Grating temperature measuring device, semiconductor equipment and temperature measuring method thereof

Abstract

According to the grating temperature measuring device, the semiconductor device and the temperature measuring method thereof, emitted light provided by an optical fiber in the grating temperature measuring device can be transmitted to a Bragg grating, the emitted light is reflected by the Bragg grating, and reflected light is generated. Because the Bragg grating is directly formed at the temperature measurement point, no medium exists between the Bragg grating and the temperature measurement wafer, the temperature of the wafer is directly reflected by the temperature of the Bragg grating, and the grating period of the Bragg grating changes in real time along with the temperature change of the temperature measurement wafer. According to the technical scheme of the invention, the central wavelength of the reflected light generated by the Bragg grating can be shifted, and the temperature of the temperature measurement wafer in the process of process treatment and / or after process treatment can be equivalently and accurately obtained in real time through the offset of the central wavelength of the reflected light of the Bragg grating.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor detection, and in particular to a grating temperature measurement device, a semiconductor device and a temperature measurement method thereof. Background Art

[0002] In the field of semiconductor manufacturing, temperature control is a key parameter to ensure the correct execution of various process steps such as material growth, deposition, etching, doping and ion implantation. The precise control of temperature is directly related to the performance and reliability of the final product. Therefore, accurate measurement and control of the temperature in the process environment is the basis for achieving high-quality semiconductor production.

[0003] At present, a large number of semiconductor manufacturing processes are carried out under vacuum or near-vacuum conditions. In this environment, there is a lack of effective heat convection transfer paths, making it impossible for traditional contact temperature sensors to accurately measure the temperature of wafers. In addition, contact temperature sensors may introduce material surface contamination, further affecting the cleanliness of the production process and the quality of the product. Even if it is technically feasible, the physical installation of the sensor faces major challenges due to the continuous operation of process equipment and the frequent movement of wafers.

[0004] Temperature measurement devices commonly used in the prior art, such as TC-Wafer, can calibrate the temperature of equipment, but they are usually only applicable to specific process environments and cannot be widely used in all process equipment. The limitations faced by these methods include poor equipment adaptability and long response time, which are particularly prominent in high-throughput production environments. Therefore, the development of a new temperature measurement technology that can accurately measure the temperature of the wafer without contact and adapt to the changing process environment is of great significance to improving the efficiency and product quality of semiconductor manufacturing. Summary of the invention

[0005] The problem solved by the present invention is to provide a grating temperature measuring device, a semiconductor device and a temperature measuring method thereof, which are used to obtain the temperature of a temperature measuring wafer in a process and / or after process in real time and equivalently.

[0006] To solve the above problems, an embodiment of the present invention provides a grating temperature measurement device, including: a temperature measurement wafer, the surface of which has a temperature measurement point; a Bragg grating formed directly at the temperature measurement point; an optical fiber, used to provide emission light to the Bragg grating, the Bragg grating reflects the emission light to generate reflected light, and the optical fiber is also used to conduct the reflected light.

[0007] Optionally, the grating temperature measurement device includes a temperature sensing unit, which includes: the Bragg grating; a waveguide, which is coupled to the Bragg grating and is used to transmit the emitted light and the reflected light; a coupling structure, which is coupled to the waveguide and corresponds to the end of the optical fiber and is used to realize the transmission of the emitted light and the reflected light between the waveguide and the optical fiber; the coupling structure is a grating coupling structure or a tapered waveguide coupling structure.

[0008] Optionally, the Bragg grating, and / or waveguide, and / or coupling structure are directly formed on the surface of the temperature measuring wafer by using an optical film layer growth process, or are directly formed on the surface of the temperature measuring wafer by using a micromachining process.

[0009] Optionally, there are one or more optical fibers, and each of the optical fibers corresponds to a temperature sensing unit.

[0010] Optionally, the number of the Bragg gratings in the temperature sensing unit is one; or the number of the Bragg gratings in the temperature sensing unit is multiple, and the multiple Bragg gratings are connected in parallel or in series through the waveguide.

[0011] Optionally, there are multiple Bragg gratings in the temperature sensing unit, and the central wavelength of reflected light from each Bragg grating is different.

[0012] Optionally, two Bragg gratings are provided at the temperature measurement point, and the center wavelengths of reflected light from the two Bragg gratings are different.

[0013] Optionally, there are multiple Bragg gratings, and the multiple Bragg gratings are distributed in a circular array on the temperature measurement wafer and / or distributed radially along the temperature measurement wafer.

[0014] Optionally, the optical fiber is configured to be installed in a wafer carrying device, and the temperature measuring point is located on a side of the temperature measuring wafer facing the wafer carrying device.

[0015] Optionally, the grating temperature measurement device further includes: a lens, located at the end of the optical fiber close to the temperature measurement wafer, for collimating and transmitting the emitted light or reflected light.

[0016] Optionally, the grating temperature measurement device also includes: a light transmitter connected to the optical fiber and used to provide the emitted light; and a demodulation device connected to the optical fiber and used to receive the reflected light.

[0017] An embodiment of the present invention also provides a semiconductor device, comprising: a wafer carrier; the grating temperature measuring device of any embodiment of the present invention, wherein in a temperature measuring state, the temperature measuring wafer is located on the wafer carrier, the surface of the temperature measuring wafer facing the wafer carrier has a temperature measuring point, and the optical fiber is arranged in the wafer carrier.

[0018] Optionally, the grating temperature measurement device includes a coupling structure, and the coupling structure is aligned with the end of the optical fiber in the wafer carrying device.

[0019] Optionally, the end of the optical fiber is flush with the bearing surface of the wafer bearing device.

[0020] Optionally, the wafer carrying device includes a wafer chuck or a robot for transferring wafers.

[0021] Optionally, the optical fiber passes through the wafer carrying device, and one end of the optical fiber away from the wafer carrying device is located outside the wafer carrying device.

[0022] An embodiment of the present invention also provides a grating temperature measurement method, comprising: providing a wafer supporting device; placing the temperature measurement wafer on the wafer supporting device, wherein the end of the optical fiber is arranged in the wafer supporting device; using a thermometer to measure the initial temperature of the temperature measurement point on the temperature measurement wafer; at the initial temperature, obtaining the center wavelength of the reflected light of the Bragg grating at the temperature measurement point as a first wavelength; performing process treatment on the temperature measurement wafer; during and / or after the process treatment, obtaining the center wavelength of the reflected light of the Bragg grating at the temperature measurement point as a second wavelength; obtaining the offset of the center wavelength of the reflected light of the Bragg grating according to the first wavelength and the second wavelength; obtaining the temperature of the temperature measurement point during and / or after the process treatment according to the offset of the center wavelength of the reflected light of the Bragg grating.

[0023] Optionally, the step of obtaining the temperature of the temperature measuring point during and / or after the process according to the offset of the central wavelength of the reflected light of the Bragg grating includes: obtaining the temperature of the temperature measuring point during and / or after the process using the following formulas (1), (2) and (3):

[0024]

[0025] ΔT=T 2 -T 1 (2);

[0026] Δλ B =λ B1 -λ B2 (3);

[0027] Among them, λB1 is the first wavelength, λ B2 is the second wavelength, Δλ B is the offset of the central wavelength of the reflected light, α is the thermal expansion coefficient of the Bragg grating material, ζ is the thermo-optic coefficient of the Bragg grating material; T 1 is the initial temperature of the wafer at the temperature measurement point, T 2 It is the temperature of the wafer measured at the temperature measurement point during and / or after the process.

