Measuring fixture

Abstract

To properly measure the suction force distribution on wafers absorbed and retained by electrostatic chucks.SOLUTION: A measuring jig has a substrate and an optical fiber. The substrate is a substrate of the same shape as a wafer for semiconductor manufacturing. The optical fiber has therein a plurality of reflective elements that can reflect light of a wavelength corresponding to the distortion of the substrate caused by stress. The optical fiber is fixed on one surface of the substrate with the plurality of reflective elements respectively positioned at a plurality of locations on one surface of the substrate.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a measuring tool and a measuring device. [Background technology]

[0002] 2. Description of the Related Art In semiconductor manufacturing equipment, when a wafer is subjected to processing such as etching or film formation, the wafer is attracted and held by an electrostatic chuck disposed in a chamber (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-31594 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique capable of appropriately measuring the distribution of attraction force on a wafer attracted and held by an electrostatic chuck. [Means for solving the problem]

[0005] A measurement tool according to an aspect of the present disclosure includes a substrate and an optical fiber. The substrate has substantially the same shape as a wafer used in semiconductor manufacturing. The optical fiber has a plurality of reflective elements therein capable of reflecting light of a wavelength corresponding to distortion of the substrate caused by stress. The optical fiber is fixed onto one surface of the substrate with the plurality of reflective elements disposed at a plurality of positions on the one surface of the substrate. Effect of the Invention

[0006] Advantageous Effects of Invention The present disclosure provides an advantage in that it is possible to appropriately measure the distribution of attraction force on a wafer attracted and held by an electrostatic chuck. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a top view showing an example of the configuration of a measurement device according to an embodiment. [Diagram 2] FIG. 2 is a schematic cross-sectional view showing a measuring jig according to an embodiment. [Diagram 3] FIG. 3 is a block diagram illustrating an example of a measuring device according to an embodiment. [Figure 4] FIG. 4 is a schematic cross-sectional view showing a measuring jig according to a modified example of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, embodiments of the measuring tool and measuring device disclosed in the present application will be described in detail with reference to the drawings. Note that the measuring tool and measuring device disclosed are not limited to the embodiments.

[0009] However, if the distribution of the clamping force on the wafer held by the electrostatic chuck is non-uniform, the temperature distribution on the wafer will also be non-uniform, which will result in changes in the processing characteristics of etching, film formation, and the like. In addition, if the distribution of the clamping force on the wafer increases globally or locally, the clamping surface of the electrostatic chuck may be scraped by the wafer, which may result in the generation of particles. For this reason, it is desirable to be able to appropriately measure the distribution of the clamping force on the wafer held by the electrostatic chuck.

[0010] [Measurement device configuration] The measuring device according to the embodiment is a device for measuring the chucking force distribution of a wafer chucking and held by an electrostatic chuck arranged in a chamber of a semiconductor manufacturing device. The semiconductor manufacturing device is, for example, a plasma processing device that performs processes such as etching and film formation using plasma. The electrostatic chuck is arranged, for example, in a chamber in which a plasma process is performed in the plasma processing device. The measuring device according to the embodiment uses a measuring jig in which an optical fiber incorporating a plurality of reflecting elements capable of reflecting light of a wavelength corresponding to the distortion of a measurement target caused by stress is fixed on a substrate simulating a wafer. The measuring device measures the chucking force distribution of the wafer by emitting light to the optical fiber while the measuring jig is chucking and held by the electrostatic chuck, and calculating the amount of distortion of the substrate at a plurality of positions based on the light reflected by the plurality of reflecting elements.

[0011] 1 is a top view showing an example of the configuration of a measuring device 1 according to an embodiment. As shown in FIG. 1, the measuring device 1 has a measuring jig 10, a measuring instrument 20, and a recording device 30.

[0012] The measuring jig 10 has a substrate 11 having substantially the same shape as a wafer used in semiconductor manufacturing, an optical fiber 12 fixed onto the upper surface of the substrate 11, and a temperature sensor 13 provided on the upper surface of the substrate 11.

[0013] The substrate 11 is a substrate simulating a wafer that is attracted and held by an electrostatic chuck disposed in a chamber of a semiconductor manufacturing device. The shape of the substrate 11 is substantially the same as that of a wafer used in semiconductor manufacturing, and is, for example, a disk shape with a thickness of about 775 μm and a diameter of about 300 mm. The substrate 11 may have dimensions other than those described above. The material for forming the substrate 11 may be, for example, silicon or a resin that is more flexible than silicon.

