment circuit 171d are set according to the detected temperature. That is, the processor 174 acquires a correction parameter corresponding to the temperature data from a group of correction parameters stored in the storage device 175. The processor 174 outputs the acquired correction parameter as a digital signal to the D / A converter 174a, thereby controlling the resistance value of the variable resistor 171b and the capacitance value of the variable capacitor 171c.

[0097] Next, measurement is performed by measuring instrument 100 (step ST5). Measurement by measuring instrument 100 is performed after lift pins 25a are lowered. For example, processor 174 may store in advance the timing at which lift pins 25a are lowered. In step ST5, the output signal (voltage signal) of C / V conversion circuit 172 and the output signal (voltage signal) of C / V conversion circuit 272 are converted into digital values by A / D converters and output as detection values to processor 174. This detection value may be associated with temperature data and stored in storage device 175, for example.

[0098] Next, constants of a function for calculating a measurement value representing capacitance are set. In one exemplary embodiment, the function is set so that the measurement value is proportional to (a·X+b). Processor 174 obtains constants a and b corresponding to the temperature data linked to the detected value from a table containing multiple constants a and b stored in storage device 178. This sets constants a and b. The detected value by measuring device 100 is converted into a measurement value representing capacitance using a function reflecting constants a and b. The obtained capacitance data may be stored in storage device 175 in a state linked to the temperature data, detected value, etc. for each sensor. For example, the capacitance data may be wirelessly output from measuring device 100 to an external computer while measuring device 100 is transported to one of containers 4a-4d by transport devices TU1 and TU2.

[0099] In one exemplary embodiment, a deviation amount (first deviation amount) of the center of the measuring device 100 relative to the center position of the edge ring ER can be derived based on the capacitances acquired by the first sensors 104A to 104C. Furthermore, a deviation amount (second deviation amount) of the center of the measuring device 100 relative to the center position of the electrostatic chuck ESC can be derived based on the capacitances acquired by the second sensors 105A to 105C. Furthermore, a deviation amount (third deviation amount) of the center of the edge ring ER relative to the center position of the electrostatic chuck ESC can be derived based on the first deviation amount and the second deviation amount. Such deviation amount can be used, for example, to calibrate transfer position data used for transfer by the transfer device TU2.

[0100] As an example, the control unit MC may calibrate the transfer position data based on at least one of the first and second deviation amounts. The control unit MC may control the transfer device TU2 of the transfer module TF so that the workpiece W (or the measuring instrument 100) is transferred based on the calibrated transfer position data. The control unit MC may also calibrate the transfer position data based on a third deviation amount.

[0101] FIG. 15 is a flow diagram showing another example of the operation of measuring device 100 from the step of adjusting the reference point to the step of measuring the capacitance. Hereinafter, detailed description of steps similar to those in FIG. 14 will be omitted. As shown in FIG. 15, measuring device 100 is transferred to chamber body 12 of a process module (step ST11). After being transferred to chamber body 12, measuring device 100 is heated by heating chamber body 12 (step ST12). For example, measuring device 100 is heated to a temperature exceeding a temperature suitable for adjusting the reference point. In one example, the temperature of measuring device 100 may be controlled by controlling the time that measuring device 100 is placed in chamber body 12.

[0102] Next, the measuring instrument 100 is transported to the load lock module by the transport device TU2 (step ST13). The measuring instrument 100 transported to the load lock module may be supported by lift pins 7a provided on the mounting table 7. Next, the measuring instrument 100 detects the temperature using the temperature sensor 179 and determines whether the detected temperature is suitable for reference point adjustment (step ST14). For example, if a temperature (set temperature) suitable for reference point adjustment is set in advance, the processor 174 determines that the temperature is the set temperature when the temperature detected by the temperature sensor 179 exceeds the set temperature and then drops to the set temperature.

[0103] If it is determined in step ST14 that the temperature is the set temperature, the detected temperature data is stored in storage device 175, and a reference point adjustment of the output voltage signal of C / V conversion circuits 172, 272 is performed (step ST15). As described above, the reference point adjustment may be a zero point adjustment. In one example, measuring device 100 is supported by lift pins 7a, thereby realizing a state in which there is no target to be detected by measuring device 100. In step ST5, a set of correction parameters is acquired, and the acquired set of correction parameters is stored in storage device 175, for example.

[0104] Next, the transfer device places the measuring device 100 on the placement area of the electrostatic chuck ESC of the process module (step ST16). In step ST16, the measuring device 100 placed in the load lock module may be transferred directly to the process module by the transfer device TU2. Alternatively, in step ST16, the measuring device 100 placed in the load lock module may be temporarily returned to one of the vessels 4a to 4d by the transfer device TU1, and then transferred to the process module by the transfer devices TU1 and TU2. When multiple measurements are performed consecutively, data on the measured capacitance may be transferred to an external computer or the like when the measuring device 100 returns to the vessel 4a or the like.

