SUBSTRATE PROCESSING SYSTEM AND METHOD FOR ESTIMATING HEIGHT OF ANNULAR MEMBER

Abstract

To accurately estimate the height of an annular member placed on a placement table.SOLUTION: A substrate processing system comprises: a substrate processing apparatus that has a placement table on which a substrate and an annular member arranged to surround the substrate are placed, and executes predetermined processing on the substrate placed on the placement table; a substrate conveying mechanism that has a substrate holding unit and carries in and out the substrate with respect to the substrate processing apparatus while holding the substrate with the substrate holding unit; a distance sensor that is provided on the substrate holding unit and measures the distance from the substrate holding unit; and a control unit. The substrate conveying mechanism places, on the placement table on which the annular member is placed, a jig substrate having a reference plane to be a reference of the height of the annular member. The distance sensor measures the distance from the substrate holding unit located above the placement table to the reference plane of the jig substrate and the distance from the substrate holding unit to the annular member. The control unit estimates the height of the annular member based on results of measurement of the distance to the reference plane and the distance to the annular member.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present disclosure relates to a substrate processing system and a method for estimating the height of an annular member. [Background technology]

[0002] Patent Document 1 discloses a technology for detecting wear of consumable parts in semiconductor manufacturing equipment. The chamber disclosed in Patent Document 1 is a chamber for processing substrates, and includes a reference part, a consumable part, a phase arm, a sensor, and a controller. The reference part does not wear during operation of the chamber, and the consumable part wears during operation of the chamber. The transfer arm is for transferring the substrate into the chamber. The sensor is configured to measure a first distance from the sensor to a surface of the consumable part when the transfer arm moves over the consumable part, and measures a second distance from the sensor to a surface of the reference part when the transfer arm moves over 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. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-50535 A Summary of the Invention [Problem to be solved by the invention]

[0004] The technology according to the present disclosure accurately estimates the height of an annular component placed on a mounting table. [Means for solving the problem]

[0005] One aspect of the present disclosure includes a substrate processing apparatus having a mounting table on which a substrate and an annular member arranged to surround the substrate are mounted, the substrate processing apparatus performing a predetermined process on the substrate mounted on the mounting table, a substrate transport mechanism having a substrate holding section and holding a substrate with the substrate holding section and transporting the substrate into and out of the substrate processing apparatus, a distance sensor provided on the substrate holding section and measuring a distance from the substrate holding section, and a control device, the substrate transport mechanism placing a fixture substrate having a reference surface serving as a reference for the height of the annular member on the mounting table on which the annular member is mounted, the distance sensor measuring a distance from the substrate holding section located above the mounting table to the reference surface of the fixture substrate, Get away measurement and while the substrate holder is moving above the stage so that the distance sensor moves in a direction crossing the annular member in a plan view, the distance from the substrate holder to the annular member is continuously measured. The control device determines the distance to the reference surface. Measurement results and the distance to the annular member Continuous Based on the measurement results, In the transverse direction The height of the annular member Distribution of A substrate processing system is provided. Effect of the Invention

[0006] According to the present disclosure, the height of an annular member placed on a mounting table can be accurately estimated. [Brief description of the drawings]

[0007] [Figure 1] 1 is a plan view showing an outline of a configuration of a wafer processing system as a substrate processing system according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a vertical cross-sectional view showing an outline of the configuration of the processing apparatus. [Diagram 3] FIG. 2 is a partially enlarged cross-sectional view of the electrostatic chuck. [Figure 4] FIG. 2 is a side view illustrating a schematic configuration of a wafer transport mechanism. [Diagram 5] FIG. 2 is a bottom view showing an outline of the configuration of the fork. [Figure 6] FIG. 2 is a plan view of an example of a jig wafer serving as a jig substrate used for estimating the height of a focus ring. [Figure 7]13A and 13B are diagrams illustrating positions of a fork and a distance sensor relative to the mounting table when estimating the height of a focus ring. [Figure 8] 13A and 13B are diagrams for explaining another mode for estimating the height of the focus ring. [Figure 9] 13A and 13B are diagrams illustrating an example of an estimation result of the height of the focus ring when the fork vibrates during movement. [Figure 10] FIG. 13 is a diagram for explaining another effect obtained by creating a profile of the height of the focus ring in the manner of Example 3. [Figure 11] FIG. 13 is a diagram for explaining another effect obtained by creating a profile of the height of the focus ring in the manner of Example 3. [Figure 12] FIG. 13 is a plan view illustrating another example of the jig wafer. [Figure 13] FIG. 11 is a cross-sectional view illustrating another example of the jig wafer. [Figure 14] FIG. 13 is a diagram showing another example of a wafer transport mechanism. [Figure 15] 11 is a diagram showing an example of a correlation between a measurement result by a distance sensor and a temperature of the distance sensor; FIG. [Figure 16] 13A and 13B are diagrams illustrating other examples of the annular member. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] For example, in a manufacturing process for semiconductor devices, a substrate processing apparatus performs a predetermined process such as an etching process using plasma on a substrate such as a semiconductor wafer (hereinafter referred to as a "wafer") This process using plasma, i.e., plasma processing, is performed in a state where the substrate is placed on a mounting table in a processing chamber whose pressure is reduced.

[0009] In addition to the substrate, annular members such as a focus ring and a cover ring are placed on the above-mentioned mounting table. The focus ring is an annular member arranged adjacent to the substrate on the mounting table, and the cover ring is an annular member arranged to cover the outer surface of the focus ring. The focus ring and the cover ring are etched and worn out by exposure to plasma. When the focus ring or the cover ring is worn out, appropriate plasma processing results may not be obtained. Specifically, for example, when the focus ring is worn out, the shape of the plasma sheath changes, and as a result, appropriate plasma processing results may not be obtained.

[0010] For this reason, a sensor is used to measure or estimate the height of an annular member such as a focus ring placed on a mounting table, and the height of the annular member (in other words, the degree of wear of the annular member) is estimated from the measurement or estimation result. For example, the amount of wear of the focus ring is determined based on the measured distance from a sensor provided on a transport arm of a substrate transport device that transports substrates to and from a processing vessel to the surface of the focus ring and the measured distance from the sensor to the surface of the mounting table (see Patent Document 1).

[0011] 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 mounting table (specifically, the substrate mounting surface on which the substrate is mounted), the height of the focus ring may not be accurately estimated. For example, the surface of the mounting table may be intentionally uneven. In this case, the estimated result of the height of the annular member may differ depending on which part of the uneven surface that forms the unevenness of the mounting table surface is measured by the sensor. However, when the unevenness is small, it is difficult to select which part of the uneven surface of the mounting table surface is measured by the sensor.