[0014] The optical fiber 12 has a plurality of fiber Bragg gratings (FBGs) 12a therein. Each FBG 12a has a refractive index higher than that of a portion of the optical fiber 12 where the plurality of FBGs 12a are not formed. Each FBG 12a can selectively reflect light of a wavelength corresponding to the strain of the substrate 11 caused by stress at a predetermined reflectance. The wavelength of the reflected light of each FBG 12a (hereinafter, appropriately referred to as the "reflection wavelength") changes according to the change in the stress applied from the substrate 11. That is, each FBG 12a can detect the change in the reflection wavelength as the strain amount of the substrate 11. The optical fiber 12 reflects the light output from the measuring device 20 to the optical fiber 12 by the plurality of FBGs 12a, and transmits the reflected light to the measuring device 20 as the measurement light of the strain of the substrate 11 caused by the stress. The plurality of FBGs 12a are an example of a plurality of reflecting elements.

[0015] The optical fiber 12 is fixed onto the upper surface of the substrate 11 with a plurality of FBGs 12a respectively arranged at a plurality of positions on the upper surface of the substrate 11. For example, as shown in Fig. 1, the optical fiber 12 is fixed onto the upper surface of the substrate 11 such that a plurality of FBGs 12a are respectively arranged at a plurality of positions arranged in a spiral shape from the center of the substrate 11 toward the periphery on the upper surface of the substrate 11.

[0016] In this manner, by fixing the optical fiber 12 onto the upper surface of the substrate 11 with a plurality of FBGs 12a respectively disposed at a plurality of positions on the upper surface of the substrate 11, the amount of distortion of the substrate 11 at the plurality of positions can be calculated by the measuring device 20. Therefore, the measuring device 1 according to the embodiment can appropriately measure the absorption force distribution of the wafer absorbed and held by the electrostatic chuck.

[0017] The temperature sensor 13 is provided on the upper surface of the substrate 11 adjacent to each FBG 12a. The temperature sensor 13 detects the temperature of the substrate 11 at each of a plurality of positions where the plurality of FBGs 12a are respectively arranged. The temperature sensor 13 is connected to a recording device 30, and the temperature of the substrate 11 detected by the temperature sensor 13 is recorded in the recording device 30. The temperature of the substrate 11 recorded in the recording device 30 is used to compensate for the amount of distortion of the substrate 11 calculated by the measuring device 20. Note that if the temperature of the substrate 11 can be considered to be uniform overall, one temperature sensor 13 may be provided at any position on the upper surface of the substrate 11.

[0018] Here, the configuration on the upper surface of the substrate 11 will be described with reference to Fig. 2. Fig. 2 is a schematic cross-sectional view showing a measuring jig 10 according to an embodiment. Fig. 2 shows a schematic cross-section of the substrate 11 and the optical fiber 12 along the longitudinal direction of the optical fiber 12. As shown in Fig. 2, the optical fiber 12 is fixed on the upper surface of the substrate 11. A plurality of FBGs 12a are formed inside the optical fiber 12 at predetermined intervals in the longitudinal direction of the optical fiber 12. The optical fiber 12 is placed in a groove 11a formed in a spiral shape on the upper surface of the substrate 11, and is bonded by an adhesive 14 at a position on the upper surface of the substrate 11 where the optical fiber 12 sandwiches the FBGs 12a.

[0019] The FBGs 12a are arranged at a plurality of positions on the upper surface of the substrate 11. Specifically, a plurality of recesses 11b arranged in a spiral shape are formed on the upper surface of the substrate 11, and the FBGs 12a are arranged at the positions of the recesses 11b, respectively, spaced apart from the bottom surfaces of the recesses 11b. By spaced apart the FBGs 12a from the bottom surfaces of the recesses 11b, the change in the refractive index of each FBG 12a in response to a temperature change in the substrate 11 is suppressed, and the change in the reflection wavelength of each FBG 12a detected as the amount of strain of the substrate 11 is less susceptible to the influence of the temperature change of the substrate 11. As a result, the detection accuracy of the amount of strain of the substrate 11 in each FBG 12a can be improved.

