Substrate processing system and method for estimating the height of a ring member

Abstract

The present invention provides a substrate processing system and a method for estimating the height of an annular member. The substrate processing system comprises: a substrate processing device having a mounting table for mounting a substrate and an annular member, and performing a predetermined process on the substrate; a substrate conveying mechanism having a substrate holding portion, holding the substrate by the substrate holding portion and conveying the substrate in and out of the substrate processing device; a distance sensor, measuring the distance from the substrate holding portion; and a control device, wherein the substrate conveying mechanism places a jig substrate having a reference surface that serves as a reference for the height of the annular member on the mounting table on which the annular member is mounted, the distance sensor measures the distance from the substrate holding portion located above the mounting table to the reference surface of the jig substrate, and the distance from the substrate holding portion to the annular member, and the control device estimates the height of the annular member based on the measurement results of the distance to the reference surface and the distance to the annular member.

Description

Technical Field

[0001] The present invention relates to a substrate processing system and a method for estimating the height of a ring-shaped component. Background Art

[0002] Patent document 1 discloses a technology related to the wear detection of consumable parts in semiconductor manufacturing equipment. The chamber disclosed in Patent document 1 is a chamber for processing substrates, and the chamber includes a reference part, consumable parts, a phase arm, a sensor, and a controller. The reference part does not wear during the operation of the chamber, and the consumable parts wear during the operation of the chamber. The conveying arm is used to convey the substrate into the chamber. The sensor is configured to measure a first distance from the sensor to the surface of the consumable part when the conveying arm moves above the consumable part, and to measure a second distance from the sensor to the surface of the reference part when the conveying arm moves above the reference part. The controller is configured to determine the amount of wear of the consumable part based on the first distance and the second distance. In Patent document 1, the reference part is a chuck that holds the substrate.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-50535 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] The technology according to the present disclosure accurately estimates the height of the ring-shaped member placed on the mounting table.

[0008] Solutions for solving problems

[0009] One embodiment of the present disclosure is a substrate processing system, comprising: a substrate processing device having a stage for mounting a substrate and a ring-shaped member arranged to surround the substrate, the substrate processing device performing a predetermined process on the substrate mounted on the stage; a substrate conveying mechanism having a substrate holding portion, the substrate conveying mechanism holding the substrate by the substrate holding portion and conveying the substrate in and out of the substrate processing device; a distance sensor provided on the substrate holding portion, the distance sensor measuring the distance from the substrate holding portion; and a control device, wherein the substrate conveying mechanism places a jig substrate on the stage on which the ring-shaped member is mounted, the jig substrate having a reference surface that serves as a reference for the height of the ring-shaped member, the distance sensor measuring the distance from the substrate holding portion located above the stage to the reference surface of the jig substrate and the distance from the substrate holding portion to the ring-shaped member, and the control device estimating the height of the ring-shaped member based on the measurement results of the distance to the reference surface and the distance to the ring-shaped member.

[0010] Effects of the Invention

[0011] According to the present disclosure, the height of the ring-shaped member placed on the mounting table can be accurately estimated. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a plan view schematically showing the structure of a wafer processing system as a substrate processing system according to the present embodiment.

[0013] Figure 2 It is a longitudinal cross-sectional view schematically showing the structure of the processing device.

[0014] Figure 3 This is a partial enlarged cross-sectional view of the electrostatic chuck.

[0015] Figure 4 It is a side view schematically showing the structure of the wafer transfer mechanism.

[0016] Figure 5 It is a bottom view schematically showing the structure of the fork portion.

[0017] Figure 6 This is a plan view of an example of a jig wafer as a jig substrate used for estimating the height of the focus ring.

[0018] Figure 7 It is a diagram showing the positions of the fork and the distance sensor relative to the stage when estimating the height of the focus ring.

[0019] Figure 8 It is a diagram for explaining another method of estimating the height of the focus ring.

[0020] Fig. 9 This is a diagram showing an example of the estimation result of the height of the focus ring when the fork portion vibrates during movement.

[0021] Fig.10 This is a diagram used to illustrate other effects produced by making the height curve of the focusing ring as in Example 3.

[0022] Fig.11 This is a diagram used to illustrate other effects produced by making the height curve of the focusing ring as in Example 3.

[0023] Fig.12 It is a top view schematically showing another example of a jig wafer.

[0024] Fig.13 It is a cross-sectional view schematically showing another example of the jig wafer.

[0025] Fig.14 It is a diagram showing another example of the wafer transfer mechanism.

[0026] Fig.15 This is a diagram showing an example of the correlation between the measurement result of the distance sensor and the temperature of the distance sensor.

[0027] Fig.16 It is a diagram showing another example of the annular member. DETAILED DESCRIPTION

[0028] For example, in the manufacturing process of semiconductor devices, a substrate processing apparatus uses plasma to perform a predetermined process such as etching on a substrate such as a semiconductor wafer (hereinafter referred to as a "wafer"). The process using plasma, i.e., plasma processing, is performed while the substrate is placed on a mounting table in a processing container after decompression.

[0029] In addition to the substrate, annular components such as a focus ring and a cover ring are placed on the above-mentioned mounting table. The focus ring is an annular component arranged adjacent to the substrate on the mounting table, and the cover ring is an annular component arranged to cover the outer side surface of the focus ring. These focus rings and cover rings are etched and consumed due to exposure to plasma. When the focus rings and cover rings are consumed, sometimes appropriate plasma processing results cannot be obtained. Specifically, for example, when the focus ring is consumed, the shape of the plasma sheath changes, and as a result, sometimes appropriate plasma processing results cannot be obtained.

[0030] Therefore, conventionally, the following operation is performed: a sensor is used to measure or estimate the height of an annular member such as a focus ring mounted on a stage, and the height of the annular member (in other words, the degree of consumption of the annular member) is estimated based on the measurement result or estimation result. For example, the consumption of the focus ring is determined based on the measured distance from the sensor to the surface of the focus ring and the measured distance from the sensor to the surface of the stage (see Patent Document 1), wherein the sensor is provided on a transfer arm of a substrate transfer device that transfers the substrate relative to the processing container.

[0031] However, when the height of an annular member such as a focus ring is estimated based on the distance from the sensor to the surface of the stage (specifically, the substrate mounting surface for mounting the substrate), the height of the focus ring cannot be accurately estimated. For example, sometimes the surface of the stage is intentionally provided with concavities and convexities. In this case, the estimation result of the height of the annular member differs depending on which part of the concave-convex surface of the stage surface forming the concave-convex surface is measured by the sensor. However, when the concave-convex surface is small, it is difficult to select which part of the concave-convex surface of the stage surface is measured by the sensor.

[0032] Therefore, the technology according to the present disclosure accurately estimates the height of the annular member placed on the mounting table.

[0033] Hereinafter, the substrate processing system and the method for estimating the height of the annular member according to the present embodiment will be described with reference to the accompanying drawings. In addition, in the present specification and the accompanying drawings, the same reference numerals are given to elements having substantially the same functional configuration, and repeated descriptions are omitted.

[0034] <Wafer processing system>

[0035] Figure 1 It is a plan view showing the structure of a wafer processing system 1 as a substrate processing system according to the present embodiment.

[0036] Figure 1 The wafer processing system 1 performs a predetermined process such as an etching process on a wafer W as a substrate under reduced pressure using plasma.

