Information Acquisition System and Information Acquisition Method

Abstract

To prevent the occurrence of troubles in processing due to improper arrangement of a member positioned near a substrate processed by a substrate processing device.SOLUTION: An information acquisition system that acquires information on a substrate processing device that processes a substrate held by a substrate holding unit includes a base body held instead of the substrate by the substrate holding unit, and a plurality of position sensors provided on the base body such that detection directions are different from each other in order to detect the position of a common detection target positioned outside the base body.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to an information acquisition system and an information acquisition method. [Background technology]

[0002] In the manufacturing process of semiconductor devices, semiconductor wafers (hereinafter referred to as wafers) are stored in a carrier and transported to a substrate processing apparatus for processing. Examples of such processing include liquid processing such as forming a coating film by supplying a coating liquid and developing. During such liquid processing, a processing liquid is supplied from a nozzle to the wafer stored in a cup. Patent Document 1 describes a developing apparatus that includes a cup with an annular protrusion that faces the lower surface of the wafer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-13932 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present disclosure is to prevent processing defects caused by members located near a substrate being processed in a substrate processing apparatus being placed in an inappropriate position. [Means for solving the problem]

[0005] The present disclosure provides an information acquisition system for acquiring information about a substrate processing apparatus that processes a substrate held by a substrate holder, the information acquisition system comprising: a base body held by the substrate holding portion instead of the substrate; a plurality of position sensors provided on the base body such that detection directions are different from each other in order to detect the position of a common detection target located outside the base body; Equipped with 、 The base body is raised and lowered by a lifting mechanism, and position detection is performed by each of the position sensors at different heights. a support part for supporting the base body is raised and lowered below the base body held by the substrate holding part by the lifting mechanism, The base body is provided with a contact sensor for detecting contact with the support portion and thereby detecting the contact height at which the support portion makes contact with the base body held by the substrate holding portion in order to detect the position of the object to be detected. Another information acquisition system of the present disclosure is an information acquisition system for acquiring information about a substrate processing apparatus that processes a substrate held by a substrate holding unit, the information acquisition system including: a base body held by the substrate holding portion instead of the substrate; a plurality of position sensors provided on the base body such that detection directions are different from each other in order to detect the position of a common detection target located outside the base body; Equipped with the detection object is a cup surrounding the substrate, an information acquisition unit that acquires information about the position of the cup based on image data acquired by imaging the cup using a first imaging unit and on results acquired by the plurality of position sensors; will be established. Another information acquisition system of the present disclosure is an information acquisition system for acquiring information about a substrate processing apparatus that processes a substrate held by a substrate holding unit, the information acquisition system including: a base body held by the substrate holding portion instead of the substrate; a plurality of position sensors provided on the base body such that detection directions are different from each other in order to detect the position of a common detection target located outside the base body; Equipped with The base body is circular; A second imaging unit that images a nozzle located on the peripheral portion of the substrate and supplying processing liquid to the peripheral portion from the central side of the base body is provided on the base body between one of the multiple position sensors and the other of the multiple position sensors in the circumferential direction of the base body. Another information acquisition system of the present disclosure is an information acquisition system for acquiring information about a substrate processing apparatus that processes a substrate held by a substrate holding unit, the information acquisition system including: a base body held by the substrate holding portion instead of the substrate; a plurality of position sensors provided on the base body such that detection directions are different from each other in order to detect the position of a common detection target located outside the base body; Equipped with The base body is circular; An interference detection unit is partially fixed to the base body and detects interference by deformation when the interference occurs with a member that is the subject of interference detection. The interference detection unit is provided at a position shifted circumferentially from the base body relative to the position sensor. Effect of the Invention

[0006] The present disclosure can prevent processing defects caused by members located near a substrate being processed in a substrate processing apparatus being placed in an inappropriate position. [Brief description of the drawings]

[0007] [Figure 1] 1 is a plan view of a substrate processing apparatus constituting an information acquisition system according to an embodiment of the present disclosure. [Diagram 2] 2 is a vertical sectional front view of a resist film forming module included in the substrate processing apparatus. FIG. [Diagram 3] FIG. 2 is a plan view of the resist film forming module. [Figure 4]FIG. 2 is an explanatory diagram showing an inspection wafer and a computing device that constitute the information acquisition system. [Diagram 5] FIG. 2 is a vertical sectional side view of the inspection wafer. [Figure 6] FIG. 2 is a vertical sectional side view of the inspection wafer. [Figure 7] FIG. 2 is a plan view of the test wafer. [Figure 8] FIG. 2 is a perspective view of the test wafer. [Figure 9] 6A to 6C are explanatory views showing the operation of a first beam-like body provided on the inspection wafer. [Figure 10] 11 is an explanatory diagram showing the operation of a second beam-like body provided on the inspection wafer. FIG. [Figure 11] 10A to 10C are explanatory diagrams showing a procedure for acquiring information about the module using the test wafer. [Figure 12] 10A to 10C are explanatory diagrams showing a procedure for acquiring information about the module using the test wafer. [Figure 13] 10A to 10C are explanatory diagrams showing a procedure for acquiring information about the module using the test wafer. [Figure 14] FIG. 4 is a graph showing an example of data acquired from the test wafer. [Figure 15] FIG. 4 is a graph showing an example of data acquired from the test wafer. [Figure 16] 11 is an explanatory diagram showing the operation of lift pins in the resist film forming module for acquiring the information. FIG. [Figure 17] 11 is an explanatory diagram showing the operation of lift pins in the resist film forming module for acquiring the information. FIG. [Figure 18] 4 is an explanatory diagram showing image data acquired from the inspection wafer. FIG. [Figure 19] 4 is an explanatory diagram showing image data acquired from the inspection wafer. FIG. [Figure 20] FIG. 4 is a graph showing data acquired from the test wafer. [Figure 21]4 is an explanatory diagram showing image data acquired by a camera provided in the resist film forming module. FIG. [Figure 22] 5A and 5B are explanatory views showing examples of cups provided in the resist film forming module. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] An information acquisition system 1 according to an embodiment of the present disclosure is shown in Fig. 1. The information acquisition system 1 is composed of a substrate processing apparatus 2, an inspection wafer 6, and a calculation device 9. To give an overview of the information acquisition system 1, the substrate processing apparatus 2 is provided with a resist film formation module 3, which forms a resist film on a wafer W, which is a circular substrate, and performs EBR (Edge Bead Removal). EBR is a process in which a solvent is ejected from a nozzle to remove a portion of a film (resist film in this embodiment) formed on the entire surface of the wafer W that covers the peripheral edge of the wafer W in a limited manner.

[0009] The inspection wafer 6 is transported to the resist film formation module 3 instead of the wafer W by the transport mechanism of the substrate processing apparatus 2, and various sensors and cameras mounted thereon detect and capture images of various components located in close proximity to the periphery of the wafer W (=the periphery of the inspection wafer 6). The acquired detection signals and image data are wirelessly transmitted to the calculation device 9, which performs various calculations, signal processing, and display, allowing an operator to inspect whether the positions of the adjacent components are appropriate. The adjacent components are specifically the components of the cup 4 surrounding the wafer W, and the nozzle for EBR.

[0010] The substrate processing apparatus 2 will be described in detail below. The substrate processing apparatus 2 is composed of a carrier block D1 and a processing block D2. The carrier block D1 and the processing block D2 are arranged on the left and right and connected to each other. The wafer W is stored in a carrier C, which is a transfer container, and is transferred to the carrier block D1 by a transfer mechanism for the carrier C (not shown). The carrier block D1 has a stage 21 on which the carrier C is placed. The carrier block D1 is also provided with an opening / closing unit 22 and a transfer mechanism 23. The opening / closing unit 22 opens and closes a transfer port formed in a side wall of the carrier block D1. The transfer mechanism 23 transfers the wafer W to the carrier C on the stage 21 through the transfer port.

[0011] The processing block D2 includes a transfer path 24 for the wafer W extending in the left-right direction, and a transfer mechanism 25 provided on the transfer path 24. The transfer mechanism 25 and the transfer mechanism 23 transfer the wafer W between the carrier C and each processing module provided in the processing block D2. A plurality of processing modules are provided on the left and right sides of the front and rear sides of the transfer path 24. The processing module on the rear side is a heating module 26, which performs a heating process to remove a solvent in the resist film. The processing module on the front side is a resist film forming module 3. In addition, a transfer module TRS on which the wafer W is temporarily placed is provided at a position near the carrier block D1 on the transfer path 24. The wafer W is transferred between the carrier block D1 and the processing block D2 via the transfer module TRS.

[0012] Next, the resist film forming module 3 will be described with reference to the vertical cross-sectional side view of FIG. 2 and the plan view of FIG. 3. The resist film forming module 3 includes a spin chuck 31 that is a substrate holding unit, and the spin chuck 31 horizontally holds the wafer W by suction at the center of the back side of the wafer W. The spin chuck 31 is connected to a rotation mechanism 33 via a vertically extending shaft 32, and the rotation mechanism 33 rotates the wafer W held by the spin chuck 31 around the vertical axis. A circular shroud 34 is provided to surround the shaft 32, and three lift pins 35 (only two are shown in FIG. 2) are provided to extend vertically through the shroud 34. The lift pins 35 are raised and lowered by a lift mechanism 36 including a pulse motor, and the wafer W is transferred between the spin chuck 31 and the transfer mechanism 25 described above. The lift pins 35 form a support unit that supports the wafer W and the wafer 6 for inspection.