[0012] Therefore, the technology disclosed herein accurately estimates the height of the annular component placed on the mounting table.

[0013] Hereinafter, a substrate processing system and a method for estimating the height of an annular member according to the present embodiment will be described with reference to the drawings. In this specification and the drawings, elements having substantially the same functional configurations are denoted by the same reference numerals, and duplicated descriptions will be omitted.

[0014] <Wafer processing system> FIG. 1 is a plan view showing an outline of the configuration of a wafer processing system 1 as a substrate processing system according to this embodiment.

[0015] A wafer processing system 1 in FIG. 1 performs a predetermined process, such as an etching process, on a wafer W as a substrate under reduced pressure using plasma. This wafer processing system 1 has a configuration in which a carrier station 10, into which a carrier C capable of accommodating a plurality of wafers W is loaded and unloaded, and a processing station 11 equipped with a plurality of various processing devices that perform the above-mentioned predetermined processing on the wafers W under reduced pressure are integrally connected. The carrier station 10 and the processing station 11 are connected via two load lock devices 12 and 13.

[0016] The load lock devices 12 and 13 have load lock chambers 12a and 13a that are configured so that the interior of the chambers can be switched between an atmospheric pressure state and a vacuum state. The load lock devices 12 and 13 are provided so as to connect an atmospheric pressure transfer device 20 and a vacuum transfer device 30, which will be described later.

[0017] The carrier station 10 includes an atmospheric pressure transfer device 20 and a carrier mounting table 21. The carrier station 10 may further include an aligner (not shown) for adjusting the orientation of the wafer W.

[0018] The atmospheric pressure transfer device 20 has an atmospheric transfer chamber 22 whose interior is kept under atmospheric pressure. The atmospheric transfer chamber 22 is connected to the load lock chambers 12a, 13a of the load lock devices 12, 13 via gate valves G1, 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, 13a under atmospheric pressure.

[0019] The transfer mechanism 23 has a transfer arm 23a, and the transfer arm 23a is, for example, configured as a multi-joint arm having a wafer holding part at its tip for holding the wafer W. The transfer mechanism 23 is configured to transfer the wafer W while holding it with the transfer arm 23a.

[0020] The carrier mounting table 21 is provided on the side of the atmospheric pressure transfer device 20 opposite to the load lock devices 12 and 13. The wafer W in the carrier C mounted on the carrier mounting table 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.

[0021] The processing station 11 includes a vacuum transfer device 30 and processing devices 40-43.

[0022] The vacuum transfer device 30 has a vacuum transfer chamber 31 whose interior is kept in a reduced pressure state (vacuum state). The vacuum transfer chamber 31 is connected to the load lock chambers 12a, 13a of the load lock devices 12, 13 via gate valves G3, G4. The vacuum transfer chamber 31 is also connected to the vacuum processing chambers 44-47, which will be described later, via gate valves G5-G8, respectively. A wafer transfer mechanism 32 is provided in the vacuum transfer chamber 31 as a substrate transfer mechanism for transferring the wafer W. The wafer transfer mechanism 32 transfers the wafer W into and out of the processing devices 40-43 via a transfer port 100a, which will be described later. The wafer transfer mechanism 32 has a transfer arm 32a. The configuration of the wafer transfer mechanism 32 will be described in detail later.

[0023] The processing apparatuses 40 to 43 perform predetermined processes, such as a film formation process, a diffusion process, an etching process, etc., on the wafer W under reduced pressure. In this embodiment, the processing apparatuses 40 to 43 perform an etching process using plasma. The processing apparatuses 40 to 43 each have a vacuum processing chamber 44 to 47 in which the above-mentioned etching process is performed on the wafer W under reduced pressure.

[0024] Furthermore, the wafer processing system 1 includes a control device 50. The control device 50 includes a control unit 51 and a display unit 52 serving as a notification unit.

[0025] Control unit 51 includes a computer equipped with, for example, a CPU and a memory, and has a storage unit (not shown) for storing various information. The storage unit stores a program for controlling wafer processing in wafer processing system 1 and a program for estimating the height of a focus ring (described later) in processing devices 40 to 43. The program may be recorded in a computer-readable storage medium and installed in control device 50 from the storage medium. The storage medium may be temporary or non-temporary. A part or all of the program may be realized by dedicated hardware (circuit board).

[0026] The display unit 52 displays various information and is configured with a display device such as a liquid crystal display or an organic display.

[0027] <Processing device 40> Next, the processing apparatus 40 will be described with reference to Figures 2 and 3. Figure 2 is a vertical cross-sectional view showing an outline of the configuration of the processing apparatus 40. Figure 3 is a partially enlarged cross-sectional view of an electrostatic chuck, which will be described later.

[0028] 2, 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.

[0029] The processing vessel 100 is a vessel configured so that the inside can be depressurized, and constitutes a vacuum processing chamber 44. A loading / unloading port 100a for a wafer W is formed in a side wall of the processing vessel 100, and a gate valve G5 is provided at the loading / unloading port 100a as an opening / closing mechanism for opening and closing the loading / unloading port 100a.

[0030] The mounting table 101 is disposed in a lower region of a plasma processing space 100s in the processing vessel 100.

[0031] The mounting table 101 is configured to support a wafer W in the plasma processing space 100s. The mounting table 101 includes a lower electrode 103, an electrostatic chuck 104, an insulator 105, and lift pins .

[0032] The lower electrode 103 is made of a conductive material such as aluminum.

[0033] The electrostatic chuck 104 is provided on the lower electrode 103, and attracts and holds the wafer W by electrostatic force. The electrostatic chuck 104 has a mounting portion 104a in the center on which the wafer W is mounted. In the electrostatic chuck 104, the upper surface of the mounting portion 104a is formed higher than the upper surface of its outer periphery. A focus ring 107 as an annular member is mounted on the upper surface of the outer periphery surrounding the mounting portion 104a of the electrostatic chuck 104.

[0034] Focus ring 107 is a member having an annular shape in a plan view (specifically, a circular shape in a plan view) and is disposed so as to surround wafer W placed on mounting portion 104a of electrostatic chuck 104, for example, to improve the uniformity of plasma processing (plasma etching processing in this example). Focus ring 107 is made of a material appropriately selected depending on the plasma processing to be performed, and is made of, for example, silicon, silicon carbide, or quartz.

