TWI905351B - Measuring instrument and measuring method - Google Patents

Abstract

This invention provides a technique for stabilizing the measurement accuracy of a measuring instrument. An exemplary embodiment of the measuring instrument of this invention includes a substrate having an upper surface and a lower surface, a plurality of sensors, and a circuit board. The plurality of sensors are arranged along the edge of the substrate, providing a plurality of downward-facing electrodes. The circuit board is mounted on the substrate. The circuit board is connected to each of the plurality of sensors. The circuit board assigns a high-frequency signal to the plurality of electrodes, generating a plurality of measured values representing electrostatic capacitance based on the voltage amplitude of each of the plurality of electrodes. The plurality of sensors protrude downwards beyond the lower surface of the substrate.

Description

Measuring instrument and measuring method

The exemplary embodiments of this invention relate to a measuring instrument and a measuring method.

Patent document 1 describes a measuring device for measuring electrostatic capacitance. The measuring device includes a substrate, a first sensor, a second sensor, and a circuit board. The substrate is disc-shaped with a diameter identical to that of the workpiece. The first sensor has a first electrode disposed along the edge of the upper surface of the substrate. The second sensor has a second electrode disposed on the lower surface of the substrate. The circuit board is mounted on the substrate and connected to the first and second sensors. The circuit board assigns high-frequency signals to the first and second electrodes. A first measured value corresponding to the electrostatic capacitance is obtained based on the voltage amplitude in the first electrode, and a second measured value corresponding to the electrostatic capacitance is obtained based on the voltage amplitude in the second electrode.

[Previous Technical Documents] [Patent Documents]

[Patent Document 1] Japanese Patent Application Publication No. 2017-228754

This invention provides a technique for stabilizing the measurement accuracy of a measuring instrument.

In one exemplary embodiment, a measuring device is provided. The measuring device includes a substrate having an upper surface and a lower surface, a plurality of sensors, and a circuit board. The plurality of sensors are arranged along the edge of the substrate and provide a plurality of downward-facing electrodes. The circuit board is mounted on the substrate. The circuit board is connected to each of the plurality of sensors. The circuit board assigns a high-frequency signal to the plurality of electrodes and generates a plurality of measured values representing electrostatic capacitance based on the voltage amplitude of each of the plurality of electrodes. The plurality of sensors protrude downward beyond the lower surface of the substrate.

According to an exemplary embodiment of the measuring instrument, the measurement accuracy of the measuring instrument can be stabilized.

1: Processing System

2a, 2b, 2c, 2d: Taiwan

4a, 4b, 4c, 4d: Containers

6D: Drive Unit

6S: Sensors

6T: Supports Taiwan

10: Plasma Treatment Equipment

12: Chamber Body

12e: Exhaust port

12g: Inbound/Outbound

14: Support Department

18a: First Board

18b: Second board

22: DC Power Supply

23: Switch

24:Refrigerant flow path

25:Through hole

25a: Top Lift Pin

26a:Piping

26b:Piping

27:Through hole

27a: Top-mounted pin

28: Gas supply pipeline

30: Upper electrode

32: Insulating shielding components

34: Roof

34a: Gas ejection port

36: Support

36a: Gas diffusion chamber

36b: Gas flow port

36c: Gas inlet

38: Gas supply pipe

40: Gas Source Group

42: Valve Group

44: Flow Controller Cluster

46: Accumulated Material Covering

48: Exhaust plate

50: Exhaust device

52: Exhaust pipe

54: Gate valve

62: High-Frequency Power Supply

64: Second High-Frequency Power Supply

66: Matcher

68: Matcher

100: Measuring device

102: Substrate

102a: Upper surface

102b: Lower surface

102N: Notch

103: Outer Cover

104: First Sensor

104A, 104B, 104C: First Sensor

105: Second Sensor (Sensor)

105A, 105B, 105C: Second sensor

106: Circuit board

108: Wiring Group

108A, 108B, 108C: Wiring Group

121: concave part

122: concave part

123: concave part

141: Electrode

142: Shielding electrode

143: Sensor Electrode

143f: Front surface

144:Substrate part

144a: Upper surface

144b: Lower surface

144c: Front end face

144d: Lower part

144u: Upper part

147: Isolated Zone

161: Sensor electrode (electrode)

161a: Inner edge

161b: Outer edge

161c: Lateral edge

162: Shielding electrode

163: Electrode

164: Isolated Zone

165: Isolated Zone

166: Insulating Components

166a: Lower surface

166b: Top surface

166L: Distance

167: Insulating Components

168: Insulation Components

171: High-frequency oscillator

172: C/V conversion circuit

172A, 172B, 172C: C/V conversion circuits

173: A/D Converter

174: Processor

175: Memory Device

176: Communication Devices

177: Power Supply

178: Memory Device

181:Wiring

182:Wiring

183:Wiring

208: Wiring Group

208A, 208B, 208C: Wiring Group

272: C/V Conversion Circuit

272A, 272B, 272C: C/V conversion circuits

281,282,283:Wiring

AN: Alignment device

AX100: Central Axis

ER: Peripheral loop

ESC: Electrostatic Chuck

GL: Grounding Potential Line

LE: lower electrode

LL1, LL2: Loading locking modules

LM: Carrier Module

MC: Control Department

P1: Part 1

P1i: Inner edge

P2: Part 2

P2i: Inner edge

PM1, PM2, PM3, PM4, PM5, PM6: Process Modules

S: Chamber

S1: Semiconductor manufacturing device

ST: Platform

SWG: Switch

TF: Transmission Module

TU1: Conveying Device

TU2: Conveying Device

TUa: transfer arm

W: Workpiece

WN: Notch

Figure 1 is a diagram illustrating the processing system.

Figure 2 is a three-dimensional view illustrating the collimator.

Figure 3 shows an example of a plasma treatment apparatus.

Figure 4 is a top view showing an example of a measuring instrument as observed from the top surface.

Figure 5 is a top view showing an example of a measuring instrument as observed from the lower surface.

Figure 6 is a perspective view showing an example of the first sensor in the measuring device.

Figure 7 is a cross-sectional view taken along line VII-VII of Figure 6.

Figure 8 is an enlarged view showing an example of the second sensor in the measuring device.

Figure 9 is an example of the configuration of the circuit board in the measuring instrument.

Figure 10 is a cross-sectional view of the second sensor along the radial direction of the measuring instrument.

Figure 11 is a flowchart illustrating one example of a measurement method using a measuring instrument.

Figure 12 is a cross-sectional view of the second sensor in another example.

Figure 13 is a cross-sectional view of the second sensor in another example.

The following describes various illustrative implementation methods.

