Substrate thickness measuring device, substrate processing system, and substrate thickness measuring method

Abstract

This substrate thickness measuring device is provided with a substrate holding unit, a thickness measuring unit, a housing, a temperature measuring unit, and a thickness calibrating unit. The substrate holding unit holds a substrate. The thickness measuring unit measures a thickness of the substrate being held by the substrate holding unit. The housing accommodates the substrate holding unit and at least a portion of the thickness measuring unit. The thickness calibrating unit calibrates the thickness measured by the thickness measuring unit. The thickness calibrating unit: obtains, as a thickness after calibration, the product of the thickness measured by the thickness measuring unit, and a preset correction factor; and changes the setting of the correction factor if a temperature measured by the temperature measuring unit deviates from a preset acceptable range.

Description

[Technical field]

[0001] The present disclosure relates to a substrate thickness measuring device, a substrate processing system, and a substrate thickness measuring method. [Background technology]

[0002] The film thickness measuring device described in Patent Document 1 has a film thickness measuring unit that measures the film thickness of a film formed on the surface of a substrate, a humidity measuring unit that measures the humidity around the film thickness measuring unit, a storage unit that stores information regarding the correlation between humidity and film thickness, and a correction unit that calculates a first correction amount for correcting the measured film thickness from the humidity measured by the humidity measuring unit and the information stored in the storage unit, and corrects the measured film thickness measured by the film thickness measuring unit using the calculated first correction amount. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2019-62003 Summary of the Invention [Problem to be solved by the invention]

[0004] One aspect of the present disclosure provides a technique for improving the measurement accuracy of a substrate thickness against temperature fluctuations of the substrate. [Means for solving the problem]

[0005] A substrate thickness measuring device according to an aspect of the present disclosure includes a substrate holding unit, a thickness measuring unit, a housing, and a temperature measuring unit. Control Unit The substrate holding unit holds a substrate. The thickness measuring unit measures the thickness of the substrate held by the substrate holding unit. The housing houses the substrate holding unit and at least a portion of the thickness measuring unit. The thickness calibrating unit calibrates the thickness measured by the thickness measuring unit. the control unit, when the temperature measured by the temperature measuring unit is within a preset allowable range, carries the substrate into the housing, and measures a thickness of the substrate by the thickness measuring unit; The thickness was measured in the thickness measuring section. The substrateThe product of the thickness and the preset correction coefficient is the calibrated The substrate The thickness to be determined The control unit performs the following steps: The temperature measured by the temperature measuring unit is set The above If it is outside the acceptable range, By carrying a calibration substrate into the housing instead of the substrate, and measuring the thickness of the calibration substrate with the thickness measuring unit, Changing the correction coefficient; of implement. Effect of the Invention

[0006] According to one aspect of the present disclosure, it is possible to improve the measurement accuracy of the thickness of a substrate against temperature fluctuations of the substrate. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a plan view showing a substrate processing system according to an embodiment. [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Diagram 3] FIG. 3 is a flowchart showing a substrate processing method according to an embodiment. [Figure 4] FIG. 4 is a plan view showing an example of the substrate thickness measuring device, and is a cross-sectional view taken along line IV-IV in FIG. [Diagram 5] FIG. 5 is a cross-sectional view taken along line VV in FIG. [Figure 6] FIG. 6 is a side view showing an example of a thickness measuring unit and a temperature adjusting unit. [Figure 7] FIG. 7 is a functional block diagram of an example of components of the control device. [Figure 8] FIG. 8 is a flowchart showing an example of setting the correction coefficient. [Figure 9] FIG. 9 is a flowchart showing an example of the calibration of the substrate thickness. [Figure 10] FIG. 10 is a diagram showing an example of the variation in measured thickness values ​​with respect to the variation in humidity. [Figure 11] FIG. 11 is a diagram showing an example of the variation in the measured thickness value with respect to the variation in the distance between the probe and the substrate. [Figure 12]FIG. 12 is a diagram showing an example of the fluctuation in the intensity of light detected by the photodetector and the fluctuation in the range of the measured thickness value with respect to the fluctuation in the distance between the probe and the substrate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In each drawing, the same or corresponding configurations are denoted by the same reference numerals, and the description may be omitted. In this specification, the X-axis direction, the Y-axis direction, and the Z-axis direction are perpendicular to each other. The X-axis direction and the Y-axis direction are horizontal directions, and the Z-axis direction is vertical.

[0009] First, a substrate processing system 1 according to one embodiment will be described with reference to Fig. 1 and Fig. 2. The substrate processing system 1 grinds a substrate W. In this specification, grinding includes polishing. The substrate processing system 1 includes a load / unload block 2, a cleaning block 3, and a grinding block 5. The load / unload block 2, the cleaning block 3, and the grinding block 5 are arranged in this order from the negative side of the X-axis to the positive side of the X-axis.

[0010] The carry-in / out block 2 includes a placement section 21 on which a cassette C containing substrates W is placed. The cassette C horizontally contains a plurality of substrates W arranged at intervals in the vertical direction. The substrates W include semiconductor substrates such as silicon wafers or compound semiconductor wafers, or glass substrates. The substrate W may further include a device layer formed on the surface of the semiconductor substrate or glass substrate. The device layer includes electronic circuits. The substrate W may also be a laminated substrate formed by bonding a plurality of substrates together.

