JP6712939B2 - Measuring instrument for capacitance measurement and method of calibrating transfer position data in a processing system using the measuring instrument - Google Patents

Description

Embodiments of the present invention relate to a measuring device for measuring capacitance and a method of calibrating transport position data in a processing system using the measuring device.

2. Description of the Related Art In manufacturing electronic devices such as semiconductor devices, a processing system for processing a disk-shaped workpiece is used. The processing system has a carrying device for carrying the work piece, and a processing device for processing the work piece. A processing apparatus generally has a chamber body and a mounting table provided in the chamber body. The mounting table is configured to support the work piece mounted thereon. The transfer device is configured to transfer the workpiece on the mounting table.

In processing a work piece in a processing apparatus, the position of the work piece on the mounting table is important. Therefore, when the position of the workpiece on the mounting table is deviated from the predetermined position, it is necessary to adjust the transfer device.

The technique described in Patent Document 1 is known as a technique for adjusting the transport device. In the technique described in Patent Document 1, a recess is formed on the mounting table. Further, in the technique described in Patent Document 1, a measuring instrument having a disk shape similar to that of a workpiece and having electrodes for measuring capacitance is used. In the technique described in Patent Document 1, the measuring device is conveyed onto the mounting table by the conveying device, and the measured value of the electrostatic capacitance depending on the relative positional relationship between the concave portion and the electrode is acquired, and the measured value is obtained. The transport device is adjusted to correct the transport position of the workpiece based on the above.

Patent No. 4956328

A plasma processing apparatus may be used as a processing apparatus of the above-mentioned processing system. The plasma processing apparatus includes a chamber body and a mounting table, like the processing apparatus described above. Further, in the plasma processing apparatus, a focus ring is provided on the mounting table so as to surround the edge of the workpiece. The focus ring is an annular plate that extends in the circumferential direction with respect to the central axis and is made of, for example, silicon.

In plasma processing of a workpiece using a plasma processing apparatus, the positional relationship between the focus ring and the workpiece is important. For example, if the disk-shaped work piece is out of position with respect to the focus ring, and the size of the gap between the focus ring and the edge of the work piece varies in the circumferential direction, a large gap will occur. The plasma may invade the inside of the working part to generate particles on the workpiece. Therefore, it is necessary to acquire highly reliable data that reflects the positional relationship between the workpiece and the focus ring transported by the transport device.

In one aspect, a measuring instrument for measuring capacitance is provided. The measuring device includes a base substrate, a plurality of first sensors, one or more second sensors, and a circuit board. The base substrate has a disc shape. A plurality of first sensors are arranged along an edge of the base substrate and provide a plurality of side electrodes, respectively. Each of the one or more second sensors has a bottom electrode provided along the bottom surface of the base substrate. The circuit board is mounted on the base board and is connected to each of the plurality of first sensors and the one or more second sensors. The circuit board provides a high frequency signal to the plurality of side electrodes and the bottom electrode, generates a plurality of first measured values representing capacitance from each of the voltage amplitudes at the plurality of side electrodes, and generates a voltage amplitude at the bottom electrode. Is configured to generate a second measured value representative of the capacitance.

In the measuring device according to one aspect, the plurality of side electrodes provided by the plurality of first sensors are arranged along an edge of the base substrate. When the measuring device is arranged in the area surrounded by the focus ring, the plurality of side electrodes face the inner edge of the focus ring. The plurality of first measured values generated from the voltage amplitudes at the side electrodes represent the capacitance that reflects the distance between each of the plurality of side electrodes and the focus ring. Therefore, according to this measuring device, measurement data reflecting the relative positional relationship between the measuring device simulating the workpiece and the focus ring can be obtained. Further, in this measuring device, the bottom electrode of each of the one or more second sensors is arranged along the bottom surface of the base substrate. The second measurement generated from the voltage amplitude at the bottom electrode represents the capacitance between the bottom electrode and the object below the meter. That is, the second measured value reflects the relative positional relationship between the bottom electrode and the object below the measuring device. Therefore, according to the second measurement value, it is possible to confirm whether or not the measuring device is arranged on the mounting table in the area surrounded by the focus ring. By using such a second measurement value, it becomes possible to confirm the reliability of the above-mentioned first measurement value.

In one embodiment, the bottom electrode of each of the one or more second sensors has a circular shape. Each of the one or more second sensors further comprises a peripheral electrode arranged to surround the bottom electrode. The circuit board is further configured to provide a high frequency signal to the peripheral electrodes and generate a third measurement of capacitance from the voltage amplitude at the peripheral electrodes.

In one embodiment, the one or more second sensors is a plurality of second sensors. The plurality of second sensors are arranged along a circle sharing the central axis of the base substrate.

In one embodiment, each of the one or more second sensors further includes a plurality of electrodes provided on the base substrate so as to extend from the upper surface of the base substrate in the plate thickness direction of the base substrate. The bottom electrode of each of the one or more second sensors is constituted by an end surface on the bottom surface side of the plurality of electrodes.

In one embodiment, each of the one or more second sensors further comprises one or more through electrodes penetrating the base substrate. The bottom electrode of each of the one or more second sensors is connected to the circuit board via the one or more through electrodes.

In one embodiment, the one or more second sensors are three or more second sensors, each of the three or more second sensors having a bottom electrode provided along a bottom surface of the base substrate. Are arranged along a circle that shares the central axis line thereof, and a part of the edge of the bottom electrode of each of the three or more second sensors has an arc shape and extends on the circle.

In another aspect, there is provided a method of calibrating transport position data in a processing system using the above instrument. The processing system includes a processing device and a transfer device. The processing apparatus has a chamber body and an electrostatic chuck. The electrostatic chuck is provided in the chamber provided by the chamber body. The electrostatic chuck has a mounting area having a circular edge. A workpiece is placed on the placement area. The transfer device transfers the workpiece on the placement area based on the transfer position data. This method includes a step of transporting a measuring device to a position on the placement area specified by the transport position data using a transport device, and three or more second sensors of the measuring instrument transported to the placement area. From the step of measuring three or more capacitances and the measured value of the capacitances of three or more, find the error between the position on the mounting area where the measuring instrument is transported and the predetermined transport position on the mounting area. And a step of calibrating the transport position data using the error.

In one embodiment, the curvature of the portion of the edge of the bottom electrode matches the curvature of the edge of the mounting area.

As described above, it is possible to acquire highly reliable data that reflects the positional relationship between the focus ring and the measuring device that imitates the workpiece.