[0037] The wafer processing system 1 has a structure in which a carrier station 10 and a processing station 11 are connected as one body, and the carrier station 10 carries in and out a carrier C capable of accommodating a plurality of wafers W, and the processing station 11 is provided with a plurality of types of processing devices for performing the above-mentioned prescribed processing on the wafers W under a reduced pressure environment. The carrier station 10 and the processing station 11 are connected by two load interlock devices 12 and 13.

[0038] The load lock devices 12 and 13 include load lock chambers 12a and 13a configured to switch between an atmospheric pressure state and a vacuum state. The load lock devices 12 and 13 are provided to connect an atmospheric pressure transfer device 20 and a vacuum transfer device 30 described later.

[0039] The carrier station 10 includes an atmospheric pressure transfer device 20 and a carrier mounting table 21. In addition, the carrier station 10 may be provided with an aligner (not shown) for adjusting the orientation of the wafer W.

[0040] The atmospheric pressure transfer device 20 has an atmospheric transfer chamber 22 whose interior is set to an atmospheric pressure environment. The atmospheric transfer chamber 22 is connected to the load lock chambers 12a and 13a of the load lock devices 12 and 13 via gate valves G1 and G2. A transfer mechanism 23 is provided in the atmospheric transfer chamber 22. The transfer mechanism 23 transfers the wafer W between the load lock chambers 12a and 13a under atmospheric pressure.

[0041] The transfer mechanism 23 includes a transfer arm 23a, which is composed of, for example, a multi-jointed arm having a wafer holding portion at the front end thereof for holding the wafer W. The transfer mechanism 23 is configured to transfer the wafer W while holding the wafer W with the transfer arm 23a.

[0042] The carrier stage 21 is provided on the side surface of the atmospheric pressure transfer device 20 opposite to the load lock devices 12 and 13. The wafer W placed in the carrier C on the carrier stage 21 is transferred into and out of the atmospheric transfer chamber 22 by a transfer arm 23a of a transfer mechanism 23 of the atmospheric pressure transfer device 20.

[0043] The processing station 11 includes a vacuum transfer device 30 and processing devices 40 to 43 .

[0044] The vacuum transfer device 30 has a vacuum transfer chamber 31 in which the interior is maintained in a reduced pressure state (vacuum state). The vacuum transfer chamber 31 is connected to the load lock chambers 12a and 13a of the load lock devices 12 and 13 via gate valves G3 and G4. In addition, the vacuum transfer chamber 31 is connected to the vacuum processing chambers 44 to 47 described later via gate valves G5 to G8, respectively. A wafer transfer mechanism 32 as a substrate transfer mechanism for transferring wafers W is provided in the vacuum transfer chamber 31. The wafer transfer mechanism 32 transfers wafers W in and out of the processing devices 40 to 43 via the loading and unloading port 100a described later. The wafer transfer mechanism 32 has a transfer arm 32a. The details of the structure of the wafer transfer mechanism 32 will be described later.

[0045] The processing devices 40 to 43 perform predetermined processing such as film forming processing, diffusion processing, etching processing, etc. on the wafer W under a reduced pressure environment. In addition, in the present embodiment, the processing devices 40 to 43 perform etching processing using plasma. In addition, the processing devices 40 to 43 respectively have vacuum processing chambers 44 to 47 in which the above-mentioned etching processing is performed on the wafer W under a reduced pressure environment.

[0046] The wafer processing system 1 further includes a control device 50. The control device 50 includes a control unit 51 and a display unit 52 as a notification unit.

[0047] The control unit 51 includes, for example, a computer having a CPU, a memory, etc., and the control unit 51 has a storage unit (not shown) for storing various information. The storage unit stores a program for controlling wafer processing in the wafer processing system 1 and a program for estimating the height of a focus ring described later in the processing devices 40 to 43. In addition, the program may be a program recorded in a computer-readable storage medium and installed from the storage medium to the control device 50. In addition, the storage medium may be a temporary storage medium or a non-temporary storage medium. Part or all of the program may be implemented by dedicated hardware (circuit board).

[0048] The display unit 52 is used to display various information and is composed of a display device such as a liquid crystal display or an organic display.

[0049] <Processing device 40>

[0050] Next, use Figure 2 and Figure 3 The processing device 40 will be described. Figure 2 It is a longitudinal cross-sectional view schematically showing the structure of the processing device 40. Figure 3 It is a partially enlarged cross-sectional view of an electrostatic chuck described later.

[0051] like Figure 2 As shown, the processing apparatus 40 includes a processing container 100 , a gas supply unit 120 , an RF (Radio Frequency) power supply unit 130 , and an exhaust system 140 . The processing apparatus 40 further includes a mounting table 101 and a shower head 102 .

[0052] The processing container 100 is a container whose interior is configured to be depressurized, and the processing container 100 constitutes a vacuum processing chamber 44. A wafer W loading and unloading port 100a is formed on the side wall of the processing container 100, and a gate valve G5 as an opening and closing mechanism is provided at the loading and unloading port 100a to open and close the loading and unloading port 100a.

[0053] The mounting table 101 is disposed in a lower region of the plasma processing space 100 s in the processing container 100 .

[0054] The mounting table 101 is configured to support the wafer W in the plasma processing space 100 s. The mounting table 101 includes a lower electrode 103 , an electrostatic chuck 104 , an insulator 105 , and lift pins 106 .

[0055] The lower electrode 103 is formed of a conductive material such as aluminum.

[0056] The electrostatic chuck 104 is provided on the lower electrode 103, and absorbs and holds the wafer W by electrostatic force. The electrostatic chuck 104 has a mounting portion 104a in the center, and the wafer W is mounted on the upper surface of the mounting portion 104a. In the electrostatic chuck 104, the upper surface of the mounting portion 104a is formed higher than the upper surface of the outer peripheral portion of the electrostatic chuck 104. A focus ring 107 as an annular member is mounted on the upper surface of the outer peripheral portion of the electrostatic chuck 104 surrounding the mounting portion 104a.

[0057] The focus ring 107 is a member that is annular (specifically, annular) in a plan view and is arranged to surround the wafer W placed on the placement portion 104a of the electrostatic chuck 104. The focus ring 107 is provided, for example, to improve the uniformity of plasma processing (plasma etching processing in this example). The focus ring 107 is formed of a material appropriately selected according to the plasma processing to be performed, for example, silicon, silicon carbide, or quartz.

[0058] The mounting portion 104a is provided with an electrode 108 for holding the wafer W by electrostatic attraction. The electrostatic chuck 104 has a structure in which the electrode 108 is sandwiched between insulating materials.

[0059] A DC voltage is applied from a DC power supply (not shown) to the electrode 108 , and the wafer W is attracted and held on the upper surface of the mounting portion 104 a of the electrostatic chuck 104 by the electrostatic force generated thereby.

[0060] Furthermore, a heater 109 as a temperature adjustment unit for adjusting the temperature of electrostatic chuck 104 is buried below electrode 108 in electrostatic chuck 104. Heater 109 adjusts the temperature of electrostatic chuck 104 to adjust the temperature of wafer W held by electrostatic chuck 104.

[0061] like Figure 3 As shown, a plurality of protrusions 104b may be provided on the upper surface of the mounting portion 104a of the electrostatic chuck 104. This can prevent the wafer W from continuing to be adsorbed to the electrostatic chuck 104 by the residual adsorption force when the voltage application to the electrode 108 is stopped. The plurality of protrusions 104b are provided, for example, at equal intervals. The protrusions 104b are formed, for example, in a cylindrical shape with a diameter of 300 μm to 500 μm and a height of 5 μm to 30 μm.

