Temperature measurement system, sensor board, and temperature measurement method

Abstract

This technology provides the ability to measure temperature over a wide temperature range within a chamber. [Solution] The temperature measurement system according to the exemplary embodiment comprises a sensor substrate, a mounting table, and a measuring device. The sensor substrate includes a base substrate, an optical ring resonator provided on the base substrate, and a waveguide provided on the base substrate and optically coupled to the optical ring resonator. The measuring device includes a laser oscillator that inputs laser light into the waveguide of the sensor substrate placed on the mounting table, and a spectrometer that receives reflected light of the laser light propagating through the waveguide and output from the waveguide.

Description

Technical Field

[0006] , , ,

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[0001] Exemplary embodiments of the present disclosure relate to a temperature measurement system, a sensor substrate, and a temperature measurement method.

Background Art

[0002] Patent Document 1 discloses a technique for measuring the temperature inside a process chamber using an infrared camera.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a technique capable of measuring temperature within a wide temperature range inside a chamber.

Means for Solving the Problems

[0005] In one exemplary embodiment, a temperature measurement system is provided. The temperature measurement system includes a sensor substrate, a mounting table, and a measurement device. The sensor substrate includes a base substrate, an optical ring resonator provided on the base substrate, and a waveguide provided on the base substrate and optically coupled to the optical ring resonator. The mounting table is configured to mount the sensor substrate. The measurement device includes a laser oscillator that inputs laser light into the waveguide of the sensor substrate mounted on the mounting table, and a spectroscope that receives the reflected light of the laser light that propagates through the waveguide and is output from the waveguide.

Effects of the Invention

[0006] According to one exemplary embodiment, temperature measurement is possible within a wide temperature range.

Brief Description of the Drawings

[0007] [Figure 1] This diagram shows an example of a processing system. [Figure 2] This is a perspective view showing an example of an aligner. [Figure 3] This figure shows an example of a plasma processing apparatus. [Figure 4] This is a schematic diagram illustrating an example of a temperature measurement system. [Figure 5] This is a plan view showing an example of a sensor board as seen from above. [Figure 6] This is a schematic perspective view showing a portion of an example sensor board. [Figure 7] This flowchart shows an example of how a temperature measurement system works. [Modes for carrying out the invention]

[0008] Various exemplary embodiments will be described below.

[0009] In one exemplary embodiment, a temperature measurement system is provided. The temperature measurement system comprises a sensor substrate, a mounting stage, and a measuring device. The sensor substrate includes a base substrate, an optical ring resonator provided on the base substrate, and a waveguide provided on the base substrate and optically coupled to the optical ring resonator. The mounting stage is configured to support the sensor substrate. The measuring device includes a laser oscillator that inputs laser light into the waveguide of the sensor substrate mounted on the mounting stage, and a spectrometer that receives reflected light of the laser light propagating through the waveguide and output from the waveguide.

[0010] In one exemplary embodiment, a sensor substrate is provided. The sensor substrate comprises a disc-shaped base substrate, an optical ring resonator provided on the base substrate, and a waveguide provided on the base substrate and optically coupled to the optical ring resonator.

[0011] In one exemplary embodiment, a temperature measurement method using the sensor substrate described above is provided. The temperature measurement method comprises the steps of: inputting laser light into a waveguide; receiving reflected light of the laser light that has propagated through the waveguide and been output from the waveguide; and calculating the temperature based on the spectrum of the received reflected light.

[0012] In the above-described temperature measurement system and sensor substrate, laser light is input to the waveguide while the sensor substrate is placed on the mounting platform. The laser light can be optically coupled with the optical ring resonator if its wavelength matches the resonant wavelength of the optical ring resonator. In this case, the intensity of the resonant wavelength component in the reflected laser light decreases. Since the resonant wavelength of the optical ring resonator is temperature-dependent, the temperature at the location of the optical ring resonator can be obtained by acquiring the resonant wavelength using a spectrometer. In such a temperature measurement system, since the sensor substrate consists of a base substrate, an optical ring resonator on the base substrate, and a waveguide, there are no constraints on the temperature range, such as battery operating temperature. Therefore, temperature measurement is possible over a wide temperature range.

[0013] In one exemplary embodiment, the measuring device may include an optical circulator that guides laser light emitted from a laser oscillator into a waveguide and also guides the laser light output from the waveguide to a spectrometer.

[0014] In one exemplary embodiment, the sensor substrate may include a lens that focuses laser light emitted from a laser oscillator into a waveguide.

[0015] In one exemplary embodiment, the waveguide may be made of a silicon-containing material.

[0016] In one exemplary embodiment, the base substrate may be made of a silicon-containing material.

[0017] In one exemplary embodiment, the sensor substrate may include a plurality of optical ring resonators.

[0018] In one exemplary embodiment, the plurality of optical ring resonators may have different radii from each other.

[0019] The mounting table in one exemplary embodiment may include lift pins for lifting up the sensor substrate. The lift pins may include an optical fiber that irradiates laser light emitted from a laser oscillator from above the lift pins.

[0020] The optical ring resonator and waveguide in one exemplary embodiment may be formed on a sensor chip disposed on a base substrate. The sensor chip includes an optical coupler that optically couples light received from the outside to the waveguide, and a lens that condenses light on the optical coupler. The lens may be formed on the lower surface of the sensor chip.

[0021] Hereinafter, various embodiments will be described in detail with reference to the drawings. In each drawing, the same or corresponding parts will be denoted by the same reference numerals.