It is a figure which illustrates a processing system. It is a perspective view which illustrates an aligner. It is a figure which shows an example of a plasma processing apparatus. It is a top view which shows an electrostatic chuck. It is a perspective view which illustrates a measuring device. It is a top view which shows the measuring instrument shown in FIG. 5 from the bottom side. It is a perspective view which shows an example of a 1st sensor. FIG. 8 is a sectional view taken along the line VIII-VIII in FIG. 7. 9 is a sectional view taken along line IX-IX in FIG. 8. FIG. FIG. 7 is a sectional view taken along line XX of FIG. 6. It is a figure which illustrates the structure of the circuit board of a measuring device. It is a longitudinal section showing another example of the 1st sensor. It is a figure which shows another example of a 2nd sensor. FIG. 14 is a cross-sectional view taken along line XIV-XIV in FIG. It is a figure which shows another example of a 2nd sensor. It is a figure which shows another example of a 2nd sensor. It is a figure which shows another example of a measuring device. It is sectional drawing which shows an electrostatic chuck typically. It is an enlarged view of the measuring device of FIG. It is a figure which illustrates the structure of the circuit board of the measuring device of FIG. 6 is a flow chart illustrating one embodiment of a method of calibrating transport position data in a processing system. It is a figure which shows the conveyance position of the measuring device with respect to an electrostatic chuck.

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

First, a processing system having a processing device for processing a disk-shaped workpiece and a transport device for transporting a processing object to the processing device will be described. FIG. 1 is a diagram illustrating a processing system. The processing system 1 includes platforms 2a to 2d, containers 4a to 4d, a loader module LM, an aligner AN, load lock modules LL1 and LL2, process modules PM1 to PM6, a transfer module TF, and a control unit MC. The number of the stands 2a to 2d, the number of the containers 4a to 4d, the number of the load lock modules LL1 and LL2, and the number of the process modules PM1 to PM6 are not limited and may be one or more. obtain.

The stands 2a to 2d are arranged along one edge of the loader module LM. The containers 4a to 4d are mounted on the bases 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 is configured to accommodate the workpiece W. The workpiece W has a substantially disc shape like a wafer.

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

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

The sensor 6S is an optical sensor and detects the edge of the workpiece W while the workpiece W is being rotated. The sensor 6S detects the deviation amount of the angular position of the notch WN (or another marker) of the workpiece W with respect to the reference angular position and the deviation amount of the center position of the workpiece W with respect to the reference position from the edge detection result. To detect. The sensor 6S outputs the deviation amount of the angular position of the notch WN and the deviation amount of the center position of the workpiece W to the control unit MC. The control unit MC calculates the amount of rotation of the support base 6T for correcting the angular position of the notch WN to the reference angular position based on the amount of deviation of the angular position of the notch WN. The control unit MC controls the drive device 6D so as to rotate the support base 6T by the rotation amount. Thereby, the angular position of the notch WN can be corrected to the reference angular position. Further, the control unit MC controls the end of the transfer device TU1 when receiving the work W from the aligner AN so that the center position of the work W coincides with a predetermined position on the end effector of the transfer device TU1. The position of the effector is controlled based on the shift amount of the center position of the workpiece W.

Returning to FIG. 2, each of the load lock module LL1 and the load lock module LL2 is provided between the loader module LM and the transfer module TF. Each of the load lock module LL1 and the load lock module LL2 provides a preliminary decompression chamber.

The transfer module TF is connected to the load lock module LL1 and the load lock module LL2 via a gate valve. The transfer module TF provides a decompression chamber capable of decompressing. A transfer device TU2 is provided in this decompression chamber. The transfer device TU2 is, for example, an articulated robot, and is controlled by the control unit MC. The transfer device TU2 is configured to transfer the workpiece W between the load lock modules LL1 to LL2 and the process modules PM1 to PM6 and between any two process modules of the process modules PM1 to PM6. ing.

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

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

The processing system 1 includes the control unit MC as described above. 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, and the like. The series of operations of the processing system 1 described above is realized by the control of each unit of the processing system 1 by the control unit MC according to the program stored in the storage device.

FIG. 3 is a diagram showing an example of a plasma processing apparatus that can be adopted as any of the process modules PM1 to PM6. The plasma processing apparatus 10 shown in FIG. 3 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 the inner wall surface thereof can be subjected to anodizing treatment. The chamber body 12 is grounded for safety.

A substantially cylindrical support portion 14 is provided on the bottom of the chamber body 12. The support portion 14 is made of, for example, an insulating material. The support portion 14 is provided in the chamber body 12 and extends upward from the bottom of the chamber body 12. A mounting table PD is provided in the chamber S provided by the chamber body 12. The mounting table PD is supported by the support portion 14.

The mounting table PD 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 disc shape. The second plate 18b is provided on the first plate 18a and is electrically connected to the first plate 18a.

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

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

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

A plurality of (for example, three) through holes 25 penetrating the mounting table PD are formed in the mounting table PD. Plural (for example, three) lift pins 25a are inserted into these plural through holes 25, respectively. Note that, in FIG. 3, one through hole 25 into which one lift pin 25a is inserted is drawn.

FIG. 4 is a plan view showing the electrostatic chuck ESC that constitutes the mounting table PD. As shown in FIG. 4, the plurality of lift pins 25a are arranged along a plurality of straight lines which are orthogonal to a circle sharing the central axis of the electrostatic chuck ESC, that is, the central axis of the mounting table PD and extending in the vertical direction. There is. The plurality of lift pins 25a may be arranged at equal intervals in the circumferential direction with respect to the central axis. These lift pins 25a are supported by a link that moves up and down by an actuator, for example. The lift pin 25a supports the workpiece W at the tip of the lift pin 25a with its tip protruding above the electrostatic chuck ESC. Then, the lift pin 25a is lowered to place the workpiece W on the electrostatic chuck ESC. Further, after the plasma processing of the workpiece W, the lift pins 25a are lifted to separate the workpiece W from the electrostatic chuck ESC. That is, the lift pins 25a are used for loading and unloading the workpiece W.

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

The plasma processing apparatus 10 also includes an upper electrode 30. The upper electrode 30 is arranged above the mounting table PD so as to face the mounting table PD. The upper electrode 30 is supported on the upper part of the chamber body 12 via an insulating shield 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 the top plate 34 is provided with a plurality of gas discharge 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 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 cooling structure. A gas diffusion space 36 a is provided inside the support 36. A plurality of gas flow holes 36b communicating with the gas discharge holes 34a extend downward from the gas diffusion chamber 36a. Further, the support 36 is formed with a gas introduction port 36c for introducing the processing gas into the gas diffusion chamber 36a, and a gas supply pipe 38 is connected to the gas introduction port 36c.