[0013] A circular cup 4 is provided around the wafer W from below to the sides of the peripheral edge of the wafer W held by the spin chuck 31, and the cup 4 is composed of a cup body 41, a lower guide portion 42, an intermediate guide portion 43, and an upper guide portion 44. The cup body 41 is formed to form an annular recess along the circumference of the wafer W, and receives processing liquid (resist and solvent) that drops or splashes from the wafer W. The components of the cup body 41 are indicated as an outer cylindrical portion 41A, a bottom body 41B, and an inner cylindrical portion 41C. The outer cylindrical portion 41A and the inner cylindrical portion 41C are upright tubular members that form the side walls of the annular recess. The bottom body 41B is a horizontal annular plate that connects the lower end of the outer cylindrical portion 41A and the lower end of the inner cylindrical portion 41C, and forms the bottom of the annular recess. The bottom body 41B is provided with an exhaust pipe 45A for exhausting the inside of the cup 4, and also has a drainage port 45B for draining the processing liquid from the recess.

[0014] Next, the lower guide portion 42 will be described. The lower guide portion 42 is a circular member formed so as to expand from the peripheral portion of the shroud 34 described above, passing over the inner cylindrical portion 41C, toward the outer cylindrical portion 41A, and is located below the wafer W held by the spin chuck 31. The upper surface of the lower guide portion 42 is formed as inclined surfaces 42A and 42B, and the inclined surface 42A is located closer to the center of the cup 4 than the inclined surface 42B. The inclined surface 42A rises toward the outside of the cup 4, and the inclined surface 42B falls toward the outside of the cup 4, so that the vertical cross section of the lower guide portion 42 is formed in a mountain shape. The inclined surface 42B guides the processing liquid that has fallen or scattered from the wafer W and adheres thereto to flow down to the bottom body 41B.

[0015] The top of the mountain shape formed by the inclined surfaces 42A, 42B protrudes upward to form an annular protrusion 46, which follows the circumference of the wafer W placed on the spin chuck 31 and is close to the peripheral edge of the wafer W. The annular protrusion 46 prevents the processing liquid supplied to the front surface of the wafer W from flowing around to the rear surface of the wafer W and depositing at a position close to the center of the wafer W, and prevents mist of the processing liquid from depositing at a position close to the center of the rear surface of the wafer W. The height of the lower guide portion 42 is adjustable relative to the shroud 34 and the cup body 41, and therefore the height of the annular protrusion 46 is adjustable relative to the bottom surface of the wafer W. In FIG. 2, the distance between the annular protrusion 46 and the bottom surface of the wafer W (referred to as the cup separation distance) is indicated as H0.

[0016] The intermediate guide portion 43 constituting the cup 4 is an annular member arranged to surround the wafer W in a plan view, and includes a vertical wall 43A attached to the inner peripheral surface of the outer cylindrical portion 41A, and an inclined portion 43B extending obliquely upward from the upper end of the vertical wall 43A toward the center of the cup 4. A through hole 43C for discharging liquid is drilled vertically in the inclined portion 43B. The upper guide portion 44 constituting the cup 4 is also an annular member arranged to surround the wafer W in a plan view. The upper guide portion 44 includes a vertical wall 44A attached to the inner peripheral surface of the outer cylindrical portion 41A, a horizontal portion 44B extending horizontally from the upper end of the vertical wall toward the center of the cup 4, and a cylindrical mouth wall 44C extending vertically upward from the tip of the horizontal portion 44B. The vertical wall 44A is provided above the vertical wall 43A of the intermediate guide portion 43, and the horizontal portion 44B is located above the inclined portion 43B of the intermediate guide portion 43.

[0017] The upper guide portion 44 and the intermediate guide portion 43 are attached to the outer cylindrical portion 41A at multiple positions in the circumferential direction, so that the height and inclination can be changed. Also, a camera 49 is provided to capture an image of the cup 4 described above from diagonally above. The camera 49, which is the first imaging portion, can capture image data of the upper side of the cup 4 (i.e., the upper guide portion 44) viewed from above.

[0018] Next, the resist supply mechanism 5A and the EBR processing mechanism 5B provided in the resist film forming module 3 will be described. The resist supply mechanism 5A includes a resist supply nozzle 51A, a resist supply unit 52A, an arm 53A, a moving mechanism 54A, and a waiting unit 55A. The resist supply nozzle 51A discharges the resist pressure-fed from the resist supply unit 52A vertically downward. The arm 53A supports the resist supply nozzle 51A, and is configured to be freely raised and lowered and horizontally moved by the moving mechanism 54A. A waiting unit 55A that opens upward is provided outside the cup 4, and the resist supply nozzle 51A moves between the opening of the waiting unit 55A and the inside of the cup 4 by the moving mechanism 54A. The resist supply nozzle 51A that has moved into the cup 4 discharges the resist onto the center of the rotating wafer W, and a resist film is formed on the entire surface of the wafer W by spin coating.

[0019] The EBR processing mechanism 5B includes a solvent supply nozzle 51B, a solvent supply unit 52B, an arm 53B, a moving mechanism 54B, and a standby unit 55B. The solvent supply nozzle 51B is a nozzle for EBR, and discharges the solvent, which is pumped from the solvent supply unit 52B, from the center side of the wafer W to the peripheral side in a diagonal downward direction. In other words, the solvent is discharged in a direction inclined with respect to the vertical direction. The arm 53B supports the solvent supply nozzle 51B, and is configured to be freely raised and lowered and freely moved horizontally by the moving mechanism 54B. A standby unit 55B that opens upward is provided outside the cup 4, and the solvent supply nozzle 51B moves between the opening of the standby unit 55B and a processing position above the wafer W in the cup 4 by the moving mechanism 54B. Note that FIG. 3 shows the solvent supply nozzle 51B in a state where it has been moved to the processing position by a solid line, and the above-mentioned EBR is performed by discharging the solvent from the solvent supply nozzle 51B at the processing position onto the rotating wafer W.

[0020] For example, the height of the solvent supply nozzle 51B is attached to the arm 53B so as to be freely adjustable. Therefore, the distance H1 (referred to as the nozzle separation distance) between the solvent supply nozzle 51B and the surface of the wafer W in the processing position shown in Fig. 2 is freely adjustable, and the landing position of the solvent discharged from the solvent supply nozzle 51B on the wafer W changes by changing the nozzle separation distance H1. Although shown only in Fig. 3, an illumination unit 48 capable of irradiating light toward the cup 4 is provided near the cup 4. When the camera 82 captures an image of the solvent supply nozzle 51B, the illumination unit 48 irradiates light onto the solvent supply nozzle 51B.

[0021] The substrate processing apparatus 2 includes a control unit 20 configured by a computer (see FIG. 1), and a program stored in a storage medium such as a compact disc, a hard disk, a memory card, or a DVD is installed in the control unit 20. The installed program includes instructions (each step) so that a control signal is output to each unit of the substrate processing apparatus 2. The control signal causes the transfer mechanisms 23 and 25 to transfer the wafer W, and each processing module to process the wafer W.

[0022] The resist film forming module 3 will now be described in further detail. The height from the lower surface of the wafer W held by the spin chuck 31 to the upper end of the inclined portion 43B of the intermediate guide portion 43 is defined as the intermediate guide portion height H2, and the height from the lower surface of the wafer W on the spin chuck 31 to the upper end of the opening wall 44C of the upper guide portion 44 is defined as the upper guide portion height H3 (see FIG. 2). Therefore, these guide portion heights (intermediate guide portion height H2 and upper guide portion height H3) are the heights from the upper surface of the spin chuck 31 (the surface on which the wafer W is placed) to the edges of the openings formed by the intermediate guide portion 43 and the upper guide portion 44.

[0023] The upper guide portion 44 and the intermediate guide portion 43 may be attached to the cup body 41 at an abnormal height due to an error during assembly or adjustment of the cup 4. This abnormal height may include being attached to the cup body 41 at an angle, causing the height of only a part of the circumferential direction to be abnormal. In such an abnormal height state, the desired exhaust performance may not be obtained, resulting in poor processing of the wafer W, or mist of the processing liquid may be scattered outside the cup 4. Furthermore, if the height of the upper guide portion 44 is abnormal, it may interfere with each nozzle passing over the cup 4.

[0024] One of the inspections using the inspection wafer 6 is to obtain the intermediate guide height H2 and the upper guide height H3. The guide heights H2 and H3 are obtained by detecting the upper end of the inclined portion 43B constituting the intermediate guide portion 43 (hereinafter referred to as the upper end of the intermediate guide portion 43) and the upper end of the mouth wall 44C constituting the upper guide portion 44 (hereinafter referred to as the upper end of the upper guide portion 44) by a proximity sensor 57 mounted on the inspection wafer 6. In obtaining the guide heights H2 and H3, a contact sensor 58 mounted on the inspection wafer 6 is also used to identify the position of the lower surface of the wafer W on the spin chuck 31. The contact sensor 58 is, for example, an acceleration gyro sensor.

[0025] Although details will be described later, three proximity sensors 57 are provided along the circumference of the inspection wafer 6, and the upper end of the intermediate guide portion 43 and the upper end of the upper guide portion 44 are detected by the proximity sensors 57 at three different points in the circumferential direction, respectively, to obtain three guide portion heights H2 and H3. In this manner, each of the intermediate guide portion 43 and the upper guide portion 44 surrounding the wafer W is a common detection target for the three proximity sensors 57, which are position sensors. Note that the guide portions 43 and 44 (the intermediate guide portion 43 and the upper guide portion 44) are located outside in a plan view with respect to the wafer W that is raised and lowered on the spin chuck 31 by the lift pins 35. Therefore, they are also located outside in a plan view with respect to the base body 61 of the inspection wafer 6 that is raised and lowered on the spin chuck 31 by the lift pins 35, as will be described later.