[0020] Furthermore, a temperature sensor 13 is provided adjacent to each FBG 12a on the upper surface of the substrate 11. The temperature sensor 13 is attached to one of the positions sandwiching each FBG 12a on the upper surface of the substrate 11 by an adhesive 14 that bonds the optical fiber 12. This allows the temperature of the substrate 11, which is used to compensate for the amount of distortion of the substrate 11, to be measured with high accuracy by the temperature sensor 13. The temperature sensor 13 may be installed at any position adjacent to each FBG 12a, and for example, the temperature sensor 13 may be provided on the bottom surface of each recess 11b corresponding to each FBG 12a.

[0021] Returning to the explanation of Fig. 1, the measuring instrument 20 is connected to the optical fiber 12 of the measuring jig 10. The measuring instrument 20 is also connected to the recording device 30 by wire or wirelessly.

[0022] 3 is a block diagram showing an example of a measuring device 20 according to an embodiment. As shown in FIG. 3, the measuring device 20 includes a light source 21, a circulator 22, a light receiver 24, and a computing device 25.

[0023] Light source 21 is, for example, a wavelength sweep type light source, and emits light whose wavelength changes over time to circulator 22. Specifically, light source 21 emits light whose wavelength changes over time to circulator 22 in a state in which measuring jig 10 is attracted and held by an electrostatic chuck arranged in a chamber of the semiconductor manufacturing equipment.

[0024] The circulator 22 outputs the light emitted from the light source 21 to the circulator 22 via the input / output port 22a to the optical fiber 12. The light emitted from the light source 21 to the optical fiber 12 via the circulator 22 and the input / output port 22a is reflected by a plurality of FBGs 12a located inside the optical fiber 12 and transmitted as reflected light to the measuring instrument 20. The circulator 22 outputs the reflected light input to the circulator 22 via the input / output port 22a to the optical receiver 24.

[0025] The photoreceiver 24 is, for example, a photodiode (PD), receives the reflected light output from the circulator 22 to the photoreceiver 24, creates light intensity data, and outputs the light intensity data to the calculation device 25. The light intensity data indicates a plurality of intensities corresponding to a plurality of wavelengths. An intensity corresponding to a certain wavelength among the plurality of intensities indicates the intensity of the reflected light of that wavelength among the reflected light received by the photoreceiver 24.

[0026] The arithmetic device 25 is, for example, a CPU (Central Processing Unit) or other arithmetic device, and calculates the amount of distortion of the substrate 11 at multiple positions on the upper surface of the substrate 11 (i.e., the positions of the multiple FBGs 12a) based on the light intensity data output from the light receiver 24. Specifically, the arithmetic device 25 calculates the amount of change in the wavelength of the reflected light (i.e., the reflected wavelength of each FBG 12a) in the light intensity data when the measuring jig 10 is attracted and held by the electrostatic chuck as the amount of distortion of the substrate 11. The amount of distortion can be converted into the stress applied to the wafer, that is, the adsorptive force of the wafer, using the so-called Hook's law. Therefore, the amount of distortion of the substrate 11 at multiple positions on the upper surface of the substrate 11 indicates the adsorptive force distribution of the wafer attracted and held by the electrostatic chuck.

[0027] Incidentally, in the measurement jig 10, the reflection wavelength of each FBG 12a used to calculate the amount of distortion of the substrate 11 changes in response to a change in temperature of the substrate 11. For this reason, an error caused by the change in temperature of the substrate 11 may occur in the amount of distortion of the substrate 11 calculated by the computing device 25.

[0028] Therefore, the calculation device 25 may compensate for the calculated amount of distortion of the substrate 11 at a plurality of positions on the upper surface of the substrate 11 (i.e., the arrangement positions of a plurality of FBGs 12a) by using the temperature of the substrate 11 recorded in the recording device 30. For example, the calculation device 25 holds in advance a correspondence relationship between the temperature of the substrate 11 and an error caused by a temperature change of the substrate 11. Then, the calculation device 25 calculates an error based on the correspondence relationship and the temperature of the substrate 11 recorded in the recording device 30, and compensates for the calculated amount of distortion of the substrate 11 by subtracting the calculated error from the calculated amount of distortion of the substrate 11. As a result, the measuring device 1 according to the embodiment can calculate the amount of distortion of the substrate 11 from which the error caused by the temperature change of the substrate 11 is cancelled, and therefore can more appropriately measure the chucking force distribution on the wafer chucking and holding by the electrostatic chuck.