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

Further, in the plasma processing apparatus 10, the 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 the etching by-product (depot) from adhering to the chamber body 12, and can be formed by coating an aluminum material with ceramics such as yttrium oxide.

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

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

The second high frequency power supply 64 is a power supply that generates a second high frequency for attracting ions to the workpiece W, and generates a high frequency having a frequency within the range of 400 kHz to 13.56 MHz, for example. The second high frequency power supply 64 is connected to the lower electrode LE via the matching unit 68. The matching device 68 has a circuit for matching the output impedance of the second high frequency power supply 64 and the input impedance of 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 the chamber S. Further, the pressure of the chamber S is set to a predetermined pressure by the exhaust device 50. Further, the gas in the chamber S is excited by the first high frequency power from the first high frequency power supply 62. As a result, plasma is generated. Then, the workpiece W is processed by the generated active species. It should be noted that ions may be drawn into the workpiece W by a bias based on the second high frequency of the second high frequency power supply 64, if necessary.

The measuring device will be described below. FIG. 5 is a perspective view illustrating a measuring device. FIG. 6 is a plan view showing the measuring instrument shown in FIG. 5 as viewed 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 the shape of the workpiece W, that is, a substantially disk shape. The diameter of the base substrate 102 is the same as the diameter of the workpiece W, and is, for example, 300 mm. The shape and size of the measuring device 100 are defined by the shape and size of the base substrate 102. Therefore, the measuring instrument 100 has a shape similar to the shape of the workpiece W, and also has a dimension similar to the dimension of the workpiece W. A notch 102N (or another marker) is formed on the edge of the base substrate 102.

The base substrate 102 has a lower portion 102a and an upper portion 102b. The lower portion 102a is a portion located closer to the electrostatic chuck ESC than the upper portion 102b when the measuring device 100 is arranged above the electrostatic chuck ESC. The lower portion 102a of the base substrate 102 is provided with a plurality of first sensors 104A to 104D for measuring capacitance. The number of the first sensors provided in the measuring device 100 may be any number of three or more. The plurality of first sensors 104A to 104D are arranged along the edge of the base substrate 102, for example, at equal intervals on the entire circumference of the edge. Specifically, the front end surface 104f of each of the plurality of first sensors 104A to 104D is provided along the edge of the lower portion 102a of the base substrate 102.

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

Further, the base substrate 102 is provided with a plurality of second sensors 105A to 105C for measuring capacitance. In addition, the number of the second sensors provided in the measuring device 100 may be an arbitrary number of one or more. In one embodiment, the three second sensors 105A to 105C are arranged at equal intervals in the circumferential direction along a circle sharing the central axis AX100 of the base substrate 102. The distance between a bottom electrode of each of the second sensors 105A to 105C, which will be described later, and the central axis AX100 may be substantially equal to the distance between the central axis of the mounting table PD and each of the lift pins 25a.

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

As shown in FIGS. 7 to 9, the first sensor 104 has a front end surface 104f, an upper surface 104t, a lower surface 104b, a pair of side surfaces 104s, and a rear end surface 104r. The front end surface 104f constitutes the front surface of the first sensor 104 in the X direction. The first sensor 104 is mounted on the base substrate 102 of the measuring instrument 100 so that the front end face 104f is oriented in the radial direction with respect to the central axis line AX100 (see FIG. 5). Further, when the first sensor 104 is mounted on the base substrate 102, the front end face 104f extends along the edge of the base substrate 102. Therefore, when the measuring device 100 is arranged on the electrostatic chuck ESC, the front end face 104f faces the inner edge of the focus ring FR.

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

The first sensor 104 has an electrode (side electrode) 143. The first sensor 104 may further include an electrode 141 and an electrode 142. The electrode 141 is made of a conductor. The electrode 141 has a first portion 141a. As shown in FIGS. 7 and 8, the first portion 141a extends in the X direction and the Y direction.

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

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

As shown in FIGS. 7 to 9, the electrodes 141 and 142 are opened on the side (X direction) of the region where the front surface 143 f of the electrode 143 is arranged, and extend so as to surround the periphery of the electrode 143. You may have. That is, the electrodes 141 and 142 may extend above, behind, and laterally of the electrode 143 so as to surround the electrode 143.

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

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

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

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

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

Hereinafter, the second sensor will be described in detail. FIG. 10 is a sectional view taken along line XX of FIG. Note that FIG. 10 shows a state in which the measuring device 100 is supported by the lift pins 25a. Hereinafter, FIG. 5, FIG. 6, and FIG. 10 will be referred to. Each of the second sensors 105A-105C includes a bottom electrode 161. In one embodiment, each of the second sensors 105A-105C further includes peripheral electrodes 162a-162d and penetrating electrodes 165a-165e. The bottom electrode 161 and the peripheral electrodes 162a to 162d are formed along the bottom surface of the base substrate 102. The penetrating electrodes 165a to 165e penetrate the base substrate 102. The bottom electrode 161, the peripheral electrodes 162a to 162d, and the through electrodes 165a to 165e are formed of conductors.

The bottom electrode 161 may have a circular shape. The size of the bottom electrode 161 is approximately the same as the size of the upper end surface of the lift pin 25a, for example. The peripheral electrodes 162a to 162d are arranged on a circle surrounding the bottom electrode 161. Each of the peripheral electrodes 162a to 162d has a planar shape defined by two arcs sharing the center of the bottom electrode 1611 and having different radii. Further, the peripheral electrodes 162a to 162d are arranged in the circumferential direction with respect to the center of the bottom electrode 161. An insulating film 169 is formed on the bottom surface of the base substrate 102. The insulating film 169 covers the bottom electrode 161 and the peripheral electrodes 162a to 162d. The insulating film 169 is made of, for example, SiO ₂ , SiN, Al ₂ O ₃ , or polyimide.

One ends of the plurality of through electrodes 165a to 165e are connected to the peripheral electrodes 162a to 162d and the bottom electrode 161, respectively. The other ends of the plurality of through electrodes 165a to 165e are electrically connected to the circuit board 106 (see FIG. 5). The plurality of through electrodes 165a to 165e may be formed by using, for example, TSV (Through-Silicon Via) technology.

The configuration of the circuit board 106 will be described below. FIG. 11: is a figure which illustrates the structure of the circuit board of a measuring device. As shown in FIG. 11, the circuit board 106 includes a high frequency oscillator 171, a plurality of C/V conversion circuits 172A to 172D, a plurality of C/V conversion circuits 180A to 180O, an A/D converter 173, a processor 174, and a storage device. 175, a communication device 176, and a power supply 177.