[0026] The reason why the multiple (three in this example) proximity sensors 57 detect multiple points on the detection target surrounding the wafer W will be described. This is because, as described above, the intermediate guide portion 43 and / or the upper guide portion 44 may be installed at an inclination, or the upper surface of the spin chuck 31 may be inclined relative to the horizontal plane, and the level may differ at each portion of the upper surface. In other words, the spin chuck 31 may be inclined relative to each member constituting the cup 4. As a result, the guide portion heights H2 and H3 may differ at each portion in the circumferential direction of the cup 4, and while one portion in the circumferential direction is normal, the other portion may be abnormal. Therefore, as described above, multiple points are detected and the guide portion heights H2 and H3 are obtained from each detection point, so that abnormalities in the heights of the intermediate guide portion 43 and the upper guide portion 44 can be accurately detected. The operator adjusts the circumferential heights of the upper guide portion 44 and / or the intermediate guide portion 43 as necessary according to the three intermediate guide portion heights H2 and the three upper guide portion heights H3 obtained. This makes it possible to prevent processing problems caused by abnormalities in the height of the upper guide portion 44 and the intermediate guide portion 43 from occurring.

[0027] The inspection wafer 6 also has a role of capturing images by the mounted cameras 81 and 82 and acquiring image data for detecting the separation distances H0 and H1 (the cup separation distance H0 and the nozzle separation distance H1). If the wafer W is processed with the cup separation distance H0 being inappropriate, the annular protrusion 46 may come into contact with the wafer W and damage the rear surface of the wafer W, or the annular protrusion 46 may be too far away from the wafer W and may not be able to fully perform its role. If the wafer W is processed with the nozzle separation distance H1 being inappropriate, the solvent supply nozzle 51B may come into contact with the wafer W and damage the wafer W, or an abnormality may occur in the width of the removed region of the resist film due to an abnormality in the landing position. The operator adjusts the height of the lower guide portion 42 on which the annular protrusion 46 is provided and / or the height of the solvent supply nozzle 51B as necessary according to the acquired separation distances H0 and H1. This makes it possible to prevent the occurrence of the above-mentioned abnormalities.

[0028] Furthermore, the inspection wafer 6 is provided with a contact-type interference detection unit, which detects whether or not this interference detection unit interferes with the annular protrusion 46, which is the first interference detection target member, and the solvent supply nozzle 51B at the processing position, which is the second interference detection target member. That is, the detection of this interference also makes it possible to obtain information on whether or not the cup separation distance H0 and the nozzle separation distance H1 are each smaller than the appropriate range.

[0029] The configuration of the inspection wafer 6 will be described below with reference to the vertical cross-sectional side views of FIG. 4, FIG. 5, and FIG. 6, and the plan view of FIG. 7. FIG. 4 to FIG. 6 show vertical cross-sectional side views at different positions. Note that FIG. 7 omits some of the components shown in FIG. 4 to FIG. 6. The inspection wafer 6 includes a circular base body 61 and a substrate 62. The base body 61 is a substrate having the same size as the wafer W, and its lower surface is configured as a flat surface similar to the lower surface of the wafer W. Therefore, the base body 61 can be transported by the transport mechanisms 23 and 25 and adsorbed and held by the spin chuck 31, similar to the wafer W. That is, the inspection wafer 6 is adsorbed and held by the spin chuck 31 instead of the wafer W, and FIG. 5 to FIG. 7 show the inspection wafer 6 in such a state of being adsorbed and held.

[0030] A substrate 62 is laminated on the upper side of a base body 61. The substrate 62 includes a main body 63 provided on the center of the base body 61. In FIG. 7 and FIG. 8 described later, the main body 63 is shown as a circle for convenience of illustration, but it is not limited to a circle and can be any shape. Various circuit parts and devices are provided on the main body 63, and are collectively shown as a parts group 64 in the figure. The parts and devices constituting the parts group 64 include a CPU and a communication device that wirelessly transmits and receives various data (including signals). Data acquired by each sensor and camera can be wirelessly transmitted to the calculation device 9 by this communication device. In addition, a signal that serves as a trigger for acquiring the data can be transmitted to each camera and each sensor via this communication device. In addition, as described later, the cameras 81, 82, the proximity sensor 57, etc. are mounted on a board other than the board 62, but data can be transmitted to the calculation device 9 and trigger signals can be received in this way via a wire 60 that connects the boards together.

[0031] A contact sensor 58 is provided on the main body 63. A battery 65 for supplying power to the parts 64, the sensors, the cameras, and a lighting unit 85 (described later) is provided in the center of the base body 61. The battery 65 and the parts 64 are disposed in the center of the base body 61.

[0032] The description will be given with reference to FIG. 9 showing a schematic perspective view of the base body 61. The above-mentioned three proximity sensors 57 are provided on the peripheral portion of the base body 61. For convenience of description, the three proximity sensors 57 may be described as 57A, 57B, and 57C to be distinguished from one another. The proximity sensors 57 are, for example, reflective optical sensors, and each irradiate infrared laser light along the radial direction of the base body 61 and toward the outside of the base body 61, and output a detection signal based on the reflected light from the detection target. Therefore, the detection directions of the three proximity sensors 57 are different from each other and are radially outward of the base body 61. The three proximity sensors 57 are provided at equal distances from the center of the base body 61 and are arranged at equal intervals along the circumferential direction of the base body 61. In addition, in the figure, 50 denotes a substrate provided upright to support the proximity sensors 57 on the base body 61, and are provided at a distance from each other in the circumferential direction in accordance with the arrangement of the proximity sensors 57.

[0033] In FIG. 9, a virtual line along the diameter of the base body 61 is indicated as 6A. As described above, the proximity sensors 57 are provided at intervals in the circumferential direction, so that the proximity sensors 57 are located in one region and the other region of the base body 61, which is divided into two equal parts by the virtual line 6A. The proximity sensors 57 are arranged in this manner in order to detect an abnormality so as to suppress the influence of the inclination of the spin chuck 31 with respect to the intermediate guide portion 43 and the upper guide portion 44 described above. More specifically, for example, it is considered that the upper surface of the spin chuck 31 is inclined with respect to the horizontal plane, so that the inspection wafer 6 is placed so that one region of the base body 61 is lower and the other region is higher. However, even in this case, the presence or absence of a height abnormality with respect to the intermediate guide portion 43 and the upper guide portion 44 can be determined by referring to the guide portion heights H2 and H3 obtained from the proximity sensors 57 in the one region and the other region, respectively, so that the occurrence of a judgment error due to the inclination can be suppressed, and the detection accuracy of the abnormality can be improved.

[0034] In Fig. 4, the laser light emitted from the proximity sensor 57 is indicated by a dotted arrow. In Fig. 4, the height between the position where the object can be detected by this laser light and the bottom surface of the base body 61 is indicated as a calibrated height H4. This calibrated height H4 is obtained in advance using a jig or the like, in order to be used in calculating the guide part heights H2 and H3.

[0035] Further explaining the substrate 62 on the base body 61, a main body 63 constituting the substrate 62 is fixed to the base body 61. A part of the periphery of the main body 63 extends toward the periphery of the main body 63 to form an elongated beam-like body 66 along the radial direction of the base body 61. A through hole 67 is formed in the periphery of the base body 61 at a position overlapping with the tip side of the beam-like body 66, penetrating the base body 61 in the thickness direction. The through hole 67 forms a connection path connecting one side (upper side) and the other side (lower side) of the base body 61 in the vertical direction.

[0036] The arrows in FIG. 8 show enlarged views of the various parts around the through hole 67. A protrusion 68 is provided on the lower surface of the tip side of the beam-like body 66, protruding downward and entering the through hole 67. The tip (lower end) of the protrusion 68 is located below the lower surface of the main body part 63, and protrudes, for example, about 1 mm from the lower surface of the main body part 63 (see FIG. 5). The protrusion 68 is located slightly away from the tip of the beam-like body 66 toward the base end side, and the tip of the beam-like body 66 is located closer to the periphery of the base body 61 than the through hole 67. Due to such an arrangement of the protrusion 68 and the through hole 67, the part of the beam-like body 66 on the base end side of the through hole 67 and the part on the tip side of the through hole 67 are supported in contact with the base body 61, respectively. That is, the upper surface region of the base body 61 including the outer edge of the through hole 67 supports the beam-like body 66.

[0037] The beam-like body 66, which is the first beam-like body, is a so-called cantilever and is configured as a first interference detection unit for acquiring information about the height of the annular protrusion 46. More specifically, the lower surface of the beam-like body 66 is not fixed to the base body 61 and is flexible in the vertical direction (thickness direction of the base body 61). Since the main body 63 to which the beam-like body 66 is connected is fixed to the base body 61 as described above, the base end of the beam-like body 66 is fixed to the base body 61. Therefore, one end of the beam-like body 66 is fixed to the center side of the base body 61, while the other end extending toward the peripheral part of the base body 61 is configured to be movable relative to the base body 61. In other words, the beam-like body 66 is partially fixed to the base body 61. A strain gauge (strain sensor) 69 is provided on the upper side of the base end (one end) of the beam-like body 66. The strain gauge 69 constituting the first signal acquisition unit configures a Wheatstone bridge circuit together with the components included in the above-mentioned component group 64, and a voltage signal output from the circuit is wirelessly transmitted to the calculation device 9 as a detection signal.