[0062] like Figure 2 As shown, the insulator 105 supports the lower electrode 103. The insulator 105 is, for example, a cylindrical member having an outer diameter equal to that of the lower electrode 103, and is made of ceramic or the like, and supports the peripheral side of the lower electrode 103.

[0063] Lift pins 106 are columnar members that are raised and lowered by protruding and retracting relative to the upper surface of mounting portion 104a of electrostatic chuck 104 and are made of, for example, ceramic. Three or more lift pins 106 are provided at intervals along the circumference of electrostatic chuck 104.

[0064] The lift pins 106 are connected to a lift mechanism 110 that lifts the lift pins 106. The lift mechanism 110 includes, for example, a support member 111 that supports the plurality of lift pins 106, and a drive unit 112 that generates a driving force that lifts the support member 111 to lift the plurality of lift pins 106. The drive unit 112 includes a drive source such as a motor that generates the driving force.

[0065] Lifting pins 106 pass through through holes 113 extending downward from the mounting portion of electrostatic chuck 104 and reaching the bottom surface of lower electrode 103 .

[0066] The shower head 102 has a function as an upper electrode and also functions as a shower head for supplying a processing gas from a gas supply unit 120 to the plasma processing space 100s. The shower head 102 is arranged above the mounting table 101 and constitutes a part of the top of the processing container 100. In addition, the shower head 102 has an electrode plate 114 arranged to face the inside of the processing container 100, and a support body 115 provided above the electrode plate 114. In addition, the shower head 102 is supported on the upper part of the processing container 100 via an insulating shielding member 116.

[0067] A plurality of ejection holes 114a are formed in the electrode plate 114. The ejection holes 114a are used to eject a processing gas or the like into the plasma processing space 100s.

[0068] The support body 115 detachably supports the electrode plate 114. A gas diffusion chamber 115a is formed inside the support body 115. A gas flow hole 115b communicating with the ejection hole 114a is formed from the gas diffusion chamber 115a.

[0069] The gas supply unit 120 includes one or more gas supply sources 121 and one or more flow controllers 122. The gas supply unit 120 is configured to supply one or more processing gases or one or more cleaning gases from the corresponding gas supply sources 121 via the corresponding flow controllers 122 to the gas diffusion chamber 115a.

[0070] In the processing device 40, a processing gas from a gas supply source 121 selected from one or more gas supply sources 121 is supplied to the gas diffusion chamber 115a via a flow controller 122. Furthermore, the processing gas supplied to the gas diffusion chamber 115a is supplied to the plasma processing space 100s in a dispersed manner in a spray shape via the gas flow holes 115b and the ejection holes 114a.

[0071] The RF power supply unit 130 includes, for example, two RF generators 131a and 131b and two matching circuits 132a and 132b. The RF generators 131a and 131b are connected to the lower electrode 103 via the matching circuits 132a and 132b, respectively, to supply RF power to the lower electrode.

[0072] The RF generator 131a generates and supplies RF power for generating plasma. The matching circuit 132a has a circuit for matching the output impedance of the RF generator 131a with the input impedance of the load (lower electrode 103).

[0073] The RF generator 131 b generates and supplies RF power (high frequency bias power) for attracting ions to the wafer W. The matching circuit 132 b has a circuit for matching the output impedance of the RF generator 131 b with the input impedance of the load (lower electrode 103 ).

[0074] The exhaust system 140 exhausts the plasma processing space 100 s and includes a vacuum pump. The exhaust system 140 is connected to an exhaust port 100 c provided at the bottom of the processing container 100 .

[0075] The structures of the processing devices 41 to 43 are the same as that of the processing device 40 , and thus the description thereof will be omitted.

[0076] <Wafer Processing>

[0077] Next, wafer processing performed using the wafer processing system 1 configured as described above will be described. The following processing is performed under the control of the control unit 51 .

[0078] First, the wafer W is taken out from the carrier C by the transfer arm 23 a of the transfer mechanism 23 , and the gate valve G1 is opened. Thereafter, the wafer W is carried into the load lock device 12 by the transfer arm 23 a .

[0079] Next, the gate valve G1 is closed to hermetically seal the interior of the load lock device 12 and reduce the pressure.

[0080] When the pressure in the load lock device 12 becomes below a specified pressure, the gate valve G3 is opened, and the wafer W is received from the support portion (not shown) in the load lock device 12 by the transfer arm 32 a of the wafer transfer mechanism 32 and removed from the load lock device 12 .

[0081] Next, after the gate valve G3 is closed, the gate valve for the processing device for the target processing (here, the gate valve G5 for the processing device 40) is opened. Next, the wafer W is moved into the processing container 100 of the processing device 40 after decompression by the transfer arm 32a. Thereafter, the lift pins 106 are raised and lowered to place the wafer W on the electrostatic chuck 104.

[0082] Next, the gate valve G5 is closed to seal the processing container 100 of the processing apparatus 40, and the interior of the processing container 100 is depressurized to a predetermined vacuum level by the exhaust system 140. In addition, a DC voltage is applied to the electrode 108 of the electrostatic chuck 104, thereby the wafer W is attracted and held on the electrostatic chuck 104 by electrostatic force.

[0083] Next, the processing gas is supplied from the gas supply unit 120 to the plasma processing space 100s via the shower head 102. In addition, a high-frequency power for generating plasma is supplied from the RF power supply unit 130 to the lower electrode 103, thereby exciting the processing gas to generate plasma. At this time, a high-frequency power for attracting ions is also supplied from the RF power supply unit 130 to the lower electrode 103. Then, the plasma etching process is performed on the wafer W by the action of the generated plasma.

[0084] When the plasma etching process is finished, the supply of high frequency power from the RF power supply unit 130 and the supply of the processing gas from the gas supply unit 120 are stopped. Next, the application of the DC voltage to the electrode 108 is stopped, and the attraction and holding of the wafer W by the electrostatic chuck 104 is stopped.

[0085] Thereafter, the gate valve G5 of the processing container 100 is opened, and the wafer W is unloaded from the processing container 100 of the processing apparatus 40 in the reverse process of loading the wafer W into the processing container 100 of the processing apparatus 40 , thereby completing a series of wafer processing.

[0086] Furthermore, before a wafer W to be processed next is loaded into the processing container 100 of the processing apparatus 40 , a cleaning gas is supplied to the processing container 100 for cleaning.

[0087] <Wafer transport mechanism>

[0088] Next, use Figure 4 and Figure 5An example of the wafer transfer mechanism 32 will be described. Figure 4 It is a side view schematically showing the structure of the wafer transfer mechanism 32 . Figure 5 It is a bottom view schematically showing the structure of a fork portion described later.

[0089] like Figure 4 As shown, the wafer transfer mechanism 32 includes a transfer arm 32a and a base 32b, and is configured to be able to transfer the wafer W while holding the wafer W with the transfer arm 32a. The number of transfer arms provided in the wafer transfer mechanism 32 may be plural.

[0090] The transfer arm 32a is constituted by, for example, a multi-jointed arm. The base 32b axially supports the base end side of the transfer arm 32a.

[0091] The transfer arm 32 a includes a first articulated arm 201 , a second articulated arm 202 , and a holding arm 203 as a substrate holding portion that holds a wafer W.