In one exemplary embodiment, a measuring device is provided. The measuring device includes a substrate having an upper surface and a lower surface, a plurality of sensors, and a circuit board. The plurality of sensors are arranged along the edge of the substrate and provide a plurality of downward-facing electrodes. The circuit board is mounted on the substrate. The circuit board is connected to each of the plurality of sensors. The circuit board assigns a high-frequency signal to the plurality of electrodes and generates a plurality of measured values representing electrostatic capacitance based on the voltage amplitude of each of the plurality of electrodes. The plurality of sensors protrude downward beyond the lower surface of the substrate.

In the aforementioned measuring device, when there is an object facing a plurality of electrodes pointing downwards from the substrate, a measured value representing the electrostatic capacitance between each electrode and the object is acquired. This measured value can vary depending on the distance between the electrode and the object. When the plurality of sensors protrude downwards from the lower surface of the substrate, the measuring device mounted on the object can be supported by the plurality of sensors. In this case, the distance between the electrodes and the object is the same for each of the plurality of sensors. Therefore, differences in measurement conditions between sensors can be suppressed, thereby stabilizing the measurement accuracy of the measuring device.

In one exemplary embodiment, a plurality of electrodes may extend along the lower surface of the substrate, and the plurality of sensors may have a plurality of insulating components respectively covering the plurality of electrodes. In this configuration, when the sensor is placed on an object, the insulating components of the plurality of sensors respectively contact the object.

In one exemplary embodiment, the plurality of insulating elements may be formed of any one of glass, ceramic, or insulating resin.

In one exemplary embodiment, a plurality of recesses, each accommodating a plurality of sensors, may be formed on the lower surface of the substrate. The plurality of sensors, when housed in their respective recesses, protrude downwards from the lower surface of the substrate. In this configuration, the plurality of sensors can be positioned with high precision within the substrate.

In one exemplary embodiment, the plurality of sensors may consist of three sensors equally spaced circumferentially along the edge of the substrate. In this configuration, the measuring instrument can be stably supported by the three sensors.

Furthermore, in another exemplary embodiment, a method for measuring the electrostatic capacitance between a measuring instrument and an object is provided. The measuring instrument has a substrate having an upper surface and a lower surface, a plurality of sensors, and a circuit board. The plurality of sensors are arranged along the edge of the substrate and provide a plurality of downward-facing electrodes. The circuit board is mounted on the substrate. The circuit board is connected to each of the plurality of sensors. The circuit board assigns a high-frequency signal to the plurality of electrodes and generates a plurality of measured values representing the electrostatic capacitance based on the voltage amplitude of each of the plurality of electrodes. The plurality of sensors protrude downward beyond the lower surface of the substrate. The method includes the step of placing the measuring instrument on the upper surface of the object in such a manner that the measuring instrument is supported by the plurality of sensors. The method includes the following steps: with the measuring device placed on the surface of the object, a high-frequency signal is applied to a plurality of electrodes, thereby generating a plurality of measured values representing the electrostatic capacitance based on the voltage amplitudes of the plurality of electrodes.

The various implementation methods are explained in detail below with reference to the accompanying drawings. Furthermore, identical or equivalent parts in each drawing are marked with the same symbols.

First, a processing system comprising a processing apparatus for processing workpieces and a conveying apparatus for conveying the workpieces to the processing apparatus will be described. Figure 1 is a diagram illustrating the processing system. The processing system 1 functions as a semiconductor manufacturing apparatus S1. The processing system 1 includes stages 2a-2d, containers 4a-4d, a carrier module LM, a alignment device AN, loading locking modules LL1, LL2, process modules PM1-PM6, a conveying module TF, and a control unit MC. Furthermore, the number of stages 2a-2d, containers 4a-4d, loading locking modules LL1, LL2, and process modules PM1-PM6 is not limited and can be any number of more than one.

Stages 2a-2d are arranged along one edge of the carrier module LM. Containers 4a-4d are respectively mounted on stages 2a-2d. Each of containers 4a-4d is, for example, a container referred to as a FOUP (Front Opening Unified Pod). Each of containers 4a-4d can be configured to house the workpiece W. The workpiece W, like a wafer, has a generally disk-shaped form.

The carrier module LM has chamber walls that divide its interior to form a transport space under atmospheric pressure. A transport device TU1 is installed within this transport space. The transport device TU1 is, for example, a multi-joint robotic arm, controlled by a control unit MC. The transport device TU1 is configured to transport the workpiece W between containers 4a-4d and the alignment device AN, between the alignment device AN and the loading and locking modules LL1-LL2, and between the loading and locking modules LL1-LL2 and containers 4a-4d.

The alignment device AN is connected to the carrier module LM. The alignment device AN is configured to adjust the position (position calibration) of the workpiece W. Figure 2 is a perspective view illustrating the alignment device. The alignment device AN includes a support platform 6T, a drive unit 6D, and a sensor 6S. The support platform 6T is a platform capable of rotating about a center axis extending in the vertical direction, configured to support the workpiece W on it. The support platform 6T rotates by the drive unit 6D. The drive unit 6D is controlled by the control unit MC. When the support platform 6T rotates by power from the drive unit 6D, the workpiece W placed on the support platform 6T also rotates.

Sensor 6S is an optical sensor that detects the edges of the workpiece W during its rotation. Based on the edge detection results, sensor 6S detects the offset of the angular position of the notch WN (or other marking) of the workpiece W relative to a reference angular position, and the offset of the center position of the workpiece W relative to the reference position. Sensor 6S outputs the offset of the angular position of the notch WN and the offset of the center position of the workpiece W to the control unit MC. Based on the offset of the angular position of the notch WN, the control unit MC calculates the rotation amount of the support stage 6T used to correct the angular position of the notch WN to the reference angular position. The control unit MC controls the drive device 6D to rotate the support stage 6T by that rotation amount. In this way, the angular position of the notch WN can be corrected to the reference angular position. Furthermore, the control unit MC controls the position of the end effector of the conveying device TU1 when receiving the workpiece W from the alignment device AN, based on the offset of the workpiece W's center position. This ensures that the center position of the workpiece W is aligned with the predetermined position on the end effector of the conveying device TU1.

Returning to Figure 1, both locking modules LL1 and LL2 are positioned between the carrier module LM and the transmission module TF. Each locking module LL1 and LL2 provides a backup depressurization chamber.

The transfer module TF is airtightly connected to the loading and locking modules LL1 and LL2 via gate valves. The transfer module TF provides a depressurization chamber. A conveying device TU2 is installed in this depressurization chamber. The conveying device TU2 is, for example, a multi-joint robot with a conveying arm TUa, controlled by the control unit MC. The conveying device TU2 is configured to convey the workpiece W between the loading and locking modules LL1-LL2 and process modules PM1-PM6, and between any two process modules PM1-PM6.