[0028] Optionally, the temperature measurement point is provided with a first Bragg grating and a second Bragg grating, and the center wavelengths of reflected light of the first Bragg grating and the second Bragg grating are different; in the step of obtaining the first wavelength, the first wavelength of the first Bragg grating and the first wavelength of the second Bragg grating are obtained; in the step of obtaining the second wavelength, the second wavelength of the first Bragg grating and the second wavelength of the second Bragg grating are obtained; in the step of obtaining the offset of the center wavelength of reflected light of the Bragg grating, the offset of the center wavelength of reflected light of the first Bragg grating and the offset of the center wavelength of reflected light of the second Bragg grating are obtained; the step of obtaining the temperature of the temperature measurement wafer at the temperature measurement point during and / or after the process treatment comprises: using the following formulas (4) and (5) to obtain the temperature of the temperature measurement wafer during and / or after the process treatment,

[0029]

[0030] Among them, Δλ B1 is the offset of the center wavelength of the reflected light from the first Bragg grating, λ B11 is the first wavelength of the first Bragg grating, Δλ B2 is the offset of the center wavelength of the reflected light from the second Bragg grating, λ B21 is the first wavelength of the second Bragg grating; α 1 is the thermal expansion coefficient of the first Bragg grating material, ζ 1 is the thermo-optic coefficient of the first Bragg grating material; is the effective elasto-optical constant of the first Bragg grating material, α 2 is the thermal expansion coefficient of the second Bragg grating material, ζ 2 is the thermo-optic coefficient of the second Bragg grating material; is the effective elastic-optical constant of the second Bragg grating material, Δε is the strain change of the Bragg grating material, T 1 is the initial temperature of the temperature measuring wafer at the temperature measuring point, T 2 It is the temperature of the temperature measuring wafer at the temperature measuring point during and / or after the process.

[0031] Optionally, in the step of measuring the initial temperature of the temperature measuring point on the temperature measuring wafer, the temperature measuring instrument used includes a thermocouple, a thermistor or an infrared temperature measuring device.

[0032] An embodiment of the present invention also provides a grating temperature measurement method based on a grating temperature measurement device, wherein the grating temperature measurement device includes a coupling structure, and the grating temperature measurement method includes: obtaining a calibration of the corresponding relationship between the center wavelength of the reflected light of the Bragg grating and the temperature; providing a wafer supporting device; placing the temperature measuring wafer on the wafer supporting device, wherein the wafer supporting device is provided with an end of an optical fiber, and the coupling structure is aligned with the end of the optical fiber in the wafer supporting device; performing process treatment on the temperature measuring wafer; during and / or after the process treatment, obtaining the center wavelength of the reflected light of the Bragg grating at the temperature measurement point; and obtaining the temperature of the temperature measurement point based on the corresponding relationship between the center wavelength of the reflected light and the temperature and the center wavelength of the reflected light.

[0033] Optionally, the step of obtaining the corresponding relationship between the central wavelength of the reflected light of the Bragg grating and the temperature includes: obtaining the central wavelength of the reflected light corresponding to the Bragg grating at multiple known temperatures respectively; fitting multiple known temperature data and corresponding data on the central wavelength of the reflected light to obtain a relationship curve between the central wavelength of the reflected light of the Bragg grating and the temperature.

[0034] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0035] The grating temperature measurement device provided by the embodiment of the present invention includes: a temperature measurement wafer, the surface of which has a temperature measurement point; a Bragg grating, which is directly formed at the temperature measurement point; an optical fiber, which is used to provide emission light to the Bragg grating, the Bragg grating reflects the emission light to generate reflected light, and the optical fiber is also used to conduct the reflected light. The emission light provided by the optical fiber can be transmitted to the Bragg grating, and the emission light is reflected by the Bragg grating to generate reflected light. Because the Bragg grating is directly formed at the temperature measurement point, there is no medium between the Bragg grating and the temperature measurement wafer, and the temperature of the Bragg grating directly reflects the temperature of the wafer, so that the grating period of the Bragg grating changes in real time with the change of the temperature of the temperature measurement wafer, so that the center wavelength of the reflected light generated by the Bragg grating will be offset, and the temperature of the temperature measurement wafer during and / or after the process treatment can be obtained in real time, equivalently, and accurately through the offset of the center wavelength of the reflected light of the Bragg grating.

[0036] The temperature measuring wafer in the semiconductor device provided by the embodiment of the present invention is located on a wafer carrier, and the surface of the temperature measuring wafer facing the wafer carrier has a temperature measuring point, a Bragg grating is directly formed at the temperature measuring point, and the end of the optical fiber is arranged in the wafer carrier. When the temperature of the temperature measuring wafer is measured by a grating temperature measuring device, the emission light provided by the optical fiber can be transmitted to the Bragg grating, and the emission light is reflected by the Bragg grating to generate reflected light. In addition, because the Bragg grating is directly formed at the temperature measuring point, there is no medium between the Bragg grating and the temperature measuring wafer, and the temperature of the Bragg grating directly reflects the temperature of the wafer, so that the grating period of the Bragg grating changes in real time with the change of the temperature of the temperature measuring wafer, so that the center wavelength of the reflected light generated by the Bragg grating will be offset, and the temperature of the temperature measuring wafer during and / or after the process treatment can be obtained in real time, equivalently, and accurately through the offset of the center wavelength of the reflected light of the Bragg grating. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a structural schematic diagram of a grating temperature measuring device according to an embodiment of the present invention;

[0038] Figure 2 yes Figure 1 In the local enlarged view, the number of Bragg gratings in the temperature sensing unit is multiple;

[0039] Figure 3 yes Figure 1 In the local enlarged view, the number of Bragg gratings in the temperature sensing unit is one;

[0040] Figure 4 is a schematic diagram of a Bragg grating and a waveguide in a grating temperature measurement device according to an embodiment of the present invention;

[0041] Figure 5 is a schematic structural diagram of a semiconductor device according to an embodiment of the present invention;

[0042] Figure 6 It is a schematic structural diagram of grating coupling structure and optical fiber alignment in a semiconductor device according to an embodiment of the present invention;

[0043] Figure 7 is a schematic structural diagram of the alignment of a coupling structure and an optical fiber in a semiconductor device according to another embodiment of the present invention;

[0044] Figure 8 is a schematic diagram of forming a Bragg grating by an optical film;

[0045] Fig. 9 is a flow chart of a grating temperature measurement method in an embodiment of the present invention;

[0046] Fig.10Schematic diagram of the shift of the central wavelength of the reflected light generated by the Bragg grating in the embodiment of the present invention. DETAILED DESCRIPTION

[0047] As can be seen from the background technology, the existing temperature measurement technology cannot accurately measure the wafer without contact and cannot adapt to the changing process environment. Specifically, it can be analyzed from the following points.

[0048] First, the accuracy of temperature measurement. In existing temperature measurement technology, the Bragg grating sensor is placed in a position that is not in direct contact with the wafer, and the heat of the wafer is conducted through the protective layer and cladding of the optical fiber. However, this setting results in the temperature of the cladding being measured instead of the temperature of the wafer itself. This deviation comes from the thermal insulation performance of the protective layer and cladding, which makes the temperature recorded by the grating significantly different from the actual temperature of the wafer under process conditions.

[0049] Second, the simulated process environment. In the traditional temperature measurement experimental setup, the optical fiber is placed between two stacked wafers for temperature measurement, which is inconsistent with the actual production process using a single wafer. This difference in experimental configuration causes the measured wafer temperature to be inconsistent with the wafer temperature in the actual process, thus failing to accurately reflect the actual process conditions.

[0050] Third, the signal transmission of the temperature measuring device. Since the optical fiber needs to be connected to the wafer for temperature measurement, this connection method limits the free transmission of the wafer between the vacuum and atmospheric environments, as well as the free transmission between different chambers of the semiconductor equipment. Especially under the process requirements that require continuous movement of the wafer, the wired temperature measuring equipment faces significant difficulties in actual operation, affecting production efficiency and the practicality of temperature measurement.

[0051] Fourth, the bonding between the wafer and the optical fiber. When using wafers and optical fibers for temperature measurement, the two need to be fixed with an adhesive. It is difficult to find an adhesive that has excellent thermal conductivity and can work under extreme temperature conditions (such as above 500 degrees or below minus 100 degrees). This adhesive needs to meet the compatibility of high and low temperature work while maintaining good thermal conductivity to ensure the accuracy of temperature measurement.