[0092] The base end side of the first articulated arm 201 is connected to the base 32 b so as to be rotatable around a vertical axis.

[0093] The second articulated arm 202 is connected to the front end side of the first articulated arm 201 so as to be rotatable around a vertical axis.

[0094] The holding arm 203 is connected to the front end side of the second articulated arm 202 so as to be rotatable around a vertical axis.

[0095] The base 32b is provided with a driving unit (not shown) for driving the lifting, rotation and extension of the conveying arm 32a. The driving unit has a driving source such as a motor, which generates a driving force for lifting the conveying arm 32a, a driving force for rotating the conveying arm 32a horizontally, and a driving force for extending and retracting the conveying arm 32a in the horizontal direction.

[0096] The holding arm 203 has a housing portion 203 a on the base end side and a fork portion 203 b on the front end side.

[0097] The interior of the housing portion 203a is formed as a hollow space.

[0098] For example Figure 5 As shown, the fork 203b has a forked shape whose lateral width is smaller than the diameter of the wafer W. The fork 203b is raised and lowered by the transfer arm 32a, and the fork 203b is moved in the horizontal direction by the transfer arm 32a rotating or extending.

[0099] The transfer arm 32 a of the wafer transfer mechanism 32 is located in the vacuum transfer chamber 31 set to a vacuum atmosphere, and the susceptor 32 b is provided in a space below the vacuum transfer chamber 31 set to an atmospheric atmosphere.

[0100] In addition, similarly to the housing portion 203a at the base end side of the holding arm 203, the interiors of the base 32b, the first joint arm 201, and the second joint arm 202 are all hollow. Furthermore, the space inside the housing portion 203a of the holding arm 203 is connected to the space inside the base 32b which is the air atmosphere through the interiors of the first joint arm 201 and the second joint arm 202.

[0101] The wafer transfer mechanism 32 configured as described above is controlled by the control device 50 .

[0102] And, if Figure 4 As shown, the wafer transfer mechanism 32 is provided with a distance measuring unit 300 .

[0103] The distance measuring unit 300 includes a distance sensor (also referred to as a sensor head) 301 and a unit controller 302 .

[0104] The distance sensor 301 measures the distance from the fork 203b (specifically, the distance sensor 301) to the target point. The distance sensor 301 is provided at the fork 203b. Specifically, for example, Figure 5 As shown, a distance sensor 301a is provided at the front end of one of the bifurcated parts of the fork 203b, and a distance sensor 301b is provided at the front end of the other part.

[0105] The unit controller 302 performs control related to measurement by the distance sensor 301 under the control of the control unit 51 .

[0106] In addition, regarding the distance measurement method using the distance sensor 301, a method that can be measured non-contact in a vacuum atmosphere, such as a light-based method, is adopted. In this case, for example, the distance sensor 301 irradiates the object with light for distance measurement and receives reflected light, and the unit controller 302 measures the distance from the fork 203b (specifically, the distance sensor 301) to the object point based on the light reception result of the distance sensor 301.

[0107] As a more specific example of a method for measuring the distance using the distance sensor 301, a white confocal method can be cited. In the case of the white confocal method, for example, white light supplied from a light source such as an LED (not shown) possessed by the unit controller 302 is irradiated from the distance sensor 301 to the object in such a manner that each wavelength contained in the white light is focused at a different height position. Moreover, only light of a wavelength focused on the object is input to the unit controller 302 via the distance sensor 301 as reflected light. The unit controller 302 calculates the distance from the fork 203b (specifically, the distance sensor 301) to the object point based on the wavelength of the input light. In addition, the distance sensor 301 is arranged in such a manner that the optical axis of the white light is substantially parallel to the vertical direction.

[0108] The white confocal method is just an example, and any method may be used as long as it can perform distance measurement with desired accuracy (for example, a resolution of 15 μm or less in the height direction and a resolution of about 0.1 mm in the horizontal direction).

[0109] The distance sensor 301 and the unit controller 302 are connected via an optical fiber 303, and the above-mentioned distance measurement light (white light) and reflected light are transmitted via the optical fiber 303. The optical fiber 303 is provided with an optical switch 304.

[0110] The cell controller 302 and the optical fiber 304 are installed in a space set to an atmospheric atmosphere outside the vacuum transfer chamber 31 .

[0111] The optical fiber 303 is arranged so as to penetrate the housing portion 203a of the holding arm 203 and the side wall of the base 32b. A feedthrough 303a is formed in the portion of the optical fiber 303 that penetrates the side wall of the housing portion 203a so as not to damage the vacuum atmosphere in the vacuum transfer chamber 31 and the processing container 100 of the processing devices 40 to 43.

[0112] In addition, the optical fiber 303 and the distance sensor 301 are arranged in a manner that does not hinder the holding arm 203 from holding the wafer W. Specifically, the optical fiber 303 is arranged along the lower surface of the holding arm 203, and the distance sensor 301 is arranged on the lower surface of the fork 203b in a manner that the upper portion of the distance sensor 301 does not abut against the wafer W when the wafer W is delivered to the fork 203b of the holding arm 203.

[0113] <Control Unit 51>

[0114] [Example 1 of estimation of height]

[0115] Next, the processing of control unit 51 when estimating the height of focus ring 107 placed on electrostatic chuck 104 will be described. Figure 6This is a plan view of an example of a jig wafer as a jig substrate used for estimating the height of the focus ring 107 . Figure 7 1 and 2 are diagrams showing the positions of the fork 203 b and the distance sensor 301 relative to the stage 101 when estimating the height of the focus ring 107 .

[0116] In the wafer processing system 1, the focus ring 107 mounted on the electrostatic chuck 104 is worn out by the aforementioned wafer processing using plasma. In order to determine the degree of wear of the focus ring 107, in the wafer processing system 1, the control unit 51 estimates the height of the focus ring 107 mounted on the electrostatic chuck 104 based on the measurement result of the distance sensor 301.

[0117] In addition, in the wafer processing system 1, when estimating the height of the focus ring 107, the following formula is used: Figure 6 The jig wafer Wj is the jig wafer Wj shown in the example. The shape and material of the jig wafer Wj when viewed from above are the same as those of the wafer W actually subjected to plasma processing. The jig wafer Wj has a reference plane Ws that serves as a reference for the height of the focus ring 107, and the jig wafer Wj is placed on the electrostatic chuck 104 with the reference plane Ws facing upward. Hereinafter, the surface of the jig wafer Wj that is facing upward when placed on the electrostatic chuck 104 is referred to as the upper surface.

[0118] In one example, the upper surface of the jig wafer Wj is formed to be flat as a whole, and the upper surface as a whole serves as a reference plane Ws.

[0119] In addition, the thickness of the jig wafer Wj may be the same as or different from the thickness of the actual wafer W. In addition, the jig wafer Wj is stored in a carrier C, for example, when not in use.

[0120] When estimating the height of the focus ring 107 , the control unit 51 controls each unit of the wafer processing system 1 (ie, outputs a control signal) so that the wafer transfer mechanism 32 places the jig wafer Wj on the electrostatic chuck 104 of the mounting table 101 on which the focus ring 107 is placed.

[0121] In addition, the control unit 51 controls each unit of the wafer processing system 1 to make the fork 203b Figure 7 As shown, it is located above the mounting table 101 on which the jig wafer Wj and the focus ring 107 are mounted.