[0038] When the base body 61 is attracted by the spin chuck 31, the projection 68 of the beam-like body 66 is located above the annular projection 46. As described above, the lower surface of the wafer W and the lower surface of the base body 61 are both flat surfaces, and therefore, when placed on the spin chuck 31, they are at the same height. Therefore, when the above-mentioned cup separation distance H0 is equal to or less than the reference value and the wafer W and the annular projection 46 interfere with each other, as shown in FIG. 9, interference also occurs between the projection 68 of the inspection wafer 6 and the annular projection 46. Such interference of the projection 68 causes deformation of the tip side of the beam-like body 66 so that it is pushed upward. The strain gauge 69 also deforms in response to the deformation of the beam-like body 66, and the signal output from the above-mentioned Wheatstone bridge circuit fluctuates in response to the change in resistance of the strain gauge 69 caused by this deformation. Therefore, by monitoring this signal, it is possible to detect the presence or absence of interference between the annular projection 46 and the projection 68, and therefore it is possible to determine whether interference occurs between the wafer W and the annular projection 46.

[0039] The reason why the beam-like body 66 is supported in contact with the base body 61 is to prevent the beam-like body 66 from being plastically deformed so that its tip sags when the annular protrusion 46 hits it and the beam-like body 66 vibrates up and down. When only a part of the circumferential direction of the annular protrusion 46 is high and the annular protrusion 46 abuts against the beam-like body 66 from the side, the base end side of the beam-like body 66 is supported by the base body 61 to prevent the base end side of the beam-like body 66 from moving downward, and the downward force is converted into a force that directs the tip side of the beam-like body 66 upward. In other words, the beam-like body 66 also plays a role in increasing the amount of upward deformation of the tip side of the beam-like body 66 relatively, thereby improving the detection accuracy.

[0040] Also, a notch is provided on the periphery of the upper surface of the base body 61 at a position different in the circumferential direction from the position where the beam-like body 66 is provided. A second beam-like body, a beam-like body 71, is fixed at its base end toward the center of the base body 61 from the notch. The tip side of the beam-like body 71 is formed elongated so as to extend above the notch in the radial direction of the base body 61. Therefore, the tip of the beam-like body 71 is floating above the base body 61. In other words, a gap is formed between the beam-like body 71 and the base body 61 by the above-mentioned notch, and this gap is indicated as 72.

[0041] The beam-like body 71 also has a cantilever like the beam-like body 66, and is configured as a second interference detection unit for acquiring information about the height of the solvent supply nozzle 51B at the processing position. By being provided above the gap 72 as described above, the tip of the beam-like body 71 is configured to be movable up and down. A strain gauge 73 is provided on the upper side of the base end of the beam-like body 71. The strain gauge 73, which is the second signal acquisition unit, configures a Wheatstone bridge circuit together with the parts included in the part group 64 like the strain gauge 69, and a voltage signal from the circuit is wirelessly transmitted to the calculation device 9 as a detection signal.

[0042] When the spin chuck 31 is rotated with the wafer 6 to be inspected attached thereto, the lower end of the solvent supply nozzle 51B may interfere with the beam-like body 71 as shown in FIG. 10 if the nozzle separation distance H1 is equal to or less than a reference value. Such interference causes the tip of the beam-like body 71 to be pushed downward through the gap 72, and the gap 72 is deformed to narrow. The strain gauge 73 also deforms in response to the deformation of the beam-like body 71, and the signal output from the Wheatstone bridge circuit including the strain gauge 73 fluctuates. Therefore, by monitoring this signal, it is possible to detect the presence or absence of interference between the solvent supply nozzle 51B and the beam-like body 71, and to determine whether the processing position of the solvent supply nozzle 51B is appropriate.

[0043] The substrates 80, 80A, and 80B on which the cameras 82, 81A, and 81B are mounted are provided on the periphery of the base body 61, and the beam-like bodies 66 and 71, the proximity sensors 57A, 57B, and 57C, and the cameras 82, 81A, and 81B are located apart from each other in the circumferential direction of the base body 61. The fields of view of the cameras 82, 81A, and 81B are directed toward the periphery of the base body 61, and the camera 82, which is the second imaging unit, is provided to image the solvent supply nozzle 51B from the center side of the base body 61. By arranging the proximity sensor 57 as described above, the camera 82 is located between one of the three proximity sensors 57 and the other proximity sensor in the circumferential direction of the base body 61. Similarly, the beam-like bodies 66 and 71 are located between one of the proximity sensors and the other proximity sensor in the circumferential direction of the base body 61.

[0044] The cameras 81A and 81B are for capturing images of the annular protrusion 46. A mirror 83A is disposed on the optical axis of the camera 81A, and a through hole 84A is formed in the base body 61. When the inspection wafer 6 is held by the spin chuck 31, the through hole 84A is positioned on the annular protrusion 46, and a part of the upper surface of the annular protrusion 46 in the circumferential direction is reflected on the mirror 83A through the through hole 84A. The camera 81A can capture an image of the part of the upper surface of the annular protrusion 46 reflected on the mirror 83A. Two illumination units 85A are embedded in the base body 61. The illumination units 85A are disposed so as to sandwich the through hole 84 in the circumferential direction of the base body 61, and irradiate light downward. When the camera 81A captures an image, light is irradiated from each illumination unit 85A to a subject below.

[0045] Similarly to the mirror 83A, through hole 84A, and lighting unit 85A corresponding to the camera 81A, a mirror, through hole, and lighting unit corresponding to the camera 81B are provided, and are shown as 83B, 84B, and 85B, respectively. The set consisting of the substrate 80A, the camera 81A, the mirror 83A, the through hole 84A, and the lighting unit 85A is provided closer to the center of the base body 61 than the set consisting of the substrate 80A, the camera 81A, the mirror 83A, the through hole 84A, and the lighting unit 85A. As a result, the area imaged by the camera 81B is located closer to the center of the base body 61 than the area imaged by the camera 81A. Therefore, the multiple cameras are provided at different positions in the radial direction of the base body 61 (i.e., the distances from the center of the base body 61 are different), and are arranged to image different positions in the radial direction. The diameter of the annular protrusion 46 is different for each resist film forming module 3. Of the cameras 81A and 81B, image data acquired from a camera positioned according to the size of the diameter of the annular projection 46 is used to acquire the cup separation distance H0.

[0046] On the base body 61, for example, a circular cover 86 whose side wall follows the circumference of the base body 61 is provided, and covers the main body 63 of the substrate 62, the battery 65, the camera 81 (81A, 81B), the camera 82, the mirrors 83A, 83B, and the proximity sensor 57. However, in order not to impede the image pickup of the solvent supply nozzle 51B by the camera 82 and the detection by the proximity sensor 57, the side wall of the cover 86 is provided with openings on the optical axis of the proximity sensor 57 in the field of view of the camera 82. In addition, in order not to impede the deformation of the beam-like bodies 66 and 71, for example, the lower end of the side wall of the cover 86 is cut out, and the tip side of the beam-like bodies 66 and 71 protrudes outside the cover 86 through this cutout and is located on the periphery of the base body 61. In addition, the side end of the cover 86 is located closer to the center of the base body 61 than the solvent supply nozzle 51B at the processing position in order to prevent interference with the solvent supply nozzle 51B.

[0047] In the example shown in FIG. 4 to FIG. 6, the center of the cover 86 is formed to have a larger height than the periphery of the cover 86, and to form a convex portion 87 facing upward. In accordance with the configuration of the cover 86, the battery 65 and the group of parts 64 can be arranged in the center of the base body 61 as described above, and the center of gravity of the base body 61 can be positioned in the center. Therefore, when the base body 61 is placed on the spin chuck 31, the base body 61 can be prevented from sagging due to its own weight. Therefore, it is possible to prevent the height of the proximity sensor 57, the beam-like bodies 66, 71, and the cameras 81, 82 from changing due to the sagging, and thus affecting the measurement results. Therefore, the cover 86 having the convex portion 87 contributes to improving the detection accuracy of anomalies. However, the cover 86 may be formed to have a relatively large thickness, so that the upper surface of the cover 86 has a flat shape.

[0048] Also, for example, when an operator handles the inspection wafer 6 by loading it onto the carrier C or performing maintenance, the inspection wafer 6 passes through a relatively narrow area. At that time, since the upper surface of the cover 86 is located at a position higher than the beam-like bodies 66, 71, even if the inspection wafer 6 collides with a wall that defines the narrow area, the cover 86 collides with the wafer, preventing the wafer 6 from colliding with the wall of the beam-like bodies 66, 71. Therefore, the beam-like bodies 66, 71 are prevented from being plastically deformed or damaged, and the cover 86 can effectively protect the beam-like bodies 66, 71.

[0049] Next, the arithmetic unit 9 will be described with reference to Fig. 4. The arithmetic unit 9 is a computer and includes a bus 91. A program storage unit 92, a wireless transmission / reception unit 93, a memory 94, a display unit 95, and an operation unit 96 are connected to the bus 91. In the program storage unit 92, a program 90 stored in a storage medium such as a compact disc, a hard disk, a memory card, or a DVD is installed.