[0029] [Method for determining abnormality of electrostatic chuck using measuring device] Meanwhile, an abnormality in an electrostatic chuck may be determined using the above-described measuring device 1. A method for determining an abnormality in an electrostatic chuck using the measuring device 1 will be described below.

[0030] First, the measuring jig 10 is attracted and held by a normal electrostatic chuck (hereinafter referred to as a "reference electrostatic chuck"). Next, while the measuring jig 10 is attracted and held by the reference electrostatic chuck, the measuring device 20 is controlled to calculate the amount of distortion of the substrate 11 at a plurality of positions on the upper surface of the substrate 11.

[0031] Next, the measuring jig 10 is attracted and held by the electrostatic chuck to be evaluated. Next, in a state in which the measuring jig 10 is attracted and held by the electrostatic chuck to be evaluated, the measuring device 20 is controlled to calculate the amount of distortion of the substrate 11 at a plurality of positions on the upper surface of the substrate 11.

[0032] Next, it is determined whether or not the difference between the amount of distortion of the substrate 11 calculated for the electrostatic chuck to be evaluated and the amount of distortion of the substrate 11 calculated for the reference electrostatic chuck is within a predetermined allowable range. If the result of the determination shows that the difference is not within the predetermined allowable range, it is determined that an abnormality has occurred in the electrostatic chuck to be evaluated.

[0033] According to this method of determining an abnormality, an abnormality in the electrostatic chuck can be easily determined.

[0034] [Variations] Next, a modified example of the measuring device 1 according to the embodiment will be described with reference to Fig. 4. In the following description, the same components as those in the above embodiment will be denoted by the same reference numerals, and detailed description thereof will be omitted.

[0035] Fig. 4 is a schematic cross-sectional view showing a measuring jig 10 according to a modified example of the embodiment. Fig. 4 shows a schematic cross-section of a substrate 11 and an optical fiber 12 along the longitudinal direction of the optical fiber 12. The measuring jig 10 shown in Fig. 4 differs from the measuring jig 10 shown in Fig. 2 mainly in that one FBG among a plurality of FBGs is used as a temperature sensor, and that a cover member is provided on the FBG used as the temperature sensor. For example, a case will be described in which the FBG 12a located at the leftmost position in Fig. 4 among a plurality of FBGs 12a is used as a temperature sensor. Hereinafter, the FBG 12a used as a temperature sensor will be referred to as an "FBG temperature sensor 12a".

[0036] The FBG temperature sensor 12a can selectively reflect light of a wavelength corresponding to the distortion of the substrate 11 caused by temperature change at a predetermined reflectance. The reflected wavelength of the FBG temperature sensor 12a changes according to the temperature change of the substrate 11. In other words, the FBG temperature sensor 12a can detect the amount of change in the reflected wavelength as the temperature of the substrate 11. The optical fiber 12 reflects the light output from the measuring instrument 20 to the optical fiber 12 at the FBG temperature sensor 12a and transmits it to the measuring instrument 20 as measurement light for the distortion of the substrate 11 caused by temperature change.

[0037] As shown in Fig. 4, a portion of the optical fiber 12 corresponding to the FBG temperature sensor 12a is covered with a cover member 15. The cover member 15 is a metallic cylindrical member with an inner diameter larger than the diameter of the optical fiber 12, and by inserting the optical fiber 12 through it, it blocks stress from the substrate 11 to the FBG temperature sensor 12a. The cover member 15 is adhered to the bottom surface of the recess 11b corresponding to the FBG temperature sensor 12a with an adhesive 15a. The recess 11b corresponding to the FBG temperature sensor 12a is shallower from the top surface of the substrate 11 than the other recesses 11b.

[0038] By covering the portion of the optical fiber 12 corresponding to the FBG temperature sensor 12a with the cover member 15, the change in the refractive index of the FBG temperature sensor 12a in response to the stress from the substrate 11 is suppressed, and the FBG temperature sensor 12a becomes less susceptible to the effects of the stress. As a result, the measurement device 1 according to the modified example can improve the detection accuracy of the temperature of the substrate 11 by the FBG temperature sensor 12a.

[0039] Furthermore, when one of the multiple FBGs 12a is used as the FBG temperature sensor 12a, the amount of distortion of the substrate 11 detected by the other FBGs 12a may be compensated for using the temperature of the substrate 11 detected by the FBG temperature sensor 12a. In this case, the calculation device 25 of the measurement device 20 operates as follows.