[0011] As shown in FIG. 1 and FIG. 2, the cleaning block 3 includes, for example, cleaning devices 31A and 31B for cleaning the substrate W after grinding, etching devices 32A and 32B for etching the substrate W after cleaning, a substrate thickness measuring device 33 for measuring the thickness of the substrate W after etching, an inversion device 34 for inverting the substrate W, a transition device 35 for temporarily storing the substrate W, and a storage device 61 for storing a calibration substrate, which will be described later. The calibration substrate is used to calibrate the thickness of the substrate W measured by the substrate thickness measuring device 33. The cleaning block 3 also includes a first transport area 36 and a second transport area 37. A first transport device 38 is provided in the first transport area 36, ​​and a second transport device 39 is provided in the second transport area 37. The first transport device 38 transports the substrate W between the cleaning devices 31A and 31B and the grinding block 5. The second transport device 39 transports the substrate W between the cassette C on the placement unit 21 and the cleaning block 3.

[0012] The cleaning devices 31A and 31B, the transition device 35, the storage device 61, and the substrate thickness measuring device 33 are stacked in the vertical direction and are arranged in a position surrounded on three sides by the first transfer region 36, the second transfer region 37, and the grinding block 5. The cleaning devices 31A and 31B, the transition device 35, the storage device 61, and the substrate thickness measuring device 33 are stacked from top to bottom in this order. However, the order is not particularly limited. The etching devices 32A and 32B are stacked in the vertical direction and arranged adjacent to the first transfer region 36 and the second transfer region 37.

[0013] The first transfer device 38 transfers the substrate W in the first transfer region 36. That is, the first transfer device 38 transfers the substrate W between multiple devices arranged adjacent to the first transfer region 36. The first transfer device 38 has multiple transfer arms that move independently. Each transfer arm is capable of moving horizontally (in both the X-axis and Y-axis directions) and vertically, and of rotating about a vertical axis. Each transfer arm holds the substrate W from below. The number of transfer arms is not particularly limited.

[0014] Similarly, the second transfer device 39 transfers the substrate W in the second transfer region 37. That is, the second transfer device 39 transfers the substrate W between multiple devices arranged next to the second transfer region 37. The second transfer device 39 has multiple transfer arms that move independently. Each transfer arm is capable of moving in the horizontal direction (both in the X-axis direction and the Y-axis direction) and the vertical direction, and of rotating about a vertical axis. Each transfer arm holds the substrate W from below.

[0015] 1, the grinding block 5 includes, for example, four holders 52A, 52B, 52C, and 52D for holding the substrate W, two tool driving units 53A and 53B for driving a grinding tool D for grinding the substrate W, and an internal transport unit 54 for transporting the substrate W within the grinding block 5. The grinding block 5 may further include a rotary table 51 that is rotated around a rotation center line R1. The four holders 52A, 52B, 52C, and 52D are provided at intervals around the rotation center line R1 and rotated together with the rotary table 51. In addition, the four holders 52A, 52B, 52C, and 52D are rotated around their respective rotation center lines R2.

[0016] The two holders 52A, 52C are disposed symmetrically about the rotation center line R1 of the turntable 51. Each of the holders 52A, 52C moves between a first load / unload position A3 where the internal transport unit 54 loads / unloads the substrate W, and a first grinding position A1 where the substrate W is ground by one tool driving unit 53A. The two holders 52A, 52C move between the first load / unload position A3 and the first grinding position A1 every time the turntable 51 rotates 180°.

[0017] The other two holding units 52B, 52D are disposed symmetrically about the rotation center line R1 of the turntable 51. Each of the holding units 52B, 52D moves between a second loading / unloading position A0 where the internal transport unit 54 loads and unloads the substrate W, and a second grinding position A2 where the substrate W is ground by another tool driving unit 53B. The other two holding units 52B, 52D move between the second loading / unloading position A0 and the second grinding position A2 every time the turntable 51 rotates 180°.

[0018] When viewed from above, the first loading / unloading position A3, the second loading / unloading position A0, the first grinding position A1, and the second grinding position A2 are arranged in this order in a counterclockwise direction. In this case, when viewed from above, the holding portion 52A, the holding portion 52B, the holding portion 52C, and the holding portion 52D are arranged in this order at 90° intervals in a counterclockwise direction.

[0019] The positions of the first loading / unloading position A3 and the second loading / unloading position A0 may be reversed, and the positions of the first grinding position A1 and the second grinding position A2 may also be reversed. That is, when viewed from above, the first loading / unloading position A3, the second loading / unloading position A0, the first grinding position A1, and the second grinding position A2 may be arranged in this order clockwise. In this case, when viewed from above, the holding portion 52A, the holding portion 52B, the holding portion 52C, and the holding portion 52D are arranged in this order clockwise at 90° intervals.

[0020] However, the number of holding parts is not limited to four. The number of tool driving parts is also not limited to two. In addition, the rotary table 51 does not have to be provided. For example, a slide table may be provided instead of the rotary table 51.

[0021] 2, the grinding block 5 includes temporary placement parts 57A, 57B, and 57C for temporarily storing the substrate W. The temporary placement parts 57A, 57B, and 57C transfer the substrate W between the internal transfer part 54 and the first transfer device 38 of the cleaning block 3. The internal transfer part 54 receives the substrate W, which has been transferred to the temporary placement parts 57A and 57B by the first transfer device 38, from the temporary placement parts 57A and 57B. In addition, the first transfer device 38 receives the substrate W, which has been transferred to the temporary placement part 57C by the internal transfer part 54, from the temporary placement part 57C.

[0022] The temporary placement units 57A and 57B also serve as alignment units that adjust the center position of the substrate W. The alignment units align the center position of the substrate W to a desired position using a guide or the like. Thereafter, the substrate W is transported to a preset loading position by the internal transport unit 54, and the substrate W is handed over to each of the holders 52A, 52B, 52C, and 52D at the loading position, whereby the centers of the holders 52A, 52B, 52C, and 52D can be aligned with the center of the substrate W when viewed from above.