Process modules PM1 through PM6 are airtightly connected to the conveyor module TF via gate valves. Each of process modules PM1 through PM6 constitutes a specialized processing device for performing plasma treatment and other processes on the workpiece W.

A series of actions during the processing of workpiece W in the processing system 1 are illustrated as follows: The conveying device TU1 of the carrier module LM removes workpiece W from any of the containers 4a-4d and conveys it to the alignment device AN. Then, the conveying device TU1 removes the workpiece W, now in position, from the alignment device AN and conveys it to one of the loading and locking modules LL1 and LL2. Subsequently, one of the loading and locking modules reduces the pressure in the preparation depressurization chamber to a specified pressure. Next, the conveying device TU2 of the transfer module TF retrieves the workpiece W from one of the loading and locking modules and conveys it to any one of the process modules PM1 to PM6. Then, one or more of the process modules PM1 to PM6 process the workpiece W. Next, the conveying device TU2 conveys the processed workpiece W from the process modules to one of the loading and locking modules LL1 and LL2. Then, the conveying device TU1 conveys the workpiece W from one of the loading and locking modules to any one of the containers 4a to 4d.

As described above, the processing system 1 includes a control unit MC. The control unit MC can be a computer equipped with a processor, memory (such as a memory device), a display device, input/output devices, and communication devices. A series of operations of the processing system 1 are implemented by the control unit MC controlling each component of the processing system 1 according to a program stored in the memory device.

Figure 3 illustrates an example of a plasma processing apparatus that can be used as any of 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 has a generally cylindrical chamber body 12. The chamber body 12 is formed, for example, of aluminum, and its inner wall surface can be anodized. The chamber body 12 is safely grounded.

A generally cylindrical support portion 14 is provided on the bottom of the chamber body 12. The support portion 14 may contain, for example, insulating material. The support portion 14 is disposed within the chamber body 12 and extends upward from the bottom of the chamber body 12. Furthermore, a platform ST is provided within the chamber S provided by the chamber body 12. The platform ST is supported by the support portion 14.

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 metal such as aluminum and are generally disc-shaped. The second plate 18b is disposed on the first plate 18a and is electrically connected to the first plate 18a.

An electrostatic chuck (ESC) is provided on the second plate 18b. The ESC has a generally disc-shaped structure in which electrodes, acting as conductive films, are positioned between a pair of insulating layers or sheets. A DC power supply 22 is electrically connected to the electrodes of the ESC via a switch 23. The ESC uses electrostatic forces, such as Coulomb force, generated by the DC voltage from the DC power supply 22 to hold the workpiece W. This allows the ESC to retain the workpiece W.

An edge ring ER is provided on the periphery of the second plate 18b. The edge ring ER is configured 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 Figure 7). Both portions P1 and P2 are ring-shaped. The second portion P2 is located on the outer side of 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 with its edge region located on the first portion P1 of the edge ring ER. The edge ring ER can be formed from any of the following materials: silicon, silicon carbide, silicon oxide, etc.

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 from the cooler unit located outside the chamber body 12 via piping 26a to the refrigerant flow path 24. The refrigerant supplied to the refrigerant flow path 24 returns to the cooler unit via piping 26b. Thus, the refrigerant circulates between the refrigerant flow path 24 and the cooler unit. By controlling the temperature of this refrigerant, the temperature of the workpiece W supported by the electrostatic chuck (ESC) is controlled.

A plurality of (e.g., three) through holes 25 are formed through the stage ST. The plurality of through holes 25 are formed inside the electrostatic chuck ESC in top view. A lifting pin 25a is inserted into each of these through holes 25. Furthermore, Figure 3 depicts one through hole 25 into which a lifting pin 25a is inserted. The lifting pin 25a is configured to move vertically within the through hole 25. The workpiece W supported on the electrostatic chuck ESC is supported by the rising of the lifting pin 25a.

A plurality of (e.g., three) through holes 27 are formed on the stage ST, located on the outer side of the electrostatic chuck ESC in top view, penetrating the stage ST (lower electrode LE). A lifting pin 27a is inserted into each of these through holes 27. Furthermore, Figure 3 depicts one through hole 27 with a lifting pin 27a inserted. The lifting pin 27a is configured to move up and down within the through hole 27. The rising of the lifting pin 27a supports the rising of the edge ring ER on the second plate 18b.

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

Furthermore, the plasma treatment apparatus 10 includes an upper electrode 30. The upper electrode 30 is positioned above and opposite the stage ST. The upper electrode 30 is supported on the upper part of the chamber body 12 by an insulating shielding member 32. The upper electrode 30 may include a top plate 34 and a support body 36. The top plate 34 faces the chamber S and has a plurality of gas ejection holes 34a. The top plate 34 may be formed 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.

The support body 36 provides flexible support for the top plate 34 and may be made of conductive materials such as aluminum. The support body 36 may have a water-cooling structure. Inside the support body 36, a gas diffusion chamber 36a is provided. A plurality of gas flow holes 36b, communicating with gas ejection holes 34a, extend downward from the gas diffusion chamber 36a. Furthermore, a gas inlet 36c is formed in the support body 36 to guide the processing gas to the gas diffusion chamber 36a, and a gas supply pipe 38 is connected to the gas inlet 36c.

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 a plurality of gas sources for a plurality of different gases. The valve group 42 includes a plurality of valves, and the flow controller group 44 includes a plurality of flow controllers, such as mass flow controllers. Each gas source 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.

Furthermore, in the plasma treatment apparatus 10, an accumulation shield 46 is detachably installed along the inner wall of the chamber body 12. The accumulation shield 46 is also located on the outer periphery of the support portion 14. The accumulation shield 46 prevents etching byproducts (accumulations) from adhering to the chamber body 12, and can be constructed by coating aluminum with a ceramic material such as yttrium oxide.

An exhaust plate 48 is provided on the bottom side of the chamber body 12, between the support portion 14 and the side wall of the chamber body 12. The exhaust plate 48 can be constructed, for example, by coating aluminum with a ceramic such as yttrium oxide. A plurality of holes are formed in the exhaust plate 48, extending through its thickness. An exhaust port 12e is provided below the exhaust plate 48 and within the chamber body 12. An exhaust device 50 is connected to the exhaust port 12e via an exhaust pipe 52. The exhaust device 50 includes a pressure regulating valve and a vacuum pump such as a turbine molecular pump, capable of depressurizing the space within the chamber body 12 to the required vacuum level. Furthermore, an inlet/outlet 12g for the workpiece W is provided on the side wall of the chamber body 12. This inlet/outlet 12g can be opened and closed by a gate valve 54.