Each of the plurality of first sensors 104A to 104D is connected to the circuit board 106 via a corresponding wiring group of the plurality of wiring groups 108A to 108D. Further, each of the plurality of first sensors 104A to 104D is connected to the corresponding C/V conversion circuit among the plurality of C/V conversion circuits 172A to 172D via some wirings included in the corresponding wiring group. Has been done. Further, each of the plurality of second sensors 105A to 105C has a corresponding C/V conversion circuit (in one embodiment, five C/V conversion circuits) among the plurality of C/V conversion circuits 180A to 180O via the plurality of wirings 184. V conversion circuit). Hereinafter, one first sensor 104 having the same configuration as each of the plurality of first sensors 104A to 104D, one wiring group 108 having the same configuration as each of the plurality of wiring groups 108A to 108D, and a plurality of C/V conversion circuits 172A. To 172S, a single C/V conversion circuit 172 having the same configuration, a plurality of second sensors 105A to 105C, a second sensor 105 having the same configuration, and a plurality of C/V conversion circuits 180A to 180O. A C/V conversion circuit 180 having the same configuration as each of the above will be described.

The wiring group 108 includes wirings 181 to 183. One end of the wiring 181 is connected to the pad 151 connected to the electrode 141. The wiring 181 is connected to the ground potential line GL connected to the ground GC of the circuit board 106. Note that the wiring 181 may be connected to the ground potential line GL via the switch SWG. Further, one end of the wiring 182 is connected to the pad 152 connected to the electrode 142, and the other end of the wiring 182 is connected to the C/V conversion circuit 172. Further, one end of the wiring 183 is connected to the pad 153 connected to the electrode 143, and the other end of the wiring 183 is connected to the C/V conversion circuit 172.

The peripheral electrodes 162a to 162d and the bottom electrode 161 of the second sensor 105 are individually connected to the circuit board 106. That is, the penetrating electrodes 165a to 165d connected to the peripheral electrodes 162a to 162d and the penetrating electrode 165e connected to the bottom electrode 161 are connected to the plurality of C/V conversion circuits 180 (one embodiment) via the individual wirings 184. In the form, they are respectively connected to five C/V conversion circuits).

The high frequency oscillator 171 is connected to a power source 177 such as a battery, and is configured to receive power from the power source 177 and generate a high frequency signal. 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 a plurality of output lines. The high frequency oscillator 171 is adapted to give the generated high frequency signal to the wiring 182, the wiring 183, and the wiring 184 via a plurality of output lines. Therefore, the high frequency oscillator 171 is electrically connected to the electrode 142 and the electrode 143 of the first sensor 104, and the high frequency signal from the high frequency oscillator 171 is applied to the electrode 142 and the electrode 143. The high-frequency oscillator 171 is electrically connected to the bottom electrode 161 and the peripheral electrodes 162a to 162d of the second sensor 105, and the high-frequency signal from the high-frequency oscillator 171 is applied to the bottom electrode 161 and the peripheral electrodes 162a to 162d. To be given.

The wiring 182 and the wiring 183 are connected to the input of the C/V conversion circuit 172. That is, the electrodes 142 and 143 of the first sensor 104 are connected to the input of the C/V conversion circuit 172. The bottom electrode 161 and the peripheral electrodes 162a to 162d are connected to the inputs of the plurality of C/V conversion circuits 180, respectively. The C/V conversion circuit 172 and the C/V conversion circuit 180 are configured to generate a voltage signal representing the capacitance of the electrode connected to the input from the voltage amplitude at the input and output the voltage signal. ing. Note that the larger the capacitance of the electrode connected to the C/V conversion circuit 172, the larger the voltage of the voltage signal output by the C/V conversion circuit 172. Similarly, the larger the electrostatic capacitance of the electrode connected to the C/V conversion circuit 180, the larger the voltage of the voltage signal output by the C/V conversion circuit 180.

The inputs of the A/D converter 173 are connected to the outputs of the plurality of C/V conversion circuits 172A to 172D and the plurality of C/V conversion circuits 180A to 180O. Further, the A/D converter 173 is connected to the processor 174. The A/D converter 173 is controlled by the control signal from the processor 174, and output signals (voltage signals) of the plurality of C/V conversion circuits 172A to 172D and output signals of the plurality of C/V conversion circuits 180A to 180O ( Voltage signal) is converted into a digital value. That is, the A/D converter 173 generates a first measurement value representing the capacitance of the electrode 143. The A/D converter 173 also generates a second measurement value representing the capacitance of the bottom electrode 161, and a plurality of third measurement values representing the capacitance of each of the peripheral electrodes 162a to 162d. .. The A/D converter 173 outputs the first measurement value, the second measurement value, and the third measurement value to the processor 174.

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 measurement data described later. Further, another storage device 178 is connected to the processor 174. The storage device 178 is a storage device such as a non-volatile memory, and stores a program read and executed by the processor 174.

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

The processor 174 is configured to control each unit of the measuring instrument 100 by executing the above-mentioned program. For example, the processor 174 supplies the electrode 142, the electrode 143, the bottom electrode 161, and the peripheral electrodes 162a to 162d with a high-frequency signal from the high-frequency oscillator 171, supplies power to the storage device 175 from the power supply 177, and supplies power to the communication device 176. The power supply from 177 is controlled. Further, the processor 174 executes the above-described program to acquire the first to third measurement values, store the first to third measurement values in the storage device 175, and execute the first to third measurements. It is designed to execute transmission of measured values.

In the measuring device 100 described above, the plurality of electrodes 143 (side electrodes) provided by the first sensors 104A to 104D are arranged along the edge of the base substrate 102. In the state where the measuring device 100 is arranged in the region surrounded by the focus ring FR, the plurality of electrodes 143 face the inner edge of the focus ring FR. The plurality of first measurement values generated from the voltage amplitudes at the electrodes 143 represent the capacitance that reflects the distance between each of the plurality of electrodes 143 and the focus ring. The capacitance C is represented by C=εS/d. ε is the permittivity of the medium between the front surface 143f of the electrode 143 and the inner edge of the focus ring FR, S is the area of the front surface 143f of the electrode 143, and d is the front surface 143f of the electrode 143 and the inner edge of the focus ring FR. Can be considered as the distance between. Therefore, according to the measuring instrument 100, measurement data reflecting the relative positional relationship between the measuring instrument 100 imitating the workpiece W and the focus ring FR can be obtained. For example, the plurality of first measurement values obtained by the measuring device 100 become smaller as the distance between the front surface 143f of the electrode 143 and the inner edge of the focus ring FR becomes larger.