[0023] The alignment unit may detect the center position of the substrate W using an optical system or the like. In this case, the control unit 9 can align the center of each of the holders 52A, 52B, 52C, and 52D with the center of the substrate W when viewed from above by correcting the previously set carry-in position based on the detection result of the alignment unit. The alignment unit may also detect the crystal orientation of the substrate W using an optical system or the like, and more specifically, may detect a notch or an orientation flat that indicates the crystal orientation of the substrate W. In a rotating coordinate system that rotates together with each of the holders 52A, 52B, 52C, and 52D, the crystal orientation of the substrate W can be aligned to a desired orientation.

[0024] The temporary placement units 57A, 57B may be stacked in the vertical direction to reduce the installation area of ​​the substrate processing system 1. The order of stacking is not limited to the order shown in the figure and may be reversed. When the temporary placement units 57A, 57B also serve as alignment units, it is preferable that they include a guide instead of an optical system. This is because when the temporary placement units 57A, 57B include a guide, the Z-axis dimension of the temporary placement units 57A, 57B can be made smaller than when they include an optical system.

[0025] The temporary rest parts 57B, 57C are disposed above the transport routes TR1, TR2 along which the internal transport part 54 transports the substrates W between the temporary rest parts 57B, 57C and a holder (e.g., holder 52D) located at the second load / unload position A0. When viewed from above, the temporary rest parts 57B, 57C overlap with the transport routes TR1, TR2.

[0026] The grinding block 5 may include an inversion unit 58 that inverts the substrate W. The inversion unit 58 is disposed above the transport paths TR1 and TR2. The inversion unit 58 and the temporary placement units 57A, 57B, and 57C are stacked in the vertical direction. For example, the inversion unit 58, the temporary placement unit 57C, the temporary placement unit 57B, and the temporary placement unit 57A are stacked from top to bottom in this order. The stacking order is not particularly limited.

[0027] 1, the substrate processing system 1 further includes a control unit 9. The control unit 9 is, for example, a computer, and includes a CPU (Central Processing Unit) 91 and a storage medium 92 such as a memory. The storage medium 92 stores programs that control various processes executed in the substrate processing system 1. The control unit 9 controls the operation of the substrate processing system 1 by causing the CPU 91 to execute the programs stored in the storage medium 92.

[0028] Next, a substrate processing method performed by the substrate processing system 1 will be described with reference to Fig. 3. The substrate processing method includes, for example, steps S101 to S111 shown in Fig. 3. Steps S101 to S111 are performed under the control of the control unit 9. Note that the substrate processing method does not need to include all the steps shown in Fig. 3, and may include steps not shown in Fig. 3.

[0029] First, the second transport device 39 takes out the substrate W from the cassette C and transports it to the transition device 35. Next, the first transport device 38 receives the substrate W from the transition device 35 and transports it to the temporary placement part 57A of the grinding block 5. The substrate W has a first main surface and a second main surface facing opposite to each other, and is transported with the first main surface facing upward.

[0030] Next, the temporary rest part 57A adjusts the center position of the substrate W (step S101). The temporary rest part 57A may detect the center position of the substrate W. Furthermore, in addition to the center position of the substrate W, the temporary rest part 57A may detect the crystal orientation of the substrate W, specifically, a notch or an orientation flat that indicates the crystal orientation of the substrate W.

[0031] Next, the internal transport unit 54 receives the substrate W from the temporary placement unit 57A and transports it to a holder (e.g., the holder 52C) located at the first load / unload position A3. The substrate W is placed on the holder 52C with its first main surface facing up. At that time, the center of the substrate W is aligned with the rotation center line R2 of the holder 52C. Thereafter, the turntable 51 is rotated 180°, and the holder 52C is moved from the first load / unload position A3 to the first grinding position A1.

[0032] Next, the tool driving unit 53A drives the grinding tool D to grind the first main surface of the substrate W (step S102). After that, the turntable 51 is rotated 180 degrees, and the holder 52C is moved from the first grinding position A1 to the first carry-in / out position A3. Next, the internal transport unit 54 receives the substrate W from the holder 52C located at the first carry-in / out position A3, and transports it to the inversion unit 58.

[0033] Next, the inverting unit 58 inverts the substrate W (step S103). The substrate W is inverted upside down so that the first main surface faces downward and the second main surface faces upward. Thereafter, the first transfer device 38 of the cleaning block 3 receives the substrate W from the inverting unit 58 and transfers it to the cleaning device 31A.

[0034] Next, the cleaning device 31A cleans the first main surface of the substrate W (step S104). The cleaning device 31A can remove particles such as grinding debris. The cleaning device 31A, for example, scrubs the substrate W. The cleaning device 31A may clean not only the first main surface of the substrate W but also the second main surface. After the substrate W is dried, the first transfer device 38 receives the substrate W from the cleaning device 31A and transfers it to the temporary placement section 57B of the grinding block 5.

[0035] Next, the temporary rest part 57B adjusts the center position of the substrate W (step S105). The temporary rest part 57B may detect the center position of the substrate W. Furthermore, in addition to the center position of the substrate W, the temporary rest part 57B may detect the crystal orientation of the substrate W, specifically, a notch or an orientation flat that indicates the crystal orientation of the substrate W.

[0036] Next, the internal transport unit 54 receives the substrate W from the temporary placement unit 57B and transports it to a holder (e.g., the holder 52D) located at the second load / unload position A0. The substrate W is placed on the holder 52D with its second main surface facing up. At that time, the center of the substrate W is aligned with the rotation center line R2 of the holder 52D. Thereafter, the turntable 51 is rotated 180°, and the holder 52D is moved from the second load / unload position A0 to the second grinding position A2.