[0035] The mounting portion 104a is provided with an electrode 108 for electrostatically attracting and holding the wafer W. The electrostatic chuck 104 has a configuration in which the electrode 108 is sandwiched between insulating materials made of an insulating material.

[0036] A DC voltage is applied from a DC power supply (not shown) to the electrode 108. The wafer W is attracted and held on the upper surface of the mounting portion 104a of the electrostatic chuck 104 by electrostatic force generated thereby.

[0037] Further, below the electrode 108 in the electrostatic chuck 104, a heater 109 is embedded as a temperature adjusting unit that adjusts the temperature of the electrostatic chuck 104. The heater 109 adjusts the temperature of the electrostatic chuck 104, thereby adjusting the temperature of the wafer W held by the electrostatic chuck 104.

[0038] 3, 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 attracted to the electrostatic chuck 104 due to a residual attracting force when the application of voltage to the electrode 108 is stopped. The plurality of protrusions 104b are provided at equal intervals, for example. The protrusions 104b are formed in a cylindrical shape with a diameter of 300 μm to 500 μm and a height of 5 μm to 30 μm, for example.

[0039] 2, 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.

[0040] The lift pins 106 are columnar members that rise and fall so as to protrude and sink from the upper surface of the mounting portion 104a of the electrostatic chuck 104, and are made of, for example, ceramic. Three or more lift pins 106 are provided at intervals from each other along the circumferential direction of the electrostatic chuck 104.

[0041] The lift pins 106 are connected to a lift mechanism 110 that raises and lowers the lift pins 106. The lift mechanism 110 has, for example, a support member 111 that supports the multiple lift pins 106, and a drive unit 112 that generates a driving force for raising and lowering the support member 111 and raises and lowers the multiple lift pins 106. The drive unit 112 has a drive source such as a motor that generates the driving force.

[0042] The lift pin 106 is inserted into a through hole 113 that extends downward from the mounting portion of the electrostatic chuck 104 to the bottom surface of the lower electrode 103 .

[0043] The shower head 102 functions as an upper electrode and also functions as a shower head that supplies a processing gas from the gas supply unit 120 to the plasma processing space 100s. The shower head 102 is disposed above the mounting table 101 and constitutes a part of the ceiling of the processing vessel 100. The shower head 102 also has an electrode plate 114 disposed facing the inside of the processing vessel 100, and a support 115 provided above the electrode plate 114. The shower head 102 is supported on the upper part of the processing vessel 100 via an insulating shielding member 116.

[0044] A plurality of discharge holes 114a are formed in the electrode plate 114. The discharge holes 114a discharge a processing gas or the like into the plasma processing space 100s.

[0045] Support body 115 detachably supports electrode plate 114. Gas diffusion chamber 115a is formed inside support body 115. A plurality of gas circulation holes 115b are formed from gas diffusion chamber 115a and communicate with discharge hole 114a.

[0046] The gas supply unit 120 includes one or more gas sources 121 and one or more flow rate controllers 122. The gas supply unit 120 is configured to supply, for example, one or more process gases or one or more cleaning gases from the corresponding gas sources 121 through the corresponding flow rate controllers 122 to the gas diffusion chamber 115a.

[0047] In the processing apparatus 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 rate controller 122. Then, the processing gas supplied to the gas diffusion chamber 115a is dispersed in a shower-like manner and supplied into the plasma processing space 100s via the gas circulation holes 115b and the discharge holes 114a.

[0048] The RF power supply unit 130 includes, for example, two RF generating units 131a and 131b and two matching circuits 132a and 132b. The RF generating units 131a and 131b are connected to the lower electrode 103 via the matching circuits 132a and 132b, respectively, and supply RF power to the lower electrode.

[0049] The RF generating unit 131a generates and supplies RF power for generating plasma. The matching circuit 132a has a circuit for matching the output impedance of the RF generating unit 131a with the input impedance on the load (lower electrode 103) side.

[0050] The RF generating unit 131b generates and supplies RF power (radio frequency bias power) for attracting ions to the wafer W. The matching circuit 132b has a circuit for matching the output impedance of the RF generating unit 131b with the input impedance on the load (lower electrode 103) side.

[0051] The exhaust system 140 exhausts the inside of the plasma processing space 100s and includes a vacuum pump. The exhaust system 140 is connected to an exhaust port 100c provided at the bottom of the processing vessel 100.

[0052] The configurations of the processing devices 41 to 43 are similar to that of the processing device 40, and therefore the description thereof will be omitted.

[0053] <Wafer processing> Next, a description will be given of wafer processing performed using the wafer processing system 1 configured as above. The following processing is performed under the control of the control unit 51.

[0054] First, the wafer W is taken out of the carrier C by the transfer arm 23a 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 23a.

[0055] Next, the gate valve G1 is closed to seal the inside of the load lock device 12 and reduce the pressure.

[0056] When the pressure inside the load lock device 12 falls below a predetermined pressure, the gate valve G3 is opened, and the wafer W is received by the transfer arm 32a of the wafer transfer mechanism 32 from a support portion (not shown) inside the load lock device 12 and removed from the load lock device 12.

[0057] Next, after the gate valve G3 is closed, a gate valve for a processing apparatus that performs a target process (here, it is assumed that this is the gate valve G5 for the processing apparatus 40) is opened. Then, the wafer W is loaded into the processing vessel 100 of the processing apparatus 40, the pressure of which has been reduced, by the transfer arm 32a. Thereafter, the lift pins 106 are raised and lowered, and the wafer W is placed on the electrostatic chuck 104.

[0058] Next, the gate valve G5 is closed to hermetically seal the processing vessel 100 of the processing device 40, and the inside of the processing vessel 100 is depressurized to a predetermined vacuum level by the exhaust system 140. A DC voltage is applied to the electrode 108 of the electrostatic chuck 104, so that the wafer W is attracted and held on the electrostatic chuck 104 by electrostatic force.

[0059] Next, a processing gas is supplied from the gas supply unit 120 to the plasma processing space 100s via the shower head 102. In addition, high frequency power for plasma generation 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, high frequency power for ion attraction is also supplied from the RF power supply unit 130 to the lower electrode 103. Then, the wafer W is subjected to a plasma etching process by the action of the generated plasma.

[0060] When the plasma etching process is to be completed, the supply of high frequency power from the RF power supply unit 130 and the supply of the process gas from the gas supply unit 120 are stopped. Next, the application of the DC voltage to the electrode 108 is stopped, and the attracting and holding of the wafer W by the electrostatic chuck 104 is stopped.