Furthermore, 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 for generating a first high-frequency signal for plasma production, for example, generating a high frequency with a frequency of 27~100MHz. The first high-frequency power supply 62 is connected to the upper electrode 30 via a matching converter 66. The matching converter 66 has circuitry for matching the output impedance of the first high-frequency power supply 62 with the input impedance of the load side (upper electrode 30 side). Furthermore, the first high-frequency power supply 62 can also be connected to the lower electrode LE via the matching converter 66.

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

In the plasma processing apparatus 10, gas from one or more gas sources selected from a plurality of gas sources is supplied to chamber S. Furthermore, the pressure in chamber S is set to a predetermined pressure by the exhaust device 50. Then, the gas in chamber S is excited by a first high frequency from a first high-frequency power supply 62, thereby generating plasma. The workpiece W is then processed using the generated active species. Furthermore, ions can be fed into the workpiece W as needed by a bias voltage based on a second high frequency from a second high-frequency power supply 64.

Next, the measuring device will be described. Figure 4 is a top view showing the measuring device viewed from the top surface. Figure 5 is a top view showing the measuring device viewed from the bottom surface. The measuring device 100 shown in Figures 4 and 5 has a substrate 102 having an upper surface 102a and a lower surface 102b. The substrate 102 is formed of silicon, for example, and has a shape that is the same as the shape of the workpiece W, i.e., a generally disc shape. The diameter of the substrate 102 is the same as the diameter of the workpiece W, for example, 300 mm. The shape and size of the measuring device 100 are determined by the shape and size of the substrate 102. Therefore, the measuring device 100 has a shape that is the same as the shape of the workpiece W and has a size that is the same as the size of the workpiece W. Furthermore, a notch 102N (or other marking) is formed at the edge of the substrate 102.

A plurality of first sensors 104A-104C for electrostatic capacitance measurement are disposed on a substrate 102. The plurality of first sensors 104A-104C are arranged at equal intervals in the circumferential direction along the edge of the substrate 102, for example, along the entire circumference of that edge. Specifically, each of the plurality of first sensors 104A-104C is disposed along the edge of the upper surface of the substrate 102. The front end face of each of the plurality of first sensors 104A-104C is along the side surface of the substrate 102.

Furthermore, a plurality of second sensors 105A-105C for electrostatic capacitance measurement are disposed on the substrate 102. The plurality of second sensors 105A-105C are arranged at equal intervals in the circumferential direction along the edge of the substrate 102, for example, along the entire circumference of that edge. Specifically, each of the plurality of second sensors 105A-105C is disposed along the edge of the lower surface side of the substrate. The sensor electrode 161 of each of the plurality of second sensors 105A-105C extends in the extending direction of the lower surface 102b of the substrate 102. Furthermore, the second sensors 105A-105C and the first sensors 104A-104C are arranged alternately in the circumferential direction at 60° intervals. Furthermore, in the following description, the first sensors 104A~104C and the second sensors 105A~105C will sometimes be collectively referred to as electrostatic capacitance sensors.

A circuit board 106 is disposed at the center of the upper surface 102a of the substrate 102. Wiring groups 108A-108C for electrically connecting the circuit board 106 and a plurality of first sensors 104A-104C are disposed between the circuit board 106 and the plurality of second sensors 105A-105C. Wiring groups 208A-208C for electrically connecting the circuit board 106 and the plurality of second sensors 105A-105C are disposed between the circuit board 106 and the second sensors 105A-105C. The circuit board 106, wiring groups 108A-108C, and wiring groups 208A-208C are covered by an outer casing 103.

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 line VII-VII of Figure 6. The first sensor 104 shown in Figures 6 and 7 is one of a plurality of first sensors 104A-104C used as measuring devices 100, and in one example, is configured as a chip-shaped component. Furthermore, in the following description, the XYZ orthogonal coordinate system will be appropriately referenced. The X direction represents the forward direction of the first sensor 104, the Y direction represents a direction orthogonal to the X direction and the width direction of the first sensor 104, and the Z direction represents a direction orthogonal to both the X and Y directions and the upward direction of the first sensor 104. In Figure 7, the edge ring ER is shown together with the first sensor 104.

The first sensor 104 includes an electrode 141, a shielding electrode 142, a sensor electrode 143, a substrate portion 144, and an insulation region 147.

The substrate portion 144 is formed, for example, from borosilicate glass or quartz. The substrate portion 144 has an upper surface 144a, a lower surface 144b, and a front end face 144c. A shielding electrode 142 is disposed below the lower surface 144b of the substrate portion 144 and extends along the X and Y directions. Furthermore, an electrode 141 dielectric insulation region 147 is disposed below the shielding electrode 142 and extends along the X and Y directions. The insulation region 147 is formed, for example, from _SiO2 , SiN, _Al2O3 , or _polyimide .

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 towards the edge ring ER side compared to 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 an exemplary embodiment, the upper portion 144u and the lower portion 144d of the front end face 144c are respectively curved surfaces with a predetermined curvature. That is, the upper portion 144u of the front end face 144c has a fixed curvature at any position, 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. Similarly, the lower portion 144d of the front end face 144c has a fixed curvature at any position, 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.

The sensor electrode 143 is disposed 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 fixed curvature at any position, which is the reciprocal of the distance between the central axis AX100 of the measuring instrument 100 and the front surface 143f.

When the first sensor 104 is used as a sensor in the measuring device 100, as described below, electrode 141 is connected to wiring 181, shielding electrode 142 is connected to wiring 182, and sensor electrode 143 is connected to wiring 183.

In the first sensor 104, the sensor electrode 143 is shielded from the lower part of the sensor 104 by the electrode 141 and the shielding electrode 142. Therefore, according to this first sensor 104, electrostatic capacitance can be measured with high directivity in a specific direction, namely the direction (X-direction) in which the front surface 143f of the sensor electrode 143 faces.

The second sensor will now be described. Furthermore, the cross-sectional shape of the second sensor will be described below. Figure 8 is a partial enlarged view of Figure 5, showing a second sensor. The second sensor 105 has a sensor electrode 161. The edges of the sensor electrode 161 are partially arc-shaped. For example, the sensor electrode 161 has a planar shape defined by an inner edge 161a, an outer edge 161b, and a side edge 161c. As an example, the outer edge 161b is an arc with a radius centered on the central axis AX100, while the side edge 161c and the inner edge 161a are straight lines. Each of the plurality of second sensors 105A-105C has a radially outward outer edge 161b extending along a common circle. The curvature of a portion of the edge of the sensor electrode 161 coincides with the curvature of the edge of the electrostatic chuck (ESC). In one exemplary embodiment, the curvature of the outer edge 161b of the radially outward edge of the sensor electrode 161 coincides with the curvature of the edge of the ESC. Furthermore, the center of curvature of the outer edge 161b, i.e., the center of the circle extending from the outer edge 161b, shares a central axis AX100.