[0037] Next, the tool driving unit 53B drives the grinding tool D to grind the second main surface of the substrate W (step S106). After that, the turntable 51 is rotated 180°, and the holder 52D is moved from the second grinding position A2 to the second carry-in / out position A0. Next, the internal transfer unit 54 receives the substrate W from the holder 52D located at the second carry-in / out position A0, and transfers it to the temporary placement unit 57C. After that, the first transfer device 38 of the cleaning block 3 receives the substrate W from the temporary placement unit 57C, and transfers it to the cleaning device 31B.

[0038] Next, the cleaning apparatus 31B cleans the second main surface of the substrate W (step S107). The cleaning apparatus 31B can remove particles such as grinding debris. The cleaning apparatus 31B, for example, scrubs the substrate W. The cleaning apparatus 31B may clean not only the second main surface of the substrate W but also the first main surface. After the substrate W is dried, the second transfer apparatus 39 receives the substrate W from the cleaning apparatus 31B and transfers it to the etching apparatus 32B.

[0039] Next, the etching device 32B etches the second main surface of the substrate W (step S108). Grinding marks on the second main surface can be removed by the etching device 32B. After the substrate W is dried, the second transfer device 39 receives the substrate W from the etching device 32B and transfers it to the reversing device .

[0040] Next, the inverting device 34 inverts the substrate W (step S109). The substrate W is inverted upside down so that the first main surface faces upward and the second main surface faces downward. Thereafter, the second transport device 39 receives the substrate W from the inverting device 34 and transports it to the etching device 32A.

[0041] Next, the etching device 32A etches the first main surface of the substrate W (step S110). Grinding marks on the first main surface can be removed by the etching device 32A. After the substrate W is dried, the second transfer device 39 receives the substrate W from the etching device 32A and transfers it to the substrate thickness measuring device 33.

[0042] Next, the substrate thickness measuring device 33 measures the thickness of the substrate W after etching (step S111). For example, it is inspected whether the thickness and thickness variation (TTV: Total Thickness Variation) of the substrate W are within a preset allowable range. Thereafter, the second transport device 39 receives the substrate W from the substrate thickness measuring device 33 and stores the received substrate W in the cassette C. Thereafter, the current process ends.

[0043] In the description of FIG. 3, the substrate processing method has been described with a focus on one substrate W. The substrate processing system 1 may simultaneously perform a plurality of processes at a plurality of positions in order to improve throughput. For example, the substrate processing system 1 simultaneously grinds the substrate W at each of the first grinding position A1 and the second grinding position A2. Meanwhile, the substrate processing system 1 performs, for example, spray cleaning of the substrate W, measurement of the thickness distribution of the substrate W, unloading the substrate W, cleaning of the substrate suction surface (upper surface) of the holder, and loading of the substrate W, in this order, at each of the first load / unload position A3 and the second load / unload position A0.

[0044] After that, the substrate processing system 1 rotates the turntable 51 by 180°. Next, the substrate processing system 1 simultaneously grinds the substrate W again at each of the first grinding position A1 and the second grinding position A2. Meanwhile, the substrate processing system 1 again performs spray cleaning of the substrate W, measurement of the thickness distribution of the substrate W, unloading the substrate W, cleaning of the substrate suction surface (upper surface) of the holder, and loading of the substrate W, in this order, at each of the first load / unload position A3 and the second load / unload position A0.

[0045] Next, a substrate thickness measuring device 33 according to one embodiment will be described with reference to Figs. 4 to 6. The substrate thickness measuring device 33 includes, for example, a housing 100, a substrate holding section 110, a rotating section 120, a moving section 130, a thickness measuring section 140, an alignment section 150, a temperature measuring section 160, a humidity measuring section 161, an exhaust section 170, an inner cover 180, and a control section 190. The control section 190 is a control device 9 It may be part of.

[0046] The housing 100 is, for example, a box having a rectangular shape in a plan view. The housing 100 accommodates, for example, a substrate holding unit 110, a rotating unit 120, a moving unit 130, at least a part of a thickness measuring unit 140 (for example, a probe 141 described later), an alignment unit 150, a temperature measuring unit 160, a humidity measuring unit 161, at least a part of an exhaust unit 170 (for example, an exhaust duct 171 described later), and an inner cover 180.

[0047] A load / unload port 101 is formed on the side of the housing 100 facing the second transfer area 37. The substrate W and the calibration substrate WA are loaded and unloaded through the load / unload port 101. The load / unload port 101 does not need to be provided with an opening / closing shutter, and may be always open. A constant air flow can be caused to flow from the second transfer area 37 into the housing 100 through the load / unload port 101, and the temperature inside the housing 100 can be maintained constant.

[0048] 5, the substrate holding part 110 holds the substrate W inside the housing 100. The substrate holding part 110 may hold a calibration substrate WA instead of the substrate W. The calibration substrate WA is used to calibrate the thickness of the substrate W measured by the thickness measuring part 140. The diameter of the substrate holding part 110 is, for example, half or less of the diameter of the substrate W. The substrate W is held horizontally.

[0049] The rotating unit 120 rotates the substrate holding unit 110 around a vertical rotation axis 121. The rotating unit 120 includes a motor 122. For example, a stepping motor is used as the motor 122. The stepping motor has multiple coils around a rotation center line, and rotates the substrate holding unit 110 by supplying current to the multiple coils in sequence. When stopping the rotation of the substrate holding unit 110, the stepping motor continues to supply current to a specific coil.

[0050] The moving unit 130 moves the substrate holding unit 110 in a horizontal direction (e.g., the Y-axis direction) perpendicular to the rotation axis 121. The moving unit 130 includes, for example, a motor 131 and a ball screw 132 that converts the rotational motion of the motor 131 into linear motion of the substrate holding unit 110, as shown in Fig. 4. The moving unit 130 has a guide rail 133 extending in the Y-axis direction, and a slider 134 that moves along the guide rail 133. The rotating unit 120 is fixed to the slider 134. The moving unit 130 moves the rotating unit 120 together with the slider 134, thereby moving the substrate holding unit 110.