[0122] Furthermore, the control unit 51 controls the wafer conveying mechanism 32 and the unit controller 302 (i.e., outputs a control signal) so that the distance sensor 301 measures the distance from the fork 203b located above the stage 101 to the reference plane Ws of the jig wafer Wj, and the distance from the fork 203b (specifically, the distance sensor 301) to the focus ring 107. Specifically, for example, the control unit 51 controls the wafer conveying mechanism 32 and the unit controller 302 so that the distance sensor 301 irradiates the distance measurement light to a predetermined reference position in the reference plane Ws of the jig wafer Wj, and the distance sensor 301 receives the reflected light of the light. Next, the control unit 51 controls the unit controller 302 to calculate the distance Lsp from the fork 203b to the predetermined reference position in the reference plane Ws of the jig wafer Wj based on the light reception result. Similarly, the control unit 51 controls the wafer transfer mechanism 32 and the unit controller 302 so that the distance sensor 301 irradiates the focus ring 107 with light for distance measurement and receives reflected light from the light. Next, the control unit 51 controls the unit controller 302 to calculate the distance Lf from the fork 203b to the focus ring 107 based on the light reception result.

[0123] In addition, below, "the distance from the fork portion 203b to ○○" may be abbreviated as "the distance to ○○".

[0124] The control unit 51 calculates, i.e. estimates, the height of the focus ring 107 based on the distance to the reference plane Ws and the distance to the focus ring 107. For example, the control unit 51 calculates the height H of the focus ring 107 (specifically, the height from the reference plane Ws) based on the following formula (1) using the distance Lsp and the distance Lf.

[0125] H=Lsp-Lf

[0126] [Example 2 of estimation of height]

[0127] Figure 8 This is a diagram for explaining another method of estimating the height of the focus ring 107 .

[0128] When the distance sensor 301 measures the distance to the focus ring 107, the control unit 51 can control the wafer transfer mechanism 32 to move the fork 203b as shown in FIG. Figure 8 The distance sensor 301a is moved as shown in the figure, so that the distance sensor 301a moves in a predetermined direction. The predetermined direction is a direction that crosses the focus ring 107 when viewed from above and is in the direction of insertion and removal of the fork 203b relative to the processing container 100 ( Figure 8 The direction in which the up and down directions intersect.

[0129] Specifically, when the distance to the focus ring 107 is measured by the distance sensor 301a, the control unit 51 can control the wafer transfer mechanism 32 so that the fork 203b rotates around the base end of the fork 203b, thereby moving the distance sensor 301a in a direction that crosses the focus ring 107 when viewed from above. In addition, the control unit 51 can control the transfer arm 32a to rotate around the base end of the transfer arm 32a, thereby moving the distance sensor 301a in a direction that crosses the focus ring 107 when viewed from above.

[0130] While the distance sensor 301a moves in the direction that crosses the focus ring 107 when viewed from above as described above, the control unit 51 controls the control unit controller 302 so that the distance sensor 301a continuously measures the distance Lf to the focus ring 107. The control unit 51 estimates, for example, a height distribution curve of the focus ring 107 in the cross direction based on the continuous measurement results of the distance Lsp to the reference point of the reference surface Ws of the jig wafer Wj and the distance Lf to the focus ring 107. Specifically, the control unit 51 calculates the height H of the focus ring 107 based on the above equation (1) for each measurement point of the distance Lf to the focus ring 107, and creates the height distribution curve of the focus ring 107 in the cross direction based on each calculation result and the position information of each measurement point. In addition, the position information of each measurement point can be calculated based on the angle and size of each structural member of the transfer arm 32a when measuring the distance Lf.

[0131] (Example 3 of height estimation)

[0132] Furthermore, when the fork portion 203b is moved in the above-mentioned traversing direction as in the above-mentioned Example 2, the fork portion 203b may vibrate during the movement. Fig. 9 1 is a diagram showing an example of the estimation result of the height of the focus ring 107 when the fork 203 b vibrates during movement.

[0133] When the height curve D of the focus ring is estimated as in the above-mentioned Example 2 when the fork 203b vibrates, in the curve D, Fig. 9 As shown, the vibration component D2 of the fork portion 203 b may be superimposed on the actual curve D1 of the height of the focus ring 107 .

[0134] The influence of the vibration component D2 of the fork portion 203b can be eliminated as follows.

[0135] That is, Figure 8As shown in FIG. 1 , while the fork 203b moves so that one distance sensor 301a moves in a direction that crosses the focus ring 107 when viewed from above, the one distance sensor 301a continuously measures the distance to the focus ring 107. In parallel with this, the other distance sensor 301b continuously measures the distance to the reference plane Ws of the jig wafer Wj. The control unit 51 estimates the height curve D of the focus ring in the cross direction based on the measurement results of the distance Lft to the focus ring 107 and the measurement results of the distance Lst to the reference plane Ws at each time point during the measurement by the distance sensor 301a and the distance sensor 301b. Specifically, the control unit 51 calculates the height Ht of the focus ring 107 based on the difference between the distance Lft and the distance Lst at each time point during the measurement by the distance sensor 301a and the distance sensor 301b, that is, based on the following formula (2).

[0136] Lst-Lft=Ht…(2)

[0137] The control unit 51 creates a height curve of the focus ring 107 in the traversing direction based on the calculation results of the height Ht at each time point during the measurement by the distance sensors 301a and 301b and the position information of the measurement point obtained by the distance sensor 301a.

[0138] The curve obtained in this way is a curve in which the influence of the vibration component D2 of the fork portion 203b is removed.

[0139] (Other effects of Example 3 of height estimation)

[0140] in addition, Fig.10 and Fig.11 It is a diagram for explaining other effects produced by making the height curve of the focus ring 107 as in the above-mentioned Example 3.

[0141] like Fig.10 As shown in FIG. 1 , sometimes the fork 203b is not parallel to the mounting table 101 but is inclined. In this case, when the height curve D of the focus ring 107 from the reference plane Ws in the above-mentioned traversing direction is estimated using the above-mentioned formula (1), as shown in FIG. Fig.11 As shown, the height curve D differs from the actual curve D1 of the height of the focus ring 107 by an amount corresponding to the inclination θ of the fork portion 203 b with respect to the stage 101 .

[0142] On the other hand, similarly to the above-mentioned Example 3, by creating a height curve of the focus ring 107 from the reference plane Ws in the above-mentioned transverse direction, the influence of the inclination θ of the fork portion 203 b with respect to the mounting table 101 can be eliminated.

[0143] <Estimation method>

[0144] Next, an example of a method for estimating the height of the focus ring 107 using the wafer processing system 1 will be described. In addition, for example, the height of the focus ring 107 is estimated every time a predetermined period of time elapses or every time a predetermined number of wafers are processed.

[0145] (Step S1: Loading the jig wafer Wj)

[0146] First, under the control of the control unit 51 , the jig wafer Wj is placed on the mounting table 101 on which the focus ring 107 is placed, by the wafer transfer mechanism 32 .

[0147] Specifically, the jig wafer Wj is taken out from the carrier C by the transfer arm 23a of the transfer mechanism 23, and the gate valve G1 is opened. Thereafter, the jig wafer Wj is transferred into the load lock device 12 by the transfer arm 23a and delivered to a support portion (not shown) in the load lock device 12.