[0022] First, a processing system for processing a workpiece will be described. Note that this processing system may include a part of a temperature measurement system according to one exemplary embodiment. FIG. 1 is a diagram illustrating the processing system. The processing system 1 includes tables 2a to 2d, containers 4a to 4d, a loader module LM, an aligner AN, load lock modules LL1 and LL2, process modules PM1 to PM6, a transfer module TF, and a control unit MC. Note that the number of tables 2a to 2d, the number of containers 4a to 4d, the number of load lock modules LL1 and LL2, and the number of process modules PM1 to PM6 are not limited and may be any number of one or more.

[0023] The bases 2a to 2d are arranged along one edge of the loader module LM. The containers 4a to 4d are each mounted on the bases 2a to 2d. Each of the containers 4a to 4d is, for example, a container called a FOUP (Front Opening Unified Pod). Each of the containers 4a to 4d may be configured to contain a workpiece W. The workpiece W has a roughly disc shape, such as a wafer.

[0024] The loader module LM has a chamber wall that defines a transport space under atmospheric pressure within it. A transport device TU1 is provided within this transport space. The transport device TU1 is, for example, an articulated robot and is controlled by the control unit MC. The transport device TU1 is configured to transport the workpiece W between containers 4a to 4d and the aligner AN, between the aligner AN and the load lock modules LL1 to LL2, and between the load lock modules LL1 to LL2 and the containers 4a to 4d.

[0025] The aligner AN is connected to the loader module LM. The aligner AN is configured to adjust (calibrate) the position of the workpiece W. Figure 2 is an illustrative perspective view of the aligner. The aligner AN has a support base 6T, a drive unit 6D, and a sensor 6S. The support base 6T is a rotatable base about an axis extending in the vertical direction. The support base 6T is configured to support the workpiece W on it. The support base 6T is rotated by the drive unit 6D. The drive unit 6D is controlled by the control unit MC. When the support base 6T rotates due to the power from the drive unit 6D, the workpiece W placed on the support base 6T also rotates.

[0026] Sensor 6S is an optical sensor. Sensor 6S detects the edges of the workpiece W while the workpiece W is rotating. From the edge detection results, Sensor 6S detects the amount of deviation of the notch WN (or another marker) on the workpiece W from the reference angular position, and the amount of deviation of the center position of the workpiece W from the reference position. Sensor 6S outputs the amount of deviation of the notch WN and the center position of the workpiece W to the control unit MC. Based on the amount of deviation of the notch WN, the control unit MC calculates the amount of rotation of the support base 6T to correct the angular position of the notch WN to the reference angular position. The control unit MC controls the drive unit 6D to rotate the support base 6T by this amount of rotation. This corrects the angular position of the notch WN to the reference angular position. In addition, the control unit MC controls the position of the end effector of the transport device TU1 when receiving the workpiece W from the aligner AN, based on the amount of deviation of the center position of the workpiece W. As a result, the center position of the workpiece W coincides with a predetermined position on the end effector of the conveying device TU1.

[0027] Returning to Figure 1, load lock module LL1 and load lock module LL2 are located between loader module LM and transfer module TF. Load lock module LL1 and load lock module LL2 each provide a pre-depressurization chamber.

[0028] The transfer module TF is hermetically connected to the load lock modules LL1 and LL2 via gate valves. The transfer module TF provides a depressurized chamber. A conveying device TU2 is provided in this depressurized chamber. The conveying device TU2 is, for example, an articulated robot having a conveying arm TUa. The conveying device TU2 is controlled by the control unit MC. The conveying device TU2 is configured to convey the workpiece W between the load lock modules LL1-LL2 and the process modules PM1-PM6, and between any two process modules among the process modules PM1-PM6.

[0029] Process modules PM1 to PM6 are hermetically connected to the transfer module TF via gate valves. Each of the process modules PM1 to PM6 is a processing unit configured to perform a specific treatment, such as plasma treatment, on the workpiece W.

[0030] The following is an example of the sequence of operations when processing the workpiece W in this processing system 1. The transport device TU1 of the loader module LM takes the workpiece W from one of the containers 4a to 4d and transports the workpiece W to the aligner AN. Next, the transport device TU1 takes the workpiece W, whose position has been adjusted, from the aligner AN and transports the workpiece W to one of the load lock modules LL1 and LL2. Next, one of the load lock modules reduces the pressure in the pre-pressure chamber to a predetermined pressure. Next, the transport device TU2 of the transfer module TF takes the workpiece W from one of the load lock modules and transports the workpiece W to one of the process modules PM1 to PM6. Then, one or more of the process modules PM1 to PM6 process the workpiece W. Finally, the transport device TU2 transports the processed workpiece W from the process module to one of the load lock modules LL1 and LL2. Next, the conveying device TU1 transports the workpiece W from one of the load lock modules to one of the containers 4a to 4d.

[0031] As described above, this processing system 1 includes a control unit MC. The control unit MC may be a computer equipped with a processor, memory and other storage devices, a display device, input / output devices, communication devices, etc. The series of operations of the processing system 1 described above are realized by the control unit MC controlling each part of the processing system 1 according to a program stored in the storage device.

[0032] Figure 3 shows an example of a plasma processing apparatus that can be adopted as one of the process modules PM1 to PM6. The plasma processing apparatus 10 shown in Figure 3 is a capacitively coupled plasma etching apparatus. The plasma processing apparatus 10 comprises a substantially cylindrical chamber body 12. The chamber body 12 is formed from, for example, aluminum, and its inner wall surface may be subjected to anodizing treatment. This chamber body 12 is grounded for safety.

[0033] A substantially cylindrical support portion 14 is provided on the bottom of the chamber body 12. The support portion 14 is made of, for example, an insulating material. The support portion 14 is located inside the chamber body 12. The support portion 14 extends upward from the bottom of the chamber body 12. A stage ST is provided inside the chamber S provided by the chamber body 12. The stage ST is supported by the support portion 14.