[0061] Thereafter, the gate valve G5 of the processing vessel 100 is opened, and the wafer W is unloaded from the processing vessel 100 of the processing apparatus 40 in the reverse order of loading the wafer W into the processing vessel 100 of the processing apparatus 40, thereby completing the series of wafer processing steps.

[0062] Before the next wafer W to be processed is loaded into the processing vessel 100 of the processing apparatus 40, a cleaning gas is supplied to the processing vessel 100 and cleaning is performed.

[0063] <Wafer transport mechanism> Next, an example of the wafer transport mechanism 32 will be described with reference to Figures 4 and 5. Figure 4 is a side view that shows a schematic configuration of the wafer transport mechanism 32. Figure 5 is a bottom view that shows an outline of the configuration of a fork, which will be described later.

[0064] 4, the wafer transfer mechanism 32 has a transfer arm 32a and a base 32b, and is configured to be able to transfer the wafer W while holding it with the transfer arm 32a. Note that the number of transfer arms provided in the wafer transfer mechanism 32 may be multiple.

[0065] The transfer arm 32a is, for example, a multi-joint arm. The base 32b supports the base end of the transfer arm 32a.

[0066] The transfer arm 32a has a first joint arm 201, a second joint arm 202, and a holding arm 203 serving as a substrate holding section for holding the wafer W. The first joint arm 201 has a base end connected to a base 32b so as to be rotatable about a vertical axis. The second joint arm 202 is connected to the tip side of the first joint arm 201 so as to be rotatable around a vertical axis. The holding arm 203 is connected to the tip side of the second joint arm 202 so as to be rotatable around a vertical axis.

[0067] A drive unit (not shown) for driving the lifting, lowering, rotating, and extending / retracting of the transfer arm 32a is provided on the base 32b. The drive unit has a drive source such as a motor that generates a drive force for lifting and lowering the transfer arm 32a, a drive force for horizontally rotating the transfer arm 32a, and a drive force for horizontally extending and retracting the transfer arm 32a.

[0068] The holding arm 203 has a housing portion 203a on the base end side and a fork 203b on the tip end side.

[0069] The inside of the accommodation portion 203a is formed as a hollow cavity. 5, the fork 203b has a bifurcated shape with a width smaller than the diameter of the wafer W. The fork 203b moves up and down as the transfer arm 32a moves up and down, and the fork 203b moves in the horizontal direction as the transfer arm 32a rotates or expands and contracts.

[0070] In the wafer transfer mechanism 32, the transfer arm 32a is located in a vacuum transfer chamber 31 that is kept in a vacuum atmosphere, and the base 32b is provided in a space below the vacuum transfer chamber 31 that is kept in an atmospheric atmosphere.

[0071] The insides of the base 32b, the first joint arm 201, and the second joint arm 202 are all hollow, similar to the housing section 203a on the base end side of the holding arm 203. The internal space of the housing section 203a of the holding arm 203 communicates with the internal space of the base 32b, which is the air atmosphere, through the insides of the first joint arm 201 and the second joint arm 202.

[0072] The wafer transfer mechanism 32 configured as above is controlled by a controller 50.

[0073] Furthermore, the wafer transport mechanism 32 is provided with a distance measuring unit 300 as shown in FIG. The distance measurement unit 300 includes a distance sensor (also called a sensor head) 301 and a unit controller 302 .

[0074] The distance sensor 301 measures the distance from the fork 203b (specifically, the distance sensor 301) to a target point. The distance sensor 301 is provided on the fork 203b, and specifically, for example, as shown in Fig. 5, one distance sensor 301a is provided at one tip of the fork 203b and one distance sensor 301b is provided at the other tip of the fork 203b. The unit controller 302 performs control related to the measurement by the distance sensor 301 under the control of the control unit 51 .

[0075] A method for measuring distance using the distance sensor 301 that allows non-contact measurement in a vacuum atmosphere, for example, a method based on light, is adopted. In this case, for example, the distance sensor 301 irradiates a target object with light for distance measurement and receives the reflected light, and the unit controller 302 measures the distance from the fork 203b (specifically, the distance sensor 301) to the target point based on the light reception result by the distance sensor 301.

[0076] A more specific example of a distance measurement method using the distance sensor 301 is a white light confocal method. When the white light confocal method is adopted, for example, white light supplied from a light source (not shown) such as an LED included in the unit controller 302 is irradiated from the distance sensor 301 to the object so that the white light is focused at a different height for each wavelength contained in the white light. Then, only the light of the 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. The distance sensor 301 is disposed so that the optical axis of the white light is approximately parallel to the vertical direction. The white light confocal method is merely one example, and any method capable of measuring distances with the desired accuracy (for example, a height resolution of 15 μm or less and a horizontal resolution of about 0.1 mm) may be used.

[0077] The distance sensor 301 and the unit controller 302 are connected via an optical fiber 303, and the above-mentioned distance measuring light (white light) and reflected light are transmitted via the optical fiber 303. An optical switch 304 is interposed in the optical fiber 303.

[0078] The unit controller 302 and the optical switch 304 are provided in a space outside the vacuum transfer chamber 31, which is under the atmospheric pressure.

[0079] The optical fiber 303 is disposed 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 at the portion of the optical fiber 303 that penetrates the side wall of the housing portion 203a so as not to impair the vacuum atmosphere in the vacuum transfer chamber 31 and the processing container 100 of the processing devices 40 to 43.

[0080] The optical fiber 303 and the distance sensor 301 are arranged so as not to interfere with the holding of the wafer W by the holding arm 203. 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 so that the upper part of the distance sensor 301 does not come into contact with the wafer W when the wafer W is transferred to the fork 203b of the holding arm 203.

[0081] <Control unit 51> (Height estimation example 1) Next, a process performed by control unit 51 when estimating the height of focus ring 107 placed on electrostatic chuck 104 will be described. Fig. 6 is a plan view of an example of a jig wafer serving as a jig substrate used for estimating the height of focus ring 107. Fig. 7 is a diagram showing the positions of fork 203b and distance sensor 301 relative to mounting table 101 when estimating the height of focus ring 107.

[0082] In wafer processing system 1, focus ring 107 placed on electrostatic chuck 104 is worn out by the above-described wafer processing using plasma. In order to determine the degree of wear of focus ring 107, control unit 51 in wafer processing system 1 estimates the height of focus ring 107 placed on electrostatic chuck 104 based on the measurement result by distance sensor 301.