[0050] The wireless transceiver 93 wirelessly transmits a signal that serves as a trigger for acquiring data to the inspection wafer 6, and wirelessly receives detection signals from each circuit including the above-mentioned strain gauges 69, 73, image data acquired by the cameras 81, 82, and detection signals from the proximity sensor 57 and the contact sensor 58. The memory 94 stores data acquired from each sensor and camera. The memory 94 also stores various data prepared in advance for acquiring the separation distances H0, H1, guide portion heights H2, H3, etc., which will be described later.

[0051] The operation unit 96 is composed of a mouse, a keyboard, etc., and the user of the information acquisition system 1 can instruct the execution of processes that can be performed by the program 90 via the operation unit 96. The calculation device 9 is also connected to the control unit 20 of the substrate processing apparatus 2, and for example, when the inspection wafer 6 is held by the spin chuck 31, a signal indicating that various data can be acquired is transmitted from the control unit 20 to the calculation device 9. Information regarding the command position of a motor constituting the lifting mechanism 36 described below is also transmitted.

[0052] Next, a method for obtaining the guide heights H2 and H3 will be briefly described. With the base body 61 of the inspection wafer 6 placed on the spin chuck 31, the lift pins 35 are raised from a standby position for the lift pins 35. Then, according to the detection signal of the contact sensor 58, a command position (first command position) of the motor of the lift mechanism 36 when the lift pins 35 come into contact with the base body 61 is identified (FIG. 11, step R1).

[0053] Next, the lift pins 35 are further lifted while being irradiated with infrared laser light from each proximity sensor 57. This lifting of the lift pins 35 is performed by irradiating the upper end of the intermediate guide portion 43 with the infrared laser as shown in Fig. 12, and then irradiating the upper end of the upper guide portion 44 as shown in Fig. 13, and is performed by a preset amount so as to reach above the upper end of the upper guide portion 44 (step R2).

[0054] Based on the detection signals respectively acquired from the proximity sensors 57, the command position of the motor when the laser light is located at the upper end of the intermediate guide section 43 (hereinafter referred to as the second command position) and the command position of the motor when the laser light is located at the upper end of the upper guide section 44 (hereinafter referred to as the third command position) are respectively specified (step R3). The motor rotates a certain angle for each input pulse, and the rotation angle corresponds to the amount of lift of the lift pins 35. The command position of the motor corresponds to the number of pulses thus input to the motor, and is information corresponding to the height of the lift pins 35. Therefore, for example, the specification of the first command position in the above step R1 corresponds to the detection of the contact height at which the lift pins 35 and the base body 61 come into contact, and the specification of the second command position and the third command position corresponds to the detection of the height of the upper ends of the guide sections 43, 44. When an encoder is connected to the motor, the encoder outputs a pulse corresponding to the height of the lift pins 35, and therefore the output from the encoder can be used as the command position of the motor.

[0055] The lift amount of the lift pin 35 per pulse input to the motor is known. If this lift amount is X mm / pulse, the intermediate guide part height H2 and the upper guide part height H3 are calculated by the following formulas 1 and 2 (step R4). The second command position and the third command position are specified from the detection signals of the proximity sensors 57A, 57B, and 57C, and formulas 1 and 2 are executed, so that the guide part heights H2 and H3 are calculated for the proximity sensors 57A, 57B, and 57C, respectively, as described above. The calculated guide part heights H2 and H3 are displayed on the display unit 95 (step R5). In this example, the units of the heights H2, H3, and H4 are mm. The above steps R1 to R5 are executed by the program 90 of the calculation device 9. The lift amount X mm / pulse and the calibrated height H4 used to calculate the guide part heights H2 and H3 are obtained in advance and stored in the memory 94 of the calculation device 9, for example. Intermediate guide height H2 = (second command position - first command position) × X + calibrated height H4 Formula 1 Upper guide height H3 = (third command position - first command position) × X + calibrated height H4 Formula 2

[0056] Steps R1 to R3 for specifying the first to third command positions will be described in more detail. After the lift pins 35 are continuously raised from the standby position by a predetermined amount, the lift is switched to a stepwise lift according to the resolution of the lift operation (the minimum amount that can be raised and lowered). In other words, the lift pins 35 are operated so as to repeatedly rise in the smallest possible range and temporarily stop rising. As an example, if the lift pins 35 can be raised and lowered by a magnitude of 0.05 mm or more, they are raised by 0.05 mm and then stopped. Specifically, if no contact is detected when the lift pins 35 are raised by 0.05 mm, and contact is detected when the lift pins 35 are raised by the next 0.05 mm, the number of pulses input to the motor at the time of the detection is set as the first command position, and the above step R1 is completed. By raising the lift pins 35 stepwise by small distances in this manner, the height at which the lift pins 35 contact the base body 61 by the contact sensor 58 is accurately specified.

[0057] Then, even after the contact is detected as described above, the lift pins 35 repeat rising according to the resolution of the lifting operation and temporarily stopping the lift. During this temporary stop of the lift, infrared rays are irradiated from the proximity sensor 57 and a detection signal is acquired (sampled), thereby performing step R2. The time for the temporary stop of the lift is set so that the detection signal is acquired multiple times. As an example, the acquisition period is set to 10 ms, the lift stop time is set to 1 second, and 100 signal acquisitions are performed during one stop of the lift. Then, as described above, the lift pins 35 rise until the irradiation position of the infrared rays from the proximity sensor 57 reaches a set height higher than the upper guide part 44, and until the height position is reached, the lift according to the resolution and the acquisition of the detection signal during the stop of the lift are repeated. In this way, the lift pins 35 raise and lower the inspection wafer 6 (in this case, raise), and infrared rays are irradiated to different heights, thereby detecting the heights of the guide parts 43 and 44.

[0058] Then, in determining the second command position and the third command position in step R3, the average value of the acquired data is calculated for each height at which the lift pin 35 is stopped. FIG. 14 is a graph showing the transition of the average value of the data when the tip of the lift pin 35 rises near the upper end of the upper guide part 44. As the lift pin 35 rises, the infrared ray irradiated from the proximity sensor 57 switches from being blocked by the upper guide part 44 to being unblocked, and the amount of reflected light toward the proximity sensor 57 decreases, causing the average value to fluctuate greatly. The command position corresponding to the height of the lift pin 35 at which this fluctuation occurs (P1 in the graph) is determined as the third command position. The second command position can also be determined according to the transition of the average value, similar to the third command position.

[0059] It should be noted that the calculation of the average value of the data acquired when the lifting is stopped is not limited to this, and an index of the variation, specifically, for example, σ, may be calculated. FIG. 15 is a graph showing the transition of σ when the tip of the lifting pin 35 rises near the upper end of the upper guide part 44. When the shielded state and the unshielded state are switched, that is, when the proximity sensor 57 irradiates the upper end of the upper guide part 44 with light, the light is diffused and the variation in the amount of received light becomes relatively large. Therefore, the command position corresponding to the height (P2 in the graph) of the lifting pin 35 at which σ is the maximum value is determined as the third command position. The second command position can also be determined in the same manner according to the transition of σ. Incidentally, the index of the variation is set to σ, but is not limited to this, and the difference between the maximum and minimum values ​​of the signal level (i.e., the range) may be used, and the heights at which this range is at its peak may be determined as the second command position and the third command position, respectively.

[0060] As described above, the second command position and the third command position are also detected with high accuracy by using the detection results from the proximity sensor 57 obtained by gradually raising the lift pins 35 by small distances and by using a large number of detection results obtained while the lift pins 35 are stopped. In the above example, the second command position and the third command position are specified by irradiating infrared rays from the proximity sensor 57 while the inspection wafer 6 is raised in a predetermined section, but the present invention is not limited to this. For example, after the inspection wafer 6 is raised to a predetermined height by the lift pins 35, the second command position and the third command position may be specified by irradiating infrared rays from each proximity sensor 57 while the inspection wafer 6 is lowered in a predetermined section toward the spin chuck 31.

[0061] However, when the resolution of the lifting operation is relatively small, it is preferable to use the following method instead of the above-mentioned method of using the detection results during the stepwise lifting of the lift pins 35 as the method of identifying the first command position in step R1. Assuming that the resolution is, for example, 0.05 mm, the explanation will be given using the schematic diagram of FIG. 16. Each arrow in FIG. 16 indicates the movement range and movement direction of the tip of the lift pins 35, and the arrows arranged on the right side in the time series indicate movement at later times. Regarding the movement range of the lift pins 35 when they are lifted, the arrows of the dashed line indicate the movement range where contact is not detected, and the arrows of the solid line indicate the movement range where contact is detected. Also, the base body 61 in the figure indicates the base body 61 at the height in a state where it is supported by the spin chuck 31.

[0062] First, as in the above example with a relatively large resolution, the lift pins 35 are continuously raised from the standby position by a predetermined amount, and then the lift is switched to a stepwise lift of, for example, 0.2 mm each according to the resolution of the lift operation. As this stepwise lift continues, in one lift section (shown as arrow V1), a contact non-detection state continues during the lift, and in the next lift section (shown as arrow V2), the state switches to a contact detection state. Then, the lift pins are lowered (shown as arrow V3) by a second amount, for example, 0.25 mm, which is larger than the first magnitude (0.2 mm) during the lift, and the tip of the lift pins 35 moves to a position lower than the arrow V2, so that the contact between the lift pins 35 and the base body 61 is temporarily released.

