Semiconductor heat treatment equipment, pyrometer and method for measuring temperature and emissivity

Abstract

The invention provides semiconductor heat treatment equipment, a pyrometer and a temperature and emissivity measurement method. The pyrometer comprises an active emissivity measurement module, a temperature measurement module and a logic circuit, the active emissivity measurement module is used for emitting detection light to a wafer and receiving reflected light of the detection light to calculate the emissivity, and the temperature measurement module is used for receiving thermal radiation light of the wafer to calculate the temperature; the logic circuit is used for receiving signals of the active emissivity measurement module and the temperature measurement module and calculating the emissivity and the temperature of the wafer; wherein the active emissivity measurement module and the temperature measurement module share at least part of light path elements. According to the embodiment of the invention, the temperature and the emissivity of the wafer can be measured at the same time, and the emissivity of the wafer can be measured actively and directly from the room temperature, so that accurate temperature monitoring in the whole process temperature range is realized.

Description

Technical Field

[0001] This application relates to the field of semiconductor manufacturing technology, specifically to a semiconductor thermal processing apparatus, a pyrometer, and a method for measuring temperature and emissivity. Background Technology

[0002] In semiconductor manufacturing, rapid thermal processing (RTP) is a critical process widely used in steps such as annealing, oxidation, and thin film deposition. RTP processes require wafers to be rapidly heated to a target temperature (e.g., 180°C to 1200°C) in an extremely short time, while maintaining extremely high temperature uniformity and control precision. In advanced processes, temperature deviations are typically required to be less than 1°C.

[0003] Currently, non-contact infrared pyrometers are the primary means of measuring wafer temperature in RTP (Remote Temperature Detection) equipment. Existing technologies commonly employ dual-color pyrometers or two pyrometers positioned on the same radius, calculating emissivity by comparing radiation signals from two different wavelengths or two nearby locations. However, this method has significant limitations: estimating emissivity from thermal radiation signals requires the object being measured to emit sufficiently strong thermal radiation signals, typically only yielding accurate emissivity data when the wafer temperature exceeds approximately 450°C, failing to cover the entire process heating from room temperature. The dual-pyrometer method essentially involves different combinations of pyrometers measuring emissivity and thermal radiation intensity separately, which is prone to significant errors in temperature calculation due to measurement position deviations or differences in optical paths. Furthermore, existing technologies typically require multiple probes and complex calibration and calculations, increasing system cost and maintenance complexity. Therefore, there is an urgent need in the field for a pyrometer solution that can rapidly and accurately measure wafer emissivity directly from low temperatures and calculate precise temperature accordingly. Summary of the Invention

[0004] The purpose of this application is to provide a semiconductor thermal processing device, a pyrometer, and a method for measuring temperature and emissivity, which can simultaneously measure wafer temperature and emissivity, and can actively and directly measure wafer emissivity from room temperature, thereby achieving accurate temperature monitoring across the entire process temperature range.

[0005] To address the aforementioned technical problems, one embodiment of this application provides a pyrometer for semiconductor heat treatment, comprising: an active emissivity measurement module, a temperature measurement module, and a logic circuit; the active emissivity measurement module is used to emit detection light onto a wafer and receive its reflected light to calculate the emissivity, and the temperature measurement module is used to receive thermal radiation light from the wafer to calculate the temperature; the logic circuit is used to receive signals from the active emissivity measurement module and the temperature measurement module, and calculate the emissivity and temperature based on the signals; wherein the active emissivity measurement module and the temperature measurement module share at least some optical path elements.