[0083] Furthermore, in the wafer processing system 1, when estimating the height of the focus ring 107, a jig wafer Wj as shown in FIG. 6 is used. The jig wafer Wj has the same shape and material in a plan view as the wafer W that is actually subjected to plasma processing. The jig wafer Wj has a reference surface Ws that serves as a reference for the height of the focus ring 107, and is placed on the electrostatic chuck 104 so that this reference surface Ws is on the upper side. Hereinafter, the surface of the jig wafer Wj that is on the upper side when placed on the electrostatic chuck 104 is referred to as the upper surface. In one example, the entire upper surface of the jig wafer Wj is formed flat, and the entire upper surface serves as a reference surface Ws. The thickness of the jig wafer Wj may be the same as or different from that of the actual wafer W. The jig wafer Wj is stored in, for example, a carrier C when not in use.

[0084] When estimating the height of focus ring 107, control unit 51 controls each part of wafer processing system 1 (i.e., outputs a control signal) so that jig wafer Wj is placed by wafer transport mechanism 32 on electrostatic chuck 104 of mounting table 101 on which focus ring 107 is placed.

[0085] Moreover, the control unit 51 controls each part of the wafer processing system 1, and as shown in FIG. 7, positions the fork 203b above the mounting table 101 on which the jig wafer Wj and the focus ring 107 are mounted. Furthermore, the control unit 51 controls the wafer transport mechanism 32 and the unit controller 302 (i.e., outputs a control signal) to cause the distance sensor 301 to measure the distance from the fork 203b positioned above the mounting table 101 to the reference surface 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 transport mechanism 32 and the unit controller 302 to cause the distance sensor 301 to irradiate light for distance measurement to a predetermined reference position on the reference surface Ws of the jig wafer Wj and cause the distance sensor 301 to receive the reflected 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 on the reference surface Ws of the jig wafer Wj based on the light reception result. Similarly, control unit 51 controls wafer transport mechanism 32 and unit controller 302 to cause distance sensor 301 to irradiate focus ring 107 with distance measurement light and cause distance sensor 301 to receive the reflected light. Next, control unit 51 controls unit controller 302 to calculate distance Lf from fork 203b to focus ring 107 based on the light reception result. In the following description, "the distance from the fork 203b to XX" may be abbreviated to "the distance to XX".

[0086] Then, control unit 51 calculates, or estimates, the height of focus ring 107 based on the distance to reference plane Ws and the distance to focus ring 107. For example, control unit 51 calculates the height H of focus ring 107 (specifically, the height from reference plane Ws) based on the following formula (1) using the above-mentioned distance Lsp and distance Lf. H=Lsp-Lf

[0087] (Height estimation example 2) FIG. 8 is a diagram for explaining another mode for estimating the height of focus ring 107. In FIG. When distance sensor 301 measures the distance to focus ring 107, controller 51 may control wafer transfer mechanism 32 to move fork 203b so that distance sensor 301a moves in a predetermined direction as shown in Fig. 8. The above-mentioned predetermined direction is a direction that crosses focus ring 107 in a plan view and intersects with the direction in which fork 203b is inserted into and removed from processing vessel 100 (the vertical direction in Fig. 8).

[0088] Specifically, control unit 51 may control wafer transfer mechanism 32 so that, when distance sensor 301a measures the distance to focus ring 107, fork 203b rotates about the base end of fork 203b, thereby moving distance sensor 301a in a direction across focus ring 107 in a plan view. Control unit 51 may also perform control so that transfer arm 32a rotates about the base end of transfer arm 32a, thereby moving distance sensor 301a in a direction across focus ring 107 in a plan view.

[0089] While the distance sensor 301a moves in a direction crossing the focus ring 107 in a plan view as described above, the control unit 51 controls the unit controller 302 so that the distance sensor 301a continuously measures the distance Lf to the focus ring 107. The control unit 51 estimates the distribution of the height of the focus ring 107 in the crossing direction, i.e., the profile, 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 for each measurement point of the distance Lf to the focus ring 107 based on the above formula (1), and creates the distribution of the height of the focus ring 107 in the crossing direction from each calculation result and position information of each measurement point. The position information of each measurement point can be calculated from the angle and size of each component of the transfer arm 32a when the distance Lf is measured.

[0090] (Height estimation example 3) Incidentally, when fork 203b is moved in the transverse direction as in the above-mentioned Example 2, fork 203b may vibrate during the movement. Fig. 9 is a diagram showing an example of an estimation result of the height of focus ring 107 when fork 203b vibrates during the movement. When fork 203b vibrates, if focus ring height profile D is estimated as in Example 2 above, profile D may be obtained by superimposing vibration component D2 of fork 203b on actual profile D1 of focus ring 107 height, as shown in FIG. 9.

[0091] In order to eliminate the influence of such vibration component D2 of the fork 203b, the following may be performed. That is, as shown in FIG. 8, while the fork 203b moves so that one distance sensor 301a moves in a direction crossing the focus ring 107 in a plan view, 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 surface Ws of the jig wafer Wj. Then, the control unit 51 estimates a height profile D of the focus ring in the crossing direction based on the measurement result of the distance Lft to the focus ring 107 and the measurement result of the distance Lst to the reference surface 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 for each time point during the measurement by the distance sensor 301a and the distance sensor 301b, i.e., based on the following formula (2). Lst-Lft=Ht …(2)

[0092] The control unit 51 creates a height profile of the focus ring 107 in the transverse direction from the calculation results of the height Ht at each point in time during measurement by the distance sensors 301a and 301b and the position information of the measurement point by the distance sensor 301a. The profile thus obtained is one in which the influence of the vibration component D2 of the fork 203b has been removed.

[0093] (Other effects of height estimation example 3) 10 and 11 are diagrams for explaining other effects obtained by creating a height profile of focus ring 107 in the manner of Example 3 described above. 10, there are cases where fork 203b is not parallel to table 101 but is inclined. In such cases, when height profile D of focus ring 107 from reference plane Ws in the transverse direction is estimated using equation (1) above, it differs from actual height profile D1 of focus ring 107 by the inclination θ of fork 203b with respect to table 101, as shown in FIG. In response to this, similarly to the above-described Example 3, by creating a profile of the height of focus ring 107 from reference plane Ws in the transverse direction, the effect of inclination θ of fork 203b with respect to mounting table 101 can be eliminated.

[0094] <Estimation method> Next, a description will be given of an example of a method for estimating the height of focus ring 107 using wafer processing system 1. Note that the height of focus ring 107 is estimated, for example, every time a predetermined period of time elapses or every time a predetermined number of wafers are processed.