[0063] Thereafter, the lift pins 35 are raised again by 0.2 mm (shown as arrow V4), and if the state where no contact is detected switches to a state where contact is detected during this rise, the lift pins 35 are lowered again by 0.25 mm (arrow V5) and then raised by 0.2 mm (arrow V6). If the state where no contact is detected switches to a state where contact is detected during this rise, the lift pins 35 are further lowered by 0.25 mm (arrow V7) and then raised by 0.2 mm (arrow V8). It is assumed that when the lift pins 35 are raised as shown by arrow V8, a switch from the state where no contact is detected to a state where contact is detected also occurs.

[0064] In this case, if the lift pins 35 are repeatedly lowered by 0.25 mm and raised by 0.2 mm next time, the tips of the lift pins 35 will be located at the height of the tips of the arrow V1. That is, the height will be below the bottom end of the height region (first height region) of the arrow V2 where contact was detected for the first time, and there will be no switch from a non-contact detection state to a contact detection state. Therefore, the height of the lift pins 35 when raised as shown by the arrow V8 is regarded as the height at which contact with the base body 61 switches between on and off, and the command value for the motor at that height is specified as the first command position.

[0065] In this way, after the lift pins 35 are raised as indicated by the arrow V2, the lift pins 35 are lowered at the second magnitude and raised at the first magnitude repeatedly, and it is assumed that the contact non-detection state remains during the lift pins 35 being raised. In this case, the motor command value for the height of the lift pins 35 when raised in this way is treated as the first command value, and the lift pins are not lowered and raised repeatedly thereafter. As a specific example, it is assumed that no contact is detected when the lift pins 35 are raised as indicated by the arrow V4 as shown in FIG. 17. In this case, the motor command value when the lift pins 35 are raised as indicated by the arrow V4 is specified as the first command position, step R1 is terminated, and the lifting and lowering operations indicated by the numbers after the arrow V5 in FIG. 16 are not performed, and the process proceeds to step R2.

[0066] 16 and 17 described above, the accuracy of the first command position is higher than if the position when the lift pins 35 are lifted as shown by arrow V2 were used as the first command position. Therefore, even if the resolution of the lifting and lowering operation of the lift pins 35 is small, that is, even if the minimum lift amount is a relatively large value, the guide part heights H2 and H3 can be calculated with high accuracy.

[0067] Next, a method of acquiring the cup separation distance H0 using image data acquired from the cameras 81A and 81B, and a method of acquiring the nozzle separation distance H1 using image data acquired from the camera 82 will be described. FIG. 18 shows image data of a part of the circumferential direction of the upper surface of the annular projection 46 captured by the camera 81A or 81B. The dotted frame indicates the pixels of the image. The number of pixels of the width L3 of the annular projection 46 is detected from the image data acquired in this way (step S1). The cup separation distance H0 is calculated based on the correspondence relationship between the number of pixels of the width L3 and the cup separation distance H0 acquired in advance (step S2). As this correspondence relationship, an equation of any degree may be prepared that uses the cup separation distance H0 and the number of pixels of the width L3 as variables, and expresses the relationship that L3 becomes smaller as H0 increases. Then, the cup separation distance H0 calculated from the correspondence relationship is displayed on the display unit 95 of the calculation device 9 (step S3).

[0068] A method of acquiring the nozzle separation distance H1 will be described. FIG. 19 shows image data of the side of the solvent supply nozzle 51B captured by the camera 82. In the image data, the number of pixels corresponding to the width L4 of the solvent supply nozzle 51B is detected (step T1). Next, in the image data, the number of pixels at the height H20 between the lower end of the solvent supply nozzle 51B specified in step T1 and the reference height H10 (pixels at a height set in advance in the image data) is detected (step T2). The H20 is set as the nozzle reference height. Then, a calculation is performed on the width L4 of the solvent supply nozzle 51B acquired in advance / the number of pixels corresponding to the width L4 acquired in step T1, and this calculated value is set as the distance in one pixel (step T3). Then, the number of pixels of the nozzle reference height H20 obtained in step T2 x the distance in one pixel obtained in step T3 is calculated. That is, the nozzle reference height H20, which is the number of pixels on the image data, is converted to the actual height (distance) (step T4).

[0069] A height difference (H30) between the surface of the wafer W when the wafer W is held by suction on the spin chuck 31 and the above-mentioned reference height H10 in the image captured by the camera 82 when the inspection wafer 6 is held by suction on the spin chuck 31 is acquired in advance. The nozzle separation distance H1 is calculated based on the actual nozzle reference height H20 obtained in the above step T4 and the height difference H30 (step T5). Specifically, as shown in FIG. 19, when the nozzle 51B appears above the reference height H20 in the image, the nozzle separation distance H1 is calculated as H20+H30, and when the nozzle 51B appears below the reference height H20 in the image, the nozzle separation distance H1 is calculated as H30-H20. The calculated nozzle separation distance H1 is displayed on the display unit 95 of the calculation device 9 (step T6). The height difference H30 acquired in advance is used because the field of view of the camera 82 is limited by being installed on the base body 61.

[0070] The above steps S1 to S3 and T1 to T6 are performed by program 90 of calculation device 9. The correspondence between the number of pixels of width L3 and cup separation distance H0, height difference H30, and actual width L4 of solvent supply nozzle 51B for executing these steps are stored in advance in memory 94 of calculation device 9.

[0071] An example of an operation procedure of the information acquisition system 1 described above will be described. In this operation procedure example, the detection of the cup separation distance H0 and the nozzle separation distance H1 by the cameras 81 and 82 described in Fig. 18 and Fig. 19 is not performed. First, the carrier C storing the inspection wafer 6 is transported to the stage 21 of the substrate processing apparatus 2. The inspection wafer 6 is transported in the order of the transport mechanism 23 → the delivery module TRS → the transport mechanism 25 → the resist film forming module 3, and is placed on the spin chuck 31 via the lift pins 35 and is adsorbed and held thereon.

[0072] For example, when an operator issues a predetermined instruction from the arithmetic device 9, the above steps R1 to R3 shown in Figs. 11 to 13 are executed, and the intermediate guide section height H2 and the upper guide section height H3 are acquired from each of the proximity sensors 57A to 57C, and are stored in the memory 94 of the arithmetic device 9 and displayed on the display unit 95. Thereafter, the lift pins 35 are lowered and the inspection wafer 6 is again attracted to the spin chuck 31, and the solvent supply nozzle 51B moves from the standby section 55B to the processing position. The inspection wafer 6 rotates once by the spin chuck 31, and detection signals from each circuit including the strain gauges 69 and 73 during this one rotation are each transmitted to the arithmetic device 9 and stored in the memory 94, and the waveforms are displayed on the display unit 95. After the inspection wafer 6 rotates once, the solvent supply nozzle 51B returns to the standby section 55B. The inspection wafer 6 is then delivered to the transport mechanism 25 via the lift pins 35, and returned to the carrier C via the transfer module TRS and the transport mechanism 23 in this order.

[0073] The operator judges whether the three acquired values ​​of the intermediate guide portion height H2 and the three acquired values ​​of the upper guide portion height H3 are all within the allowable range. The operator also judges whether the waveforms of the detection signals acquired from the strain gauges 69, 73 are normal. Specifically, the operator judges the waveforms by comparing the waveforms with reference data acquired by rotating the spin chuck 31 holding the inspection wafer 6 once under conditions where there is no interference between the solvent supply nozzle 51B and the annular protrusion 46 and the beam-like bodies 66, 71.

[0074] If either guide portion height H2 or H3 is outside the allowable range, the worker corrects the installation of intermediate guide portion 43 and / or upper guide portion 44. If the waveform of the detection signal from strain gauge 69 and / or strain gauge 73 becomes abnormal, the worker adjusts the height of lower guide portion 42 having annular protrusion 46 and / or solvent supply nozzle 51B.

[0075] Thereafter, the carrier C storing the wafer W is transported to the stage 21 of the substrate processing apparatus 2. The wafer W is transported in the order of the transport mechanism 23 → the transfer module TRS → the transport mechanism 25 → the resist film forming module 3 → the transport mechanism 25 → the heating module 26 → the transport mechanism 25 → the transfer module TRS, and is returned to the carrier C by the transport mechanism 23. During this transport, in the resist film forming module 3, resist is discharged from the resist supply nozzle 51A onto the center of the surface of the wafer W rotated by the spin chuck 31, and a resist film is formed on the entire surface of the wafer W by spin coating. Thereafter, the solvent supply nozzle 51B moves from the standby section 55B to the processing position, and a solvent is supplied to the peripheral portion of the rotating wafer W, and the resist film on the peripheral portion is removed.

[0076] Next, the following describes the case where the inspection wafer 6 is subjected to acquisition of the separation distances H0 and H1 by the cameras 81 and 82 instead of the interference detection by the beam-like bodies 66 and 71, focusing on the differences from the above-mentioned operation procedure. For example, after the lift pins 35 lift the inspection wafer 6 and acquire the guide heights H2 and H3 as described above, the lift pins 35 descend and the inspection wafer 6 is again attracted to the spin chuck 31. Then, after the solvent supply nozzle 51B moves to the processing position, the spin chuck 31 rotates intermittently, for example, at intervals of a predetermined angle, and when the rotation stops, the camera 81A or 81B, 82 captures the image data to acquire the image data. The acquired image data is sequentially transmitted to the calculation device 9 by wireless.