In one exemplary embodiment, the second sensor 105 further includes a shielding electrode 162 surrounding the sensor electrode 161. The shielding electrode 162 is frame-shaped and surrounds the entire circumference of the sensor electrode 161. The shielding electrode 162 and the sensor electrode 161 are separated from each other by an electrically insulating region 164 between them. In another exemplary embodiment, the second sensor 105 further includes an electrode 163 surrounding the shielding electrode 162 on the outside. The electrode 163 is frame-shaped and surrounds the entire circumference of the shielding electrode 162. Shielding electrode 162 and electrode 163 are separated from each other by an electrically insulating region 165 between them.

The configuration of the circuit board 106 will now be described. Figure 9 is a diagram illustrating the configuration of the circuit board of the measuring device. The circuit board 106 includes a high-frequency oscillator 171, a plurality of C/V (capacitance-voltage) conversion circuits 172A-172C, a plurality of C/V conversion circuits 272A-272C, an A/D (analog-to-digital) converter 173, a processor 174, a memory device 175, a communication device 176, and a power supply 177. In one example, the processor 174, the memory device 175, etc., constitute the computing device.

A plurality of first sensors 104A-104C are connected to the circuit board 106 via corresponding wiring groups 108A-108C. Furthermore, a plurality of first sensors 104A-104C are connected to corresponding C/V conversion circuits 172A-172C via wiring groups included in their respective wiring groups. A plurality of second sensors 105A-105C are connected to the circuit board 106 via corresponding wiring groups 208A-208C. Furthermore, the plurality of second sensors 105A to 105C are each connected to a corresponding C/V conversion circuit in the plurality of C/V conversion circuits 272A to 272C via several wires included in the corresponding wiring groups. Hereinafter, a first sensor 104 having the same structure as each of the first sensors 104A to 104C, a wiring group 108 having the same structure as each of the wiring groups 108A to 108C, and a C/V conversion circuit 172 having the same structure as each of the C/V conversion circuits 172A to 172C will be described. Furthermore, the following will be explained: a second sensor 105 having the same configuration as each of the second sensors 105A~105C; a wiring group 208 having the same configuration as each of the wiring groups 208A~208C; and a C/V conversion circuit 272 having the same configuration as each of the C/V conversion circuits 272A~272C.

Wiring group 108 includes wirings 181 to 183. One end of wiring 181 is connected to electrode 141. Wiring 181 is connected to the ground potential line GL, which is connected to the ground electrode GC of circuit board 106. Alternatively, wiring 181 can also be connected to the ground potential line GL via switch SWG. Wiring 182 is connected to shield electrode 142, and the other end is connected to C/V conversion circuit 172. Wiring 183 is connected to sensor electrode 143, and the other end is connected to C/V conversion circuit 172.

Wiring group 208 includes wires 281 to 283. One end of wire 281 is connected to electrode 163. This wire 281 is connected to the ground potential line GL, which is connected to the ground electrode GC of the circuit board 106. Alternatively, wire 281 can also be connected to the ground potential line GL via switch SWG. Furthermore, one end of wire 282 is connected to shield electrode 162, and the other end of wire 282 is connected to C/V conversion circuit 272. Also, one end of wire 283 is connected to sensor electrode 161, and the other end of wire 283 is connected to C/V conversion circuit 272.

A high-frequency oscillator 171 is connected to a power source 177, such as a battery, to receive power from the power source 177 and generate a high-frequency signal. Furthermore, the power source 177 is also connected to a processor 174, a memory device 175, and a communication device 176. The high-frequency oscillator 171 has a plurality of output lines. The high-frequency oscillator 171 assigns the generated high-frequency signal to wirings 182 and 183, and wirings 282 and 283, via the plurality of output lines. Therefore, the high-frequency oscillator 171 is electrically connected to the shielding electrode 142 and the sensor electrode 143 of the first sensor 104, and the high-frequency signal from the high-frequency oscillator 171 is assigned to the shielding electrode 142 and the sensor electrode 143. Also, the high-frequency oscillator 171 is electrically connected to the sensor electrode 161 and the shielding electrode 162 of the second sensor 105, and the high-frequency signal from the high-frequency oscillator 171 is assigned to the sensor electrode 161 and the shielding electrode 162.

At the input of C/V conversion circuit 172, a wiring 182 connected to shielding electrode 142 and a wiring 183 connected to sensor electrode 143 are connected. That is, at the input of C/V conversion circuit 172, the shielding electrode 142 and sensor electrode 143 of the first sensor 104 are connected. Furthermore, at the input of C/V conversion circuit 272, the sensor electrode 161 and shielding electrode 162 are connected respectively. C/V conversion circuits 172 and 272 are configured to generate a voltage signal with an amplitude corresponding to the potential difference at their inputs and output the voltage signal. The C/V converter 172 generates a voltage signal corresponding to the electrostatic capacitance formed by the first sensor 104. That is, the larger the electrostatic capacitance connected to the sensor electrode of the C/V converter 172, the larger the voltage of the output voltage signal of the C/V converter 172. Similarly, the larger the electrostatic capacitance connected to the sensor electrode of the C/V converter 272, the larger the voltage of the output voltage signal of the C/V converter 272.

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

A memory device 175 is connected to the processor 174. The memory device 175 is a volatile memory or other memory device, for example, constituting memory measurement data. Furthermore, another memory device 178 is connected to the processor 174. The memory device 178 is a non-volatile memory or other memory device, for example, storing a program that is read and executed by the processor 174.

Communication device 176 is a communication device based on any wireless communication standard. For example, communication device 176 is based on Bluetooth (a registered trademark). Communication device 176 is configured to wirelessly transmit measurement data stored in memory device 175.

The processor 174 is configured to control various parts of the measuring device 100 by executing the aforementioned program. For example, the processor 174 controls the supply of high-frequency signals from the high-frequency oscillator 171 to the shielding electrode 142, the sensor electrode 143, the sensor electrode 161, and the shielding electrode 162. Furthermore, the processor 174 controls the power supply from the power supply 177 to the memory device 175 and the power supply from the power supply 177 to the communication device 176. Moreover, by executing the aforementioned program, the processor 174 obtains 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, when the detected value output from the A/D converter 173 is set to X, the processor 174 obtains the measured value based on the detected value, such that the measured value becomes a value proportional to (a‧X+b). Here, a and b are constants that vary depending on circuit conditions, etc. The processor 174 may, for example, have a formula (function) that specifies that the measured value becomes a value proportional to (a‧X+b).