[0034] The stage ST has a lower electrode LE and an electrostatic chuck ESC. The lower electrode LE includes a first plate 18a and a second plate 18b. The first plate 18a and the second plate 18b are made of a metal such as aluminum and are substantially disc-shaped. The second plate 18b is provided on the first plate 18a and is electrically connected to the first plate 18a.

[0035] An electrostatic chuck ESC is provided on the second plate 18b. The electrostatic chuck ESC has a structure in which electrodes, which are conductive films, are arranged between a pair of insulating layers or insulating sheets, and has a substantially disc shape. A DC power supply 22 is electrically connected to the electrodes of the electrostatic chuck ESC via a switch 23. This electrostatic chuck ESC attracts the workpiece W by electrostatic force such as Coulomb force generated by the DC voltage from the DC power supply 22. In this way, the electrostatic chuck ESC can hold the workpiece W.

[0036] An edge ring ER is provided on the periphery of the second plate 18b. This edge ring ER is provided so as to surround the edge of the workpiece W and the electrostatic chuck ESC. The edge ring ER has an annular plate shape. The workpiece W is conveyed onto the electrostatic chuck ESC by conveying devices TU1 and TU2 so that the center position of the workpiece W and the center position of the edge ring ER coincide. This edge ring ER can be formed from any of various materials such as silicon, silicon carbide, or silicon oxide.

[0037] A refrigerant flow path 24 is provided inside the second plate 18b. The refrigerant flow path 24 constitutes a temperature control mechanism. Refrigerant is supplied to the refrigerant flow path 24 from a chiller unit located outside the chamber body 12 via piping 26a. The refrigerant supplied to the refrigerant flow path 24 is returned to the chiller unit via piping 26b. In this way, refrigerant circulates between the refrigerant flow path 24 and the chiller unit. By controlling the temperature of this refrigerant, the temperature of the workpiece W supported by the electrostatic chuck ESC is controlled.

[0038] The stage ST has multiple (for example, three) through holes 25 that penetrate the stage ST. The multiple through holes 25 are formed on the inside of the electrostatic chuck ESC in a plan view. A lift pin 25a is inserted into each of these through holes 25. In Figure 3, one through hole 25 with one lift pin 25a inserted is depicted. The lift pin 25a is provided to be vertically movable within the through hole 25. The workpiece W supported on the electrostatic chuck ESC is raised by the rise of the lift pin 25a. For example, the lift pin 25a can receive the workpiece W transported by the transport device TU2 based on transport position data and place the workpiece W on the electrostatic chuck ESC. The lift pin 25a can also transfer the workpiece W placed on the electrostatic chuck ESC to the transport device TU2. Details of the lift pin 25a will be described later.

[0039] The stage ST has multiple (e.g., three) through-holes 27 that penetrate the stage ST (lower electrode LE) at a position outside the electrostatic chuck ESC in a plan view. A lift pin 27a is inserted into each of these through-holes 27. In Figure 3, one through-hole 27 with one lift pin 27a inserted is depicted. The lift pin 27a is provided to be vertically movable within the through-hole 27. The rise of the lift pin 27a causes the edge ring ER supported on the second plate 18b to rise. For example, the lift pin 27a can transfer a worn edge ring ER to the transport device TU2. The lift pin 27a can also receive a replacement edge ring ER transported by the transport device TU2 based on transport position data and place the edge ring ER in the designated position. The replacement edge ring ER may be an unused edge ring or a used edge ring with minimal wear.

[0040] Furthermore, the plasma processing apparatus 10 is provided with a gas supply line 28. The gas supply line 28 supplies heat transfer gas, such as He gas, from the heat transfer gas supply mechanism between the upper surface of the electrostatic chuck ESC and the back surface of the workpiece W.

[0041] The plasma processing apparatus 10 also includes an upper electrode 30. The upper electrode 30 is positioned above the stage ST and opposite to the stage ST. The upper electrode 30 is supported on the upper part of the chamber body 12 via an insulating shielding member 32. The upper electrode 30 may include a top plate 34 and a support 36. The top plate 34 faces the chamber S. The top plate 34 is provided with a plurality of gas discharge holes 34a. The top plate 34 may be formed from silicon or quartz. Alternatively, the top plate 34 may be constructed by forming a plasma-resistant film, such as yttrium oxide, on the surface of an aluminum base material.

[0042] The support 36 detachably supports the top plate 34. The support 36 may be made of a conductive material such as aluminum. The support 36 may have a water-cooling structure. A gas diffusion chamber 36a is provided inside the support 36. Multiple gas passage holes 36b that communicate with the gas discharge hole 34a extend downward from this gas diffusion chamber 36a. The support 36 also has a gas inlet 36c that guides the processed gas into the gas diffusion chamber 36a. A gas supply pipe 38 is connected to this gas inlet 36c.

[0043] A gas source group 40 is connected to the gas supply pipe 38 via a valve group 42 and a flow controller group 44. The gas source group 40 includes multiple gas sources for multiple types of gas. The valve group 42 includes multiple valves, and the flow controller group 44 includes multiple flow controllers such as mass flow controllers. Each of the multiple gas sources in the gas source group 40 is connected to the gas supply pipe 38 via a corresponding valve in the valve group 42 and a corresponding flow controller in the flow controller group 44.

[0044] Furthermore, in the plasma processing apparatus 10, a deposit shield 46 is detachably provided along the inner wall of the chamber body 12. The deposit shield 46 is also provided on the outer circumference of the support portion 14. The deposit shield 46 prevents etching by-products (deposits) from adhering to the chamber body 12. The deposit shield 46 can be constructed by coating an aluminum material with ceramics such as yttrium oxide.