[0052] In order to solve the above problems, the grating temperature measurement device provided by the embodiment of the present invention includes: a temperature measurement wafer, the surface of which has a temperature measurement point; a Bragg grating, which is directly formed at the temperature measurement point; an optical fiber, which is used to provide emission light to the Bragg grating, the Bragg grating reflects the emission light to generate reflected light, and the optical fiber is also used to conduct the reflected light. The emission light provided by the optical fiber can be transmitted to the Bragg grating, and the emission light is reflected by the Bragg grating to generate reflected light. Because the Bragg grating is directly formed at the temperature measurement point, there is no medium between the Bragg grating and the temperature measurement wafer, and the temperature of the Bragg grating directly reflects the temperature of the wafer, so that the grating period of the Bragg grating changes in real time with the change of the temperature of the temperature measurement wafer, so that the center wavelength of the reflected light generated by the Bragg grating will be offset, and the temperature of the temperature measurement wafer during and / or after the process treatment can be obtained in real time, equivalently and accurately through the offset of the center wavelength of the reflected light of the Bragg grating.

[0053] In order to make the above-mentioned purposes, features and advantages of the embodiments of the present invention more obvious and understandable, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0054] Figure 1 It is a structural schematic diagram of a grating temperature measuring device according to an embodiment of the present invention; Figure 2 yes Figure 1 In the local enlarged view, the number of Bragg gratings in the temperature sensing unit is multiple; Figure 3 yes Figure 1 In the local enlarged view, the number of Bragg gratings in the temperature sensing unit is one.

[0055] The grating temperature measurement device includes: a temperature measurement wafer 101, the surface of the temperature measurement wafer 101 has a temperature measurement point (not shown in the figure); a Bragg grating 102, which is directly formed at the temperature measurement point; an optical fiber 103, which is used to provide emission light to the Bragg grating 102, the Bragg grating 102 reflects the emission light to generate reflected light, and the optical fiber 103 is also used to conduct the reflected light.

[0056] In the grating temperature measurement device provided by the embodiment of the present invention, the emission light provided by the optical fiber 103 can be transmitted to the Bragg grating 102, and the emission light is reflected by the Bragg grating 102 to generate reflected light. The Bragg grating 102 is directly formed at the temperature measurement point, so there is no medium between the Bragg grating 102 and the temperature measurement wafer 101, and the temperature of the Bragg grating 102 directly reflects the temperature of the wafer, so that the grating period of the Bragg grating 102 changes in real time with the change of the temperature of the temperature measurement wafer 101, so that the center wavelength of the reflected light generated by the Bragg grating 102 will be offset, and the temperature of the temperature measurement wafer 101 during and / or after the process treatment can be obtained in real time, equivalently, and accurately through the offset of the center wavelength of the reflected light of the Bragg grating 102.

[0057] The temperature measuring wafer 101 has temperature measuring points on its surface. Specifically, the temperature measuring wafer 101 is used as the main body of the temperature to be measured, and a Bragg grating 102 is set at the temperature measuring point on its surface.

[0058] In this embodiment, the temperature measuring wafer 101 has multiple temperature measuring points. Setting multiple temperature measuring points on the temperature measuring wafer 101 can measure the temperature at different positions of the temperature measuring wafer 101 to obtain more comprehensive temperature distribution information of the temperature measuring wafer 101.

[0059] In this embodiment, the number of the Bragg gratings 102 is multiple, and the multiple Bragg gratings 102 are distributed in a circumferential array on the temperature measuring wafer 101 and / or radially distributed along the temperature measuring wafer 101. As an example, the multiple temperature measuring points are distributed in a circumferential array on the temperature measuring wafer 101 and the temperature measuring wafer 101 is distributed radially, which can measure the temperature at different radial positions on the surface of the temperature measuring wafer 101, as well as the temperature on each ring of the same radial size, which helps to obtain the temperature distribution at various locations on the surface of the temperature measuring wafer 101 in real time and accurately during the process.

[0060] The Bragg grating 102 is formed directly at the temperature measuring point. There is no intermediate medium between the Bragg grating 102 and the temperature measuring wafer 101, thereby avoiding temperature lag and error caused by the medium. Therefore, the temperature change at the temperature measuring point can be quickly transmitted to the Bragg grating 102, causing the period of the Bragg grating 102 to change, so that the central wavelength of the reflected light is offset, which can reflect the temperature change at the temperature measuring point in real time and accurately.

[0061] As an example, each temperature measurement point is provided with one Bragg grating 102. As another example, each temperature measurement point is provided with two Bragg gratings 102, and the center wavelengths of the reflected lights of the two Bragg gratings 102 are different.

[0062] Arranging two Bragg gratings 102 with different center wavelengths of reflected light at each temperature measurement point can eliminate the influence of the internal strain of the temperature measurement wafer 101 on the temperature measurement error. Specifically, during the process, such as the thin film deposition process, strain may be generated inside the temperature measurement wafer 101, and the strain will also cause the center wavelength of the reflected light of the Bragg grating 102 to shift. If only a single Bragg grating 102 is used for measurement at a temperature measurement point, the influence of the internal strain of the temperature measurement wafer 101 on the center wavelength shift of the reflected light of the Bragg grating 102 will be ignored, and the temperature change will be confused with the strain, resulting in temperature measurement errors. Therefore, by arranging two Bragg gratings 102 at one temperature measurement point, it can be considered that the temperature and strain of the position points where the two Bragg gratings 102 are located are the same. In the case where the center wavelengths of the reflected light of the two Bragg gratings 102 are different, after obtaining the offsets of two different wavelengths, the temperature change and internal strain of the temperature measurement wafer 101 can be obtained, thereby obtaining a more accurate temperature measurement result of the temperature measurement point.

[0063] like Figure 2 and Figure 3 As shown, the grating temperature measuring device includes a temperature sensing unit (not shown in the figure), and the temperature sensing unit includes: the Bragg grating 102; a waveguide 104, the waveguide 104 is coupled to the Bragg grating 102, and is used to transmit the emitted light and the reflected light; a coupling structure 105, coupled to the waveguide 104, and corresponds to the end of the optical fiber 103 in the optical fiber 103 close to the temperature measuring wafer 101, and is used to realize the transmission of the emitted light and the reflected light between the temperature sensing unit and the optical fiber 103, the coupling structure 105 is a grating coupling structure, and the coupling method between the optical fiber 103 and the waveguide 104 is grating coupling.

[0064] The temperature sensing unit includes a Bragg grating 102, a waveguide 104 and a coupling structure 105. The Bragg grating 102 senses temperature changes by the change in the wavelength of the reflected light; the waveguide 104 is responsible for transmitting the emitted light and the reflected light between the Bragg grating 102 and the coupling structure 105; the coupling structure 105 is used to receive the emitted light in the optical fiber 103, couple the emitted light into the waveguide, transmit it to the Bragg grating 102, and effectively couple the reflected light into the optical fiber 103, thereby realizing the transmission of the optical signal. The Bragg grating 102, the waveguide 104 and the coupling structure 105 cooperate with each other to realize the transmission of the optical signal from the optical fiber 103 to the Bragg grating 102, and the process of the optical signal returning from the Bragg grating 102 to the optical fiber 103. The optical signal has a fast propagation speed and can reflect the temperature change of the temperature measuring wafer 101 in real time and accurately, ensuring the high precision and high reliability of temperature sensing.

[0065] In this embodiment, the coupling structure 105 is located at the end of the temperature sensing unit and is used to achieve smooth transmission of the emitted light and reflected light between the temperature sensing unit and the optical fiber 103 .

[0066] like Figure 4 As shown, the Bragg grating 102 and the waveguide 104 are an integrated structure. The central wavelength of the reflected light of the Bragg grating 102 will shift with the change of temperature, and the waveguide 104 serves as a transmission path for the optical signal to ensure that the optical signal can be efficiently transmitted. Designing the Bragg grating 102 and the waveguide 104 as an integrated structure can reduce the loss of the optical signal during the transmission process and improve the accuracy and stability of the measurement.