In the measuring device 100 described above, when the measuring device 100 is positioned within the area enclosed by the edge ring ER, a plurality of sensor electrodes 143 and shielding electrodes 142 face the inner edge of the edge ring ER. The measured value, generated based on the potential difference between the signals of the sensor electrodes 143 and the signals of the shielding electrodes 142, represents the electrostatic capacitance reflecting the distance between each of the plurality of sensor electrodes 143 and the edge ring ER. Furthermore, the electrostatic capacitance C is represented by C = εS/d. ε represents the dielectric constant of the medium between the front surface 143f of the sensor electrode 143 and the inner edge of the edge ring ER; S represents the area of the front surface 143f of the sensor electrode 143; and d can be considered as the distance between the front surface 143f of the sensor electrode 143 and the inner edge of the edge ring ER.

Therefore, measurement data reflecting the relative positional relationship between the measuring device 100 and the edge ring ER of the simulated workpiece W can be obtained using the measuring device 100. For example, the greater the distance between the front surface 143f of the sensor electrode 143 and the inner edge of the edge ring ER, the smaller the plurality of measurement values obtained by the measuring device 100. Therefore, the offset of each sensor electrode 143 in each radial direction of the edge ring ER can be determined based on the measured values representing the electrostatic capacitance of each sensor electrode 143 of the first sensors 104A~104C. Furthermore, the positional error of the measuring device 100 can be calculated based on the offset of the sensor electrodes 143 of the first sensors 104A~104C in each radial direction.

Furthermore, with the measuring device 100 mounted on the electrostatic chuck ESC, multiple sensor electrodes 161 and shielding electrodes 162 face the electrostatic chuck ESC. As mentioned above, the electrostatic capacitance C is represented by C = εS/d. ε is the dielectric constant of the medium between the sensor electrodes 161 and the electrostatic chuck ESC, d is the distance between the sensor electrodes 161 and the electrostatic chuck ESC, and S can be considered as the area of overlap between the sensor electrodes 161 and the electrostatic chuck ESC when viewed from above. The area S varies depending on the relative positional relationship between the measuring device 100 and the electrostatic chuck ESC. Therefore, based on the measuring device 100, measurement data reflecting the relative positional relationship between the measuring device 100 and the electrostatic chuck ESC of the simulated workpiece W can be obtained.

In one example, when the measuring instrument 100 is moved to a predetermined moving position, i.e., a position on the electrostatic chuck ESC where the center of the electrostatic chuck ESC coincides with the center of the measuring instrument 100, the outer edge 161b of the sensor electrode 161 may coincide with the edge of the electrostatic chuck ESC. In this case, for example, if the sensor electrode 161 shifts radially outward relative to the electrostatic chuck ESC due to the shift of the measuring instrument 100's moving position from the predetermined moving position, the area S will become smaller. That is, the electrostatic capacitance measured by the sensor electrode 161 will be smaller than the electrostatic capacitance when the measuring instrument 100 is moved to the predetermined moving position. Therefore, based on the measured values of the electrostatic capacitance of each sensor electrode 161 of the second sensors 105A~105C, the offset of each sensor electrode 161 in each radial direction of the electrostatic chuck ESC can be calculated. Furthermore, the positional error of the measuring device 100 can be calculated based on the offset of each sensor electrode 161 of the second sensors 105A~105C in each radial direction.

Next, the second sensor 105 will be described in more detail. Figure 10 is a cross-sectional view of the second sensor along the radial direction of the measuring instrument, schematically showing a cross-section of the second sensor 105. As shown in Figure 10, the second sensor 105 protrudes downward from the lower surface 102b of the substrate 102. In one example of the measuring instrument 100, recesses 121 are formed on the lower surface 102b of the substrate 102 to accommodate the electrodes 161, 162, and 163 included in the second sensor 105. That is, three recesses 121 are formed at equal intervals in the circumferential direction on the lower surface 102b to accommodate the electrodes 161, 162, and 163 included in the three second sensors 105. The depth of the recess 121 is greater than the thickness of the electrodes 161, 162, and 163. Furthermore, the recess 121 has a shape that, when viewed from above, surrounds the electrodes 161, 162, and 163. In one example, the second sensor 105 has an electrical insulating member 166 covering the electrodes 161, 162, and 163. The insulating member 166 may be plate-shaped. The insulating member 166 may be formed of any of glass, ceramic, or insulating resin. For example, the insulating resin may be epoxy resin.

The insulating member 166, viewed from above, is shaped along the contour of the recess 121 and has an outer shape that is slightly larger than the contour of the recess 121. Electrodes 161, 162, and 163 are formed on the upper surface 166b of the insulating member 166. The periphery of the upper surface 166b of the insulating member 166 is fixed to the periphery of the recess 121 in the lower surface 102b. Thus, the electrodes 161, 162, and 163 are disposed within the space formed by the recess 121 and the insulating member 166. In this case, the aforementioned insulating regions 164 and 165 are formed by space. This space can be sealed or connected to the outside.

With the above configuration, the second sensor 105, when fixed to the corresponding recess 121, protrudes downward from the lower surface 102b of the substrate 102. In the example of FIG. 10, the amount by which the second sensor 105 protrudes from the lower surface 102b is the distance 166L from the lower surface 102b to the lower end of the second sensor 105 in the thickness direction of the substrate 102. Furthermore, in one example, the lower end of the second sensor 105 is the lower surface 166a of the insulating member 166. In one example, the upper surface 166b of the insulating member 166 is fixed to the lower surface 102b; therefore, the distance 166L is the same as the thickness from the upper surface 166b to the lower surface 166a of the insulating member 166. In one example, the distance 166L can be approximately 0.05 mm to 0.5 m. For instance, the distance 166L can be determined based on the material constituting the insulating member 166. Furthermore, the distance 166L is not limited to the range illustrated above.

Next, the measurement method for the electrostatic capacitance using the aforementioned measuring device 100 will be explained. Figure 11 is a flowchart showing the measurement method using the measuring device. As shown in Figure 11, in one example of the measurement method, firstly, the measuring device 100 is transported (step ST1), and then the transported measuring device 100 is placed (step ST2). As described above, the transport device TU2 in the processing system 1 is controlled by the control unit MC. In one example, the transport device TU2 can transport the workpiece W and the measuring device 100 to the placement area of the electrostatic chuck ESC based on the transport position data sent from the control unit MC. The placement area can be the upper surface of the electrostatic chuck ESC. In steps ST1 and ST2, the measuring device 100 is transported to a position on the mounting area specified by the transport position data using the transfer device TU2. Specifically, the transfer device TU1 transports the measuring device 100 to one of the mounting locking modules LL1 and LL2. Then, based on the transport position data, the transfer device TU2 transports the measuring device 100 from one mounting locking module to any of the process modules PM1 to PM6, placing the measuring device 100 on the mounting area of the electrostatic chuck ESC. On the mounting area, the measuring device 100 is mounted on the upper surface of the electrostatic chuck ESC, which is the object, with the substrate 102 supported by a plurality of second sensors 105. In this state, the lower surface 166a of the insulating components 166 of the plurality of second sensors 105 abuts against the upper surface of the electrostatic chuck ESC. The transport position data can be, for example, pre-defined coordinate data in which the position of the measuring device 100's central axis AX100 coincides with the edge ring ER or the center position of the mounting area.