[0040] That is, the calculation device 25 calculates the temperature of the substrate 11 based on the reflected light (i.e., light intensity data) reflected by the FBG temperature sensor 12a and received by the optical receiver 24. The calculation device 25 calculates the amount of distortion of the substrate 11 at the position corresponding to the other FBG 12a based on the reflected light (i.e., light intensity data) reflected by the other FBG 12a and received by the optical receiver 24. Then, the calculation device 25 compensates for the calculated amount of distortion of the substrate 11 at the position corresponding to the other FBG 12a by using the calculated temperature of the substrate 11. For example, the calculation device 25 holds in advance a correspondence relationship between the temperature of the substrate 11 and an error caused by a temperature change of the substrate 11. Then, the calculation device 25 calculates an error based on the correspondence relationship and the temperature of the substrate 11 recorded in the recording device 30, and compensates for the calculated amount of distortion of the substrate 11 by subtracting the calculated error from the calculated amount of distortion of the substrate 11. As a result, the measuring apparatus 1 according to the modified example can calculate the amount of distortion of the substrate 11 with errors caused by temperature changes in the substrate 11 canceled, thereby making it possible to more appropriately measure the adsorptive force distribution of a wafer adsorbed and held by an electrostatic chuck.

[0041] In the above-mentioned modified example, one of the FBGs 12a is used as a temperature sensor, but two or more FBGs 12a may be used as a temperature sensor. Also, all the FBGs 12a may be used as temperature sensors to obtain the temperature distribution of the substrate 11, thereby measuring the temperature distribution of the wafer attracted and held by the electrostatic chuck.

[0042] As described above, the measuring jig (e.g., measuring jig 10) according to the embodiment includes a substrate (e.g., substrate 11) and an optical fiber (e.g., optical fiber 12). The substrate has substantially the same shape as a wafer for manufacturing semiconductors. The optical fiber has a plurality of reflective elements (e.g., FBG 12a) therein capable of reflecting light of a wavelength corresponding to the distortion of the substrate caused by stress. The optical fiber is fixed onto one surface of the substrate with a plurality of reflective elements disposed at a plurality of positions on the one surface of the substrate. Therefore, according to the present embodiment, it is possible to appropriately measure the chucking force distribution on a wafer chucked and held by an electrostatic chuck.

[0043] Furthermore, in the measuring jig according to the embodiment, the substrate may have one or more recesses (e.g., recess 11b) on one surface. The multiple reflective elements may be disposed at the positions of the one or more recesses, respectively, spaced apart from the bottom surfaces of the one or more recesses. Therefore, according to the present embodiment, the detection accuracy of the distortion amount of the substrate at each reflective element can be improved.

[0044] Furthermore, the measuring tool according to the embodiment may further include a temperature sensor (e.g., temperature sensor 13) provided on one surface of the substrate. The temperature sensor may be provided adjacent to each reflecting element. Therefore, according to the present embodiment, the temperature of the substrate used for compensating for the amount of distortion of the substrate can be measured with high accuracy by the temperature sensor.

[0045] Furthermore, in the measurement jig according to the embodiment, the optical fiber may be bonded with an adhesive (e.g., adhesive 14) at a position on one surface of the substrate where the reflective elements are sandwiched. The temperature sensor may be bonded with an adhesive for bonding the optical fiber at one of the positions on one surface of the substrate where the reflective elements are sandwiched. Therefore, according to the present embodiment, the temperature of the substrate used to compensate for the amount of distortion of the substrate can be measured with high accuracy by the temperature sensor.

[0046] In addition, in the measurement jig according to the embodiment, at least one of the multiple reflecting elements (e.g., FBG temperature sensor 12a) may be used as a temperature sensor. The measurement jig may further include a cover member (e.g., cover member 15) that covers a portion of the optical fiber corresponding to the at least one reflecting element used as a temperature sensor and blocks stress from the substrate to the at least one reflecting element. Therefore, according to the present embodiment, it is possible to improve the detection accuracy of the substrate temperature in the at least one reflecting element used as a temperature sensor.

[0047] In the measuring tool according to the embodiment, the substrate may be made of a resin that is more flexible than silicon. Therefore, according to the embodiment, the substrate can be easily distorted due to stress, and the detection accuracy of the substrate distortion amount at each reflecting element can be further improved.