[0067] It should be noted that the Bragg grating 102, and / or the waveguide 104, and / or the coupling structure 105 are directly formed on the surface of the temperature measuring wafer 101 by using an optical film layer growth process, or are directly formed on the surface of the temperature measuring wafer 101 by using a micro-machining process. As an example, the Bragg grating 102, the waveguide 104 and the coupling structure 105 are directly formed on the surface of the temperature measuring wafer 101 by using an optical film layer growth process or a micro-machining process, so the Bragg grating 102 and the waveguide 104 are an integrated structure with the temperature measuring wafer 101, so that there is no medium (such as adhesive) between the Bragg grating 102 and the waveguide 104 and the temperature measuring wafer 101, which is conducive to directly reflecting the temperature change and can adapt to the process environment of extreme temperature.

[0068] In this embodiment, the Bragg grating 102 is generally composed of periodically changing refractive index regions, which are realized by depositing thin film materials with different refractive indices on a substrate material. The material of the Bragg grating 102 includes silicon nitride.

[0069] In this embodiment, the waveguide 104 includes a channel for guiding light waves. The waveguide 104 includes a core layer and a cladding layer that wraps the core layer. The material of the core layer includes silicon nitride or polysilicon (Poly-Si), and the material of the cladding layer includes silicon dioxide.

[0070] In this embodiment, the coupling structure 105 includes periodic or non-periodic grooves, and utilizes the Bragg diffraction condition to achieve light coupling, which can effectively couple the light from the optical fiber 103 to the waveguide 104. The coupling structure 105 is generally made of metal or dielectric materials, such as aluminum (Al), gold (Au) and silver (Ag), or dielectric materials with high refractive index such as silicon nitride and titanium dioxide.

[0071] As an example, the number of the Bragg grating 102 in the temperature sensing unit is one. When the grating temperature measurement device is working, there is only one kind of emitted light and one kind of reflected light in each temperature sensing unit, which simplifies the complexity of reflected light processing.

[0072] As another example, the temperature sensing unit has a plurality of Bragg gratings 102. When the grating temperature measuring device is working, there are multiple reflected lights in each temperature sensing unit, so that one temperature sensing unit can measure the temperature of multiple temperature measuring points, which improves the flexibility of measurement, simplifies the arrangement of the optical fiber 103 and the waveguide 104, and reduces the cost of the grating temperature measuring device.

[0073] In this embodiment, the number of the Bragg gratings 102 in the temperature sensing unit is multiple, and the center wavelengths of the reflected light of each Bragg grating 102 are different. The different center wavelengths of the reflected light of each Bragg grating 102 are conducive to distinguishing the center wavelengths of the reflected light of different temperature measurement points to avoid confusion. It should be noted that when the number of the Bragg gratings 102 in the temperature sensing unit is multiple, except for the different center wavelengths of the reflected light, the other parameters are the same.

[0074] Specifically, the multiple Bragg gratings 102 in the temperature sensing unit are connected in parallel or in series through the waveguide 104, so that real-time and accurate measurement of multiple temperature measurement points can be achieved. Specifically, the Bragg gratings 102 connected in parallel in the temperature sensing unit enable each Bragg grating 102 to independently receive the transmitted light, provide the reflected light signal, and sense the temperature changes of different temperature measurement points at the same time. The Bragg gratings 102 connected in series can transmit the reflected light of multiple temperature measurement points through one channel, which is suitable for occasions where the reflected light of multiple temperature measurement points needs to be transmitted in a limited channel.

[0075] The optical fiber 103 is used as a transmission medium for optical signals, and is used to provide emission light to the Bragg grating 102 and receive the emission light reflected by the Bragg grating 102 .

[0076] In this embodiment, by precisely aligning the end of the optical fiber 103 with the coupling structure 105 on the temperature measurement wafer 101, and the bidirectional transmission function of the optical fiber 103, which provides both transmitted light and received reflected light, the grating temperature measurement device can monitor the reflected light signal of the Bragg grating 102 in real time, thereby realizing real-time detection of temperature changes at the temperature measurement point.

[0077] In this embodiment, the end of the optical fiber 103 is directly packaged on the coupling structure 105, so as to achieve close coupling between the optical fiber 103 and the coupling structure 105, reduce the attenuation and reflection of the optical signal during transmission, and help to significantly reduce the loss and interference during the optical signal transmission process. In addition, the direct packaging of the end of the optical fiber 103 on the coupling structure 105 can also simplify the assembly process.

[0078] In other embodiments, the temperature measuring wafer and the end of the optical fiber may not be packaged together, and the temperature measuring wafer and the optical fiber are independent structures. In this solution, since the temperature measuring wafer is not mechanically connected to the optical fiber, the temperature measuring wafer can be freely transmitted between vacuum and atmospheric environments and between different chambers of the semiconductor device.

[0079] In this embodiment, the grating temperature measuring device further includes: a lens 106 (such as Figure 2 As shown), it is located at the end of the optical fiber 103 close to the temperature measurement wafer 101, and is used to collimate the emitted light or reflected light.

[0080] The grating temperature measuring device further includes: a light transmitter (not shown in the figure), connected to the optical fiber 103, and used to provide the emitted light; a demodulation device 107 (such as Figure 1 ), connected to the optical fiber 103, for receiving the reflected light; a coupler 108 (as shown Figure 1 ), located on the optical fiber 103, for transmitting the emitted light and reflecting the reflected light to the demodulation device 107.

[0081] In this embodiment, the emission light emitted by the light emitter is transmitted to the Bragg grating 102 in the temperature sensing unit through the optical fiber 103. The Bragg grating 102 reflects the emission light of a specific wavelength. The light emitter is used to provide a stable and high-quality light source.

[0082] In this embodiment, the demodulation device 107 is used to receive the optical signal reflected by the Bragg grating 102, and perform demodulation analysis on it, and obtain the spectrum of the reflected light through the demodulation device 107, and obtain the central wavelength of the reflected light according to the spectrum. Specifically, the demodulation device 107 includes a spectrometer.

[0083] In this embodiment, the function of the coupler 108 is to realize the transmission of the optical signal. On the one hand, it allows the optical signal passing through the optical transmitter to reach the Bragg grating 102, and on the other hand, it transmits the reflected light provided by the Bragg grating 102 to the demodulation device 107. Specifically, the coupler 108 can be a fiber coupler or a fiber splitter.

[0084] In this embodiment, the number of the optical fiber 103 is one or more, and each of the optical fibers 103 corresponds to a temperature sensing unit. When the grating temperature measuring device is working, the end of the optical fiber 103 close to the temperature measuring wafer 101 in the optical fiber 103 is aligned with the coupling structure 105 of the Bragg grating 102 through a lens, and the other end of the optical fiber 103 corresponds to the optical transmitter and the demodulation device 107. When the grating temperature measuring device is working, the optical transmitter emits light, and the emitted light enters the coupling structure 105 of the temperature sensing unit after being collimated by the lens, and is transmitted to the Bragg grating 102 through the waveguide 104. The Bragg grating 102 reflects the reflected light of a specific wavelength, and the reflected light is transmitted to the coupling structure 105 through the waveguide 104. After entering the optical fiber 103, it is reflected by the coupler 108 and transmitted to the demodulation device 107 for processing.

[0085] refer to Figure 5 and Figure 6 The present invention also provides a semiconductor device, including: a wafer carrier 100; the aforementioned grating temperature measuring device, in the temperature measuring state, the temperature measuring wafer 101 is located on the wafer carrier 100, the surface of the temperature measuring wafer 101 facing the wafer carrier 100 has a temperature measuring point, and the optical fiber 103 is detachably fitted in the wafer carrier 100.

[0086] It should be noted that when performing temperature measurement, the optical fiber 103 is matched in the wafer carrier 100, and the temperature measurement wafer is set on the wafer carrier 100; when the temperature measurement is completed, the optical fiber 103 and the temperature measurement wafer 101 are moved out of the semiconductor device.