[0051] The thickness measuring unit 140 measures the thickness of the substrate W held by the substrate holding unit 110. The thickness measuring unit 140 may be used to measure the thickness variation in the radial direction of the substrate W. There are three thickness measurement points, for example, the center of the substrate W, the periphery of the substrate W, and the midpoint between the center and the periphery of the substrate W. The thickness measurement points can be moved in the radial direction of the substrate W by the moving unit 130. In addition, the thickness measurement points can be moved in the circumferential direction of the substrate W by the rotating unit 120. The thickness measuring unit 140 may be used to measure the thickness variation in the circumferential direction of the substrate W. Note that the thickness measurement points may be moved by moving or rotating the probe 141 of the thickness measuring unit 140 instead of the substrate holding unit 110.

[0052] The thickness measuring unit 140 may be of a contact type or a non-contact type, but is preferably of a non-contact type. The thickness measuring unit 140 is, for example, of a spectral interference type, and measures the thickness of the substrate W by causing light reflected from the upper surface of the substrate W to interfere with light reflected from the lower surface of the substrate W and analyzing the waveform of the interference wave. The thickness measuring unit 140 transmits the measured data to the control unit 190.

[0053] 6 , the thickness measurement unit 140 includes a probe 141 that irradiates light toward the substrate W and receives light reflected by the substrate W, a light source 143 connected to the probe 141 via an optical fiber 142, a photodetector 145 connected to the probe 141 via an optical fiber 144, and a box 146 that accommodates the light source 143 and the photodetector 145. The thickness measurement unit 140 includes a calculation unit 1401 that calculates the thickness of the substrate W by analyzing the waveform of the light detected by the photodetector 145. The calculation unit 1401 is provided outside the box 146.

[0054] The probe 141 includes a lens 141a that focuses light toward the substrate W. The optical axis of the lens 141a is, for example, horizontal, and a mirror 140a is provided beyond the lens 141a. The mirror 140a reflects light downward toward the substrate W. The mirror 140a reflects the light reflected by the substrate W toward the lens 141a and guides it to the optical fiber 144. Note that the mirror 140a may not be provided, and the optical axis of the lens 141a may be disposed vertically. However, if the mirror 140a is used, the height of the probe 141 can be lowered, and the height of the housing 100 can be lowered.

[0055] The probe 141 is provided inside the housing 100, whereas the box 146 is provided outside the housing 100. A light source 143 and a photodetector 145 are provided outside the housing 100. The light source 143 and the photodetector 145 are heat sources. By disposing the heat source outside the housing 100, temperature fluctuations inside the housing 100 can be suppressed, temperature fluctuations of the substrate W can be suppressed, and the measurement accuracy of the thickness of the substrate W can be improved.

[0056] The temperature adjustment unit 147 adjusts the temperature inside the box 146 to a desired temperature. The temperature adjustment unit 147 absorbs heat from a heat source inside the box 146. The amount of heat generated by the light source 143 is greater than the amount of heat generated by the photodetector 145. The temperature adjustment unit 147 can suppress temperature fluctuations inside the box 146, and can suppress temperature fluctuations of the photodetector 145. As a result, fluctuations in the measured value of the thickness of the substrate W caused by temperature fluctuations of the photodetector 145 can be suppressed.

[0057] The temperature adjustment unit 147 includes, for example, a temperature adjustment plate 148 and a temperature adjustment medium supplier 149. The temperature adjustment plate 148 is in contact with, for example, the lower surface of the box 146, and absorbs heat inside the box 146. The temperature adjustment plate 148 may be disposed inside the box 146. The temperature adjustment medium supplier 149 supplies a temperature adjustment medium adjusted to a desired temperature to the temperature adjustment plate 148. The temperature adjustment medium absorbs heat from the temperature adjustment plate 148 while flowing through a flow path inside the temperature adjustment plate 148. After being discharged from the temperature adjustment plate 148, the temperature adjustment medium may be cooled by the temperature adjustment medium supplier 149 and returned to the temperature adjustment plate 148 again.

[0058] The alignment unit 150 (see FIG. 5) detects the position of a notch that indicates the crystal orientation of the substrate W. In a rotating coordinate system that rotates together with the substrate holding unit 110, the alignment unit 150 can detect the radial coordinate and angular coordinate of the notch. The alignment unit 150 detects the position of the notch, for example, by irradiating the periphery of the substrate W with light and receiving the irradiated light. The alignment unit 150 and the thickness measuring unit 140 can be used to investigate the relationship between the crystal orientation of the substrate W and the variation in thickness of the substrate W. Note that an orientation flat may be formed on the periphery of the substrate W instead of the notch. The alignment unit 150 may detect the position of the orientation flat instead of the notch.

[0059] Temperature measuring unit 160 (see FIG. 4) measures the temperature inside housing 100. Temperature measuring unit 160 transmits the measured data to control unit 190. Humidity measuring unit 161 measures the humidity inside housing 100. The measured humidity is, for example, relative humidity. Humidity measuring unit 161 transmits the measured data to control unit 190. Temperature measuring unit 160 and humidity measuring unit 161 are integrated in FIG. 4, but may be provided separately.