[0006] Optionally, the active emissivity measurement module includes: a pulsed light source for emitting pulsed light of a specific wavelength; a first photodetector for monitoring the light emission state of the pulsed light source; a beam splitter disposed in the optical path of the pulsed light source for reflecting part of the pulsed light to the wafer and transmitting the reflected light returning from the wafer to a second photodetector; a light guide element for guiding light to and from the wafer; a first reflector for reflecting and rectifying the pulsed light from the beam splitter to the light guide element and rectifying the light received by the light guide element from the wafer's thermal radiation; a second reflector for reflecting and rectifying the reflected light from the beam splitter to the second photodetector; a first filter disposed between the pulsed light source and the beam splitter; and a second filter disposed between the beam splitter and the second reflector, wherein the first and second filters are used to select light of a specific wavelength band; wherein the logic circuit calculates the reflectivity of the wafer by comparing the pulsed light intensity information received by the first and second photodetectors, and then calculates the emissivity.

[0007] Optionally, the temperature measurement module shares the light guide element, first reflector, beam splitter, second filter, second reflector, and second photodetector with the active emissivity measurement module; the thermal radiation light from the wafer passes sequentially through the light guide element, first reflector, beam splitter, second filter, and second reflector, and is received by the second photodetector; the logic circuit combines the measured emissivity and thermal radiation intensity to calculate the wafer temperature using the blackbody radiation formula.

[0008] Optionally, the optical centers of the light guide element, the first reflector, the beam splitter, the second filter, the second reflector, and the second photodetector are located on a first straight line; the optical centers of the pulsed light source, the first filter, the beam splitter, and the first photodetector are located on a second straight line; the first straight line and the second straight line are perpendicular to each other.

[0009] Optionally, the emissivity ε is calculated using the formula ε = 1 - τ - ρ, where τ is the transmittance and ρ is the reflectivity; the blackbody radiation formula is expressed as:

[0010]

[0011] Where, μ λ (λ, T) represents the thermal radiation intensity of an object at temperature T at a detection wavelength λ, where λ is the detection wavelength, T is the object temperature, h is Planck's constant, c is the speed of light, and k is Boltzmann's constant.

[0012] Optionally, the pulsed light source is an infrared LED light source with a working wavelength range of 800-1000nm.

[0013] Optionally, the logic circuit includes a signal processing unit, which is one of a lock-in amplifier, a Boxcar averager, or a resonant amplifier, for extracting the intensity of the pulsed light from the signal of the second photodetector.

[0014] Optionally, the logic circuit includes a photoelectric component module and an I / O and logic circuit module; the photoelectric component module includes analog front-ends of the first photodetector and the second photodetector, used to receive optical signals and convert them into electrical signals; the I / O and logic circuit module is configured to calculate the temperature by comparing the pulse light intensity information received by the first photodetector and the second photodetector, and to realize a data communication interface with external devices and receive external configuration commands.

[0015] Another aspect of this application provides a method for measuring wafer temperature and emissivity using the aforementioned pyrometer, comprising: controlling the active emissivity measurement module to emit pulsed light toward the back of the wafer and detecting the intensity of its reflected light; calculating the reflectivity of the wafer based on the reflected light intensity; calculating the emissivity based on the reflectivity; detecting the intensity of continuous light emitted by the wafer through the temperature measurement module; and calculating the wafer temperature using the blackbody radiation formula based on the emissivity and the continuous light intensity.

[0016] Another embodiment of this application provides a semiconductor thermal processing apparatus, including: a reaction chamber, a heating lamp assembly for heating a wafer, a support mechanism for supporting and rotating the wafer, a main controller, and the aforementioned pyrometer. The main controller is communicatively connected to the pyrometer and is used to send configuration instructions to the pyrometer and receive wafer temperature and emissivity data from the pyrometer.

[0017] Optionally, the heating lamp assembly is divided into multiple controllable heating zones, and multiple high-temperature gauges are provided, each corresponding to a wafer below one of the multiple heating zones for measurement; the device is configured to perform independent closed-loop temperature control on the corresponding heating zone based on the temperature measured by each probe.