[0095] (Step S1: Loading the jig wafer Wj) First, under the control of the controller 51, the jig wafer Wj is placed by the wafer transfer mechanism 32 on the stage 101 on which the focus ring 107 is placed.

[0096] Specifically, the jig wafer Wj is removed 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 carried into the load lock device 12 by the transfer arm 23a, and is delivered to a support portion (not shown) in the load lock device 12.

[0097] Next, the transfer arm 23a is removed from the load lock device 12, and the gate valve G1 is closed to seal the inside of the load lock device 12 and reduce the pressure.

[0098] When the pressure inside the load lock device 12 falls below a predetermined pressure, the gate valve G3 is opened, and the jig wafer Wj is received from a support portion (not shown) inside the load lock device 12 by the transport arm 32a of the wafer transport mechanism 32 and removed from the load lock device 12.

[0099] Next, after the gate valve G3 is closed, the gate valve for the processing apparatus for which the height of the focus ring 107 is to be measured (here, it is assumed that this is the gate valve G5 for the processing apparatus 40) is opened. Then, the fork 203b of the transfer arm 32a holding the jig wafer Wj is inserted into the processing vessel 100 of the processing apparatus 40, the pressure of which has been reduced. Thereafter, the lift pins 106 are raised and lowered, and the fork 203b is removed from the processing vessel 100, and the jig wafer Wj is placed on the electrostatic chuck 104 of the mounting table 101 via the lift pins 106 in the processing vessel 100.

[0100] (Step S2: Measurement of reference point) Next, under the control of the control unit 51, the distance Lsp from the fork 203b positioned above the mounting table 101 to a reference point on the reference surface Ws of the jig wafer Wj is measured by the distance sensor 301. Specifically, the fork 203b is reinserted into the processing vessel 100 of the processing device 40 and moved above the mounting table 101. Then, the distance sensor 301a and the distance sensor 301b measure the distance Lsp to the reference point on the reference surface Ws of the jig wafer Wj. Note that the distance Lsp to the reference point on the reference surface Ws when the fork 203b is in an ideal state (a state in which the fork 203b is not inclined relative to the mounting table 101 and the fork 203b is not drooping), i.e., the design value of the distance Lsp, is stored in advance in a storage unit (not shown).

[0101] (Step S3: Measurement of the distance to the reference surface Ws and the distance to the focus ring 107) Next, under the control of control unit 51, distance sensor 301 measures the distance from fork 203b positioned above mounting table 101 to focus ring 107, and the distance from fork 203b to reference plane Ws. Specifically, for example, fork 203b is moved so that one distance sensor 301a moves in a direction crossing the one distance sensor 301a side of focus ring 107 in a plan view. During this movement, one distance sensor 301a continuously measures the distance to focus ring 107, and the other distance sensor 301b continuously measures the distance to reference surface Ws of jig wafer Wj. Furthermore, fork 203b is moved such that, for example, the other distance sensor 301a moves in a direction crossing the other distance sensor 301a side of focus ring 107 in a plan view. During this movement, the other distance sensor 301b continuously measures the distance to focus ring 107, and the distance sensor 301a continuously measures the distance to reference surface Ws of jig wafer Wj.

[0102] (Step S4: Estimation of the height of the focus ring 107) Then, control unit 51 estimates the height of focus ring 107 based on the measurement result in step S3. Specifically, for example, control unit 51 calculates the height Ht of focus ring 107 on the distance sensor 301a side for each time point during the measurement in step S3 based on the difference between the distance Lft and the distance Lst, i.e., based on the above formula (2). Control unit 51 creates a profile of the height of focus ring 107 in the direction crossed by distance sensor 301a from the calculation result of the height Ht for each time point during the measurement in step S3 and position information of the measurement point by distance sensor 301a. Furthermore, for the distance sensor 301b side of focus ring 107, control unit 51 creates a profile of the height of focus ring 107 in the direction crossed by distance sensor 301b in the same manner as for distance sensor 301a side.

[0103] The height profile of focus ring 107 created in step S4 may be corrected based on distance Lsp to the reference point on reference surface Ws of jig wafer Wj measured by distance sensor 301a and distance sensor 301b in step S2 and a design value of distance Lsp. This makes it possible to eliminate the influence of sagging of fork 203b due to its own weight due to aging or the like from the estimated result of the height profile of focus ring 107.

[0104] (Step S5) In parallel with step S4 or after step S4, under the control of the control unit 51, the jig wafer Wj is unloaded. Specifically, the fork 203b is removed from and reinserted into the processing vessel 100 of the processing device 40, and the lift pins 106 are raised and lowered, so that the jig wafer Wj is received by the fork 203b. Then, the jig wafer Wj is unloaded from the processing vessel 100 of the processing device 40 in a procedure reverse to that of loading the wafer W into the processing vessel 100 of the processing device 40.

[0105] <Effects of this embodiment> As described above, in this embodiment, when estimating the height of focus ring 107, jig wafer Wj having a reference plane Ws of the height of focus ring 107 is placed on mounting table 101, specifically, on the upper surface of mounting portion 104a of electrostatic chuck 104 of mounting table 101. Then, the height of focus ring 107 is estimated based on the measurement results of the distance to the reference plane Ws and the distance to focus ring 107 by distance sensor 301 provided on fork 203b of wafer transport mechanism 32. Therefore, even if a plurality of convex portions 104b are provided on the upper surface of mounting portion 104a of electrostatic chuck 104 of mounting table 101 as shown in FIG. 3, the height of focus ring 107 can be accurately estimated.

[0106] The height of the focus ring 107 is important 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 this height affects the shape of the plasma sheath and the plasma processing result. However, the upper surface of the mounting portion 104a of the electrostatic chuck 104 may be worn out when plasma processing is repeated, so the height of the focus ring 107 estimated based on the upper surface of the mounting portion 104a of the electrostatic chuck 104 may not correspond to 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. In contrast, in this 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 used as the reference plane Ws for the height of the focus ring 107. The jig wafer Wj is located outside the processing vessel 100 during plasma processing, so it is not worn out. Therefore, even if the upper surface of the mounting portion 104a of the electrostatic chuck 104 is worn, the height of focus ring 107 estimated in this embodiment corresponds to the height based on the upper surface of the wafer W placed on the upper surface of the mounting portion 104a. Therefore, according to this embodiment, it is possible to accurately determine whether the degree of wear of focus ring 107 is within a range that does not affect the shape of the plasma sheath.

[0107] Furthermore, according to this embodiment, the height of focus ring 107 can be estimated without exposing the inside of processing vessel 100 to the atmosphere.