[0048] Moreover, the measuring device according to the embodiment includes a measuring jig (e.g., measuring jig 10), a light source (e.g., light source 21), a light receiver (e.g., light receiver 24), and a calculation unit (e.g., calculation unit 25). The measuring jig includes a substrate (e.g., substrate 11) and an optical fiber (e.g., optical fiber 12). The substrate is a substrate having substantially the same shape as a wafer for manufacturing semiconductors. The optical fiber has a plurality of reflecting elements (e.g., FBG 12a) therein capable of reflecting light of a wavelength corresponding to the distortion of the substrate caused by stress. The optical fiber is fixed on one surface of the substrate with the plurality of reflecting elements respectively arranged at a plurality of positions on the one surface of the substrate. The light source emits light to the optical fiber of the measuring jig with the measuring jig being attracted and held by an electrostatic chuck arranged in a chamber of the semiconductor manufacturing device. The light receiver receives the light reflected by the plurality of reflecting elements. The calculation unit calculates the amount of distortion of the substrate at a plurality of positions on the one surface of the substrate based on the light received by the light receiver. Therefore, according to this embodiment, it is possible to appropriately measure the absorption force distribution of the wafer attracted and held by the electrostatic chuck.

[0049] Here, it is also conceivable to detect the amount of distortion of the substrate using a strain gauge that detects the resistance value of a resistive element relative to an electrical signal as the amount of distortion. However, when detecting the amount of distortion of the substrate using a strain gauge, the electrical characteristics of the strain gauge change due to high-frequency noise in the chamber of the semiconductor manufacturing equipment and the voltage applied to the electrostatic chuck, and this reduces the detection accuracy of the amount of distortion of the substrate. In contrast, according to this embodiment, the amount of distortion of the substrate can be detected without using a strain gauge. As a result, according to this embodiment, the chucking force distribution can be measured with high accuracy without being affected by high-frequency noise in the chamber of the semiconductor manufacturing equipment and the voltage applied to the electrostatic chuck.

[0050] Furthermore, in the measuring device according to the embodiment, the measuring jig may further include a temperature sensor (e.g., temperature sensor 13) provided on one surface of the substrate. The measuring device may further include a recording device that records the temperature of the substrate detected by the temperature sensor. Therefore, according to this embodiment, the temperature of the substrate recorded in the recording device can be used to compensate for the amount of distortion of the substrate.

[0051] In addition, in the measuring apparatus according to the embodiment, the calculation unit may compensate for the calculated amount of distortion of the substrate at multiple positions on one surface of the substrate by using the temperature of the substrate recorded in the recording device. Therefore, according to the present embodiment, it is possible to calculate the amount of distortion of the substrate from which an error caused by a change in the temperature of the substrate is cancelled, and therefore it is possible to more appropriately measure the clamping force distribution of the wafer clamped by the electrostatic chuck.

[0052] Furthermore, in the measurement device according to the embodiment, at least one of the multiple reflecting elements (e.g., FBG temperature sensor 12a) may be used as a temperature sensor. The measurement tool may further include a cover member that covers a portion of the optical fiber that corresponds to the at least one reflecting element used as a temperature sensor and blocks stress from the substrate. Therefore, according to the present embodiment, it is possible to improve the detection accuracy of the substrate temperature in the at least one reflecting element used as a temperature sensor.

[0053] In addition, in the measurement apparatus according to the embodiment, the calculation unit may calculate the temperature of the substrate based on light reflected by at least one of the plurality of reflecting elements and received by the receiver. The calculation unit may calculate an amount of distortion of the substrate at a position corresponding to another reflecting element based on light reflected by another reflecting element of the plurality of reflecting elements and received by the receiver. The calculation unit may compensate for the calculated amount of distortion of the substrate at the position corresponding to the other reflecting element by using the calculated temperature of the substrate. Therefore, according to the present embodiment, it is possible to calculate an amount of distortion of the substrate from which an error caused by a change in the temperature of the substrate is cancelled, and therefore it is possible to more appropriately measure the chucking force distribution of a wafer chucking and held by an electrostatic chuck.

[0054] Although the embodiments have been described above, the embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. Indeed, the above-described embodiments may be embodied in various forms. Furthermore, the above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the claims.

[0055] For example, in the above embodiment, the light source 21 of the measuring device 20 is a swept-wavelength light source, but the disclosed technology is not limited to this. The light source 21 may be a broadband light source capable of emitting light including multiple wavelength components. In this case, an optical spectrum analyzer may be used as the optical receiver 24.