[0148] Next, the transfer arm 23 a is pulled out from the load-lock device 12 , and the gate valve G1 is closed to hermetically seal the inside of the load-lock device 12 and reduce the pressure.

[0149] When the pressure in the load interlock device 12 becomes below the specified pressure, the gate valve G3 is set to an open state, and the transfer arm 32a of the wafer transfer mechanism 32 receives the fixture wafer Wj from the support part (not shown) in the load interlock device 12 and removes the fixture wafer Wj from the load interlock device 12.

[0150] Next, after the gate valve G3 is set to the closed state, the gate valve for the processing device to be measured for the height of the focus ring 107 (here, the gate valve G5 for the processing device 40) is set to the open state. Next, the fork 203b of the transfer arm 32a holding the jig wafer Wj is inserted into the processing container 100 of the processing device 40 after decompression. Thereafter, the lifting pins 106 are raised and lowered to pull the fork 203b out of the processing container 100, and the jig wafer Wj is placed on the electrostatic chuck 104 of the mounting table 101 in the processing container 100 via the lifting pins 106.

[0151] (Step S2: Determine reference point)

[0152] Next, under the control of the control unit 51 , the distance sensor 301 measures the distance Lsp from the fork 203 b located above the mounting table 101 to a reference point on the reference surface Ws of the jig wafer Wj.

[0153] Specifically, the fork 203b is inserted into the processing container 100 of the processing device 40 again and moved to the top of the mounting table 101. Then, the distance Lsp to the reference point in the reference plane Ws of the jig wafer Wj is measured by the distance sensor 301a and the distance sensor 301b respectively. In addition, the distance Lsp to the reference point in the reference plane Ws when the fork 203b is in an ideal state (there is no tilt of the fork 203b relative to the mounting table 101, the fork 203b is not drooped, etc.), that is, the design value of the above distance Lsp is stored in advance in the storage unit (not shown).

[0154] (Step S3: Measuring the distance to the reference surface Ws and the distance to the focus ring 107)

[0155] Next, under the control of the control unit 51 , the distance sensor 301 measures the distance from the fork 203 b located above the mounting table 101 to the focus ring 107 and the distance from the fork 203 b to the reference surface Ws.

[0156] Specifically, for example, the fork 203b moves so that one distance sensor 301a moves in a direction that crosses the focus ring 107 when viewed from above and is close to the one distance sensor 301a. During this movement, the one distance sensor 301a continuously measures the distance to the focus ring 107, and the other distance sensor 301b continuously measures the distance to the reference surface Ws of the jig wafer Wj.

[0157] Furthermore, for example, the fork 203b moves so that the other distance sensor 301a moves in a direction that crosses the focus ring 107 when viewed from above and is close to the other distance sensor 301a. During this movement, the other distance sensor 301b continuously measures the distance to the focus ring 107, and the distance sensor 301a continuously measures the distance to the reference surface Ws of the jig wafer Wj.

[0158] (Step S4: Estimating the height of the focus ring 107)

[0159] Then, the control unit 51 estimates the height of the focus ring 107 based on the measurement result of step S3 .

[0160] Specifically, for example, the control unit 51 calculates the height Ht of the focus ring 107 based on the difference between the distance Lft and the distance Lst at each time point during the measurement performed on the side of the focus ring 107 close to the distance sensor 301a in step S3, that is, the above formula (2). The control unit 51 creates a height curve of the focus ring 107 in the direction traversed by the distance sensor 301a based on the calculation results of the height Ht at each time point during the measurement performed in step S3 and the position information of the measurement point obtained by the distance sensor 301a.

[0161] In addition, the control unit 51 also creates a height curve of the focus ring 107 in the direction in which the distance sensor 301 b traverses, similarly to the side close to the distance sensor 301 a .

[0162] Furthermore, the height profile of the focus ring 107 produced in step S4 may be corrected based on the distance Lsp to the reference point on the reference surface Ws of the jig wafer Wj measured by the distance sensor 301a and the distance sensor 301b in step S2 and the design value of the distance Lsp. Thus, when the fork portion 203b sags due to its own weight due to changes over time, the influence of the sag can be eliminated based on the estimation result of the height profile of the focus ring 107.

[0163] (Step S5)

[0164] In parallel with step S4 or after step S4 , the jig wafer Wj is unloaded under the control of the control unit 51 .

[0165] Specifically, the fork 203b is pulled out and inserted again into the processing container 100 of the processing apparatus 40, and the lifting pins 106 are raised and lowered to allow the fork 203b to receive the jig wafer Wj. Then, the jig wafer Wj is unloaded from the processing container 100 of the processing apparatus 40 in the reverse process of the process of loading the wafer W into the processing container 100 of the processing apparatus 40.

[0166] <Effects of the present embodiment>

[0167] As described above, in the present embodiment, when estimating the height of the focus ring 107, the jig wafer Wj having the reference plane Ws of the height of the focus ring 107 is placed on the stage 101, specifically, on the upper surface of the placement portion 104a of the electrostatic chuck 104 of the stage 101. The height of the focus ring 107 is estimated based on the measurement results of the distance to the reference plane Ws and the distance to the focus ring 107 obtained by the distance sensor 301 provided on the fork 203b of the wafer transfer mechanism 32. Therefore, even if Figure 3As shown in the figure, a plurality of protrusions 104 b are provided on the upper surface of the mounting portion 104 a of the electrostatic chuck 104 of the mounting table 101 , and the height of the focus ring 107 can also be accurately estimated.

[0168] In addition, the height of the focus ring 107 is important in terms of the height based on the upper surface of the wafer W placed on the upper surface of the mounting portion 104a of the electrostatic chuck 104. This is because the height affects the shape of the plasma sheath and affects the plasma processing results. However, when the plasma processing is repeated, the upper surface of the mounting portion 104a of the electrostatic chuck 104 is sometimes consumed, so the height of the focus ring 107 estimated based on the upper surface of the mounting portion 104a of the electrostatic chuck 104 and the height based on the upper surface of the wafer W placed on the upper surface of the mounting portion 104a of the electrostatic chuck 104 are sometimes not consistent. In contrast, in the present embodiment, the upper surface of the jig wafer Wj placed on the upper surface of the mounting portion 104a of the electrostatic chuck 104 is set as the reference plane Ws of the height of the focus ring 107. Moreover, in the plasma processing, the jig wafer Wj is located outside the processing container 100, so it is not consumed. Therefore, even when the upper surface of the mounting portion 104a of the electrostatic chuck 104 is consumed, the height of the focus ring 107 estimated as in the present embodiment corresponds to the height based on the upper surface of the wafer W mounted on the upper surface of the mounting portion 104a. Therefore, according to the present embodiment, it is possible to accurately understand whether the degree of consumption of the focus ring 107 is within a range that does not affect the shape of the plasma sheath.

[0169] Furthermore, according to the present embodiment, the height of the focus ring 107 can be estimated without opening the inside of the processing chamber 100 to the atmosphere.

[0170] Furthermore, in the present embodiment, the fork 203b is moved so that the distance sensor 301a moves in a direction that crosses the focus ring 107 when viewed from above, and the height curve of the focus ring 107 in the cross direction is estimated. If the life of the focus ring 107 is determined based on the estimation result of the height curve of the focus ring 107 in the cross direction, the following effect is achieved compared to the case where the life of the focus ring 107 is determined based on the estimation result of the height of one point of the focus ring 107. That is, when the consumption of the focus ring 107 varies in the radial direction of the focus ring 107, the life of the focus ring 107 can be determined more accurately.