[0060] The exhaust unit 170 exhausts gas from within the housing 100. Particles may be generated inside the housing 100 due to the rotation and movement of the substrate holder 110. The exhaust unit 170 exhausts the particles generated inside the housing 100 to the outside of the housing 100 together with the gas, and suppresses the adhesion of the particles to the substrate W. The exhaust unit 170 includes, for example, an exhaust duct 171 and an exhaust source 172 connected to the exhaust duct 171. The exhaust duct 171 has, for example, a pair of first exhaust ducts 171a, 171b extending in the Y-axis direction, and a second exhaust duct 171c connecting the pair of first exhaust ducts 171a, 171b. The pair of first exhaust ducts 171a, 171b each have a plurality of exhaust ports 171d spaced apart in the Y-axis direction. The exhaust source 172 is, for example, a vacuum pump.

[0061] 5, the internal cover 180 partitions the inside of the housing 100 to suppress the outflow of particles caused by the rotation and movement of the substrate holding part 110. The internal cover 180 has, for example, a rectangular frame-shaped side wall 181 arranged along the side of the housing 100, and a top plate 182 covering the side wall 181 from above. The top plate 182 has an opening which is the movement path of the rotation shaft 121. The rotating part 120, the moving part 130, and the exhaust duct 171 are provided below the top plate 182. The load / unload port 101 is provided above the top plate 182. The load / unload port 101 is partitioned by the top plate 182 to suppress the outflow of particles.

[0062] Next, an example of components of the control unit 190 will be described with reference to Fig. 7. Note that each functional block shown in Fig. 7 is conceptual, and does not necessarily have to be physically configured as shown. All or a part of each functional block can be functionally or physically distributed and integrated in any unit. All or any part of each processing function performed by each functional block can be realized by a program executed by a CPU, or can be realized as hardware using wired logic.

[0063] The control unit 190 is a computer. For example, as shown in FIG. 7, the control unit 190 has a rotation control unit 191, a movement control unit 192, an exhaust control unit 193, a thickness acquisition unit 194, a temperature acquisition unit 195, a humidity acquisition unit 196, and a thickness calibration unit 197. The rotation control unit 191 controls the rotation unit 120. The movement control unit 192 controls the movement unit 130. The exhaust control unit 193 controls the exhaust unit 170. The thickness acquisition unit 194 acquires the thickness measured by the thickness measurement unit 140. The temperature acquisition unit 195 acquires the temperature measured by the temperature measurement unit 160. The humidity acquisition unit 196 acquires the humidity measured by the humidity measurement unit 161. The thickness calibration unit 197 Thickness measuring unit 140 The measured thickness is calibrated by

[0064] The rotation control unit 191 controls the supply current I to the motor 122 when the rotation of the substrate holder 110 is stopped. STOP is the current I supplied to the motor 122 when rotating the substrate holder 110. ROTATE The current I supplied to the motor 122 when the substrate holder 110 is stopped from rotating is controlled to 5% to 20%. STOP The stop current I STOP The current I supplied to the motor 122 when rotating the substrate holder 110 is ROTATE The current for rotation I ROTATE Also called.

[0065] Conventionally, the stopping current I STOP is the current for rotation I ROTATE, the amount of heat generated by the motor 122 was large, and a large amount of heat was transferred from the motor 122 to the substrate W via the substrate holding part 110. As a result, the temperature fluctuation of the substrate W was large, and the measurement accuracy of the thickness of the substrate W was low. In particular, when the substrate holding part 110 held only the central part of the substrate W, a temperature gradient occurred in the radial direction of the substrate W, and the measurement accuracy of the thickness of the substrate W was low.

[0066] According to this embodiment, the rotation control unit 191 is current I STOP For rotation, current I ROTATE The motor 122 is controlled to have a temperature of 5% to 20% or less. This makes it possible to suppress heat generation by the motor 122, suppress temperature fluctuations in the substrate W, and improve the measurement accuracy of the thickness of the substrate W. In particular, when the substrate holding part 110 holds only the central part of the substrate W, it is possible to suppress the occurrence of a temperature gradient in the radial direction of the substrate W, and improve the measurement accuracy of the thickness of the substrate W.

[0067] Next, an example of setting the correction coefficient will be described with reference to Fig. 8. First, the second transport device 39 takes out the calibration substrate WA from the storage device 61 and carries it inside the housing 100 of the substrate thickness measuring device 33 (step S201). The second transport device 39 passes the calibration substrate WA to the substrate holding unit 110 and exits to the outside of the housing 100. The substrate holding unit 110 holds the calibration substrate WA. The calibration substrate WA may have the same diameter, thickness, and material as the substrate W.

[0068] Next, the thickness measuring unit 140 measures the thickness of the calibration substrate WA (step S202). Before measuring the thickness of the calibration substrate WA, the alignment unit 150 may detect the position of the notch of the calibration substrate WA. The position of the thickness measurement point is set in advance, and is adjusted by the rotation unit 120 and the movement unit 130 based on the detection result of the alignment unit 150.

[0069] Next, the thickness calibration unit 197 sets the ratio (t0 / t1) of the thickness t1 of the calibration substrate WA measured in step S202 above to the pre-stored standard thickness t0 of the calibration substrate WA as a correction coefficient (step S203). The standard thickness t0 of the calibration substrate WA is measured, for example, using a measurement device other than the substrate thickness measurement device 33, and is stored in a storage medium in association with the positions of the measurement points. When there are multiple measurement points, a correction coefficient may be found for each measurement point, or a correction coefficient common to the multiple measurement points may be found. As the latter correction coefficient, for example, the average value of the ratio (t0 / t1) is used.

[0070] Next, the second transport device 39 receives the calibration substrate WA from the substrate holding unit 110 and transports it outside the housing 100 (step S204). The second transport device 39 transports the calibration substrate WA to the storage device 61. The storage device 61 stores the calibration substrate WA again. Then, the current process ends. Step S204 (transporting the calibration substrate WA) may be performed after step S202 (measuring the thickness of the calibration substrate WA) or before step S203 (setting the correction coefficient).