[0087] The temperature measuring wafer 101 in the embodiment of the present invention is arranged on the wafer carrying device 100, and the surface of the temperature measuring wafer 101 facing the wafer carrying device 100 has a temperature measuring point, and the Bragg grating 102 is directly formed at the temperature measuring point. The end of the optical fiber 103 is arranged in the wafer carrying device 100. When the temperature of the temperature measuring wafer 101 is measured by using a grating temperature measuring device, the emission light provided by the optical fiber 103 can be transmitted to the Bragg grating 102, and the emission light is reflected by the Bragg grating 102 to generate reflected light. In addition, because the Bragg grating 102 is directly formed at the temperature measurement point, there is no medium between the Bragg grating 102 and the temperature measurement wafer 101, and the temperature of the Bragg grating directly reflects the temperature of the wafer. Therefore, the grating period of the Bragg grating 102 changes in real time with the change of the temperature of the temperature measurement wafer 101, so that the central wavelength of the reflected light generated by the Bragg grating 102 will be offset. Through the offset of the central wavelength of the reflected light of the Bragg grating 102, the temperature of the temperature measurement wafer 101 during and / or after the process treatment can be obtained in real time, equivalently and accurately, and non-contact temperature measurement can be achieved, thereby avoiding the wafer contamination problem that may be caused by traditional temperature measurement methods and adapting to the complex and changeable semiconductor manufacturing environment.

[0088] The wafer carrier 100 is a structure capable of firmly adsorbing or fixing the temperature measurement wafer 101 to ensure stable positioning of the temperature measurement wafer 101 during the measurement process.

[0089] In this embodiment, the wafer carrier 100 includes a wafer chuck or a robot for transferring wafers. In other embodiments, other tools capable of fixing wafers may also be used.

[0090] In this embodiment, the optical fiber 103 is arranged in the wafer carrier 100 so as to accurately align the end of the optical fiber 103 with the coupling structure 105 on the temperature measurement wafer 101. In addition, the bidirectional transmission function of the optical fiber 103 not only provides transmitted light but also receives reflected light, so that the grating temperature measurement device can monitor the reflected light signal of the Bragg grating 102 in real time, thereby realizing real-time detection of temperature changes at the temperature measurement point.

[0091] In this embodiment, the end of the optical fiber 103 is directly packaged on the coupling structure 105, so as to achieve close coupling between the optical fiber 103 and the coupling structure 105, reduce the attenuation and reflection of the optical signal during the transmission process, and help to significantly reduce the loss and interference during the optical signal transmission process. In addition, the direct packaging of the end of the optical fiber 103 on the coupling structure 105 can also simplify the assembly process. In other embodiments, the temperature measuring wafer and the end of the optical fiber may not be packaged together, and the temperature measuring wafer and the optical fiber are independent structures.

[0092] In this embodiment, the optical fiber 103 passes through the wafer carrying device 100 , so that the end of the optical fiber 103 is directly exposed from the surface of the temperature measuring wafer 101 , which is convenient for alignment with the coupling structure 105 .

[0093] It should be noted that the end of the optical fiber 103 close to the temperature measurement wafer 101 in the optical fiber 103 is fixedly disposed on the wafer carrying device 100 .

[0094] In this embodiment, the end of the optical fiber 103 is flush with the bearing surface of the wafer bearing device 100. By setting the end of the optical fiber to be flush with the bearing surface of the wafer, the emission light provided by the optical fiber 103 can be evenly irradiated to the coupling structure, and the reflected light provided by the coupling structure 105 can be evenly transmitted to the optical fiber 103, which is conducive to improving the transmission capacity of the emission light and the collection capacity of the reflected light, and reducing the transmission loss of the emission light and the reflected light between the optical fiber and the coupling structure.

[0095] In this embodiment, the optical fiber 103 runs through the wafer carrier, and one end of the optical fiber 103 away from the wafer carrier 100 is located outside the wafer carrier. Since one end of the optical fiber 103 extends to the outside of the wafer carrier, it is helpful to connect with the external light source and demodulation equipment, thereby reducing the loss and interference of the optical signal during the transmission process. In addition, this layout makes the design of the device more diversified, allowing the optical fiber 103 to adapt to various space constraints while ensuring that the integrity of the optical connection is not affected. As an example, when the grating temperature measurement device is in a chamber, the end of the optical fiber 103 away from the wafer carrier 100 is located outside the chamber.

[0096] Specifically, the temperature measurement point is located on the surface of the temperature measuring wafer 101 facing the wafer carrier 100, and the corresponding Bragg grating 102 is located on the surface of the temperature measuring wafer 101 facing the wafer carrier 100, which helps to achieve precise alignment between the coupling structure 105 and the end of the optical fiber 103, and is beneficial to the effective transmission of the emitted light and the reception of the reflected light. In addition, when performing some process treatments, such as ion implantation, the temperature measuring wafer 101 needs to be completely exposed to the process environment. The Bragg grating 102 is located on the surface of the temperature measuring wafer 101 facing the wafer carrier 100, which can make the Bragg grating 102 less susceptible to damage caused by the implanted ions, thereby ensuring that the Bragg grating 102 can still accurately sense the temperature changes of the temperature measuring wafer 101 under these processes.

[0097] It should be noted that the wafer carrier 100 is provided with a first alignment mark for alignment with the temperature measuring wafer 101; the temperature measuring wafer 101 is provided with a second alignment mark, and the second alignment mark and the first alignment mark on the wafer carrier 100 are used to align the coupling structure 105 with the end of the optical fiber 103. When the grating temperature measuring device is working, the second alignment mark on the temperature measuring wafer 101 is aligned with the first alignment mark on the wafer carrier 100, and the alignment of the coupling structure 105 with the end of the optical fiber 103 is achieved. When the temperature measuring wafer 101 is placed on the wafer carrier 100, an external optical device is used to identify the coordinates of the first alignment mark and the second alignment mark, and the mark on the temperature measuring wafer 101 is aligned with the mark on the wafer carrier 100 based on the coordinate information of the two.

[0098] In another embodiment, the coupling mode between the optical fiber 103 and the waveguide 104 is edge coupling. Figure 7As shown, the end of the optical fiber 103 is arranged on the surface of the wafer carrier 100, and the end of the optical fiber 103 is parallel to the plane of the wafer 101, and the coupling structure 105 is a tapered waveguide coupling structure (not shown), so that the emitted light in the optical fiber 103 is transmitted to the waveguide 104 through the tapered waveguide coupling structure, and the light reflected by the Bragg grating 102 reaches the optical fiber 103 through the tapered waveguide coupling structure.

[0099] It should be noted that the wafer carrier 100 is also provided with a cooling mechanism for taking away the heat of the temperature measuring wafer 101 and cooling the temperature measuring wafer 101 to simulate the process environment of actual wafer processing.

[0100] like Figures 1 to 7 As shown, a Bragg grating 102 is formed on the surface of a wafer 101, and a plurality of reflection layers of the Bragg grating 102 are arranged in the surface direction of the wafer 101. In another embodiment, the plurality of reflection layers of the Bragg grating 102 may also be arranged perpendicular to the surface direction of the wafer 101, such as Figure 8 As shown, specifically, a Bragg grating 102 is formed by coating a multilayer optical film on the surface of a wafer 101, and other structures are the same as those in the above embodiment.

[0101] The embodiment of the present invention also provides a grating temperature measurement method based on the above grating temperature measurement device. Fig. 9 It is a flow chart of the grating temperature measurement method according to an embodiment of the present invention. It should be noted that the device for implementing the grating temperature measurement method is not limited to the grating temperature measurement device, and the above-mentioned grating temperature measurement device is now taken as an example.

[0102] The following combination Figures 1 to 7 ,refer to Fig. 9 , the temperature measurement method is explained in detail.

[0103] Step S1 , providing a wafer carrying device 100 .

[0104] The wafer carrier 100 is a structure capable of firmly adsorbing or fixing the temperature measurement wafer 101 to ensure stable positioning of the temperature measurement wafer 101 during the measurement process.

[0105] Step S2 , placing the temperature measurement wafer 101 on a wafer carrying device 100 , wherein the end of the optical fiber 103 is disposed in the wafer carrying device 100 .

[0106] It should be noted that, in the step of placing the temperature measuring wafer 101 on the wafer carrier 100 , the temperature measuring wafer 101 is arranged on the wafer carrier 100 , and the surface of the temperature measuring wafer 101 facing the wafer carrier 100 has the temperature measuring point.