[0018] Compared to existing technologies, this application integrates an active emissivity measurement module, a temperature measurement module, and logic circuitry. This integrated design breaks away from the traditional need for two separate devices (one for emissivity and one for temperature). It ensures that emissivity and thermal radiation intensity are measured from the exact same physical location and optical path, fundamentally eliminating systematic errors caused by measurement position deviations or optical path differences, and significantly improving the accuracy and reliability of temperature calculations. By sharing the optical path, the pyrometer structure becomes very compact, reducing manufacturing costs and assembly complexity. Attached Figure Description

[0019] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0020] Figure 1 This is a schematic diagram of the structure of a pyrometer according to an embodiment of this application;

[0021] Figure 2 This is a schematic diagram of the structure of a pyrometer according to another embodiment of this application;

[0022] Figure 3 This is a schematic diagram of the structure of a semiconductor heat treatment apparatus according to an embodiment of this application.

[0023] Figure 4 This is a schematic diagram of the structure of a wafer according to an embodiment of this application;

[0024] Figure 5 This is a flowchart of a method for measuring wafer temperature and emissivity using a pyrometer according to an embodiment of this application. Detailed Implementation

[0025] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] It should be noted that the following description covers various aspects of embodiments within the scope of the appended claims. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this application, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0027] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The drawings only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0028] Additionally, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that practice can be carried out without these specific details.

[0029] In practical applications, the heat treatment process for semiconductor workpieces can be a rapid thermal annealing process. In thermal annealing, the wafer undergoes both open-loop and closed-loop heating. The wafer is first heated to a lower set temperature using constant power, at which point the entire system enters a relatively stable and controllable state, and the heating process enters closed-loop control. For example, wafer surfaces are typically deposited with different materials (such as polysilicon, silicon dioxide, silicon nitride, metals, etc.) and different film thicknesses. These factors cause differences in emissivity at different locations on the wafer surface, which dynamically change. Non-contact temperature measurement requires simultaneously measuring both the thermal radiation intensity and emissivity at the location being measured to calculate the wafer temperature at that location. Therefore, accurate temperature readings can only be obtained by simultaneously and accurately measuring both emissivity and thermal radiation intensity.

[0030] Based on this, this application provides a high-temperature meter for semiconductor heat treatment that can simultaneously measure wafer temperature and emissivity, such as... Figure 1 As shown, the pyrometer in this embodiment includes: an active emissivity measurement module, a temperature measurement module, and a logic circuit; the active emissivity measurement module is used to emit detection light to the wafer and receive its reflected light to calculate the emissivity, and the temperature measurement module is used to receive the thermal radiation light from the wafer to calculate the temperature; the logic circuit is used to receive signals from the active emissivity measurement module and the temperature measurement module, and calculate the emissivity and temperature of the wafer based on the signals; wherein, the active emissivity measurement module and the temperature measurement module share at least some optical path elements.

[0031] Specifically, in one alternative embodiment, such as Figure 1 and Figure 2 As shown, the active emissivity measurement module includes: a pulsed light source 201, a first photodetector 204, a beam splitter 203, a second photodetector 304, a light guide element 4, a first reflector 301, a second reflector 303, a first filter 202, and a second filter 302.

[0032] The pulsed light source 201 is preferably an infrared LED light source used to emit pulsed light of a specific wavelength; its operating wavelength range is 800nm-1000nm, more preferably 800nm-920nm. The light source is driven to emit modulated pulsed light with a fixed frequency.

[0033] The first filter 202 is positioned after the pulse light source 201 and between the pulse light source 201 and the beam splitter 203. It is used to purify the emitted light, ensuring that only pulse light of a specific wavelength enters the system and suppressing stray light.

[0034] Beam splitter 203 is disposed in the pulsed light path to reflect part of the pulsed light back to the wafer and transmit the reflected light returning from the wafer to the second photodetector 304.

[0035] The first photodetector 204 receives a portion of the pulsed light transmitted from the beam splitter 203 to monitor the light output state (such as light output intensity and stability) of the pulsed light source, serving as a reference signal for subsequent calculations.