[0077] The above steps S1 to S3 are executed for each image data acquired by the camera 81 (81A, 81B), and the cup separation distance H0 is calculated and displayed on the screen. It is possible to determine which of the cameras 81A and 81B to use and capture images only with that camera, or to acquire images with both cameras and select an image in which the annular protrusion 46 is captured by the program 90 to calculate the cup separation distance H0. Also, among the multiple image data acquired by the camera 82, for example, an image in which the solvent supply nozzle 51B is captured is selected by the program 90 of the computing device 9 as shown in FIG. 19. Then, the above steps T1 to T6 are executed for the selected image data, and the nozzle separation distance H1 is calculated and displayed on the screen. An operator who sees the H0 and H1 displayed in this way adjusts the height of the annular protrusion 46 and / or the nozzle 51B as necessary.

[0078] Although the acquisition of the separation distances H0, H1 by the cameras 81, 82 and the detection of interference by the beam-like bodies 66, 71 are selectively performed, both may be performed. In addition, although it has been described that the operator judges each abnormality based on the acquired guide part heights H2, H3, separation distances H0, H1, and signal waveforms from the strain gauges 69, 73 of the beam-like bodies 66, 71, the program 90 may compare the values ​​and signal waveforms stored in the memory 94 with reference data. In that case, if the program 90 judges an abnormality, a predetermined display may be displayed on the display unit 95 as an alarm, or a predetermined sound may be output from the speaker constituting the computing device 9.

[0079] As described above, by using the inspection wafer 6, it is possible to obtain the guide part heights H2, H3 at three different locations in the circumferential direction of the cup 4. As described above, by obtaining the heights at a plurality of locations in this manner, the influence of the inclination of the upper guide part 44 and the intermediate guide part 43 relative to the spin chuck 31 is suppressed, and abnormalities in the heights of the upper guide part 44 and the intermediate guide part 43 can be detected with high accuracy. Therefore, abnormalities in the processing of the wafer W can be prevented, and a decrease in the yield of semiconductor products manufactured from the wafer W can be prevented.

[0080] Also, suppose that the center of the inspection wafer 6 is held eccentrically with respect to the center of the spin chuck 31. Suppose that this eccentric holding causes one of the proximity sensors 57 to move away from the opening edge of the middle guide portion 43 and the upper guide portion 44, resulting in a decrease in detection accuracy or an inability to detect. However, by providing a plurality of proximity sensors 57, there is also the advantage that detection can be performed using the other proximity sensors 57. As described in FIG. 9, the proximity sensors 57 are provided in one region and the other region separated by the virtual line 6A. This arrangement is effective for suppressing the influence of the inclination between the guide portions 43, 44 and the spin chuck 31, as described above, but is also effective for suppressing the influence of the eccentricity between the spin chuck 31 and the inspection wafer 6. This is because, even if the proximity sensor 57 in one region moves away from the opening edge of the guide portions 43, 44 due to eccentricity, causing a decrease in detection accuracy, the proximity sensor 57 in the other region is close to the opening edge of the guide portions 43, 44, so that detection can be performed reliably. The number of proximity sensors 57 is not limited to the above-mentioned example, and may be two or more than three.

[0081] In the inspection wafer 6, the proximity sensor 57, the cameras 81, 82, and the beam-like bodies 66, 71 are arranged circumferentially offset from one another on a common base body 61. By using these in this arrangement, in addition to obtaining the guide part heights H2, H3, it is also possible to detect interference with the nozzle and the annular protrusion 46, and to obtain the separation distances H0, H1. Therefore, by transporting the inspection wafer 6 to the resist film forming module 3 once, this information can be obtained, which is advantageous in that the time required for inspection can be shortened.

[0082] By the way, in acquiring the guide part heights H2 and H3, an example different from the example described as steps R1 to R5 will be described below. In this acquisition example, unlike the previously described example in which the lift pins 35 are raised in stages, the lift pins 35 are continuously raised at a relatively low speed. Below, with reference to FIG. 20, the differences from the case of raising them in stages will be mainly described. FIG. 20 is a timing chart showing the rise speed of the lift pins 35, the detection signal from the contact sensor 58, and the transition of the detection signal from one of the three proximity sensors 57. The chart also shows signal waveforms obtained by processing each detection signal from the contact sensor 58 and the proximity sensor 57 with a predetermined algorithm. This signal processing is performed, for example, by the calculation device 9 that receives the detection signal. The data sampling rate for both the contact sensor 58 and the proximity sensor 57 is set to 10 ms.

[0083] First, the inspection wafer 6 is held on the spin chuck 31 and is irradiated with light from the proximity sensor 57. Then, the lift pins 35 are raised from the standby position, and when they have risen a predetermined amount, the speed is reduced, for example, to 0.2 mm / sec. The lift pins 35 come into contact with the inspection wafer 6 to lift the inspection wafer 6, and when the inspection wafer 6 has risen a predetermined amount, the slow lift of 0.2 mm / sec is released. The height at which this slow lift is released is a height at which the infrared irradiation position of the proximity sensor 57 is located above the upper guide portion 44, in terms of design. While the lift pins 35 are being raised in this manner, detection signals are acquired from each of the contact sensor 58 and the proximity sensor 57.

[0084] A peak is detected in the detection signal waveform of the contact sensor 58 after data processing. In the graph, the time when the peak is detected is indicated as t1. A peak is also detected in the detection signal waveform of the proximity sensor 57 after data processing. The peak that appears at an early time corresponds to the upper end of the intermediate guide portion 43, and the peak that appears at a later time corresponds to the upper end of the upper guide portion 44. In the graph, the time when the peak corresponding to the upper end of the intermediate guide portion 43 appears and the time when the peak corresponding to the upper end of the upper guide portion 44 appears are indicated as t2 and t3, respectively. From the sampling rate of each sensor and the lifting speed of the lifting pins 35 described above, the distance that the lifting pins 35 rise from when a detection signal is acquired at a certain time until the next detection signal is acquired is 0.002 mm.

[0085] Therefore, the guide portion heights H3 and H4 can be calculated from the following formulas 3 and 4. In formulas 3 and 4, the units of H2 to H4 are mm. When obtaining the guide portion heights H2 and H3 in this manner, it is not necessary to specify the command position of the motor as described in steps R1 to R5, and therefore obtaining the command position of the motor is not essential for obtaining the guide portion heights H2 and H3. Intermediate guide height H2 = (number of data points from time t1 to t2 - 1) × 0.002 + calibrated height H4 Equation 3 Upper guide height H3 = (number of data points at times t1 to t3 - 1) × 0.002 + calibrated height H4 Equation 4

[0086] Incidentally, as shown in FIG. 3, the resist film forming module 3 is provided with a camera 49 for capturing an image of the upper guide portion 44. FIG. 21 shows image data 100 captured by the camera 49, which is image data on the upper end of the cup 4, i.e., the upper guide portion 44. For example, the image data 100 is captured at any timing and compared with reference image data 101 captured in advance. The reference image data 101 is image data captured by the camera 49 when each part of the upper guide portion 44 is at a normal height. Then, a deviation amount A1 of the height of the upper guide portion 44 between the image data 100 and the reference image data 101 is acquired. The deviation amount A1 is compared with a reference value, and if it exceeds the reference value, it is assumed that there is an abnormality.

[0087] However, as described with reference to Figs. 11 to 13, if all of the upper guide portion heights H3 acquired from the three proximity sensors 57 are normal, the height of the upper guide portion 44 is deemed normal. In other words, the height of the upper guide portion 44 is determined to be abnormal only when both the upper guide portion height H3 and the deviation amount A1 are abnormal. The image data 100 is transmitted to the calculation device 9, for example, and the reference image data 101 is stored in the memory 94, and the program 90 of the calculation device 9, which is the information acquisition unit, determines whether or not there is an abnormality. This determination of abnormality corresponds to the acquisition of information about the position of the cup 4.

[0088] It should be noted that this determination is merely an example, and if only one of the deviation amount A1 and the upper guide portion height H3 is abnormal, it may be determined that there is an abnormality in the height of the upper guide portion 44. As described above, by using both the image data 100 acquired from the camera 49 and the upper guide portion height H3 obtained from each proximity sensor 57, that is, data with different viewpoints or fields of view for the same object, as a means for detecting an abnormality, it is possible to detect an abnormality with higher accuracy.

[0089] In the above example, the contact sensor 58 that detects the contact between the lift pins and the base body 61 is described as an acceleration gyro sensor, but it is not limited to an acceleration gyro sensor as long as it can detect the contact. For example, it may be a sensor that has only one of the functions of an acceleration sensor and a gyro sensor, or it may be a vibration sensor. In this way, the contact sensor 58 used is one that can detect the difference in the movement and attitude of the inspection wafer 6 immediately before and after the contact.

[0090] Figure 22 shows a modified example of the cup 4. The intermediate guide portion 43 is supported at different circumferential positions by three support columns 102 (only two are shown in the figure). The three support columns 102 are provided at equal intervals in the circumferential direction of the cup 4, and their lower ends penetrate the bottom of the cup 4 and are connected to a lifting mechanism 103, so that they can be raised and lowered independently of each other. By raising and lowering each of the support columns 102, the height and inclination of the upper guide portion 44 of the cup body 41 can be freely adjusted by the lifting mechanism 103.

[0091] For example, when the inspection wafer 6 is carried into the device, the inspection wafer 6 is oriented in a predetermined direction so that the detection positions of the upper guide portion 44 by the proximity sensors 57A-57C are positions supported by the supports 102. If there is an abnormal value for the intermediate guide portion height H2 detected by each of the proximity sensors 57A-57C, the support 102 at the position detected by the abnormal proximity sensor 57 is raised or lowered by the deviation between the abnormal value and the allowable value. This brings the intermediate guide portion height H2 within the allowable range and eliminates the abnormality. The upper guide portion 44 may also be configured in the same manner as the intermediate guide portion 43 in this example so that the height abnormality is eliminated.