[0045] An exhaust plate 48 is provided at the bottom of the chamber body 12, between the support portion 14 and the side wall of the chamber body 12. The exhaust plate 48 can be constructed, for example, by coating aluminum with ceramics such as yttrium oxide. Multiple holes are formed in the exhaust plate 48, penetrating in the direction of its plate thickness. Below the exhaust plate 48, and in the chamber body 12, an exhaust port 12e is provided. An exhaust device 50 is connected to the exhaust port 12e via an exhaust pipe 52. The exhaust device 50 includes a pressure regulating valve and a vacuum pump such as a turbomolecular pump. The exhaust device 50 can reduce the pressure in the space inside the chamber body 12 to a desired vacuum level. In addition, an inlet / outlet 12g for workpieces W is provided in the side wall of the chamber body 12. This inlet / outlet 12g can be opened and closed by a gate valve 54.

[0046] The plasma processing apparatus 10 further includes a first high-frequency power supply 62 and a second high-frequency power supply 64. The first high-frequency power supply 62 is a power supply that generates a first high frequency for plasma generation. The first high-frequency power supply 62 generates a high frequency having a frequency of, for example, 27 to 100 MHz. The first high-frequency power supply 62 is connected to the upper electrode 30 via a matching unit 66. The matching unit 66 has a circuit for matching the output impedance of the first high-frequency power supply 62 with the input impedance of the load side (upper electrode 30 side). The first high-frequency power supply 62 may also be connected to the lower electrode LE via the matching unit 66.

[0047] The second high-frequency power supply 64 is a power supply that generates a second high frequency for drawing ions into the workpiece W. The second high-frequency power supply 64 generates a high frequency in the range of, for example, 400 kHz to 13.56 MHz. The second high-frequency power supply 64 is connected to the lower electrode LE via a matching circuit 68. The matching circuit 68 has a circuit for matching the output impedance of the second high-frequency power supply 64 with the input impedance of the load side (lower electrode LE side).

[0048] In the plasma processing apparatus 10, gas is supplied to the chamber S from one or more gas sources selected from a plurality of gas sources. The pressure in the chamber S is set to a predetermined pressure by the exhaust device 50. Furthermore, the gas in the chamber S is excited by a first high frequency from the first high frequency power supply 62. This generates plasma. The workpiece W is then processed by the generated active species. If necessary, ions may be drawn into the workpiece W by a bias based on a second high frequency from the second high frequency power supply 64.

[0049] Next, the temperature measurement system will be described. Figure 4 is a schematic diagram illustrating the temperature measurement system. Figure 5 is a schematic plan view of the sensor substrate as seen from above. Figure 6 is a schematic perspective view of a part of the sensor substrate. One exemplary embodiment of the temperature measurement system S1 comprises a sensor substrate 100, the stage ST (mounting platform) described above, and a measuring device 200. In this temperature measurement system S1, the temperature of the sensor substrate 100 placed on the stage ST is measured.

[0050] The sensor substrate 100 includes a base substrate 102, an optical ring resonator 161, a waveguide 163 (silicon waveguide), and an optical coupler 165. The base substrate 102 has a shape similar to that of the workpiece W, i.e., a roughly disc shape. The diameter of the base substrate 102 is the same as the diameter of the workpiece W, for example, 300 mm. The TTV (Total Thickness Variation) of the base substrate 102 is the same as the TTV of the workpiece W, for example, 10 μm. The base substrate 102 may have various sizes depending on the standard. A notch 100N is formed on the edge of the base substrate 102. The base substrate 102 may have another marker, such as an orientation flat, instead of the notch 100N. The base substrate 102 is made of a silicon-containing material. For example, the base substrate 102 may be a silicon substrate (so-called bare silicon).

[0051] The optical ring resonator 161, waveguide 163, and optical coupler 165 are provided on a base substrate 102 and are made of a silicon-containing material. In one exemplary embodiment, the optical ring resonator 161, waveguide 163, and optical coupler 165 are formed on an SOI (Silicom On Insulator) wafer 150 (sensor chip) provided on the base substrate 102. The SOI wafer 150 has a Si substrate 151, an SiO2 layer 153 laminated on the Si substrate 151, and a Si layer 155 laminated on the SiO2 layer 153. The optical ring resonator 161, waveguide 163, and optical coupler 165 may be formed on the Si layer by techniques such as photolithography and dry etching. The SOI wafer 150 is fixed to the base substrate 102. For example, the SOI wafer 150 may be fixed to the base substrate 102 by joining the Si substrate 151 and the base substrate 102 by welding or the like. Alternatively, the SOI wafer 150 may be bonded to the base substrate 102 with a highly thermally conductive adhesive.

[0052] In one exemplary embodiment, the sensor substrate 100 includes a plurality of optical ring resonators 161. For example, by having 20 or more optical ring resonators, the sensor substrate 100 can perform temperature measurements at 20 or more locations on the stage ST. In one example of the sensor substrate 100, a plurality of optical ring resonators 161 are arranged so as to be dispersed from each other in the circumferential and radial directions in a plan view. In the example shown in Figure 5, the sensor substrate 100 is provided with 25 or more optical ring resonators 161. That is, one optical ring resonator 161 is placed at the center of the sensor substrate 100, and six optical ring resonators 161 are placed at the same radius positions surrounding this optical ring resonator 161. Then, eight optical ring resonators 161 are placed around these six optical ring resonators 161, and twelve optical ring resonators 161 are placed around these eight optical ring resonators 161. For example, if the stage ST has multiple temperature-controlled zones that are individually temperature-controlled, at least one optical ring resonator 161 may correspond to each temperature-controlled zone.

[0053] Waveguides 163 are formed close to optical ring resonators 161 so as to be optically coupled to them. Waveguides 163 may be optically coupled to multiple optical ring resonators 161. In the example in Figure 5, three waveguides 163 are provided. The first waveguide 163A is close to the optical ring resonator 161 at the center of the substrate and the six optical ring resonators 161 surrounding this optical ring resonator 161. The second waveguide 163B is close to the eight optical ring resonators 161 surrounding these six optical ring resonators 161. The third waveguide 163C is close to the twelve optical ring resonators 161 provided on the periphery of the sensor substrate 100.