[0036] The first reflector 301 is used to reflect and rectify the pulsed light from the beam splitter 203 onto the light guide element 4, and to rectify the light received by the light guide element 4 from the thermal radiation of the wafer.

[0037] The light guide element 4 is preferably a quartz light guide, which has good infrared transmission performance and thermal stability. It is used to guide the pulsed light to and from the wafer. The second reflector 303 is used to reflect and bundle the reflected light from the beam splitter 203 to the second photodetector 304. Specifically, the light guide element 4 guides the pulsed light to the test position on the back side of the wafer within the reaction cavity. The pulsed light reflected back from the back side of the wafer passes through the light guide element 4 and the first reflector 301 again, is transmitted through the beam splitter 203, and is reflected by the second reflector 303.

[0038] The second filter 302 is disposed between the beam splitter 203 and the second reflector 303 in the reflected light path to filter out background stray light and ensure that only signals in the pulse light band are received by the detector.

[0039] The second photodetector 304 receives the reflected pulse light returning from the wafer, which is reflected by the second reflector 303.

[0040] In this embodiment, the logic circuit calculates the reflectivity of the wafer by comparing the pulse light intensity information received by the first photodetector 204 and the second photodetector 304, and then calculates the emissivity.

[0041] In an alternative embodiment, reference is made to... Figure 2 The logic circuit also includes a photoelectric component module 5 and an I / O and logic circuit module 6. The photoelectric component module 5 includes analog front-ends of a first photodetector 204 and a second photodetector 304, used to receive light signals and convert them into electrical signals; the I / O and logic circuit module 6 is configured to calculate the temperature by comparing the pulse light intensity information received by the first photodetector 204 and the second photodetector 304, and to realize a data communication interface with external devices and receive external configuration commands.

[0042] The optoelectronic component module 5 also includes a light source driving unit for driving the pulse light source 201 to emit pulse light at a predetermined frequency and duty cycle.

[0043] In this embodiment, both the first filter 202 and the second filter 302 can be infrared bandpass filters, and both the first photodetector 204 and the second photodetector 304 can be photodiodes. When using the pyrometer of this embodiment to detect temperature and emissivity, the pulse light source 201 emits pulse light with a fixed frequency. After being filtered by the first filter 202, the pulse light passes through the beam splitter 203. A portion of the pulse light passes through the beam splitter 203 and illuminates the first photodetector 204, which monitors the operating status of the pulse light source 201. The other portion of the pulse light is reflected by the beam splitter 203, passes through the first reflector 301 and the quartz light guide 4, and finally illuminates the emissivity measurement location on the back of the wafer. The pulse light illuminating the back of the wafer is reflected back by the wafer and re-intruded into the quartz light guide 4. After passing through the first reflector 301, the beam splitter 203, and the second filter 302, it is received by the second photodetector 304 after passing through the second reflector 303. The pulse light intensity information measured by the second photodetector 304 and the first photodetector 204 is processed to obtain the infrared light reflectance on the back side of the wafer, and then the emissivity of the wafer is calculated through the emissivity.

[0044] Optionally, the pyrometer in this embodiment of the application further includes a connecting component 1 for fixing the pyrometer inside the reaction chamber.

[0045] In this embodiment, the temperature measurement module and the active emissivity measurement module can share the light guide element 4, the first reflector 301, the beam splitter 203, the second filter 302, the second reflector 303, and the second photodetector 304. The thermal radiation light from the wafer passes sequentially through the light guide element 4, the first reflector 301, the beam splitter 203, the second filter 302, and the second reflector 303, and is received by the second photodetector 304. The logic circuit combines the measured emissivity and thermal radiation intensity to calculate the wafer temperature using the blackbody radiation formula.

[0046] Preferably, the optical centers of the light guide element 4, the first reflector 301, the beam splitter 203, the second filter 302, and the second photodetector 304 are located on a first straight line, forming the main optical path; while the optical centers of the pulsed light source 201, the first filter 202, the beam splitter 203, and the first photodetector 204 are located on a second straight line; the first straight line and the second straight line are perpendicular to each other. This "T"-shaped or "L"-shaped optical path layout makes the structure very compact, stable, and easy to assemble and calibrate.