[0092] In the information acquisition system 1 described above, the control unit 20 and the arithmetic device 9 are provided separately, but the control unit 20 may also serve as the arithmetic device 9. In addition, although each piece of data is wirelessly transmitted to the arithmetic device 9 in the example described above, for example, a removable memory may be mounted on the base body 61 of the inspection wafer 6 and the data may be stored in the memory. In that case, an operator may remove the memory from the inspection wafer 6 that has been returned to the carrier C after data acquisition and transfer each piece of data to the arithmetic device 9. Therefore, the inspection wafer 6 may not be configured to wirelessly transmit image data. Note that the inspection wafer 6 and the arithmetic device 9 may be connected by wire, and various pieces of data may be transmitted to the arithmetic device 9.

[0093] The inspection wafer 6 is configured so that each of the proximity sensors 57 is provided at a height corresponding to the lower end of the nozzle 51B at the processing position on the base body 61. Then, the inspection wafer 6 is rotated once together with the spin chuck 31, and it is determined whether or not the solvent supply nozzle 51B is detected by each of the proximity sensors 57. Since the spin chuck 31 may be tilted as described above, for example, even if one of the multiple proximity sensors 57 does not detect the nozzle 51B, if another sensor detects the nozzle 51B, the height of the nozzle 51B is considered to be normal. On the other hand, if none of the multiple proximity sensors 57 detect the nozzle 51B, the height of the nozzle 51B is considered to be abnormal. In this way, the multiple proximity sensors 57 are not limited to being used to detect an abnormality in the height of the cup 4. In addition, the proximity sensor 57 is not limited to being a sensor that detects an object by irradiating light such as infrared light, and may be a sensor that detects an object by outputting ultrasonic waves, for example.

[0094] Incidentally, the camera 82 is provided to capture an image of the solvent supply nozzle 51B, but may be provided to capture an image of the resist supply nozzle 51A, and the distance between the resist supply nozzle 51A and the surface of the wafer W may be acquired. The liquid processing module provided in the substrate processing apparatus 2 is not limited to the resist film forming module 3. It may be a module that supplies a processing liquid for forming a coating film other than a resist film, such as an anti-reflection film or an insulating film, from a nozzle to the surface of the wafer W to form a film, or a module that supplies a cleaning liquid, a developing liquid, or an adhesive for bonding a plurality of wafers W to each other from a nozzle to the surface of the wafer W. In this way, information on the height between the nozzle that supplies a processing liquid other than a resist and the surface of the wafer W can also be acquired by the method of the embodiment described above.

[0095] Furthermore, the processing liquid supplied from the nozzle to the peripheral portion of the wafer W is not limited to a solvent, but may be, for example, a coating liquid for forming a coating film. Information about the height between the nozzle and the surface of the wafer W can be acquired by the methods described above. The inspection wafer 6 is not limited to being transported from the outside to the substrate processing apparatus 2 by the carrier C. For example, a module for storing the inspection wafer 6 may be provided in the substrate processing apparatus 2, and the wafer 6 may be transported between the module and the resist film forming module 3.

[0096] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The above-described embodiments may be omitted, substituted, modified, and combined in various forms without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0097] W wafer 31 Spin Chuck 57 Proximity Sensor 6 Test Wafer 61 Base body

Claims

1. 1. An information acquiring system for acquiring information regarding a substrate processing apparatus for processing a substrate held by a substrate holder, comprising: a base body held by the substrate holding portion instead of the substrate; a plurality of position sensors provided on the base body such that detection directions are different from each other in order to detect the position of a common detection target located outside the base body; Equipped with The base body is raised and lowered by a lifting mechanism, and position detection is performed by each of the position sensors at different heights. a support part for supporting the base body is raised and lowered below the base body held by the substrate holding part by the lifting mechanism, An information acquisition system in which the base body is provided with a contact sensor for detecting contact with the support portion and thereby detecting the contact height between the support portion and the base body held by the substrate holding portion in order to detect the position of the object to be detected.

2. When the contact by the contact sensor is detected while the support portion is rising through a height region of a first size, The information acquisition system of claim 1, wherein the descent of the support part at a second magnitude greater than the first magnitude, followed by the raising of the support part at the first magnitude, is repeated until the contact is no longer detected during the raising or the height of the support part when it next rises at the first magnitude becomes a height below the lower end of the one height region, and the contact height is acquired.

3. 1. An information acquiring system for acquiring information regarding a substrate processing apparatus for processing a substrate held by a substrate holder, comprising: a base body held by the substrate holding portion instead of the substrate; a plurality of position sensors provided on the base body such that detection directions are different from each other in order to detect the position of a common detection target located outside the base body; Equipped with the detection object is a cup surrounding the substrate, an information acquisition unit that acquires information about a position of the cup based on image data acquired by imaging the cup using a first imaging unit and on results acquired by the plurality of position sensors; An information acquisition system is provided.

4. 1. An information acquiring system for acquiring information regarding a substrate processing apparatus for processing a substrate held by a substrate holder, comprising: a base body held by the substrate holding portion instead of the substrate; a plurality of position sensors provided on the base body such that detection directions are different from each other in order to detect the position of a common detection target located outside the base body; Equipped with The base body is circular; An information acquisition system in which a second imaging unit that images a nozzle located on the peripheral portion of the substrate and supplies processing liquid to the peripheral portion from the central side of the base body is provided on the base body between one of the multiple position sensors and another of the multiple position sensors in the circumferential direction of the base body.

5. 1. An information acquiring system for acquiring information regarding a substrate processing apparatus for processing a substrate held by a substrate holder, comprising: a base body held by the substrate holding portion instead of the substrate; a plurality of position sensors provided on the base body such that detection directions are different from each other in order to detect the position of a common detection target located outside the base body; Equipped with The base body is circular; An information acquisition system in which an interference detection unit is partially fixed to the base body and detects interference by deformation when it interferes with a component that is the subject of interference detection, and is provided at a position shifted circumferentially from the base body relative to the position sensor.

6. a cover for covering the position sensor is provided on the base body; the interference detection unit is provided on the periphery of the base body, outside the cover, The information acquisition system according to claim 5 , wherein an upper surface of the cover on the base body is higher than the interference detection unit.

7. The base body is circular; the plurality of position sensors are disposed in a first region and a second region that are divided by a virtual line along a diameter of the base body, 7. The information acquisition system according to claim 1, wherein a detection direction of each of the plurality of position sensors is a radially outward direction of the base body.

8. 1. An information acquiring method for acquiring information regarding a substrate processing apparatus for processing a substrate held by a substrate holder, comprising: holding a base body by the substrate holding portion instead of the substrate; detecting a position of a detection target object located outside the base body and common to the position sensors, using a plurality of position sensors provided on the base body such that detection directions are different from each other; Equipped with A step of raising and lowering the base body by a lifting mechanism, Position detection is performed by each of the position sensors at different heights, a support portion for supporting the base body is raised below the base body held by the substrate holding portion by the lifting mechanism; An information acquisition method in which a contact sensor provided on the base body detects the contact height at which the support part comes into contact with the base body held by the substrate holding part, and the position of the object to be detected is acquired based on the contact height.

9. When the contact by the contact sensor is detected while the support portion is rising through a height region of a first size, The information acquisition method described in claim 8, wherein the contact height is acquired by repeating the descent of the support part at a second magnitude greater than the first magnitude, followed by the raising of the support part at the first magnitude, until the contact is no longer detected during the raising, or until the height of the support part when it next rises at the first magnitude is below the lower end of the one height region.

10. 1. An information acquiring method for acquiring information regarding a substrate processing apparatus for processing a substrate held by a substrate holder, comprising: holding a base body by the substrate holding portion instead of the substrate; detecting a position of a detection target object located outside the base body and common to the position sensors, using a plurality of position sensors provided on the base body such that detection directions are different from each other; Equipped with the detection object is a cup surrounding the substrate, An information acquisition method comprising a step of acquiring information about the position of the cup based on image data acquired by imaging the cup with a first imaging unit and the acquisition results by the multiple position sensors.

11. 1. An information acquiring method for acquiring information regarding a substrate processing apparatus for processing a substrate held by a substrate holder, comprising: holding a base body by the substrate holding portion instead of the substrate; detecting a position of a detection target object located outside the base body and common to the position sensors, using a plurality of position sensors provided on the base body such that detection directions are different from each other; Equipped with The base body is circular; supplying a processing liquid to a peripheral portion of the substrate through a nozzle located above the peripheral portion; capturing an image of the nozzle from a central portion of the base body by a second imaging unit provided on the base body between one position sensor and another position sensor among the plurality of position sensors in a circumferential direction of the base body; An information acquisition method comprising:

12. 1. An information acquiring method for acquiring information regarding a substrate processing apparatus for processing a substrate held by a substrate holder, comprising: holding a base body by the substrate holding portion instead of the substrate; detecting a position of a detection target object located outside the base body and common to the position sensors, using a plurality of position sensors provided on the base body such that detection directions are different from each other; Equipped with The base body is circular; An information acquisition method comprising a step of detecting interference by deformation occurring when an interference detection unit, which is provided at a position shifted circumferentially from the base body relative to the position sensor and partially fixed to the base body, interferes with a member to be detected by interference detection.

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