Further, in the measuring device 100, the bottom electrodes 161 of the second sensors 105A to 105C are arranged along the bottom surface of the base substrate 102. The second measurement generated from the voltage amplitude at the bottom electrode 161 represents the capacitance between the bottom electrode 161 and the object below the meter 100. That is, the second measurement value reflects the relative positional relationship between the bottom electrode 161 and the object below the measuring device 100. In one embodiment, the second measurement reflects the relative positional relationship between bottom electrode 161 and lift pin 25a, which is an object below meter 100. Specifically, the second measurement value becomes large when the bottom electrode 161 and the tip of the lift pin 25a face each other, and on the other hand, when the position of the bottom electrode 161 deviates from the tip position of the lift pin 25a. Becomes smaller. As described above, the positional relationship between the bottom electrodes 161 of the second sensors 105A to 105C and the central axis AX100 of the measuring instrument 100 is approximately equal to the positional relationship between the central axis of the mounting table PD and each of the lift pins 25a. I am doing it. Therefore, when the second measurement value is equal to or larger than the predetermined value, it can be confirmed that the measuring device 100 is arranged in the region surrounded by the focus ring FR by the lowering of the lift pin 25a. Therefore, according to the second measurement value, it is possible to confirm whether or not the measuring device 100 is arranged on the mounting table PD in the area surrounded by the focus ring FR. By using such a second measurement value, it becomes possible to confirm the reliability of the above-mentioned first measurement value. Therefore, according to the measuring instrument 100, it is possible to acquire highly reliable data that reflects the positional relationship between the measuring instrument 100 imitating the workpiece W and the focus ring FR.

Further, each of the second sensors 105A to 105C is provided with peripheral electrodes 162a to 162d so as to surround the bottom electrode 161. By using the plurality of third measurement values obtained from the voltage amplitudes of the peripheral electrodes 162a to 162d together with the second measurement value, the measuring instrument 100 is placed on the mounting table PD in the area surrounded by the focus ring FR. It is possible to confirm more accurately whether or not it is placed in.

Further, as described above, in the first sensor 104 mounted on the measuring device 100, the electrode 143 (sensor electrode) is provided on the electrode 141, and the electrode 142 is provided between the electrode 141 and the electrode 143. The second part of is interposed. When using the first sensor 104, the switch SWG is closed to set the potential of the electrode 141 to the ground potential, and the high frequency signal is supplied to the electrodes 142 and 143. At this time, the voltage amplitude of the electrode 143 is not affected by the electrostatic capacitance from the direction in which the electrode 141 is provided with respect to the electrode 143, that is, from below the first sensor 104, and the specific direction, that is, the electrode 143. The voltage amplitude reflects the electrostatic capacitance in the direction (X direction) in which the front surface 143f of the is facing. Therefore, according to the first sensor 104, the capacitance can be measured with high directivity in the specific direction.

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

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

Hereinafter, another example of the first sensor that can be mounted on the measuring device 100 will be described. FIG. 12 is a vertical cross-sectional view showing another example of the first sensor. FIG. 12 shows a vertical sectional view of the first sensor 204, and also shows the focus ring FR together with the first sensor 204.

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

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

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

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

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

Hereinafter, another example of the second sensor that can be mounted on the measuring device 100 instead of the second sensors 105A to 105C will be described. 13A is a plan view showing a plurality of electrodes of a second sensor of another example as seen from the bottom side of the measuring instrument, and FIG. 13B is a top view of the second sensor of the second sensor. It is a top view seen from above. Further, FIG. 14 is a cross-sectional view taken along line XIV-XIV in FIG. Note that FIG. 14 shows a state in which the measuring device 100 is supported by the lift pins 25a.

The second sensor 305 includes a plurality of electrodes 365. The plurality of electrodes 365 are provided on the base substrate 102 so as to extend from the upper surface of the base substrate 102 in the plate thickness direction of the base substrate 102. In the second sensor 305, the plurality of electrodes 365 penetrate the base substrate 102. Each of the plurality of electrodes 365 provides an end surface 365 a on the bottom surface side of the base substrate 102. The end surface 365a of the plurality of electrodes 365 constitutes a bottom electrode and a plurality of peripheral electrodes. Specifically, as shown in (a) of FIG. 13, among the end faces 365a of the plurality of electrodes 365, the end faces 365a of some of the electrodes 365 existing in the central circular region 361 form the bottom electrode. ing. Further, the end surfaces 365a of some electrodes 365 existing in the peripheral regions 362a to 362d surrounding the region 361 form peripheral electrodes. In the example shown in FIG. 13, the number of peripheral areas is four. These peripheral regions 362a to 362d are defined by two arcs having different radii, and are arranged in the circumferential direction with respect to the center of the region 361. As shown in FIG. 14, an insulating film 169 is formed on the bottom surface of the base substrate 102. The insulating film 169 covers the end surfaces 365a of the plurality of electrodes 365.

Pattern electrodes 366a to 366e facing the peripheral regions 362a to 362d and the region 361 and having substantially the same shape as the peripheral regions 362a to 362d and the region 361 are formed on the upper surface of the base substrate 102. The electrode 365 providing the end surface 365a in the peripheral region 362a is connected to the pattern electrode 366a. The electrode 365 providing the end surface 365a in the peripheral region 362b is connected to the pattern electrode 366b. The electrode 365 providing the end surface 365a in the peripheral region 362c is connected to the pattern electrode 366c. The electrode 365 that provides the end surface 365a in the peripheral region 362d is connected to the pattern electrode 366d. The electrode 365 that provides the end surface 365a in the region 361 is connected to the pattern electrode 366e. Each of the second sensors 105A to 105C described above requires a step of forming a bottom electrode and a peripheral electrode in addition to the through electrodes 165a to 165e. On the other hand, in the second sensor 305, since the plurality of electrodes 365 extending in the plate thickness direction of the base substrate 102 provide the bottom electrode and the peripheral electrodes similarly to the penetrating electrodes 165a to 165e, the bottom electrode and the peripheral electrode are formed when the second sensor 305 is formed. A separate process of forming the peripheral electrode is unnecessary.

Hereinafter, another example of the second sensor that can be mounted on the measuring instrument 100 instead of the second sensors 105A to 105C will be described. FIG. 15 is a sectional view showing still another example of the second sensor.