[0071] The substrate thickness measuring device 33 of this embodiment measures the thickness of the substrate W after etching. In this case, before step S201 (carrying in the calibration substrate WA) in Fig. 8, the second transport device 39 may take out the calibration substrate WA from the storage device 61 and transport it to the etching device 32A or 32B. The calibration substrate WA is washed with pure water by the etching device 32A or 32B, and then dried, and then carried into the housing 100 of the substrate thickness measuring device 33 by the second transport device 39. In the same state as the substrate W, the thickness t1 of the calibration substrate WA can be measured, and the ratio (t0 / t1), which is a correction coefficient, can be set.

[0072] The temperature acquisition unit 195 acquires the temperature T0 inside the housing 100 when the thickness t1 of the calibration substrate WA is measured using the temperature measurement unit 160, and stores it in a storage medium. The humidity acquisition unit 196 acquires the humidity H0 inside the housing 100 when the thickness t1 of the calibration substrate WA is measured using the humidity measurement unit 161, and stores it in a storage medium.

[0073] Next, an example of substrate thickness calibration will be described with reference to Fig. 9. First, the temperature acquisition unit 195 acquires the temperature T inside the housing 100 using the temperature measurement unit 160 (step S301). Next, the thickness calibration unit 197 checks whether the temperature T acquired by the temperature acquisition unit 195 is within an allowable range (step S302). The allowable range is represented by a lower limit value Tmin and an upper limit value Tmax. The lower limit value Tmin and the upper limit value Tmax are each set based on the temperature T0 inside the housing 100 when the thickness t1 of the calibration substrate WA is measured, and are set, for example, to sandwich that temperature T0.

[0074] If the temperature T acquired by the temperature acquisition unit 195 is within the allowable range (step S302, YES), steps S303 to S306 described below are performed, and the thickness of the substrate W is measured and calibrated.

[0075] First, the second transfer device 39 carries the substrate W into the housing 100 of the substrate thickness measuring device 33 (step S303). The second transfer device 39 passes the substrate W to the substrate holding unit 110 and exits to the outside of the housing 100. The substrate holding unit 110 holds the substrate W.

[0076] Next, the thickness measuring unit 140 measures the thickness t2 of the substrate W (step S304). Before measuring the thickness t2 of the substrate W, the alignment unit 150 may detect the position of the notch of the substrate W. The position of the thickness measurement point is set in advance, and is adjusted by the rotation unit 120 and the movement unit 130 based on the detection result of the alignment unit 150.

[0077] Next, the thickness calibration unit 197 calibrates the thickness t2 of the substrate W measured in step S304 (step S305). Specifically, the thickness calibration unit 197 obtains the product (t2×t0 / t1) of the thickness t2 measured by the thickness measurement unit 140 and a preset correction coefficient (t0 / t1) as the calibrated thickness. This improves the measurement accuracy of the thickness of the substrate W.

[0078] Next, the second transfer device 39 receives the substrate W from the substrate holding unit 110 and transports it outside the housing 100 (step S306). Then, the current process ends. Step S306 (transporting the substrate W) may be performed after step S304 (measuring the thickness of the substrate W) or before step S305 (calibrating the thickness of the substrate W).

[0079] On the other hand, if the temperature T acquired by the temperature acquisition unit 195 is outside the allowable range (step S302, NO), steps S201 to S204 shown in Fig. 8 are performed, the correction coefficient (t0 / t1) is calculated again, and the setting is changed. After that, the processing from step S301 shown in Fig. 9 is performed again.

[0080] According to this embodiment, as described above, the thickness calibration unit 197 changes the setting of the correction coefficient when the temperature T measured by the temperature measurement unit 160 falls outside a preset allowable range. Thereafter, the thickness calibration unit 197 calibrates the thickness t2 of the substrate W measured by the thickness measurement unit 140 using the changed correction coefficient. The correction coefficient can be changed as appropriate in response to temperature fluctuations of the substrate W, and the measurement accuracy of the thickness of the substrate W can be improved.

[0081] The thickness calibration unit 197 may calibrate the thickness t2 measured by the thickness measurement unit 140 based on the humidity measured by the humidity measurement unit 161. As shown in FIG. 10, the higher the humidity, the smaller the measured thickness value tends to be. This tendency is approximately expressed by a linear equation. The slope a of the fluctuation of the measured thickness value with respect to the fluctuation of the humidity is, for example, negative. By calibrating the thickness t2 according to the humidity, the measurement accuracy of the thickness t2 can be improved.

[0082] For example, the thickness calibration unit 197 first calculates the difference ΔH (ΔH=H-H0) between the humidity H0 inside the housing 100 when the thickness t1 of the calibration substrate WA is measured and the humidity H inside the housing 100 when the thickness t2 of the substrate W is measured. Next, the thickness calibration unit 197 calculates the product (ΔH×a) of the difference (ΔH=H-H0) and the slope a of the fluctuation in the measured thickness value with respect to the humidity fluctuation shown in Fig. 10. The thickness calibration unit 197 determines the difference (t2-ΔH×a) between the thickness t2 measured by the thickness measurement unit 140 and the product (ΔH×a) as the calibrated thickness.

[0083] Next, with reference to Fig. 11, an example of fluctuations in the measured thickness value in response to fluctuations in the distance L between the probe 141 and the substrate W will be described. In Fig. 11, the distance L being zero means that the focus of the lens 141a is on the substrate W. As shown in Fig. 11, the further the distance L is from zero, the more likely the measured thickness value is to fluctuate.