Next, the electrostatic capacitance is acquired by the measuring device 100 (step ST3). That is, with the measuring device 100 placed on the surface of the electrostatic chuck ESC, a high-frequency signal is applied to a plurality of electrodes, thereby generating a plurality of measured values representing the electrostatic capacitance based on the voltage amplitude of each of the plurality of electrodes. Specifically, the measuring device 100 acquires a plurality of bit values (measured values) corresponding to the magnitude of the electrostatic capacitance between the edge ring ER and the sensing electrodes 161 of the first sensors 104A~104C, and stores the plurality of bit values in the memory device 175. Furthermore, the measuring device 100 acquires a plurality of bit values (measured values) corresponding to the magnitude of the electrostatic capacitance between the mounting area of the electrostatic chuck ESC (object) and the respective sensing electrodes 161 of the second sensors 105A-105C, and stores these multiple bit values in the memory device 175. In an exemplary embodiment, based on the electrostatic capacitance acquired by the first sensors 104A-104C, the offset (error) of the center of the measuring device 100 relative to the center position of the edge ring ER can be derived. Furthermore, based on the electrostatic capacitances acquired by the second sensors 105A-105C, the offset of the center of the measuring device 100 relative to the center of the electrostatic chuck ESC can be derived. This offset can be used, for example, for calibrating transport position data used in the transport process performed by the transport device TU2.

As described above, in one exemplary embodiment, a measuring device 100 is provided. The measuring device 100 includes a substrate 102 having a flat lower surface 102b, a plurality of second sensors 105, and a circuit board 106. The plurality of second sensors 105 are arranged along the edge of the substrate 102 and provide a plurality of electrodes 161 facing the lower surface of the recess 121. The circuit board 106 is mounted on the substrate 102. The circuit board 106 is connected to each of the plurality of second sensors 105. The circuit board 106 assigns high-frequency signals to the plurality of electrodes 161 and generates a plurality of measured values representing electrostatic capacitance based on the voltage amplitude of each of the plurality of electrodes 161. A plurality of second sensors 105 protrude downward from the lower surface 102b of the substrate 102.

In the aforementioned measuring device 100, when there is an object (in one example, an electrostatic chuck ESC) facing a plurality of sensor electrodes 161 toward the lower surface of the recess 121 of the substrate 102, a measured value representing the electrostatic capacitance between each sensor electrode 161 and the object is obtained. This measured value can vary depending on the distance between the sensor electrode 161 and the object. When the object is uneven, some of the plurality of sensors may detach from the object when the measuring device is placed on the object. For example, when the center of the object is convex, it is believed that the periphery of the substrate may partially detach from the object due to the contact between the center of the object and the center of the substrate. In such cases, it is assumed that the distance between the electrodes and the object will differ among the multiple sensors. For example, when the object is an electrostatic chuck (ESC), it is assumed that the surface of the ESC will not be flat due to wear and tear, individual differences, etc. Furthermore, when warping or other defects occur on the substrate 102, it is assumed that even if the measuring instrument 100 is placed on a flat object, the distance between the electrodes and the object will still differ among the multiple sensors. For example, the substrate 102 of the measuring instrument 100 has undergone the prescribed machining for mounting the circuit board 106, etc. Furthermore, it is assumed that the measuring instrument 100 will be used in an environment, for example, approximately 20 to 80 degrees Celsius. It is anticipated that the substrate 102 of the measuring instrument 100 may warp, strain, or otherwise experience these issues due to the aforementioned manufacturing or environmental factors.

In the case of a plurality of second sensors 105 protruding downwards from the lower surface 102b of the substrate 102, as in the example of the measuring device 100, the measuring device 100 mounted on the electrostatic chuck ESC can be supported by the plurality of second sensors 105. Therefore, for example, even if the center of the electrostatic chuck ESC protrudes, contact between the center of the substrate 102 and the center of the electrostatic chuck ESC can be suppressed. Thus, the distance between the sensor electrode 161 and the upper surface of the electrostatic chuck ESC is the same for each of the plurality of second sensors 105. In one example, the distance between sensor electrode 161 and the upper surface of the electrostatic chuck ESC is equal to the distance 166L from the lower surface 102b to the lower end of the second sensor 105. Therefore, differences in measurement conditions between sensors can be suppressed, thereby stabilizing the measurement accuracy of the measuring instrument 100.

In one exemplary embodiment, a plurality of sensor electrodes 161 extend along the extending direction of the lower surface 102b of the substrate 102, and a plurality of second sensors 105 have a plurality of insulating members 166 respectively covering the plurality of sensor electrodes 161. In this configuration, when the measuring device 100 is placed on the electrostatic chuck ESC, the insulating members 166 of the plurality of second sensors 105 are respectively configured to contact the upper surface of the electrostatic chuck ESC.

In one exemplary embodiment, the plurality of insulating components 166 are formed of any one of glass, ceramic, or insulating resin, thus being relatively inexpensive and easy to manufacture.

In one exemplary embodiment, a plurality of recesses 121 are formed on the lower surface 102b of the substrate 102, each respectively accommodating a plurality of second sensors 105. The plurality of second sensors 105, while accommodated in their respective recesses 121, protrude downwards from the lower surface 102b of the substrate 102. In this configuration, the plurality of second sensors 105 can be positioned with high precision within the substrate 102. Furthermore, the thickness of the measuring device 100 can be suppressed from increasing.

In one exemplary embodiment, the plurality of second sensors 105 may be three sensors equally spaced circumferentially along the edge of the substrate 102. In this configuration, the measuring device 100 can be stably supported by the three second sensors 105. Furthermore, when the measuring device 100 is supported by the second sensors 105, the insulating components 166 of all the second sensors 105 abut against the upper surface of the electrostatic chuck (ESC).

The above provides an illustrative description of the embodiments, but the embodiments are not limited to these illustrative embodiments, and various omissions, substitutions, and modifications are possible.