[0105] In step ST16, when the measuring instrument 100 is placed on the electrostatic chuck ESC, the temperature is detected by the temperature sensor 179, and a correction parameter corresponding to the temperature data is acquired. The processor 174 outputs the acquired correction parameter as a digital signal to the D / A converter 174a, thereby controlling the resistance value of the variable resistor 171b and the capacitance value of the variable capacitor 171c. Subsequently, measurement is performed by the measuring instrument 100 (step ST17).

[0106] As described above, one exemplary embodiment provides an adjustment method for adjusting a measuring device 100 in a processing system 1 for performing a process. The processing system 1 includes a process module providing a heatable chamber body 12 and transport devices TU2 and TU2 for transporting the measuring device 100 into the chamber body 12. The measuring device 100 includes a disk-shaped base substrate 101, sensor electrodes 143 and 161 provided on the base substrate 101 for obtaining a measurement value representing the capacitance between the measuring device 100 and an opposing object, and a temperature sensor 179 provided on the base substrate 101. The adjustment method includes a step of transporting the measuring device 100 into the chamber body 12 of the process module. The adjustment method includes a step of heating the chamber body 12 to raise the temperature of the measuring device 100 transported into the chamber S. The adjustment method includes a step of determining, using the temperature sensor 179, whether the heated measuring device 100 is in a predetermined temperature state. The adjustment method includes a step of supporting measuring device 100 within processing system 1 so that, when measuring device 100 is determined to be in a predetermined temperature state, there is no object from which capacitance can be acquired in an area facing sensor electrodes 143, 161. The adjustment method also includes a step of performing reference point adjustment on measuring device 100 that is supported.

[0107] For example, when adjusting the reference point in a room-temperature environment with a certain level of dehumidification, it is possible to perform the adjustment in a dedicated storage container. In this case, the value of the reference point adjustment may fluctuate due to environmental changes when the measuring device 100 is moved from the storage container to the processing system 1. Furthermore, the measurement values of the measuring device 100 are likely to change depending on the temperature environment. If the reference point adjustment (zero point adjustment) is performed at a certain temperature, the deviation in the measurement value increases the further the temperature deviates from that temperature, and the measurement accuracy decreases. For example, if the reference point adjustment is performed in a room-temperature environment as in the example of Figure 13, the deviation in the measurement value is likely to increase when the measuring device 100 is used in a high-temperature environment where plasma processing is performed.

[0108] In the above embodiment, measuring device 100 is heated in a process module and managed to maintain a predetermined temperature state. Then, when the predetermined temperature state is reached, reference point adjustment of measuring device 100 is performed. In this case, it is possible to perform reference point adjustment of measuring device 100 at a temperature state close to the temperature at which the process is performed, thereby improving the accuracy of capacitance measurement in the environment in which the process is performed.

[0109] Although various exemplary embodiments have been described above, the present invention is not limited to the above-described exemplary embodiments, and various omissions, substitutions, and modifications may be made. Furthermore, elements in different embodiments may be combined to form other embodiments.

[0110] The load lock module is not limited to a configuration in which the workpiece W (measuring device 100) is moved up and down by the lift pins 7a. For example, the load lock module may have a mounting table that moves up and down. In this case, the mounting surface of the mounting table on which the measuring device 100 is placed is not subject to detection by the sensor electrodes 143, 161 of the measuring device 100. In other words, the mounting surface, as an example, may have a diameter smaller than the diameter of the base substrate 101 so as not to face the three second sensors 105 of the measuring device 100.

[0111] In one exemplary embodiment, the meter 100 is stored in a dedicated storage container before measurement, but the meter 100 may also be stored in a dedicated HOUP, which may be arranged as a container 4a, for example.

[0112] From the foregoing, it will be understood that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the appended claims. [Explanation of symbols]

[0113] 1...processing system, 12...chamber body, 100...measuring device, 101...base substrate, TU2, TU2...transport device, 143...sensor electrode, 161...sensor electrode, 179...temperature sensor.

Claims

[Claim 1] 1. A method for adjusting a measuring instrument in a processing system for performing a process, comprising: The processing system includes: a process module providing a heatable chamber; a transport device that transports the measuring device into the chamber, The measuring instrument is A base substrate; a sensor electrode provided on the base substrate for obtaining a measurement value representing a capacitance between the sensor electrode and an object facing the sensor electrode; a temperature sensor provided on the base substrate, The method comprises: transporting the measuring instrument into the chamber of the process module; a step of heating the chamber to raise the temperature of the measuring device transferred into the chamber; a step of determining whether the heated measuring device is in a predetermined temperature state by the temperature sensor; supporting the measuring device within the processing system such that, when it is determined that the measuring device is in a predetermined temperature state, the object from which the capacitance can be acquired is not present in an area facing the sensor electrode; performing a reference point adjustment of the measuring device supported within the processing system.

Images