[0107] In the present embodiment, because the temperature measurement point is located on the surface of the temperature measuring wafer 101 facing the wafer carrier 100, the corresponding Bragg grating 102 is located on the surface of the temperature measuring wafer 101 facing the wafer carrier 100, which helps to achieve precise alignment between the coupling structure 105 and the end of the optical fiber 103, which is beneficial to the effective transmission of the emitted light and the reception of the reflected light. In addition, when performing some process treatments, such as ion implantation, the wafer needs to be completely exposed to the process environment. The Bragg grating 102 is located on the surface of the temperature measuring wafer 101 facing the wafer carrier 100, which can make the Bragg grating 102 less susceptible to damage caused by the implanted ions, thereby ensuring that the Bragg grating 102 can be accurately measured under these process conditions to sense the temperature changes of the temperature measuring wafer 101.

[0108] In this embodiment, the wafer carrier 100 is provided with a first alignment mark (not shown in the figure), and the temperature measuring wafer 101 is provided with a second alignment mark (not shown in the figure). When the temperature measuring wafer 101 is provided on the wafer carrier 100, the first alignment mark and the second alignment mark cooperate to enable the coupling structure 105 on the temperature measuring wafer 101 and the optical fiber end of the wafer carrier 100 to be accurately aligned. Specifically, when the temperature measuring wafer 101 is provided on the wafer carrier 100, an external optical device is used to identify the coordinates of the first alignment mark and the coordinates of the second alignment mark, and the first alignment mark is aligned with the second alignment mark based on the coordinate information of the two.

[0109] Step S3, using a thermometer to measure the initial temperature T of the temperature measuring point on the temperature measuring wafer 101 1 .

[0110] By measuring the initial temperature T of the temperature measuring point 1 The reference temperature of the temperature measuring point before the process treatment can be obtained as the reference data for the subsequent temperature change calculation, so as to prepare for the subsequent acquisition of the temperature during and / or after the process treatment.

[0111] In this embodiment, the initial temperature T of the temperature measuring point on the temperature measuring wafer 101 is measured. 1 In the step, the temperature measuring instrument used includes a thermocouple, a thermistor or an infrared temperature measuring device to measure the initial temperature T of the temperature measuring wafer 101. 1 As an example, a thermocouple is used to measure the initial temperature T of the temperature measuring wafer 101. 1 When the thermocouple probe is placed at the temperature measuring point, read the initial temperature T 1 The value of .

[0112] Step S4, at the initial temperature T 1 When the central wavelength of the reflected light of the Bragg grating 102 at the temperature measurement point is obtained as the first wavelength λ B1 .

[0113] At the initial temperature T 1 The first wavelength λ of the Bragg grating 102 is obtained when B1 , as the reference point of the central wavelength of the emitted light. In the subsequent grating temperature measurement process, during and / or after the process of the temperature measurement wafer 101, the central wavelength of the reflected light of the Bragg grating 102 at the temperature measurement point will shift with the change of temperature. By comparing the first wavelength λ B1 and the central wavelength of the reflected light during and / or after the process, the specific offset of the central wavelength of the reflected light during and / or after the process can be determined.

[0114] Specifically, the first wavelength λ is obtained B1 The steps include: at the initial temperature T 1 When the temperature is measured, a first spectrum of the reflected light of the Bragg grating 102 at the temperature measurement point is obtained; according to the first spectrum, the position of the reflection peak in the first spectrum is set as the first wavelength λ B1 .

[0115] In this embodiment, the process of obtaining the first spectrum diagram of the reflected light of the Bragg grating 102 at the temperature measurement point includes: the light transmitter provides the transmitted light, the transmitted light is transmitted through the optical fiber 103 to the end of the optical fiber close to the temperature measurement wafer 101, the end of the optical fiber transmits the transmitted light to the coupling structure 105 of the temperature sensing unit, the transmitted light enters the temperature sensing unit through the coupling structure 105, and transmits the transmitted light to the Bragg grating 102 through the waveguide 104, the Bragg grating 102 reflects the transmitted light to generate reflected light; the reflected light enters the optical fiber 103 via the waveguide 104 and the coupling structure 105, and the reflected light is transmitted to the demodulation device 107 through the optical fiber 103; the demodulation device 107 performs spectral analysis on the received reflected light to obtain the first spectrum diagram of the reflected light.

[0116] In this embodiment, the first spectrum shows the initial temperature T 1 The reflection intensity of the reflected light generated at the Bragg grating 102 is λ, and the reflection peak position in the first spectrum graph corresponds to the first wavelength λ of the Bragg grating 102. B1 .

[0117] Step S5, performing process treatment on the temperature measurement wafer 101.

[0118] The temperature measuring wafer 101 is subjected to process treatment to simulate the actual working environment during wafer processing. During and / or after the process treatment of the temperature measuring wafer 101, the temperature of the temperature measuring wafer 101 changes, so that the temperature of the Bragg grating 102 changes in real time, causing the central wavelength of the reflected light of the Bragg grating 102 to change.

[0119] In this embodiment, the step of performing a process on the temperature measuring wafer 101 includes: providing an ion implantation device; and using the ion implantation device to perform ion implantation on a surface of the temperature measuring wafer 101 that is away from the wafer supporting device 100 .

[0120] It should be noted that when an ion implantation device is used to implant ions into the surface of the temperature measuring wafer 101 that is away from the wafer carrier 100, because the Bragg grating 102, waveguide 104, coupling structure 105 and optical fiber 103 are arranged on the surface of the temperature measuring wafer 101 close to the wafer carrier 100, the ion beam generated by the ion implantation device will not cause damage to the Bragg grating 102, waveguide 104, coupling structure 105 and optical fiber 103.

[0121] Step S6, during and / or after the process, the center wavelength of the reflected light of the Bragg grating 102 at the temperature measurement point is obtained as the second wavelength λ B2 .

[0122] In the subsequent temperature measurement process, the second wavelength λ B2 With the initial temperature T 1 The first wavelength λ B1 By comparison, the offset of the central wavelength of the reflected light of the Bragg grating 102 can be calculated, and the temperature change of the temperature measuring wafer 101 can be obtained based on the offset.

[0123] In this embodiment, the second wavelength λ is obtained during and / or after the temperature measurement wafer 101 is processed. B2 The steps include: obtaining a second spectrum of the reflected light of the Bragg grating 102 during and / or after the temperature measurement wafer 101 is processed; according to the second spectrum, the position of the reflection peak in the second spectrum is the second wavelength λ B2 .

[0124] In this embodiment, the process of obtaining the second spectrum is similar to the process of obtaining the first spectrum, which will not be described in detail. B2 The process of obtaining the first wavelength λ B1 The process is similar and will not be described here.

[0125] Step S7, according to the first wavelength λ B1 and the second wavelength λ B2 , and obtain the offset of the central wavelength of the reflected light of the Bragg grating 102.

[0126] The temperature of the temperature measuring wafer 101 changes before and after the process treatment. The offset of the central wavelength of the emission light of the Bragg grating 102 can be converted into the temperature change of the temperature measuring wafer 101 before and after the process treatment, preparing for the subsequent calculation of the temperature during and / or after the process treatment.

[0127] In this embodiment, the first wavelength λ B1 and the second wavelength λ B2 By comparing the positions of the reflection peaks of the two, the offset of the central wavelength of the reflected light of the Bragg grating 102 is calculated to be Δλ B =|λ B2 -λ B1 |.

[0128] Step S8, obtaining the temperature of the temperature measuring point during and / or after the process according to the offset of the central wavelength of the reflected light of the Bragg grating 102.

[0129] The central wavelength of the reflected light of the Bragg grating 102 will shift as the temperature changes, and there is a clear mathematical relationship between the shift and the temperature change. B1 and the second wavelength λ B2 The temperature of the temperature measuring point during and / or after the process can be deduced from the offset, thereby achieving accurate monitoring of the temperature change of the temperature measuring point during the process.