Figure 12, like Figure 10, is a cross-sectional view of another example of a second sensor along the radial direction of the measuring device. In the example of Figure 12, a recess 122 for accommodating the second sensor 105 is formed on the lower surface 102b of the substrate 102. That is, three recesses 122 for accommodating three second sensors 105 are formed at equal intervals in the circumferential direction on the lower surface 102b. The recesses 122 have a shape that can surround the electrodes 161, 162, and 163 when viewed from above. One example of the second sensor 105 has an insulating member 167 covering the electrodes 161, 162, and 163. One example of the insulating member 167 may be plate-shaped. The insulating component 167 may be formed of any of glass, ceramic, or insulating resin. The insulating resin may, for example, be an epoxy resin.

The insulating member 167, viewed from above, has a shape that follows the contour of the recess 121. Electrodes 161, 162, and 163 are embedded in the insulating member 167. That is, the insulating member 167 is disposed between the electrodes 161, 162, and 163 and the top surface of the recess 122, between electrodes 161 and 162, between electrodes 162 and 163, on the outer periphery of the electrode 163, and on the lower surface side of the electrodes 161, 162, and 163. The aforementioned insulating regions 164 and 165 are formed by the insulating member 167. The insulating component 167 is fixed to the substrate 102 with its upper central portion housed within the recess 122 in a vertical direction. The lower portion of the insulating component 167 protrudes from the recess 122 further below the lower surface 102b of the substrate 102. This suppresses deviations in the measurement conditions between the second sensors 105, thereby stabilizing measurement accuracy. Furthermore, in the configuration shown in FIG. 12, the thickness of the portion of the insulating component 167 lower than the electrodes 161, 162, and 163 can be designed with relative freedom. For example, by reducing this thickness, the distance between the electrodes 161, 162, and 163 and the object can be reduced, thereby improving the sensitivity of the second sensor 105.

Furthermore, Figure 13, like Figures 10 and 12, is a cross-sectional view of another example of the second sensor along the radial direction of the measuring device. In the example of Figure 13, a recess 123 for accommodating the second sensor 105 is formed on the lower surface 102b of the substrate 102. That is, three recesses 123 for accommodating three second sensors 105 are formed at equal intervals in the circumferential direction on the lower surface 102b. The recesses 123 have a shape that can surround the electrodes 161, 162, and 163 when viewed from above. The second sensor 105 has an insulating member 168 covering the electrodes 161, 162, and 163. In one example, the insulating member 168 may be generally plate-shaped. The insulating component 168 may be formed of any of glass, ceramic, or insulating resin. The insulating resin may, for example, be an epoxy resin.

The insulating member 168, viewed from above, is shaped along the contour of the recess 123. The insulating member 168 is disposed between electrodes 161 and 162, between electrodes 162 and 163, on the outer periphery of electrode 163, and on the lower surface side of electrodes 161, 162, and 163. That is, electrodes 161, 162, and 163 are disposed on the upper surface side of the insulating member 168. The aforementioned insulating regions 164 and 165 are formed by the insulating member 168. The insulating member 168 is fixed to the substrate 102 with its upper portion, closer to the center in the vertical direction, housed within the recess 123. The lower portion of the insulating component 168 protrudes downward from the recess 123 beyond the lower surface 102b of the substrate 102. This suppresses differences in measurement conditions between the second sensors 105, thereby stabilizing measurement accuracy. Furthermore, in the configuration shown in FIG13, similar to the configuration in FIG12, the thickness of the portion of the insulating component 168 lower than the electrodes 161, 162, and 163 can be designed with relative freedom.

Furthermore, Figure 10 shows an example where a space is formed by the recess 121 and the insulating member 166, but this space can also be filled with an insulating material. The insulating material filling the space can be the same as or different from the material constituting the insulating member 166. When the space is filled with an insulating material, the second sensor 105 can be easily assembled onto the substrate 102. Also, similar to the configurations in Figures 12 and 13, the thickness of the insulating member 166 can be easily reduced.

As explained above, the various embodiments of this invention are described in this specification for illustrative purposes. It should be understood that various modifications can be made without departing from the scope and intent of this invention. Therefore, the various embodiments disclosed in this specification are not intended to be limiting; the true scope and intent are indicated by the appended patent application.

102: Substrate 102b: Lower surface 105: Second sensor (sensor) 121: Recess 161: Sensor electrode (electrode) 162: Shielding electrode 163: Electrode 164: Insulation area 165: Insulation area 166: Insulation component 166a: Lower surface 166b: Upper surface 166L: Distance

Claims (5)

A measuring device comprising: a substrate having a lower surface; a plurality of sensors disposed along the edge of the substrate and providing a plurality of electrodes facing an object facing the lower surface of the substrate; and a circuit board mounted on the substrate and connected to each of the plurality of sensors, the circuit board being configured to impart high-frequency signals to the plurality of electrodes and generate a plurality of measured values representing electrostatic capacitance based on the voltage amplitude of each of the plurality of electrodes; and a plurality of recesses for respectively arranging the plurality of sensors formed on the lower surface of the substrate, wherein the plurality of sensors, when disposed in corresponding recesses, protrude further downward than the lower surface of the substrate. The measuring device of claim 1, wherein the plurality of electrodes extend along the extending direction of the lower surface of the substrate, and the plurality of sensors have a plurality of insulating components that respectively cover the plurality of electrodes. The measuring device of claim 2, wherein the plurality of insulating components are formed of any one of glass, ceramic or insulating resin. The measuring device according to any one of claims 1 to 3, wherein the plurality of sensors are three sensors arranged at equal intervals in the circumferential direction along the edge of the substrate. A method for measuring the electrostatic capacitance between a measuring instrument and an object, the measuring instrument comprising: a substrate having a lower surface; a plurality of sensors disposed along the edge of the substrate and each providing a plurality of electrodes facing the object, the object facing the lower surface of the substrate; and a circuit board mounted on the substrate and connected to each of the plurality of sensors, the circuit board being configured to impart high-frequency signals to the plurality of electrodes and generate a plurality of measured values representing the electrostatic capacitance based on the voltage amplitude of each of the plurality of electrodes; the measuring instrument comprises: a substrate having a lower surface; a substrate having a lower surface; a substrate having a lower surface; and a circuit board having a lower surface; the substrate having a lower surface; and a circuit board having a lower surface; the circuit board ... The lower surface of the substrate has a plurality of recesses for respectively arranging the plurality of sensors, wherein the plurality of sensors, when arranged in the corresponding recesses, protrude further downward than the lower surface of the substrate; and the method includes the following steps: placing the measuring device on the upper surface of the object in such a manner that the measuring device is supported by the plurality of sensors; and, with the measuring device placed on the upper surface of the object, assigning a high-frequency signal to the plurality of electrodes, thereby generating a plurality of measured values representing electrostatic capacitance based on the voltage amplitudes of the plurality of electrodes.