The second sensor 405 shown in FIG. 15 has a plurality of electrodes 465. The plurality of electrodes 465 are provided on the base substrate 102 so as to extend from the upper surface of the base substrate 102 in the plate thickness direction of the base substrate 102. In the second sensor 405, the plurality of electrodes 465 provide the end surface 465 a in the middle between the top surface and the bottom surface of the base substrate 102. Similar to the end surfaces 365a of the plurality of electrodes 365 of the second sensor 305, the end surfaces 465a of the plurality of electrodes 465 form a bottom electrode and a plurality of peripheral electrodes. In the measuring device 100 equipped with the second sensor 405, the base substrate 102 may be, for example, a glass substrate. Also in the production of the second sensor 405, the step of separately forming the bottom electrode and the plurality of peripheral electrodes is unnecessary.

Hereinafter, another example of the second sensor that can be mounted on the measuring instrument 100 instead of the second sensors 105A to 105C will be described. FIG. 16 is a sectional view showing still another example of the second sensor.

Similar to the second sensor 305, the second sensor 505 shown in FIG. 16 has a plurality of electrodes 365 arranged in each of the region 361 and the peripheral regions 362a to 362d. The second sensor 505 further includes surrounding electrodes 370a to 370e. The surrounding electrodes 370a to 370e are formed of a conductor and are insulated from the electrode 365 inside the second sensor 505. The surrounding electrode 370a is formed along the bottom surface of the base substrate so as to collectively surround the end surface 365a of the group of electrodes 365 arranged in the peripheral region 362a. A via electrode 371a penetrating the base substrate is connected to the surrounding electrode 370a. The surrounding electrode 370b is formed along the bottom surface of the base substrate so as to collectively surround the end surface 365a of the group of electrodes 365 arranged in the peripheral region 362b. A via electrode 371b penetrating the base substrate is connected to the surrounding electrode 370b. In addition, the surrounding electrode 370c is formed along the bottom surface of the base substrate so as to collectively surround the end surface 365a of the group of electrodes 365 arranged in the peripheral region 362c. A via electrode 371c penetrating the base substrate is connected to the surrounding electrode 370c. In addition, the surrounding electrode 370d is formed along the bottom surface of the base substrate so as to collectively surround the end surface 365a of the group of electrodes 365 arranged in the peripheral region 362d. A via electrode 371d penetrating the base substrate is connected to the surrounding electrode 370d. Further, the surrounding electrode 370e is formed along the bottom surface of the base substrate so as to collectively surround the end face 365a of the group of electrodes 365 arranged in the region 361. A via electrode 371e penetrating the base substrate is connected to the surrounding electrode 370e. A high-frequency oscillator 171 is electrically connected to each of the via electrodes 371a to 371e, and a high-frequency signal is applied to each of the surrounding electrodes 370a to 370e. In the second sensor 505, the end surface 365a of the group of electrodes 365 is shielded from the outside of the surrounding electrode by the surrounding electrode that surrounds the end surface 365a of the group of electrodes 365 among the surrounding electrodes 370a to 370e. Therefore, the directivity of the second sensor 505 is improved in the capacitance measurement.

Although various embodiments have been described above, various modifications can be configured without being limited to the above-described embodiments. For example, the plasma processing apparatus has been illustrated as an example of the process modules PM1 to PM6, but the process modules PM1 to PM6 may be any processing apparatus as long as they use the electrostatic chuck and the focus ring. Further, the plasma processing apparatus 10 described above is a capacitively coupled plasma processing apparatus, but the plasma processing apparatus that can be used as the process modules PM1 to PM6 is an inductively coupled plasma processing apparatus or a surface wave such as a microwave. It can be any plasma processing apparatus, such as the plasma processing apparatus utilized.

Further, in the above-described embodiment, the positional relationship between the bottom electrodes of the plurality of second sensors and the central axis line AX100 of the measuring device 100 substantially matches the positional relationship between the central axis line of the mounting table PD and the lift pins 25a. The positional relationship between the bottom electrodes of the plurality of second sensors and the central axis line AX100 of the measuring device 100 is not limited to this. For example, the distance between each of the bottom electrodes of the plurality of second sensors and the central axis AX100 of the measuring device 100 is substantially equal to the distance between the central axis of the mounting table PD and the edge of the electrostatic chuck. Good.

Hereinafter, a measuring instrument according to such another embodiment will be described. That is, the measuring device in which the distance between each of the bottom electrodes of the plurality of second sensors and the central axis line AX100 of the measuring device is substantially equal to the distance between the central axis line of the mounting table PD and the edge of the electrostatic chuck will be described. To do. It should be noted that the measuring device according to the other embodiment can also be used in the processing system shown in FIG. 1. FIG. 17 is a plan view showing the measuring device from the bottom side. The measuring device 600 shown in FIG. 17 includes a base substrate 102. On the lower portion 102a of the base substrate 102, four first sensors 104A to 104D for measuring capacitance are provided. Further, in the lower portion 102a of the base substrate 102, four second sensors 605A to 605D are provided instead of the second sensors 105A to 105C shown in FIG. In addition, the number of the second sensors provided in the measuring device 600 may be an arbitrary number of three or more. The second sensors 605A to 605D are arranged at equal intervals in the circumferential direction along a circle sharing the central axis AX100 of the base substrate 102. Further, the second sensors 605A to 605D and the first sensors 104A to 104D are alternately arranged in the circumferential direction. Each of the four second sensors 605A to 605D has a bottom electrode 606 provided along the bottom surface of the base substrate 102.

FIG. 18 is a cross-sectional view of the electrostatic chuck, showing a state in which the workpiece is placed on the electrostatic chuck. In one embodiment, the electrostatic chuck ESC has a structure in which an electrode E, which is a conductive film, is arranged between a pair of insulating layers or insulating sheets, and has a substantially disc shape. The electrostatic chuck ESC has a mounting area R on which the workpiece W and the measuring device 600 are mounted. The mounting area R has a circular edge. The workpiece W and the measuring device 600 have an outer diameter larger than the outer diameter of the mounting region R.