[0054] Optical ring resonators 161 adjacent to a common waveguide 163 have different radii. That is, the seven optical ring resonators 161 adjacent to the first waveguide 163A have different radii. The eight optical ring resonators 161 adjacent to the second waveguide 163B have different radii. The twelve optical ring resonators 161 adjacent to the third waveguide 163C have different radii.

[0055] The optical coupler 165 is formed at one end of each waveguide 163. The optical coupler 165 optically couples light received from the outside to the waveguide 163. The optical coupler 165 also outputs light propagated from the waveguide 163 to the outside. For example, the optical coupler 165 may be a grating coupler. In one exemplary embodiment, the optical coupler 165 is positioned to correspond to the position of the lift pin 25a provided on the stage ST. That is, when the sensor substrate 100 is placed on the stage ST (electrostatic chuck ESC), the position of the optical coupler 165 and the position of the lift pin 25a may coincide in a plan view.

[0056] The sensor substrate 100 has a lens 151a for focusing external light onto the optical coupler 165 (see Figure 6). This lens 151a may be configured to focus parallel light onto the optical coupler 165. In one exemplary embodiment, the lens 151a is formed at a position corresponding to each of the optical couplers 165. That is, the lens 151a is formed at a position that coincides with the optical coupler 165 in a plan view. For example, the lens 151a is provided on the Si substrate 151 of the SOI wafer 150. In the illustrated example, the lens 151a is provided so as to protrude from the lower surface of the Si substrate 151. Therefore, for example, the base substrate 102 may have a recess 103 capable of accommodating the lens 151a at a position corresponding to the lens 151a. The position of the recess 103 may coincide with the position of the lift pin 25a in a plan view.

[0057] As described above, the stage ST has a lift pin 25a formed inside the electrostatic chuck ESC in a plan view. In one exemplary embodiment, the lift pin 25a has a single-mode optical fiber 25c inside it. For example, the lift pin 25a has a cylindrical pin body 25b that is movable up and down within the through hole 25, and a single-mode optical fiber 25c fixed inside the pin body 25b. In one example, the upper end of the pin body 25b may form a lens 25d. In this case, the optical fiber 25c may be fixed inside the pin body 25b so that the laser light L1 emitted from the lens 25d is parallel light. The optical fiber 25c may be movable in the axial direction within the pin body 25b. In this case, the position of the optical fiber 25c may be controlled so that the laser light L1 emitted from the lens 25d is parallel light when the laser light L1 is output.

[0058] The measuring device 200 includes a laser oscillator 210, an optical circulator 220, and a spectrometer 230. The laser oscillator 210 outputs laser light L1 for input to the waveguide 163 of the sensor substrate 100 mounted on the stage ST. For example, the laser oscillator 210 is a variable laser oscillator in which the wavelength of the output laser light can be arbitrarily adjusted. In one exemplary embodiment, the laser oscillator 210 may be an infrared laser oscillator that outputs an infrared laser. In one exemplary embodiment, the operation of the laser oscillator 210 may be controlled by a control unit MC. The laser oscillator 210 is controlled to output laser light in a predetermined wavelength range. For example, the laser oscillator 210 outputs laser light with a center wavelength of 1550 nm and a wavelength range of 1530 nm to 1570 nm.

[0059] The optical circulator 220 guides the laser light L1 output from the laser oscillator 210 to the waveguide 163 and the reflected light L2 returning from the waveguide 163 to the spectrometer 230. The optical circulator 220 shown in Figure 4 has a first port 221, a second port 222, and a third port 223. Light input to the first port 221 is output from the second port 222, and light input to the second port 222 is output from the third port 223. The first port 221 is connected to the laser oscillator 210. The third port 223 is connected to the spectrometer 230. The second port 222 is connected to the optical fiber 25c of the lift pin 25a. In the illustrated example, the second port 222 is connected to the optical fiber 25c of the lift pin 25a via an optical switch 240 for switching the path of light. In the illustrated example, the optical switch 240 may be controlled so that the optical circulator 220 is connected to one of the three optical fibers 25c.

[0060] The spectrometer 230 is connected to the third port 223 of the optical circulator 220. In one exemplary embodiment, laser light L1 output from the laser oscillator 210 is input to the optical fiber 25c of the lift pin 25a via the optical circulator 220 and the optical switch 240. The laser light L1 input to the optical fiber 25c is input to the waveguide 163 of the sensor substrate 100 via the lens 151a and the optical coupler 165. The laser light L1 input to the waveguide 163 is reflected at the end of the waveguide 163 to become reflected light L2, which is input to the spectrometer 230 via the lens 151a, the optical coupler 165, the optical circulator 220, etc.

[0061] The spectrometer 230 analyzes (acquires) the spectrum of the input reflected light L2. The laser light L1 input to the waveguide 163 can be optically coupled with the optical ring resonator 161 if its wavelength matches the resonant wavelength of the optical ring resonator 161. In this case, the intensity of the resonant wavelength component in the reflected light L2 of the laser light L1 decreases.

[0062] When the temperature of the optical ring resonator 161 changes, the optical path length of the optical ring resonator 161 changes due to changes in refractive index, expansion and contraction of the material, etc., causing the resonance wavelength of the optical ring resonator 161 to shift. In other words, the resonance wavelength of the optical ring resonator 161 is temperature-dependent. Due to this characteristic of the optical ring resonator 161, the temperature at the location of the optical ring resonator 161 can be measured with high accuracy by detecting the resonance wavelength from the spectrum of reflected light L2. For example, the spectrometer 230 may have previously acquired data showing the relationship between the resonance wavelength and temperature for each optical ring resonator 161. In this case, the spectrometer 230 can calculate the temperature from the resonance wavelength of reflected light L2 obtained by spectral analysis of the reflected light L2. In one example, the spectrometer 230 analyzes the spectrum of reflected light L2 to have a resolution of 0.01°C or less.