[0047] The logic circuit in this embodiment receives a reference signal from the first photodetector 204 and a reflected signal from the second photodetector 304. Since the reflected signal is very weak and mixed with the background noise of the wafer's thermal radiation, the signal processing unit in the logic circuit (which can be a lock-in amplifier, a Boxcar averager, or a resonant amplifier) ​​is used to extract the intensity of the pulsed light from the signal from the second photodetector 304. By comparing the reference signal and the extracted reflected signal, the reflectivity ρ of the wafer's back surface for this wavelength of light can be calculated. According to Kirchhoff's law of thermal radiation, its emissivity ε can be calculated using the formula ε = 1 - τ - ρ, where τ is the transmittance (τ ≈ 0) for opaque or nearly opaque wafers.

[0048] Substituting the emissivity ε obtained from the previous calculation into the blackbody radiation formula:

[0049]

[0050] Wherein, μ λ (λ, T) represents the thermal radiation intensity of an object at temperature T at a detection wavelength λ, where λ is the detection wavelength, T is the object temperature, h is Planck's constant, c is the speed of light, and k is Boltzmann's constant. The logic circuit can calculate the true temperature T of the wafer by solving this equation.

[0051] In this embodiment, while the active emissivity measurement module is operating, the continuous-spectrum infrared light emitted by the wafer's own thermal radiation is transmitted in reverse along a shared optical path identical to the reflected pulse light: that is, sequentially passing through the optical guide element 4, the first reflector 301, the beam splitter 203, the second filter 302, and the second reflector 303, and finally received by the second photodetector 304. The second photodetector 304 sends the received total light intensity signal (including DC thermal radiation signal and AC reflected pulse signal) to the logic circuit. The logic circuit first uses the signal processing unit to extract the AC reflected pulse signal (for emissivity calculation). Simultaneously, it also measures the DC component in the total signal, which represents the thermal radiation intensity of the wafer in this band. Substituting the calculated emissivity ε and the measured thermal radiation intensity into the blackbody radiation formula, the true temperature T of the wafer can be calculated. Since the emissivity ε and thermal radiation intensity are measured synchronously and along the same path, they can be perfectly matched and substituted into the blackbody radiation formula to calculate an accurate temperature value.

[0052] Compared to existing technologies, this application integrates an active emissivity measurement module, a temperature measurement module, and logic circuitry. This integrated design breaks away from the traditional need for two separate devices (one for emissivity and one for temperature). It ensures that emissivity and thermal radiation intensity are measured from the exact same physical location and optical path, fundamentally eliminating systematic errors caused by measurement position deviations or optical path differences, significantly improving the accuracy and reliability of temperature calculations. By actively emitting pulsed light, it breaks the traditional dependence on the wafer's own thermal radiation intensity, making it possible to accurately measure emissivity from room temperature. Employing techniques such as lock-in amplification greatly suppresses background noise, enabling the extraction of weak reflected pulse signals from a strong thermal radiation background, ensuring measurement accuracy under low signal-to-noise ratio conditions. By sharing the optical path, it ensures coaxial and common-path measurements of emissivity and thermal radiation intensity, measuring the true physical state of the same point, eliminating systematic errors.

[0053] This application also provides a semiconductor thermal processing apparatus, such as... Figure 3 As shown, it includes: a reaction chamber 14, a heating lamp group 11 for heating the wafer 13, a support mechanism 12 for supporting and rotating the wafer 13, a main controller, and at least one of the above-mentioned pyrometers. The main controller is communicatively connected to the pyrometer and is used to send configuration instructions to the pyrometer and receive wafer temperature and emissivity data from the pyrometer.