FIG. 19 is a partially enlarged view of FIG. 17, showing one second sensor. The edge of the bottom electrode 606 is partially arcuate. That is, the bottom electrode 606 has a planar shape defined by two arcs 606a and 606b having different radii about the central axis AX100. The radially outer circular arc 606b in the bottom electrode 606 of each of the plurality of second sensors 605A to 605D extends on a common circle. Further, the circular arc 606a on the radially inner side of the bottom electrode 606 of each of the plurality of second sensors 605A to 605D extends on another common circle. A part of the curvature of the edge of the bottom electrode 606 matches the curvature of the edge of the electrostatic chuck ESC (mounting region R). In one embodiment, the curvature of the circular arc 606b forming the radially outer edge of the bottom electrode 606 matches the curvature of the edge of the mounting region R of the electrostatic chuck ESC. The center of curvature of the circular arc 606b, that is, the center of the circle on which the circular arc 606b extends shares the central axis AX100.

In one embodiment, each of the second sensors 605A-605D further includes an electrode 607 surrounding the bottom electrode 606. The electrode 607 has a frame shape and surrounds the bottom electrode 606 over the entire circumference thereof. The electrode 607 and the bottom electrode 606 are separated from each other such that the insulating region 608 is interposed therebetween. Also, in one embodiment, each of the second sensors 605A-605D further includes an electrode 609 that surrounds the electrode 607 outside the electrode 607. The electrode 609 has a frame shape and surrounds the electrode 607 over the entire circumference. The electrode 607 and the electrode 609 are separated from each other so that the insulating region 610 is interposed therebetween.

FIG. 20 is a diagram illustrating the configuration of the circuit board of the measuring instrument. The measuring device 600 has a circuit board 106A. The circuit board 106A corresponds to the circuit board 106 in the measuring instrument 100. As shown in FIG. 20, the circuit board 106A includes a high frequency oscillator 171, a plurality of C/V conversion circuits 172A to 172D, a plurality of C/V conversion circuits 680A to 680D, an A/D converter 173, a processor 174, and a storage device. 175, a communication device 176, a power supply 177, and a storage device 178.

The bottom electrodes 606 of the second sensors 605A to 605D are connected to the corresponding C/V conversion circuits of the C/V conversion circuits 680A to 680D via the corresponding wirings 681. The electrodes 607 of the second sensors 605A to 605D are connected to the corresponding C/V conversion circuits of the C/V conversion circuits 680A to 680D via the corresponding wirings 682. The bottom electrode 606 and the electrode 607 of each of the second sensors 605A to 605D are electrically connected to the high frequency oscillator 171 so that a high frequency signal from the high frequency oscillator 171 is applied to them. Each of the C/V conversion circuits 680A to 680D is configured to generate a voltage signal representing the capacitance of the electrode connected to the input from the voltage amplitude at the input and output the voltage signal. Further, the electrodes 609 of the second sensors 605A to 605D are connected to the ground potential line GL via the corresponding wiring 683. Note that the wiring 683 may be connected to the ground potential line GL via the switch SWG.

The inputs of the A/D converter 173 are connected to the outputs of the plurality of C/V conversion circuits 680A to 680D. As a result, the A/D converter 173 generates a digital value (measurement value) representing the capacitance of the bottom electrode 606. The A/D converter 173 outputs the generated digital value to the processor 174.

Hereinafter, a method of calibrating the transport position data in the processing system 1 using the measuring device 600 will be described. As described above, the transfer unit TU2 in the processing system 1 is controlled by the control unit MC. In one embodiment, the transfer device TU2 can transfer the workpiece W and the measuring device 600 onto the mounting area R of the electrostatic chuck ESC based on the transfer position data transmitted from the control unit MC. FIG. 21 is a flow chart showing a method of calibrating the transfer device of the processing system according to the embodiment.

In the method MT shown in FIG. 21, first, the step ST1 is executed. In step ST1, the measuring device 600 is transported by the transport device TU2 to the position on the placement area R specified by the transport position data. Specifically, the transport device TU1 transports the measuring instrument 600 to one of the load lock modules LL1 and LL2. Then, the transfer device TU2 transfers the measuring device 600 from one of the load lock modules to any of the process modules PM1 to PM6 based on the transfer position data, and mounts the measuring device 600 on the electrostatic chuck ESC. Place on the region R. The transport position data is, for example, coordinate data that is predetermined so that the position of the central axis AX100 of the measuring device 600 coincides with the center position of the mounting area R.

In the subsequent step ST2, the measuring device 600 measures the capacitance. Specifically, the measuring device 600 includes a plurality of digital values (corresponding to the magnitude of the capacitance between the mounting region R of the electrostatic chuck ESC and the bottom electrodes 606 of the second sensors 605A to 605D ( The measured value) is acquired and the plurality of digital values are stored in the storage device 175. It should be noted that the plurality of digital values may be acquired at a predetermined timing under the control of the processor 174. In one embodiment, the capacitance measurement by the first sensors 104A to 104D may be performed at the timing of the capacitance measurement by the second sensors 605A to 605D.

In the subsequent step ST3, the measuring instrument 600 is unloaded from the process module and returned to any of the transfer module TF, the load lock modules LL1 and LL2, the loader module LM, and the containers 4a to 4d. In the subsequent step ST4, the error between the position on the mounting area R where the measuring instrument 600 is transferred and the predetermined transfer position on the mounting area R is derived. The predetermined transport position may be the center position of the placement area R. In step ST3 of the embodiment, first, the plurality of digital values stored in the storage device 175 are transmitted to the control unit MC. The plurality of digital values may be transmitted from the communication device 176 to the control unit MC in response to a command from the control unit MC, or a predetermined timing is controlled by the processor 174 based on the count of the timer provided on the circuit board 106A. May be transmitted to the control unit MC. Subsequently, the control unit MC derives the error in the transport position of the measuring device 600 based on the received digital values. In one embodiment, the control unit MC has a data table indicating the relationship between the transport position of the measuring instrument 600 on the mounting area R and the digital value acquired by the second sensors 605A to 605D. In this data table, for example, the relationship between the position of the bottom electrode 606 in each radial direction of the mounting region R and the digital value representing the capacitance of the bottom electrode 606 at the position is registered.

FIG. 22 is a diagram showing the transport position of the measuring instrument with respect to the mounting area of the electrostatic chuck. FIG. 22A shows the positional relationship between the mounting region R and one bottom electrode 606 when the measuring instrument 600 is transported to a predetermined transport position. 22B and 22C show the positional relationship between the placement region R and one bottom electrode 606 when the measuring instrument 600 is transported with a deviation from a predetermined transport position. As shown in (b) of FIG. 22, when the bottom electrode 606 is displaced to the outside of the mounting region R in the radial direction with respect to the mounting region R, the capacitance measured by the bottom electrode 606 is a predetermined value. The capacitance becomes smaller than the capacitance when the measuring instrument 600 is transported to the transport position ((a) in FIG. 22). As shown in (c) of FIG. 22, when the bottom electrode 606 is displaced radially inward of the mounting region R with respect to the mounting region R, the static electricity measured by the bottom electrode 606 is affected by the electrode E. The capacitance is larger than the capacitance when the measuring instrument 600 is transported to a predetermined transport position ((a) in FIG. 22). Therefore, by referring to the data table by using the digital value representing the capacitance of the bottom electrode 606 of each of the second sensors 605A to 605D, the shift amount of each bottom electrode 606 in each radial direction of the mounting region R can be calculated. You can ask. Then, the error in the transport position of the measuring device 600 can be obtained from the deviation amount of the bottom electrode 606 of each of the second sensors 605A to 605D in each radial direction.