[0130] Specifically, the step of obtaining the temperature of the temperature measuring point during and / or after the process according to the offset of the central wavelength of the reflected light of the Bragg grating 102 includes:

[0131] The temperature T of the temperature measuring point during and / or after the process is obtained by using the following formulas (1) to (3): 2 :

[0132]

[0133] AT=T 2 -T 1 (2);

[0134] Δλ B =λ B1 -λ B2 (3);

[0135] Among them, λ B1 is the first wavelength, λ B2 is the second wavelength, Δλ B is the offset of the central wavelength of the reflected light, α is the thermal expansion coefficient of the Bragg grating material, ζ is the thermo-optic coefficient of the Bragg grating material; T 1is the initial temperature of the wafer at the temperature measurement point, T 2 It is the temperature of the wafer measured at the temperature measurement point during and / or after the process.

[0136] It should be noted that during some process treatments, the wafer will be strained, causing the center wavelength of the reflected light to drift. Therefore, the offset value of the center wavelength of the emitted light is actually caused by two variables: temperature and strain.

[0137] In order to solve this problem, two Bragg gratings 102 are arranged at the temperature measurement point, namely a first Bragg grating and a second Bragg grating, and the center wavelengths of the reflected light of the first Bragg grating and the second Bragg grating are different. Moreover, because the first Bragg grating and the second Bragg grating are arranged at the same temperature measurement point, the temperature of the first Bragg grating and the second Bragg grating are the same, and the strain before and after the process is the same.

[0138] In the step of measuring the initial temperature of the temperature measuring point on the temperature measuring wafer 101, the initial temperatures T of the first Bragg grating and the second Bragg grating are obtained. 1 .

[0139] like Fig.10 As shown, in the step of obtaining the first wavelength, the first wavelength λ of the first Bragg grating is obtained. B11 and the first wavelength λ of the second Bragg grating B21 In the step of obtaining the second wavelength, the second wavelength λ of the first Bragg grating is obtained. B12 and the second wavelength λ of the second Bragg grating B22 .like Fig.10 As shown, the first wavelength λ of the first Bragg grating B11 Shifted to a second wavelength λ B12 , the first wavelength λ of the first Bragg grating B21 Shifted to a second wavelength λ B22 .

[0140] In the step of obtaining the offset of the central wavelength of the reflected light of the Bragg grating 102, the offset of the central wavelength of the reflected light of the first Bragg grating and the offset of the central wavelength of the reflected light of the second Bragg grating are obtained. Specifically, the offset Δλ of the central wavelength of the reflected light of the first Bragg grating is B1 =|λ B12 -λ B11 |, the offset of the center wavelength of the reflected light of the second Bragg grating Δλ B2 =|λ B22 -λ B21 |.

[0141] The step of obtaining the temperature of the temperature measuring wafer 101 at the temperature measuring point during and / or after the process includes: using the following formulas (4) and (5) to obtain the temperature T of the temperature measuring wafer 101 during and / or after the process 2 .

[0142]

[0143] Among them, Δλ B1 is the offset of the center wavelength of the reflected light from the first Bragg grating, λ B11 is the first wavelength of the first Bragg grating, Δλ B2 is the offset of the center wavelength of the reflected light from the second Bragg grating, λ B21 is the first wavelength of the second Bragg grating; α 1 is the thermal expansion coefficient of the first Bragg grating material, ζ 1 is the thermo-optic coefficient of the first Bragg grating material; is the effective elasto-optical constant of the first Bragg grating material, α 2 is the thermal expansion coefficient of the second Bragg grating material, ζ 2 is the thermo-optic coefficient of the second Bragg grating material; is the effective elastic-optical constant of the second Bragg grating material, Δε is the strain change of the Bragg grating material, T 1 is the initial temperature of the temperature measuring wafer 101 at the temperature measuring point, T 2 It is the temperature of the temperature measuring wafer 101 at the temperature measuring point during and / or after the process.

[0144] The embodiment of the present invention also provides another grating temperature measurement method based on the above-mentioned grating temperature measurement device, the grating temperature measurement device includes a coupling structure 105, and the grating temperature measurement method includes: obtaining a calibration of the corresponding relationship between the center wavelength of the reflected light of the Bragg grating 102 and the temperature; providing a wafer carrier 100; placing the temperature measurement wafer 101 on the wafer carrier 100, the wafer carrier 100 is provided with an end of an optical fiber 103, and the coupling structure 105 is aligned with the end of the optical fiber 103 in the wafer carrier 100; performing process treatment on the temperature measurement wafer 101; during and / or after the process treatment, obtaining the center wavelength of the reflected light of the Bragg grating 102 at the temperature measurement point; and obtaining the temperature of the temperature measurement point based on the corresponding relationship between the center wavelength of the reflected light and the temperature and the center wavelength of the reflected light.

[0145] The corresponding relationship between the center wavelength of the reflected light and the temperature is calibrated, which is the basis of the entire grating temperature measurement method. The center wavelength of the reflected light of the Bragg grating 102 at different temperatures is calibrated by experiments, and the precise corresponding relationship between the temperature and the change of the center wavelength of the reflected light is established. This corresponding relationship is the basis for subsequent temperature reading. Before the temperature measurement operation begins, the temperature measurement wafer 101 is placed on the wafer carrier 100; during and / or after the process treatment, the end of the optical fiber 103 in the wafer carrier 100 and the Bragg grating 102 transmit the emitted light and the reflected light. Specifically, the emitted light provided by the optical fiber 103 is reflected after passing through the Bragg grating 102, and the reflected light is transmitted through the optical fiber 103. The spectrometer monitors the change of the center wavelength of the light reflected by the Bragg grating 102 in real time, and reads the temperature of the current temperature measurement wafer 101 in real time according to the previously established relationship between the center wavelength of the reflected light and the temperature.

[0146] This temperature measurement method is based on the relationship between the central wavelength of the reflected light and the temperature. It can read the temperature of the temperature measurement wafer 101 in real time without calculation, thereby improving production efficiency and temperature measurement accuracy, realizing non-contact temperature measurement, avoiding the wafer contamination problem that may be caused by traditional temperature measurement methods, and adapting to the complex and changeable semiconductor manufacturing environment.

[0147] In this embodiment, the step of obtaining the corresponding relationship between the central wavelength of the reflected light of the Bragg grating 102 and the temperature includes: obtaining the central wavelength of the reflected light corresponding to the Bragg grating 102 at multiple known temperatures respectively; fitting multiple temperature data and corresponding data of the central wavelength of the reflected light to obtain a relationship curve between the central wavelength of the reflected light of the Bragg grating 102 and the temperature.

[0148] By measuring the central wavelength of the reflected light of the Bragg grating 102 at multiple known temperatures and fitting these data, a relationship curve between temperature and the central wavelength of the reflected light is established, which provides a basis for subsequent temperature readings. This relationship curve allows, in practical applications, only the central wavelength of the reflected light of the Bragg grating 102 needs to be measured to directly obtain the corresponding temperature value through the curve, thereby achieving contactless and high-precision temperature monitoring.

[0149] In this embodiment, the Bragg grating 102 is placed in a chamber where the temperature can be precisely controlled, for example, the temperature is gradually increased from room temperature to the highest temperature of the chamber; during this process, the change in the central wavelength of the reflected light of the Bragg grating 102 at each temperature measurement point is recorded, and a relationship curve between the central wavelength of the reflected light and the temperature is generated by using statistical or mathematical fitting techniques, such as the least squares method. Then, additional verification experiments are conducted to test the accuracy and practicality of the fitting curve, and the relationship curve is adjusted and optimized when necessary to ensure its high accuracy and reliability in practical applications.

[0150] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A grating temperature measuring device, characterized in that: include: A temperature measuring wafer, wherein the surface of the temperature measuring wafer has temperature measuring points; Bragg grating, formed directly at the temperature measurement point; The optical fiber is used to provide emission light to the Bragg grating, the Bragg grating reflects the emission light to generate reflected light, and the optical fiber is also used to conduct the reflected light.

2. The grating temperature measuring device according to claim 1, characterized in that: The grating temperature measuring device comprises a temperature sensing unit, and the temperature sensing unit comprises: The Bragg grating; a waveguide coupled to the Bragg grating and configured to transmit the emitted light and the reflected light; A coupling structure, coupled to the waveguide and corresponding to the end of the optical fiber, for realizing the transmission of the emitted light and the reflected light between the waveguide and the optical fiber; The coupling structure is a grating coupling structure or a tapered waveguide coupling structure.