[0054] In this embodiment, the pyrometer can be fixed inside the reaction chamber 14 via the connecting component 1, and the main controller and the pyrometer can be connected via the communication cable 7 to realize information exchange between the pyrometer and the main controller. The support mechanism 12 may include: a rotatable support ring 121 and a liftable support pin 122.

[0055] The heating lamp group 11 is divided into multiple controllable heating zones. Each lamp group can be divided into multiple zones centered on the central axis of the wafer 13, such as... Figure 3 and Figure 4 As shown, there are, for example, seven regions: Z1, Z2, Z3, Z4, Z5, Z6, and Z7, and these regions are controlled individually. Multiple pyrometers are provided, such as T1, T2, T3, T4, T5, T6, and T7 pyrometers, each corresponding to the wafer 13 below the multiple heating regions for measurement. The device is configured to perform independent closed-loop temperature control on the corresponding heating region based on the temperature measured by each probe.

[0056] It should be noted that in the embodiments of this application, only one of the multiple pyrometers (such as T4) needs to be used to simultaneously measure wafer emissivity and wafer temperature. The remaining pyrometers can be ordinary pyrometers in the prior art (i.e., those that only have the function of measuring wafer temperature). The wafer emissivity measured by T4 can be used in the temperature calculation of other pyrometers to achieve accurate wafer temperature measurement.

[0057] In other embodiments, multiple pyrometers (which combine wafer emissivity and wafer temperature measurement functions) from the embodiments of this application can be used to measure the temperature of wafers with different radii.

[0058] Under standard rapid annealing process conditions, such as low pressure of 1–760 Torr, process temperature of 180–1200°C, and process gas containing oxygen, nitrogen, ammonia, oxygen and nitrogen, or oxygen and hydrogen, the total gas flow rate is 1–60 slm. The wafer 13, conveyed into the reaction chamber 14, is supported by support pins 122, positioning it directly above the wafer support ring 121. The heating lamp assembly 11 above the wafer 13 and wafer support ring 121 initially heats the wafer 13 and wafer support ring 121 at a predetermined open-loop power (e.g., 5%–20%). During the initial open-loop heating time (e.g., 5-8 seconds), the temperature and heating rate of the wafer support ring 121 are measured using a second pyrometer at the second measuring point. Based on the open-loop heating power of the heating lamp group 11 above the wafer 13 and the temperature and heating rate of the wafer support ring 121, the open-loop heating power of the heating lamp group 11 above the wafer support ring 121 is automatically adjusted so that the temperature difference between the wafer support ring 121 and the wafer 13 is less than a set value (e.g., 30°C). When the temperature of the wafer 13 and the wafer support ring 121 reach a preset value (e.g., 200°C), the wafer support pin 122 descends, the wafer 13 contacts the wafer support ring 121, and the wafer support ring 121 begins to rotate. The pyrometer measures temperatures T1, T2, T3, T4, T5, T6, and T7, and temperature control is performed in seven regions Z1, Z2, Z3, Z4, Z5, Z6, and Z7. The wafer then enters the closed-loop heating step.

[0059] This embodiment integrates a pyrometer into the heat treatment equipment, enabling precise closed-loop control of the wafer temperature from the initial open-loop heating to the final process temperature. Particularly in multi-zone heating systems, it provides independent and accurate temperature feedback for each heating zone. More precise wafer temperature measurement facilitates more accurate temperature control, significantly improving temperature uniformity within the wafer, reducing wafer warpage caused by thermal stress, and ultimately enhancing process stability and production yield.

[0060] This application also provides a method for measuring wafer temperature and emissivity, which is applied to the aforementioned pyrometer, such as... Figure 5As shown, the specific process is as follows:

[0061] In step 101, the active emissivity measurement module is controlled to emit pulsed light toward the back of the wafer and its reflected light intensity is detected.

[0062] In step 102, the reflectivity of the wafer is calculated based on the intensity of the reflected light; and the emissivity is calculated based on the reflectivity.

[0063] In step 103, the intensity of continuous light emitted by the wafer through the temperature measurement module is detected.