[0063] In one exemplary embodiment, optical ring resonators 161 adjacent to a common waveguide 163 have different radii. In this case, the sizes of the optical ring resonators 161 are designed so that the ranges of their resonant wavelengths in the temperature range to be measured do not overlap, allowing the optical ring resonators 161 to be identified from the acquired resonant wavelength. For example, suppose that in the temperature range to be measured, the size of the first optical ring resonator is designed to have a range of a first resonant wavelength (first range), and the size of the second optical ring resonator is designed to have a range of a second resonant wavelength (second range). If the first range and the second range do not overlap, if the resonant wavelength detected from the reflected light belongs to the first range, it can be determined to correspond to the first optical ring resonator, and if it belongs to the second range, it can be determined to correspond to the second optical ring resonator.

[0064] Next, an example of the operation of the temperature measurement system will be described. Figure 7 is a flowchart showing an example of the operation of the temperature measurement system. The operation in this flowchart may be controlled by one or more control devices. In one example, the operation of the temperature measurement system S1 may be controlled by the control unit MC of the processing system 1 (in this case, the temperature measurement system S1 includes the control unit MC).

[0065] First, the sensor substrate 100 is loaded into the process module PM (step ST1). For example, the sensor substrate 100 may be placed in one of the containers 4a to 4d by an operator. In this case, the transport devices TU1 and TU2 transport the sensor substrate 100 from one of the containers 4a to 4d into the target chamber S under the control of the control unit MC. The sensor substrate 100 transported into the chamber S is placed on the electrostatic chuck ESC (stage ST) based on the transport position data stored in the control unit MC. The transport position data may be, for example, coordinate data of a position where the center of the sensor substrate 100 and the center of the electrostatic chuck ESC coincide with each other. The circumferential position of the sensor substrate 100 may be positioned at a predetermined position by the aligner AN so that the optical coupler 165 and the lift pin 25a coincide.

[0066] Next, laser light L1 is output from the laser oscillator 210 (step ST2). The laser light L1 output from the laser oscillator 210 is input to the first port 221 of the optical circulator 220 and output from the second port 222. Then, the laser light L1 is output from the lens 25d of the lift pin 25a via the optical fiber 25c selected by the optical switch 240.

[0067] Next, the intensity of the reflected light L2 is measured (step ST3), and it is determined whether or not the intensity of the reflected light L2 is insufficient (step ST4). In step ST1, if the sensor substrate 100 is transported accurately, the lens 25d and lens 151a of the lift pin 25a coincide with each other in a plan view. In this case, the laser light L1 output from lens 25d in step ST2 passes through the base substrate 102 and irradiates the optical coupler 165 via lens 151a. The laser light L1 then propagates through the waveguide 163 and returns as reflected light L2 at the end of the waveguide 163. This reflected light L2 is input to the spectrometer 230 via the optical circulator 220, so that sufficient reflected light L2 can be observed by the spectrometer 230. On the other hand, if the sensor substrate 100 is not transported accurately in step ST1, the intensity of the observed reflected light L2 will decrease.

[0068] For example, in steps ST3 and ST4, it is determined whether the reflected light L2 measured by the spectrometer 230 has sufficient intensity to measure the resonance wavelength. As an example, it may be determined whether the signal-to-noise ratio of the measured data of the reflected light L2 is equal to or greater than a predetermined signal-to-noise ratio.

[0069] If it is determined in step ST4 that the intensity of the reflected light L2 is insufficient, the positional relationship between the sensor substrate 100 and the lift pin 25a is adjusted (step ST5). In step ST5, the distance between the lift pin 25a and the sensor substrate 100 (lens 151a) may be adjusted by first moving the lift pin 25a vertically. For example, the lift pin 25a may be moved up and down while measuring the intensity of the reflected light L2, and the position where the highest intensity is observed may be stored. If sufficient intensity is obtained by adjusting the lift pin 25a, the process may proceed to step ST6.

[0070] If sufficient intensity cannot be obtained by adjusting the lift pin 25a, the transport position of the sensor substrate 100 is adjusted. For example, the position of the sensor substrate 100 may be adjusted based on the reflected light intensity from each waveguide 163, or the transport position of the sensor substrate 100 may be adjusted by a predetermined adjustment amount. The position adjustment of the sensor substrate 100 and steps ST3 and ST4 are repeated, and when it is determined that the intensity of the reflected light L2 is sufficient, the process proceeds to step ST6.

[0071] In step ST6, the spectrum of reflected light L2 is measured. That is, the spectrometer 230 analyzes the spectrum of the input reflected light L2 and obtains the resonance wavelength from that spectrum. As described above, since the intensity of reflected light L2 decreases at the resonance wavelength, a wavelength with an intensity below a predetermined threshold may be obtained as the resonance wavelength.

[0072] Next, the acquired resonant frequency is converted to temperature (step ST7). The spectrometer 230 may have data in advance showing the relationship between the resonant wavelength and temperature at each optical ring resonator 161. In this case, the temperature can be derived from the acquired resonant wavelength. For example, the measurement data from the spectrometer 230 may be transmitted to the control unit MC. In this case, the control unit MC can calculate the temperature because it has data showing the relationship between the resonant wavelength and temperature.