[0084] The distance L may vary when the probe 141 is fixed. Factors that cause the distance L to vary include, for example, (1) expansion and contraction of members due to temperature fluctuations, (2) fluctuations in thickness between the substrates W, (3) inclination of the guide rails 133, (4) surface accuracy of the substrate holder 110, and (5) deflection of the substrate W due to its own weight.

[0085] In order to minimize the fluctuation range of the measured thickness value due to the fluctuation of the distance L caused by the above (1) to (5), the probe 141 is placed at a position where the distance L is zero. Specifically, the probe 141 is placed at a position where the intensity of the light detected by the photodetector 145 is maximized.

[0086] 12 shows an example of the fluctuation in the intensity of light detected by the photodetector 145 and the fluctuation in the range of the measured thickness values ​​with respect to the fluctuation in the distance L between the probe 141 and the substrate W. In FIG. 12, the fluctuation range of the measured thickness values ​​is due to the above factors (1) to (5).

[0087] 12, if the probe 141 is placed at a position where the intensity of the light detected by the photodetector 145 is maximized, that is, if the distance L is zero, the fluctuation range of the measured thickness value becomes as small as possible. Therefore, the thickness of the substrate W can be measured with high accuracy.

[0088] Although the embodiments of the substrate thickness measuring device, substrate processing system, and substrate thickness measuring method according to the present disclosure have been described above, the present disclosure is not limited to the above embodiments. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the claims. Naturally, these also fall within the technical scope of the present disclosure.

[0089] This application claims priority based on Patent Application No. 2021-130839 filed with the Japan Patent Office on August 10, 2021, and the entire contents of Patent Application No. 2021-130839 are incorporated by reference into this application. [Explanation of symbols]

[0090] 1. Substrate Processing System 33 Substrate thickness measuring device 100 Case 110 Board holding part 140 Thickness measurement section 160 Temperature measurement section 197 Thickness Calibration Department W substrate

Claims

1. A substrate holder for holding a substrate; a thickness measuring unit for measuring a thickness of the substrate held by the substrate holding unit; a housing that accommodates the substrate holding unit and at least a part of the thickness measuring unit; A temperature measuring unit that measures a temperature inside the housing; A control unit; Equipped with The control unit is When the temperature measured by the temperature measuring unit is within a preset allowable range, the substrate is carried into the housing, the thickness of the substrate is measured by the thickness measuring unit, and the product of the thickness of the substrate measured by the thickness measuring unit and a preset correction coefficient is calculated as the thickness of the substrate after calibration; A substrate thickness measuring device which, when the temperature measured by the temperature measuring unit falls outside the preset tolerance range, carries out the following steps: bringing a calibration substrate into the housing instead of the substrate; and measuring the thickness of the calibration substrate with the thickness measuring unit to change the setting of the correction coefficient.

2. 2. The substrate thickness measuring device according to claim 1, wherein the control unit sets the ratio (t0 / t1) of a pre-stored standard thickness (t0) of the calibration substrate to the thickness (t1) of the calibration substrate measured by the thickness measuring unit as the correction coefficient.

3. the thickness measuring unit includes a probe that irradiates light toward the substrate and receives the light reflected by the substrate, a light source connected to the probe via an optical fiber, a photodetector connected to the probe via an optical fiber, and a box that houses the light source and the photodetector; 3. The substrate thickness measuring device according to claim 1, wherein the probe is provided inside the housing, and the box is provided outside the housing.

4. The substrate thickness measuring device according to claim 3 , further comprising a temperature adjusting unit that adjusts a temperature inside the box.

5. 4. The substrate thickness measuring device according to claim 3, wherein the probe is placed at a position where the intensity of the light detected by the photodetector is maximized.

6. a motor that rotates the substrate holder; The substrate thickness measuring device of claim 1 or 2, wherein the control unit controls the current supplied to the motor when the substrate holding unit is stopped from rotating to be 5% to 20% or less of the current supplied to the motor when the substrate holding unit is rotating.

7. a humidity measuring unit for measuring the humidity inside the housing, 3. The substrate thickness measuring device according to claim 1, wherein the control unit calibrates the thickness measured by the thickness measuring unit based on the humidity measured by the humidity measuring unit.

8. The substrate thickness measuring device according to claim 1 or 2, an etching apparatus for etching the substrate; a transport device that transports the substrate to the substrate thickness measuring device and the etching device; Equipped with The transfer device transfers the substrate, which has been etched, cleaned, and dried in the etching device, to the substrate thickness measuring device.

9. The substrate thickness measuring device according to claim 1 or 2, a storage device for storing the calibration substrate; a transport device that transports the calibration substrate to the substrate thickness measuring device and the storage device; A substrate processing system comprising:

10. An etching apparatus for etching the substrate, 10. The substrate processing system according to claim 9, wherein the transport device transports the substrate that has been etched, cleaned, and dried in the etching device, and the calibration substrate that has been cleaned and dried in the etching device, to the substrate thickness measuring device.

11. A substrate thickness measurement method for measuring a thickness of a substrate using a substrate thickness measurement device including: a substrate holding part for holding a substrate; a thickness measurement part for measuring a thickness of the substrate held by the substrate holding part; a housing for accommodating the substrate holding part and at least a part of the thickness measurement part; and a temperature measurement part for measuring a temperature inside the housing, the method comprising: when the temperature measured by the temperature measuring unit is within a preset allowable range, carrying the substrate into the housing, measuring a thickness of the substrate by the thickness measuring unit, and determining a product of the thickness of the substrate measured by the thickness measuring unit and a preset correction coefficient as a calibrated thickness of the substrate, A substrate thickness measurement method comprising: when a temperature measured by the temperature measurement unit falls outside the preset tolerance range, carrying a calibration substrate into the housing instead of the substrate; and measuring a thickness of the calibration substrate with the thickness measurement unit to change the setting of the correction coefficient.

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