3. The grating temperature measuring device according to claim 2, characterized in that: The Bragg grating, and / or waveguide, and / or coupling structure are directly formed on the surface of the temperature measuring wafer by using an optical film layer growth process, or are directly formed on the surface of the temperature measuring wafer by using a micromachining process.

4. The grating temperature measuring device according to claim 2, characterized in that: The number of the optical fibers is one or more, and each of the optical fibers corresponds to a temperature sensing unit.

5. The grating temperature measuring device according to claim 2, characterized in that: The number of the Bragg grating in the temperature sensing unit is one; Alternatively, there are multiple Bragg gratings in the temperature sensing unit, and the multiple Bragg gratings are connected in parallel or in series through the waveguide.

6. The grating temperature measuring device according to claim 2, characterized in that: The temperature sensing unit includes a plurality of Bragg gratings, and the reflected light center wavelengths of the Bragg gratings are different.

7. The grating temperature measuring device according to claim 1, characterized in that: The temperature measurement point is provided with two Bragg gratings, and the center wavelengths of the reflected lights of the two Bragg gratings are different.

8. The grating temperature measuring device according to claim 1, characterized in that: There are multiple Bragg gratings, and the multiple Bragg gratings are distributed in a circular array on the temperature measurement wafer and / or distributed radially along the temperature measurement wafer.

9. The grating temperature measuring device according to claim 1, characterized in that: The optical fiber is configured to be installed in a wafer carrier, and the temperature measurement point is located on a side of the temperature measurement wafer facing the wafer carrier.

10. The grating temperature measuring device according to claim 1, characterized in that: The grating temperature measurement device also includes: a lens, which is located at the end of the optical fiber close to the temperature measurement wafer and is used to collimate and transmit the emitted light or the reflected light.

11. The grating temperature measuring device according to claim 1, characterized in that: The grating temperature measuring device also includes: An optical transmitter, connected to the optical fiber, and configured to provide the emitted light; A demodulation device is connected to the optical fiber and is used to receive the reflected light.

12. A semiconductor device, characterized in that: include: Wafer carrier; According to the grating temperature measuring device as described in any one of claims 1-11, in the temperature measuring state, the temperature measuring wafer is located on the wafer carrying device, the surface of the temperature measuring wafer facing the wafer carrying device has a temperature measuring point, and the optical fiber is arranged in the wafer carrying device.

13. The semiconductor device according to claim 12, wherein: The grating temperature measurement device includes a coupling structure, and the coupling structure is aligned with the end of the optical fiber in the wafer carrying device.

14. The semiconductor device according to claim 12, wherein: The end of the optical fiber is flush with the bearing surface of the wafer bearing device.

15. The semiconductor device according to claim 12, wherein: The wafer carrying device includes a wafer chuck or a robot for transferring wafers.

16. The semiconductor device according to claim 12, wherein: The optical fiber runs through the wafer carrying device, and one end of the optical fiber away from the wafer carrying device is located outside the wafer carrying device.

17. A temperature measurement method based on the grating temperature measurement device according to any one of claims 1 to 11, characterized in that: include: Providing a wafer carrier; Placing the temperature measuring wafer on a wafer carrying device, wherein the end of the optical fiber is arranged in the wafer carrying device; Using a thermometer to measure the initial temperature of the temperature measuring point on the temperature measuring wafer; At the initial temperature, the center wavelength of the reflected light of the Bragg grating at the temperature measurement point is obtained as a first wavelength; Performing process treatment on the temperature measurement wafer; During and / or after the process, the center wavelength of the reflected light of the Bragg grating at the temperature measurement point is obtained as a second wavelength; Obtaining an offset of a central wavelength of reflected light from a Bragg grating according to the first wavelength and the second wavelength; The temperature of the temperature measuring point during and / or after the process is obtained according to the offset of the central wavelength of the reflected light of the Bragg grating.

18. The temperature measurement method according to claim 17, characterized in that: The step of obtaining the temperature of the temperature measuring point during and / or after the process according to the offset of the central wavelength of the reflected light of the Bragg grating comprises: The temperature of the temperature measuring point during and / or after the process is obtained by using the following formulas (1), (2) and (3): ΔT = T2 - T1 (2); Dl B =λ B1 -l B2 (3); Among them, λ B1 is the first wavelength, λ B2 is the second wavelength, Δλ B is the central wavelength offset of the reflected light, α is the thermal expansion coefficient of the Bragg grating material, ζ is the thermo-optical coefficient of the Bragg grating material; T1 is the initial temperature of the temperature measuring wafer at the temperature measuring point, and T2 is the temperature of the temperature measuring wafer at the temperature measuring point during and / or after the process treatment.

19. The temperature measurement method according to claim 17, characterized in that: The temperature measurement point is provided with a first Bragg grating and a second Bragg grating, and the center wavelengths of reflected light of the first Bragg grating and the second Bragg grating are different; In the step of obtaining the first wavelength, a first wavelength of the first Bragg grating and a first wavelength of the second Bragg grating are obtained; In the step of obtaining the second wavelength, the second wavelength of the first Bragg grating and the second wavelength of the second Bragg grating are obtained; In the step of obtaining the offset of the central wavelength of the reflected light of the Bragg grating, the offset of the central wavelength of the reflected light of the first Bragg grating and the offset of the central wavelength of the reflected light of the second Bragg grating are obtained; The step of obtaining the temperature of the temperature measuring wafer at the temperature measuring point during and / or after the process includes: The temperature of the temperature measuring wafer during and / or after the process is obtained by using the following formulas (4) and (5): Among them, Δλ B1 is the offset of the center wavelength of the reflected light from the first Bragg grating, λ B11 is the first wavelength of the first Bragg grating, Δλ B2 is the offset of the center wavelength of the reflected light from the second Bragg grating, λ B21 is the first wavelength of the second Bragg grating; α1 is the thermal expansion coefficient of the first Bragg grating material, ζ1 is the thermo-optic coefficient of the first Bragg grating material; is the effective elasto-optical constant of the first Bragg grating material, α2 is the thermal expansion coefficient of the second Bragg grating material, ζ2 is the thermo-optical coefficient of the second Bragg grating material; is the effective elastic optical constant of the second Bragg grating material, Δε is the strain change of the Bragg grating material, T1 is the initial temperature of the temperature measuring wafer at the temperature measuring point, and T2 is the temperature of the temperature measuring wafer at the temperature measuring point during and / or after the process.

20. The temperature measurement method according to claim 17, characterized in that: In the step of measuring the initial temperature of the temperature measuring point on the temperature measuring wafer, the temperature measuring instrument used includes a thermocouple, a thermistor or an infrared temperature measuring device.

21. A temperature measurement method based on the grating temperature measurement device according to any one of claims 1 to 11, characterized in that: The grating temperature measuring device comprises a coupling structure, including: Obtaining the corresponding relationship calibration between the center wavelength of the reflected light of the Bragg grating and the temperature; Providing a wafer carrier; Placing the temperature measurement wafer on a wafer carrying device, wherein the wafer carrying device is provided with an end of an optical fiber, and the coupling structure is aligned with the end of the optical fiber in the wafer carrying device; Performing process treatment on the temperature measurement wafer; During and / or after the process, obtaining the center wavelength of the reflected light of the Bragg grating at the temperature measurement point; The temperature of the temperature measurement point is obtained based on the corresponding relationship between the central wavelength of the reflected light and the temperature and the central wavelength of the reflected light.

22. The temperature measurement method according to claim 21, characterized in that: The step of obtaining the corresponding relationship between the central wavelength of the reflected light of the Bragg grating and the temperature comprises: Under a plurality of known temperatures, respectively obtaining the central wavelength of the reflected light corresponding to the Bragg grating; A relationship curve between the central wavelength of the reflected light of the Bragg grating and the temperature is obtained by fitting a plurality of known temperature data and corresponding data of the central wavelength of the reflected light.

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