[0073] As described above, in one exemplary embodiment, a temperature measurement system S1 is provided. The temperature measurement system S1 comprises a sensor substrate 100, a stage ST (mounting platform), and a measuring device 200. The sensor substrate 100 includes a base substrate 102, an optical ring resonator 161 provided on the base substrate 102, and a waveguide 163 provided on the base substrate 102 and optically coupled to the optical ring resonator 161. The stage ST is configured to support the sensor substrate 100. The measuring device 200 includes a laser oscillator 210 that inputs laser light to the waveguide 163 of the sensor substrate 100 mounted on the stage ST, and a spectrometer 230 that receives reflected light of the laser light propagating through the waveguide 163 and output from the waveguide 163.

[0074] In the temperature measurement system S1 described above, with the sensor substrate 100 mounted on the stage ST, laser light is input to the waveguide 163. The laser light can be optically coupled with the optical ring resonator 161 when its wavelength matches the resonant wavelength of the optical ring resonator 161. In this case, the intensity of the resonant wavelength component in the reflected light of the laser light decreases. Since the resonant wavelength of the optical ring resonator 161 is temperature-dependent, the temperature at the location of the optical ring resonator 161 can be obtained by acquiring the resonant wavelength with the spectrometer 230. In such a temperature measurement system S1, since the sensor substrate 100 is composed of a base substrate, an optical ring resonator 161 on the base substrate 102, and a waveguide 163, there are no constraints on the temperature range, such as the battery operating temperature. Therefore, temperature measurement is possible over a wide temperature range. For example, the measurement temperature range may be approximately -100°C to +250°C.

[0075] Furthermore, since the above-described temperature measurement system S1 uses a measurement technique that utilizes light, it is not affected by electrical noise caused by plasma, etc., and therefore, compared to, for example, electrical measurement techniques, stable measurements are possible. In addition, since the above-described temperature measurement system S1 detects minute changes in the resonance wavelength with a high-precision spectrometer, it can have a high temperature resolution of, for example, 0.01°C or less.

[0076] In one exemplary embodiment, the measuring device 200 may include an optical circulator 220. The optical circulator 220 guides the laser light emitted from the laser oscillator 210 to the waveguide 163 and guides the reflected light output from the waveguide 163 to the spectrometer 230. In this configuration, the optical circulator 220 appropriately separates the laser light L1 incident on the waveguide 163 from the reflected light L2 output from the waveguide 163. Furthermore, the device configuration can be made compact.

[0077] In one exemplary embodiment, the sensor substrate 100 may include a lens 151a that focuses the laser light emitted from the laser oscillator 210 into the waveguide 163. In this configuration, the laser light can be efficiently focused into the waveguide 163, and light loss can be suppressed.

[0078] In one exemplary embodiment, the waveguide 163 may be made of a silicon-containing material. In this configuration, optical loss in the waveguide 163 can be suppressed.

[0079] In one exemplary embodiment, the base substrate may be made of a silicon-containing material. In this configuration, temperature changes in the stage ST can be appropriately reflected in the sensor substrate.

[0080] In one exemplary embodiment, the sensor substrate 100 may include a plurality of optical ring resonators 161. In particular, one exemplary embodiment includes 20 or more optical ring resonators 161. This configuration allows for simultaneous measurement of multiple temperature points, enabling a more detailed analysis of the temperature distribution.

[0081] In one exemplary embodiment, the multiple optical ring resonators 161 may have different radii. In this configuration, the resonant wavelengths of each optical ring resonator 161 can be made different from each other.

[0082] In one exemplary embodiment, the stage ST may include a lift pin 25a for lifting the sensor substrate 100. The lift pin 25a may include an optical fiber 25c that emits laser light from a laser oscillator 210 from above the lift pin 25a. In this configuration, the output end of the laser light can be brought close to the sensor substrate 100, and the laser light can be accurately directed onto the sensor substrate.

[0083] In one exemplary embodiment, the optical ring resonator 161 and waveguide 163 may be formed on an SOI wafer 150 (sensor chip) placed on a base substrate 102. The SOI wafer 150 includes an optical coupler 165 that optically couples light received from the outside to the waveguide 163, and a lens 151a that focuses the light onto the optical coupler 165. The lens 151a may be formed on the lower surface of the SOI wafer 150. This configuration allows for miniaturization using a sensor chip, and the sensor substrate can be made more compact.

[0084] Although various exemplary embodiments have been described above, the invention is not limited to the exemplary embodiments described above, and various omissions, substitutions, and modifications may be made. Furthermore, it is possible to combine elements from different embodiments to form other embodiments.

[0085] For example, the placement of the optical ring resonator 161 and waveguide 163 on the sensor substrate 100 is not limited to the illustrated example. In particular, the placement of the optical ring resonator 161 may be arbitrarily determined by the configuration of the temperature control zone of the mounting platform to be measured.

[0086] From the above description, it will be understood that the various embodiments of this disclosure are described herein for illustrative purposes and can be modified in various ways without departing from the scope and spirit of this disclosure. Accordingly, the various embodiments disclosed herein are not intended to limit the scope and spirit, and the true scope and spirit are shown by the appended claims.