[0108] Furthermore, in this embodiment, fork 203b is moved so that distance sensor 301a moves in a direction across focus ring 107 in a plan view, and a height profile of focus ring 107 in the crossing direction is estimated. Determining the life of focus ring 107 based on the estimated result of the height profile of focus ring 107 in the crossing direction has the following advantages compared to determining the life of focus ring 107 based on the estimated result of the height of one point on focus ring 107. That is, when there is a difference in the amount of wear of focus ring 107 in the radial direction of focus ring 107, the life of focus ring 107 can be determined more accurately.

[0109] In this embodiment, a height profile in the transverse direction is obtained for two portions of focus ring 107, namely, the side of distance sensor 301a and the side of distance sensor 301b in focus ring 107. If the life of focus ring 107 is determined based on the height profiles for these two portions, the following effect can be obtained. That is, when there is a difference in the amount of wear of focus ring 107 in the circumferential direction of focus ring 107, the life of focus ring 107 can be determined more accurately.

[0110] <Another example of a jig wafer> 12 and 13 are a plan view and a cross-sectional view, respectively, that diagrammatically show another example of a jig wafer. As shown in Figures 12 and 13, the jig wafer Wj' has a plurality of correction surfaces Wr spaced a predetermined distance in the height direction from the reference surface Ws, and the plurality of correction surfaces Wr have different distances from the reference surface Ws in the height direction. In the illustrated example, correction surfaces Wr1 to Wr3 are provided as the correction surface Wr for each of the distance sensor 301a and the distance sensor 301b. The distances of the correction surfaces Wr1 to Wr3 from the reference surface Ws are determined in advance with high accuracy. In the example shown in the figure, a groove recessed from the reference surface Ws is formed in 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 in the jig wafer Wj, and the correction surfaces Wr1 to Wr3 may be constituted by the top surface of the convex portion. 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.

[0111] When the jig wafer Wj' is placed on the jig and used, the distance sensor 301 also measures the distances to the multiple correction surfaces Wr when it measures the distance to the reference surface Ws and the distance to the focus ring 107. For example, the distance sensor 301 measures the distance to the correction surface Wr1 and the distance to the correction surface Wr2. Then, the control unit 51 corrects the measurement result by the distance sensor 301 based on the measurement results of the distances to the multiple correction surfaces Wr. Specifically, the control unit 51 obtains, for example, a difference between the distance to the correction surface Wr1 and the distance to the correction surface Wr2 measured by the distance sensor 301. Then, the control unit 51 corrects the measurement result by the distance sensor 301 so that this difference approaches a design value of the difference. This allows the distance sensor 301 to more accurately measure the distance to the reference surface Ws and the distance to the focus ring 107, and allows the height of the focus ring 107 to be more accurately estimated. The design value of the difference is stored in advance in a storage unit (not shown).

[0112] When the height of focus ring 107 is estimated using jig wafer Wj' as in the above-described Example 3, correction surface Wr is provided in the following region of jig wafer Wj': That is, correction surface Wr is provided in a region on jig wafer Wj' where continuous measurement of the distance to reference surface Ws by distance sensors 301a, 301b is not hindered when fork 203b is moved.

[0113] <Other Examples of Wafer Transfer Mechanism 32> FIG. 14 is a diagram showing another example of the wafer transport mechanism 32. As shown in FIG. As described above, the mounting table 101 is provided with the heater 109. When the electrostatic chuck 104 needs to be heated by the heater 109 during plasma processing, it is preferable to continue heating by the heater 109 even during the process of estimating the height of the focus ring 107 in order to suppress a decrease in throughput. However, if the heating by the heater 109 is continued, the temperature of the distance sensor 301 may increase when the fork 203b is positioned above the mounting table 101. 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.

[0114] 14, a temperature sensor 401 may be provided to measure the temperature of distance sensor 301, and the temperature of distance sensor 301 at the time distance sensor 301 makes a measurement may be measured by temperature sensor 401. Then, control unit 51 may correct the measurement result by distance sensor 301 based on the measurement result of the temperature of distance sensor 301 at the time distance sensor 301 makes a measurement.

[0115] 14, the temperature sensor 401 is provided near the distance sensor 301. For example, the temperature sensor 401 is provided at a position adjacent to the distance sensor 301 on the lower surface of the fork 203b. When two distance sensors, 301a and 301b, are provided as the distance sensor 301, for example, the temperature sensor 401 is provided for each of the distance sensors 301a and 301b.

[0116] The temperature measurement result by the temperature sensor 401 is sent to the control unit 51 via the gateway board 402. The gateway board 402 is housed in the housing portion 203a of the holding arm 203. The gateway board 402 and the temperature sensor 401 are connected via a wiring 403, and the gateway board 402 and the control unit 51 are connected via a communication cable 404.

[0117] The wiring 403 is disposed so as to penetrate the bottom wall of the accommodation portion 203a of the holding arm 203. A feedthrough 403a is formed at the portion of the wiring 403 that penetrates the bottom wall of the accommodation portion 203a so as not to impair the vacuum atmosphere in the vacuum transfer chamber 31 and the processing container 100 of the processing apparatuses 40 to 43.

[0118] In the case where the temperature sensor 401 is used, for example, when the distance sensor 301 measures the distance to the focus ring 107 or the reference plane Ws, the temperature of the distance sensor 301 at each measurement point is also measured by the temperature sensor 401. Specifically, for example, as in the above-mentioned 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 measurement point is also measured by the temperature sensor 401. Note that hereinafter, "continuously measuring the distance with the distance sensor 301a while moving the fork 203b" is referred to as "scanning measurement by the distance sensor 301a."

[0119] Furthermore, when the temperature sensor 401 is used, the distance to a predetermined portion on the jig wafer Wj or the jig wafer Wj' is measured at least twice with a time interval by the distance sensor 301, and the temperature of the distance sensor 301 at each measurement point is also measured by the temperature sensor 401. Specifically, for example, before and after the scanning measurement by the distance sensor 301a, the distance to the correction surface Wr1 on the jig wafer Wj' is measured by the distance sensor 301a, and the temperature of the distance sensor 301a at each measurement point is also obtained by the temperature sensor 401.

[0120] The control unit 51 obtains a correlation between the measurement result by the distance sensor 301 and the temperature of the distance sensor 301 based on the at least two measurement results of the distance to a 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. Specifically, for example, as shown in Fig. 15, the control unit 51 obtains the correlation (i.e., correction formula) R from the distance Lt1 to the correction surface Wr1 measured by the distance sensor 301a before the scanning measurement by the distance sensor 301a and the temperature T1 at the time of the measurement, and the distance Lt2 to the correction surface Wr1 measured by the distance sensor 301a after the scanning measurement by the distance sensor 301a and the temperature T2 at the time of the measurement.