[0056] Furthermore, in the above embodiment, a case has been described where a plurality of recesses 11b are formed on the upper surface of the substrate 11, but the plurality of recesses 11b may be formed as one continuous recess.

[0057] Furthermore, in the above embodiment, the measurement device 20 and the recording device 30 are separate devices. However, the measurement device 20 and the recording device 30 may be incorporated into a single device. [Explanation of symbols]

[0058] 1. Measuring equipment 10 Measuring fixture 11 Substrate 11b Recess 12 Optical Fiber 12a FBG 13 Temperature Sensor 14. Adhesive 15 Cover member 20 Measuring instruments 21 Light source 24 Receiver 25 Arithmetic unit 30 Recording Device

Claims

1. A substrate having substantially the same shape as a wafer for semiconductor manufacturing; an optical fiber having a plurality of reflecting elements therein capable of reflecting light of a wavelength corresponding to the distortion of the substrate caused by stress, the plurality of reflecting elements being disposed at a plurality of positions on the one surface of the substrate, the optical fiber being fixed on the one surface of the substrate; A measuring tool comprising: The substrate is A groove portion extending on the one surface; a plurality of recesses formed in a line along an extension direction of the groove portion at positions overlapping the groove portion on the one surface; having The optical fiber is disposed in the groove, the plurality of reflective elements are disposed at positions of the plurality of recesses, respectively, spaced apart from bottom surfaces of the plurality of recesses; a first adsorption step of adsorbing the measuring jig to a first electrostatic chuck; a first calculation step of calculating a first distortion amount at the plurality of positions of the substrate by measuring light reflected from the reflecting element while the measuring jig is attracted to the first electrostatic chuck; a second adsorption step of adsorbing the measuring jig to a second electrostatic chuck; a second calculation step of calculating a second distortion amount at the plurality of positions of the substrate by measuring light reflected from the reflecting element while the measuring jig is attracted to the second electrostatic chuck; a determining step of determining whether or not there is an abnormality in the second electrostatic chuck based on a difference between the first distortion amount and the second distortion amount; The present invention is used in a method for determining an abnormality in an electrostatic chuck, Measuring fixture.

2. A substrate having approximately the same shape as a wafer for semiconductor manufacturing; an optical fiber having a plurality of reflecting elements therein capable of reflecting light of a wavelength corresponding to the distortion of the substrate caused by stress, the plurality of reflecting elements being disposed at a plurality of positions on the one surface of the substrate, the optical fiber being fixed on the one surface of the substrate; A measuring tool comprising: a first adsorption step of adsorbing the measuring jig to a first electrostatic chuck; a first calculation step of calculating a first distortion amount at the plurality of positions of the substrate by measuring light reflected from the reflecting element while the measuring jig is attracted to the first electrostatic chuck; a second adsorption step of adsorbing the measuring jig to a second electrostatic chuck; a second calculation step of calculating a second distortion amount at the plurality of positions of the substrate by measuring light reflected from the reflecting element while the measuring jig is attracted to the second electrostatic chuck; a determining step of determining whether or not there is an abnormality in the second electrostatic chuck based on a difference between the first distortion amount and the second distortion amount; The method includes: The abnormality determination method includes: calculating a first temperature, which is the temperature of the substrate in the first calculation; calculating a second temperature, which is the temperature of the substrate in the second calculation; compensating for the first amount of distortion using the first temperature; compensating for the second amount of distortion using the second temperature; Also includes Measuring fixture.

3. The measuring tool according to claim 1 , further comprising a temperature sensor provided on one surface of the substrate.

4. The measuring tool of claim 3 , wherein the temperature sensor is provided adjacent each of the reflective elements.

5. the optical fibers are bonded to the one surface of the substrate at positions sandwiching the respective reflective elements by an adhesive; 5. The measuring tool according to claim 4, wherein the temperature sensor is attached to one of the positions on the one surface of the substrate between which the reflecting elements are sandwiched, by the adhesive that bonds the optical fiber.

6. At least one of the plurality of reflective elements is used as a temperature sensor, 3. The measuring tool according to claim 1, further comprising a cover member that covers a portion of the optical fiber corresponding to the at least one reflecting element used as a temperature sensor and blocks stress from the substrate to the at least one reflecting element.

7. 7. The measuring tool according to claim 1, wherein the substrate is made of silicon or a resin having a higher flexibility than silicon.

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