[0171] In addition, in the present embodiment, the height curves in the above-mentioned traversing direction are obtained for two parts of the focus ring 107, namely, the part close to one distance sensor 301a and the part close to the other distance sensor 301b. If the life of the focus ring 107 is determined based on the height curves of these two parts, the following effect is achieved. That is, when the consumption of the focus ring 107 varies in the circumferential direction of the focus ring 107, the life of the focus ring 107 can be determined more accurately.

[0172] <Other examples of jig wafers>

[0173] Fig.12 and Fig.13 A top view and a cross-sectional view schematically show another example of the jig wafer.

[0174] like Fig.12 and Fig.13 As shown, the jig wafer Wj′ has a plurality of correction surfaces Wr separated from the reference surface Ws by a predetermined distance in the height direction, and the distances of the plurality of correction surfaces Wr from the reference surface Ws in the height direction are different from each other.

[0175] In the example of the drawing, the distance sensor 301 a and the distance sensor 301 b are provided with correction surfaces Wr1 to Wr3 as correction surfaces Wr, respectively.

[0176] The distances of the correction surfaces Wr1 to Wr3 from the reference surface Ws are determined in advance with high precision. In the example of the attached figure, a groove recessed from the reference surface Ws is formed on the jig wafer Wj, and the bottom surface of the groove constitutes the correction surfaces Wr1 to Wr3. However, unlike this example, a convex portion protruding from the reference surface Ws may be formed on the jig wafer Wj, and the correction surfaces Wr1 to Wr3 may be constituted by the top surface of the convex portion.

[0177] The distances of the correction surfaces Wr1 , Wr2 , and Wr3 from the reference surface Ws are, for example, 100 μm, 50 μm, and 25 μm, respectively.

[0178] When the jig wafer Wj' is placed and used, the distance to the reference surface Ws and the distance to the focus ring 107 are measured by the distance sensor 301, and the distance to the plurality of correction surfaces Wr are also measured. For example, the distance to the correction surface Wr1 and the distance to the correction surface Wr2 are measured by the distance sensor 301.

[0179] Furthermore, the control unit 51 corrects the measurement result of the distance sensor 301 based on the measurement results of the distances to the plurality of correction surfaces Wr. Specifically, the control unit 51 obtains, for example, the difference between the distance to the correction surface Wr1 and the distance to the correction surface Wr2 measured by the distance sensor 301. Furthermore, the control unit 51 corrects the measurement result of the distance sensor 301 in such a manner that the difference approaches the design value of the difference. Thus, the distance to the reference surface Ws and the distance to the focus ring 107 can be measured more accurately by the distance sensor 301, and the height of the focus ring 107 can be estimated more accurately. The design value of the difference is pre-stored in a storage unit (not shown).

[0180] Furthermore, when the height of the focus ring 107 is estimated using the jig wafer Wj' as in the aforementioned Example 3, the calibration surface Wr is provided in the following region of the jig wafer Wj'. That is, the calibration surface Wr is provided in a region on the jig wafer Wj' that does not prevent the distance sensors 301a and 301b from continuously measuring the distance to the reference plane Ws when the fork 203b is moved.

[0181] <Other Examples of Wafer Transfer Mechanism 32>

[0182] Fig.14 It is a diagram showing another example of the wafer transfer mechanism 32 .

[0183] As described above, the stage 101 is provided with the heater 109. When the electrostatic chuck 104 needs to be heated by the heater 109 during plasma processing, in order to suppress a decrease in productivity, it is preferable to continue heating by the heater 109 also during the process of estimating the height of the focus ring 107. However, when the heater 109 continues to heat, when the fork 203b is positioned above the stage 101, the temperature of the distance sensor 301 may rise. In addition, the measurement result of the distance sensor 301 may depend on the temperature. In this case, the height of the focus ring 107 estimated based on the measurement result of the distance sensor 301 is affected by the temperature.

[0184] To avoid this situation, Fig.14 As shown, a temperature sensor 401 for measuring the temperature of the distance sensor 301 may be provided, and the temperature of the distance sensor 301 when the distance sensor 301 is measuring is measured by the temperature sensor 401. Furthermore, the control unit 51 may correct the measurement result of the distance sensor 301 based on the measurement result of the temperature of the distance sensor 301 when the distance sensor 301 is measuring.

[0185] For example Fig.14As shown, the temperature sensor 401 is provided near the distance sensor 301. For example, the temperature sensor 401 is provided at a position on the lower surface of the fork 203b adjacent to the distance sensor 301. When two distance sensors, namely, the distance sensor 301a and the distance sensor 301b, are provided as the distance sensor 301, for example, the temperature sensor 401 is provided for each of the distance sensor 301a and the distance sensor 301b.

[0186] The temperature measurement result of the temperature sensor 401 is sent to the control unit 51 via the gateway board 402. The gateway board 402 is accommodated in the storage portion 203a of the holding arm 203. The gateway board 402 and the temperature sensor 401 are connected via the wiring 403, and the gateway board 402 and the control unit 51 are connected via the communication line 404.

[0187] The wiring 403 is arranged to pass through the bottom wall of the receiving portion 203a of the holding arm 203. A feedthrough 403a is formed at the portion of the wiring 403 passing through the bottom wall of the receiving portion 203a so as not to damage the vacuum atmosphere in the vacuum transfer chamber 31 and the processing container 100 of the processing apparatuses 40 to 43.

[0188] When the temperature sensor 401 is used, for example, when the distance sensor 301 measures the distance to the focus ring 107 and the reference surface Ws, the temperature of the distance sensor 301 at each measurement time point is also measured by the temperature sensor 401. Specifically, for example, as in the aforementioned Examples 2 and 3, when the distance sensor 301a continuously measures the distance while the fork 203b is moved, the temperature of the distance sensor 301 at each distance measurement time point is also measured by the temperature sensor 401. In addition, hereinafter, "continuously measuring the distance by the distance sensor 301a while the fork 203b is moved" is referred to as "scanning distance measurement by the distance sensor 301a".

[0189] In addition, when the temperature sensor 401 is used, the distance to the predetermined portion of the jig wafer Wj or the jig wafer Wj' is measured at least twice by the distance sensor 301 at intervals, and the temperature of the distance sensor 301 at each measurement time point is measured by the temperature sensor 401. Specifically, for example, before and after the scanning distance measurement by the distance sensor 301a, the distance to the calibration surface Wr1 of the jig wafer Wj' is measured by the distance sensor 301a, and the temperature of the distance sensor 301a at each measurement time point is acquired by the temperature sensor 401.

[0190] The control unit 51 obtains the correlation between the measurement result of the distance sensor 301 and the temperature of the distance sensor 301 based on the at least two measurement results obtained by measuring the distance to the predetermined portion of the jig wafer Wj or the jig wafer Wj′ by the distance sensor 301 and the measurement result of the temperature of the distance sensor 301 at each measurement time point. Specifically, for example, Fig.15 As shown, the control unit 51 obtains the above-mentioned correlation (i.e., correction formula) R based on the distance Lt1 to the position of the correction surface Wr1 measured by the distance sensor 301a before the distance sensor 301a performs scanning distance measurement and the temperature T1 during the measurement, and the distance Lt2 to the correction surface Wr1 measured by the distance sensor 301a after the distance sensor 301a performs scanning distance measurement and the temperature T2 during the measurement.