[0087] Various exemplary embodiments included in this disclosure are described below. [E1] A temperature measurement system, A sensor substrate comprising a base substrate, an optical ring resonator provided on the base substrate, and a waveguide provided on the base substrate and optically coupled to the optical ring resonator, A mounting platform on which the sensor substrate is placed, and A temperature measurement system comprising a laser oscillator that inputs laser light into the waveguide of the sensor substrate placed on the mounting platform, and a measuring device that includes a spectrometer that receives reflected light of the laser light propagating through the waveguide and output from the waveguide. [E2] The temperature measurement system according to [E1], wherein the measuring device includes an optical circulator that guides the laser light irradiated from the laser oscillator to the waveguide and guides the laser light output from the waveguide to the spectrometer. [E3] The temperature measurement system according to [E1] or [E2], wherein the sensor substrate includes a lens that focuses the laser light irradiated from the laser oscillator into the waveguide. [E4] The aforementioned waveguide is made of a silicon-containing material, and the temperature measurement system is as described in any of [E1] to [E3]. [E5] The temperature measurement system according to any one of [E1] to [E4], wherein the base substrate is made of a material containing silicon. [E6] The temperature measurement system according to any one of [E1] to [E5], wherein the sensor substrate includes a plurality of optical ring resonators. [E7] The temperature measurement system according to [E6], wherein the plurality of optical ring resonators have different radii from each other. [E8] The temperature measurement system according to any one of [E1] to [E7], wherein the plurality of optical ring resonators is 20 or more optical ring resonators. [E9] The measuring device is a temperature measuring system according to any one of [E1] to [E8], having a resolution of 0.01°C or less. [E10] The mounting base includes lift pins for lifting up the sensor substrate, The temperature measurement system according to any one of [E1] to [E9], wherein the lift pin includes an optical fiber that irradiates the laser light emitted from the laser oscillator from the top of the lift pin. [E11] A disc-shaped base substrate, An optical ring resonator provided on the base substrate, A sensor substrate comprising a waveguide provided on the base substrate and optically coupled to the optical ring resonator. [E12] The optical ring resonator and the waveguide are formed on a sensor chip arranged on the base substrate. The aforementioned sensor chip is An optical coupler that optically couples light received from an external source to the waveguide, The optical coupler is equipped with a lens for focusing the light, The lens is formed on the lower surface of the sensor chip, as described in [E11]. [E13] The aforementioned waveguide is made of a silicon-containing material, as described in [E11] or [E12]. [E14] The base substrate is made of a material containing silicon, and is a sensor substrate according to any one of [E11] to [E13]. [E15] The sensor substrate is a sensor substrate according to any one of [E11] to [E14], comprising a plurality of optical ring resonators. [E16] The sensor substrate according to [E15], wherein the plurality of optical ring resonators have different radii from each other. [E17] A method for measuring temperature using a sensor substrate, The aforementioned sensor board is A disc-shaped base substrate, An optical ring resonator provided on the base substrate, The system comprises a waveguide provided on the base substrate and optically coupled to the optical ring resonator, The method is, The process of inputting laser light into the waveguide, The process of receiving the reflected light of the laser light that propagates through the waveguide and is output from the waveguide, A method for measuring temperature, comprising the step of calculating the temperature based on the spectrum of the reflected light received. [Explanation of Symbols]

[0088] S1...Temperature measurement system, 100...Sensor substrate, 102...Base substrate, 161...Optical ring resonator, 163...Waveguide, 200...Measurement device, 210...Laser oscillator, 220...Optical circulator, 230...Spectrometer.

Claims

1. A temperature measurement system, A sensor substrate comprising a base substrate, an optical ring resonator provided on the base substrate, and a waveguide provided on the base substrate and optically coupled to the optical ring resonator, A mounting platform on which the sensor substrate is placed, and A temperature measurement system comprising a laser oscillator that inputs laser light into the waveguide of the sensor substrate placed on the mounting platform, and a measuring device that includes a spectrometer that receives reflected light of the laser light propagating through the waveguide and output from the waveguide.

2. The temperature measurement system according to claim 1, wherein the measuring device includes an optical circulator that guides the laser light irradiated from the laser oscillator to the waveguide and guides the laser light output from the waveguide to the spectrometer.

3. The temperature measurement system according to claim 1, wherein the sensor substrate includes a lens that focuses the laser light irradiated from the laser oscillator into the waveguide.

4. The temperature measurement system according to claim 1, wherein the waveguide is made of a material containing silicon.

5. The temperature measurement system according to claim 1, wherein the base substrate is made of a material containing silicon.

6. The temperature measurement system according to claim 1, wherein the sensor substrate includes a plurality of optical ring resonators.

7. The temperature measurement system according to claim 6, wherein the plurality of optical ring resonators have different radii from each other.

8. The temperature measurement system according to claim 6, wherein the plurality of optical ring resonators are 20 or more optical ring resonators.

9. The temperature measurement system according to claim 1, wherein the measuring device has a resolution of 0.01°C or less.

10. The mounting base includes lift pins for lifting up the sensor substrate, The temperature measurement system according to any one of claims 1 to 9, wherein the lift pin includes an optical fiber that irradiates the laser light emitted from the laser oscillator from the top of the lift pin.

11. A disc-shaped base substrate, An optical ring resonator provided on the base substrate, A sensor substrate comprising a waveguide provided on the base substrate and optically coupled to the optical ring resonator.

12. The optical ring resonator and the waveguide are formed on a sensor chip arranged on the base substrate. The aforementioned sensor chip is An optical coupler that optically couples light received from an external source to the waveguide, The optical coupler is equipped with a lens for focusing the light, The sensor substrate according to claim 11, wherein the lens is formed on the lower surface of the sensor chip.

13. The sensor substrate according to claim 11, wherein the waveguide is made of a material containing silicon.

14. The sensor substrate according to claim 11, wherein the base substrate is made of a material containing silicon.

15. The sensor substrate according to claim 11, wherein the sensor substrate includes a plurality of optical ring resonators.

16. The sensor substrate according to claim 15, wherein the plurality of optical ring resonators have different radii from each other.

17. A method for measuring temperature using a sensor substrate, The aforementioned sensor board is A disc-shaped base substrate, An optical ring resonator provided on the base substrate, The system comprises a waveguide provided on the base substrate and optically coupled to the optical ring resonator, The method is, The process of inputting laser light into the waveguide, The process of receiving the reflected light of the laser light that propagates through the waveguide and is output from the waveguide, A method for measuring temperature, comprising the step of calculating the temperature based on the spectrum of the reflected light received.

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