When the error in the transfer position of the measuring device 600 is larger than the predetermined threshold value, it is determined in the subsequent step ST5 that the transfer position data needs to be calibrated. In this case, in step ST6, the transport position data is corrected by the controller MC so as to remove the error. Then, in step ST7, the measuring instrument 600 is conveyed again to the same process module as the process module to which the measuring instrument 600 was conveyed immediately before, and the steps ST2 to ST5 are executed again. On the other hand, when the error in the transport position of the measuring device 600 is smaller than the predetermined threshold value, it is determined in step ST5 that calibration of the transport position data is not necessary. In this case, in step ST8, it is determined whether the measuring instrument 600 is to be conveyed to another process module to which the measuring instrument 600 should be conveyed next. Next, when another process module to which the measuring instrument 600 is to be transported remains, in the subsequent step ST9, the measuring instrument 600 is transported to the another process module, and steps ST2 to ST5 are executed. On the other hand, if there is no other process module left to which the measuring instrument 600 is to be transported next, the method MT ends.

Thus, according to the method MT using the measuring device 600, the measuring device 600 provides a plurality of digital values that can be used in the calibration of the transfer position data used for the transfer by the transfer device TU2. By using such a plurality of digital values, it becomes possible to calibrate the transport position data as needed. By using the transport position data thus calibrated for transporting the workpiece W by the transport device TU2, the workpiece W can be transported to a predetermined transport position.

Further, in one embodiment, the bottom electrode 606 of each of the second sensors 605A to 605D is arranged along a circle sharing the central axis line AX100 of the base substrate 102. In this case, when the measuring instrument 600 is transported so that the central axis line AX100 of the base substrate 102 is aligned with the center of the mounting area R which is a predetermined transport position, the bottom portions of the second sensors 605A to 605D are each. Ideally, the digital value representing the capacitance of the electrode 606 will be the same. Therefore, the error in the transport position of the measuring device 600 can be easily obtained.

Further, a part of the edge of the bottom electrode 606 of each of the second sensors 605A to 605D has an arc shape and extends on a circle having a diameter substantially matching the diameter of the mounting region R. .. Further, the curvature of the part of the edge of the bottom electrode 606 matches the curvature of the edge of the mounting region R. Therefore, it is possible to accurately measure the deviation amount in each radial direction between the transport position of the measuring device 600 and the predetermined transport position.

100... Measuring device, 102... Base substrate, 104... 1st sensor, 104A-104D... 1st sensor, 105... 2nd sensor, 105A-105C... 2nd sensor, 143... Electrode (side electrode), 161... Bottom part Electrodes, 162a to 162d... Peripheral electrodes, 165a to 165e... Through electrodes, 106... Circuit board, PD... Mounting table, ESC... Electrostatic chuck, FR... Focus ring, 600... Measuring instrument, 605A-605D... Second sensor, 606... Bottom electrode.

Claims (8)

A measuring instrument for measuring capacitance,
A base substrate having a disc shape,
A plurality of first sensors each providing a plurality of side electrodes arranged along an edge of the base substrate;
One or more second sensors each having a bottom electrode provided along a bottom surface of the base substrate;
A circuit board mounted on the base substrate and connected to each of the plurality of first sensors and the one or more second sensors, wherein a high-frequency signal is applied to the plurality of side electrodes and the bottom electrode. Giving a plurality of first measured values representing capacitance from each of the voltage amplitudes at the plurality of side electrodes, and generating a second measured value representing capacitance from the voltage amplitude at the bottom electrode. The circuit board configured as described above,
Measuring instrument equipped with. The bottom electrode of each of the one or more second sensors has a circular shape,
Each of the one or more second sensors further includes a peripheral electrode disposed to surround the bottom electrode,
The circuit board is further configured to provide the high frequency signal to the peripheral electrodes and generate a third measured value representing capacitance from a voltage amplitude at the peripheral electrodes.
The measuring instrument according to claim 1. The one or more second sensors are a plurality of second sensors,
The plurality of second sensors are arranged along a circle sharing the central axis of the base substrate,
The measuring instrument according to claim 1 or 2. Each of the one or more second sensors further includes a plurality of electrodes provided on the base substrate so as to extend in a plate thickness direction of the base substrate from an upper surface of the base substrate,
The bottom electrode of each of the one or more second sensors is constituted by an end surface of the plurality of electrodes on the side of the bottom surface.
The measuring instrument according to any one of claims 1 to 3. Each of the one or more second sensors further includes one or more through electrodes penetrating the base substrate,
The bottom electrode of each of the one or more second sensors is connected to the circuit board via the one or more through electrodes.
The measuring instrument according to any one of claims 1 to 3. The one or more second sensors are three or more second sensors,
Each of the three or more second sensors has a bottom electrode provided along the bottom surface of the base substrate, and is arranged along a circle sharing the central axis of the base substrate,
Part of an edge of the bottom electrode of each of the three or more second sensors has an arc shape and extends on the circle.
The measuring instrument according to claim 1. A method of calibrating transport position data in a processing system using the measuring instrument of claim 6, comprising:
The processing system is
A chamber main body and an electrostatic chuck, which is provided in the chamber provided by the chamber main body, has a mounting area having a circular edge, and on which a workpiece is mounted is mounted. A processing device having
A transport device that transports the workpiece on the placement area based on the transport position data,
And the method comprises
A step of transporting the measuring device using the transport device to a position on the placement area specified by the transport position data,
Measuring three or more capacitances by the three or more second sensors of the measuring device conveyed to the placement area;
From the measurement values of the three or more capacitances, a step of obtaining an error with respect to a predetermined transport position on the preceding placement region, of the position on the placement region where the measuring device is transported,
Calibrating the transport position data using the error,
Including the method. The method according to claim 7, wherein the curvature of the part of the edge of the bottom electrode matches the curvature of the edge of the placement region.

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