[0191] Furthermore, the control unit 51 corrects the measurement result of the distance from the focus ring 107 to the reference surface Ws measured by the distance sensor 301 at each measurement time point based on the obtained correlation and the temperature of the distance sensor 301 at each measurement time point. Figure 5 The measurement result of the distance sensor 301a at each measurement time point in the scanning distance measurement is corrected by using the correlation R and the temperature of the distance sensor 301a at each measurement time point in the scanning distance measurement.

[0192] If the height of the focus ring 107 is calculated / estimated based on the measurement result of the distance sensor 301 a after correction, the influence of the temperature change during the measurement of the distance sensor 301 can be eliminated.

[0193] In addition, when the temperature sensor 401 is provided and the jig wafer Wj' is used, the thermal expansion of the depth of the groove of the jig wafer Wj' is very small compared to the temperature change of the measurement result of the distance sensor 301, so the influence on the measurement result of the distance sensor 301 is small and can be ignored. However, since the temperature of the jig wafer Wj' can be estimated based on the set temperature of the heater 109, the measurement result obtained by measuring the depth of the groove of the jig wafer Wj' (i.e., the distance to the correction surfaces Wr1 to Wr3) by the distance sensor 301a can be corrected based on the estimated result. If the height of the focus ring 107 is calculated / estimated based on the measurement result of the distance sensor 301a after the correction, the influence of the thermal expansion of the jig wafer Wj' can be eliminated.

[0194] <Other Examples of Ring-Shaped Members>

[0195] Fig.16 It is a diagram showing another example of the annular member.

[0196] In addition to the focus ring 107, the mounting table 101 may also be provided with Fig.16 As shown, a cover ring 500 as an annular member is also placed, and the cover ring 500 is arranged so as to cover the outer surface of the focus ring 107. The technology disclosed in the present disclosure can also be applied to estimating the height of the cover ring 500 placed on the mounting table 101.

[0197] The embodiments disclosed herein are to be considered in all respects as illustrative and non-restrictive. The embodiments described above may be omitted, replaced, or modified in various ways without departing from the appended claims and the gist thereof.

[0198] Description of Reference Numerals

[0199] 1: wafer processing system; 32: wafer transfer mechanism; 40-43: processing device; 101: mounting table; 107: focusing ring; 203b: fork; 301, 301a, 301b: distance sensor; 500: cover ring; Lf: distance to focusing ring; Lft: distance to focusing ring; Lsp: distance to reference plane; Lst: distance to reference plane; W: wafer; Wj: fixture wafer; Wj': fixture wafer; Ws: reference plane.

Claims

1. A substrate processing system comprising: A substrate processing device comprising a mounting table for mounting a substrate and a ring-shaped member arranged in a manner to surround the substrate, wherein the substrate processing device performs a predetermined process on the substrate mounted on the mounting table; A substrate transport mechanism having a substrate holding portion, the substrate transport mechanism holds a substrate by the substrate holding portion and transports the substrate in and out of the substrate processing device; a distance sensor disposed on the substrate holding portion, the distance sensor being used to measure the distance from the substrate holding portion; as well as Control device, The substrate conveying mechanism places a jig substrate on the placing table on which the annular member is placed, and the jig substrate has a reference surface that serves as a reference for the height of the annular member. The distance sensor measures the distance from the substrate holding portion located above the mounting table to the reference surface of the jig substrate and the distance from the substrate holding portion to the annular member. The control device estimates the height of the annular member based on the measurement results of the distance to the reference surface and the distance to the annular member, The distance sensor continuously measures the distance from the substrate holding portion to the annular member while the substrate holding portion moves above the mounting table so that the distance sensor moves in a direction crossing the annular member when viewed from above. The control device estimates a height distribution of the annular member in the traversing direction based on a measurement result of the distance to the reference surface and continuous measurement results of the distance to the annular member.

2. The substrate processing system according to claim 1, characterized in that: At least two distance sensors are provided on the substrate holding portion, During the period when the substrate holding portion moves above the mounting table so that one of the distance sensors moves in the direction crossing the annular member when viewed from above, the one distance sensor continuously measures the distance from the substrate holding portion to the annular member, and the other distance sensors continuously measure the distance from the substrate holding portion to the reference surface of the jig substrate, The control device estimates the height distribution of the annular member in the traversing direction based on the measurement results of the distance to the reference plane and the measurement results of the distance to the annular member at each time point during the measurement by the one distance sensor and the other distance sensor.

3. The substrate processing system according to claim 1 or 2, characterized in that: The jig substrate has a plurality of calibration surfaces that are at different predetermined distances from the reference surface, and the plurality of calibration surfaces are at different distances from the reference surface in a height direction. The distance sensor measures the distance from the substrate holding portion to each of the plurality of calibration surfaces of the jig substrate. The control device corrects the measurement result of the distance sensor based on the measurement result of the distance to each of the plurality of calibration surfaces.

4. The substrate processing system according to claim 1 or 2, characterized in that: A temperature sensor is further provided, wherein the temperature sensor is used to measure the temperature of the distance sensor. The control device corrects the measurement result of the distance sensor based on the measurement result of the temperature of the distance sensor when the distance sensor performs measurement.

5. The substrate processing system according to claim 4, characterized in that: The distance sensor measures the distance from the substrate holding portion to a predetermined portion of the jig substrate at least twice. The temperature sensor measures the temperature of the distance sensor at each time point when the distance sensor measures the distance to the predetermined portion. The control device acquires a correlation between a measurement result of the distance sensor and a temperature of the distance sensor based on at least two measurement results of the distance to the predetermined portion and a temperature of the distance sensor at each time point when the measurement is performed, The control device corrects the measurement result of the distance sensor based on the temperature of the distance sensor when the measurement is performed and the correlation.

6. The substrate processing system according to claim 1 or 2, characterized in that: The annular member is at least one of a focus ring disposed so as to be adjacent to the substrate on the mounting table and a cover ring disposed so as to cover the outer side surface of the focus ring.

7. A method for estimating the height of a ring-shaped member, for estimating the height of a ring-shaped member in a substrate processing system, The substrate processing system comprises: A substrate processing device comprising a mounting table for mounting a substrate and the annular member arranged in a manner to surround the substrate, the substrate processing device performing a predetermined process on the substrate mounted on the mounting table; a substrate transport mechanism having a substrate holding portion, the substrate transport mechanism holding a substrate by the substrate holding portion and transporting the substrate in and out of the substrate processing apparatus; and a distance sensor disposed on the substrate holding portion, the distance sensor being used to measure the distance from the substrate holding portion, The method for estimating the height of the annular member comprises the following steps: The jig substrate is placed on the placing table on which the annular member is placed by the substrate conveying mechanism, wherein the jig substrate has a reference surface that serves as a reference for the height of the annular member; Measuring the distance from the substrate holding portion located above the mounting table to the reference surface of the jig substrate and the distance from the substrate holding portion to the annular member by the distance sensor; as well as estimating the height of the annular member based on the measurement results of the distance to the reference surface and the distance to the annular member, wherein, while the substrate holding portion moves above the mounting table so that the distance sensor moves in a direction that crosses the annular member when viewed from above, the distance sensor continuously measures the distance from the substrate holding portion to the annular member, The height distribution of the annular member in the traversing direction is estimated based on the measurement result of the distance to the reference surface and the continuous measurement results of the distance to the annular member.

Images