[0121] Then, the control unit 51 corrects the measurement results of the distance to the focus ring 107 or the reference surface Ws by the distance sensor 301 at each measurement time point based on the acquired correlation and the temperature of the distance sensor 301 at each measurement time point. Specifically, for example, the control unit 51 corrects the measurement results by the distance sensor 301a at each measurement time point during the scan distance measurement based on the acquired correlation R in FIG. 5 and the temperature of the distance sensor 301a at each measurement time point during the scan distance measurement.

[0122] If the height of focus ring 107 is calculated or estimated based on the corrected measurement result by distance sensor 301a, the effect of temperature changes during measurement by distance sensor 301 can be eliminated.

[0123] When a jig wafer Wj' is used with temperature sensor 401 provided, the thermal expansion of the groove depth of jig wafer Wj' is very small compared to the temperature change of the measurement result of distance sensor 301, and therefore has little effect on the measurement result of distance sensor 301, and can be ignored. However, since the temperature of jig wafer Wj' can be estimated from the set temperature of heater 109, the measurement result of the groove depth of jig wafer Wj' (i.e., the distance to correction surfaces Wr1 to Wr3) by distance sensor 301a may be corrected based on the estimated result. If the height of focus ring 107 is calculated / estimated based on the corrected measurement result by distance sensor 301a, the effect of the thermal expansion of jig wafer Wj' can be eliminated.

[0124] <Other examples of annular members> FIG. 16 is a diagram showing another example of the annular member. 16 , in addition to focus ring 107, a cover ring 500 may be placed on mounting table 101 as an annular member so as to cover the outer surface of focus ring 107. The technology of the present disclosure can also be applied to estimating the height of cover ring 500 placed on mounting table 101.

[0125] The embodiments disclosed herein should be considered as illustrative and not restrictive in all respects. The above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0126] 1. Wafer Processing System 32 Wafer transport mechanism 40~43 Processing equipment 101 Placement table 107 Focus Ring 203b Fork 301, 301a, 301b Distance sensor 500 Covering Lf Distance to focus ring Lft Distance to focus ring Lsp Distance to the reference plane Lst Distance to the reference plane W wafer Wj Jig wafer Wj' Jig wafer Ws reference plane

Claims

1. a substrate processing apparatus including a mounting table on which a substrate and an annular member arranged to surround the substrate are mounted, the substrate processing apparatus performing a predetermined process on the substrate mounted on the mounting table; a substrate transport mechanism having a substrate holding section, the substrate being held by the substrate holding section and transported into and out of the substrate processing apparatus; a distance sensor provided on the substrate holder for measuring a distance from the substrate holder; A control device, the substrate transport mechanism places a jig substrate having a reference surface that serves as a reference for the height of the annular member on the stage on which the annular member is placed; the distance sensor measures a distance from the substrate holding part located above the mounting table to the reference surface of the fixture substrate, and continuously measures a distance from the substrate holding part to the annular member while the substrate holding part is moving above the mounting table in a direction across the annular member in a plan view; The control device estimates a height distribution of the annular member in the transverse direction based on the measurement of the distance to the reference surface and successive measurement of the distance to the annular member.

2. At least two of the distance sensors are provided on the substrate holding part, while the substrate holding part is moving above the mounting table so that one of the distance sensors moves in the direction crossing the annular member in a plan view, the one of the distance sensors continuously measures the distance from the substrate holding part to the annular member, and the other of the distance sensors continuously measures the distance from the substrate holding part to the reference surface of the jig substrate; The substrate processing system of claim 1, wherein the control device estimates a distribution of heights of the annular member in the crossing direction based on measurement results of the distance to the reference surface and the distance to the annular member at each point during measurement by the one distance sensor and the other distance sensor.

3. the jig substrate has a plurality of correction surfaces spaced apart from the reference surface by predetermined distances different from one another, and the distances of the plurality of correction surfaces from the reference surface in a height direction are different from one another; the distance sensor measures a distance from the substrate holding unit to each of the plurality of correction surfaces of the jig substrate; 3. The substrate processing system according to claim 1, wherein the control device corrects a measurement result by the distance sensor based on a measurement result of the distance to each of the plurality of correction surfaces.

4. A temperature sensor for measuring a temperature of the distance sensor is further provided.

4. The substrate processing system according to claim 1, wherein the control device corrects a measurement result by the distance sensor based on a measurement result of a temperature of the distance sensor at the time when the distance sensor makes a measurement.

5. The distance sensor measures a distance from the substrate holder to a predetermined portion of the jig substrate at least twice; The temperature sensor measures a temperature of the distance sensor at each time point when the distance sensor measures the distance to the predetermined portion; The control device includes: obtaining a correlation between the measurement result by the distance sensor and the temperature of the distance sensor based on at least two measurement results of the distance to the predetermined portion and the temperature of the distance sensor at each of the measurement times; 5. The substrate processing system according to claim 4, wherein a measurement result by the distance sensor is corrected based on a temperature of the distance sensor at the time of the measurement and the correlation.

6. 6. The substrate processing system according to claim 1, wherein the annular member is at least one of a focus ring arranged adjacent to the substrate on the mounting table or a cover ring arranged to cover an outer surface of the focus ring.

7. 1. A method for estimating a height of an annular component in a substrate processing system, comprising: The substrate processing system includes: a substrate processing apparatus including a mounting table on which a substrate and the annular member arranged to surround the substrate are mounted, the substrate processing apparatus performing a predetermined process on the substrate mounted on the mounting table; a substrate transport mechanism having a substrate holding section, the substrate being held by the substrate holding section and transported into and out of the substrate processing apparatus; a distance sensor provided to the substrate holder and measuring a distance from the substrate holder, placing a jig substrate having a reference surface that serves as a reference for the height of the annular member on the stage on which the annular member is placed, by the substrate transport mechanism; a step of measuring a distance from the substrate holding part located above the mounting table to the reference surface of the jig substrate with the distance sensor, and continuously measuring a distance from the substrate holding part to the annular member with the distance sensor while the substrate holding part is moving above the mounting table so that the distance sensor moves in a direction across the annular member in a plan view; and estimating a distribution of the height of the annular member in the transverse direction based on the measurement results of the distance to the reference plane and continuous measurement results of the distance to the annular member.

Images