[0064] In step 104, the temperature of the wafer is calculated using the blackbody radiation formula based on the emissivity and the continuous light intensity.

[0065] This embodiment achieves synchronous, in-situ measurement of emissivity and temperature. The actively emitted pulsed light signal and the wafer's own thermal radiation signal can be effectively distinguished in the time or frequency domain. This allows for the precise extraction of the reflected light signal using powerful signal processing techniques (such as lock-in amplification) even when the wafer temperature is very low and the thermal radiation signal is weak, thereby enabling accurate calculation of the emissivity. This allows for precise temperature measurement starting from room temperature, filling a gap in existing technologies.

[0066] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0067] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

[0068] Those skilled in the art will understand that the above embodiments are specific embodiments for implementing the present invention, and in practical applications, various changes in form and detail may be made without departing from the spirit and scope of the present invention.

Claims

1. A pyrometer for semiconductor heat treatment, characterized in that, include: Active emissivity measurement module, temperature measurement module, and logic circuit; The active emissivity measurement module is used to emit detection light to the wafer and receive its reflected light to calculate the emissivity; the temperature measurement module is used to receive the thermal radiation light from the wafer to calculate the temperature. The logic circuit is used to receive signals from the active emissivity measurement module and the temperature measurement module, and to calculate the emissivity and temperature based on the signals; The active emissivity measurement module and the temperature measurement module share at least some optical path components.

2. The pyrometer according to claim 1, characterized in that, The active emissivity measurement module includes: A pulsed light source, used to emit pulsed light of a specific wavelength; A first photodetector is used to monitor the light emission status of the pulsed light source; A beam splitter is disposed in the optical path of the pulse light source to reflect part of the pulse light to the wafer and transmit the reflected light returning from the wafer to the second photodetector. Optical guide elements are used to guide light to and from the wafer; The first reflecting mirror is used to reflect and rectify the pulsed light from the beam splitter to the light guide element, and to rectify the light received by the light guide element from the thermal radiation of the wafer. The second reflector is used to reflect and bundle the reflected light from the beam splitter to the second photodetector; The first filter is positioned between the pulsed light source and the beam splitter. A second filter is disposed between the beam splitter and the second reflector. The first filter and the second filter are used to select light in a specific wavelength band. The logic circuit calculates the reflectivity of the wafer by comparing the pulse light intensity information received by the first photodetector and the second photodetector, and then calculates the emissivity.

3. The pyrometer according to claim 2, characterized in that, The temperature measurement module shares the optical guide element, first reflector, beam splitter, second filter, second reflector, and second photodetector with the active emissivity measurement module; The thermal radiation light from the wafer passes sequentially through the optical guide element, the first reflector, the beam splitter, the second filter, and the second reflector, and is received by the second photodetector. The logic circuit, in conjunction with the measured emissivity and thermal radiation intensity, calculates the temperature of the wafer using the blackbody radiation formula.

4. The pyrometer according to claim 2, characterized in that, The optical centers of the light guide element, the first reflector, the beam splitter, the second filter, the second reflector, and the second photodetector are located on the first straight line; The optical centers of the pulsed light source, the first filter, the beam splitter, and the first photodetector are located on the second straight line; The first line is perpendicular to the second line.

5. The pyrometer according to claim 3, characterized in that, The emissivity ε is calculated using the formula ε = 1 - τ - ρ, where τ is the transmittance and ρ is the reflectivity. The blackbody radiation formula is expressed as follows: Where, μ λ (λ, T) represents the thermal radiation intensity of an object at temperature T at a detection wavelength λ, where λ is the detection wavelength, T is the object temperature, h is Planck's constant, c is the speed of light, and k is Boltzmann's constant.

6. The pyrometer according to claim 2, characterized in that, The pulsed light source is an infrared LED light source with a working wavelength range of 800-1000nm.

7. The pyrometer according to claim 2, characterized in that, The logic circuit includes a signal processing unit, which is one of a lock-in amplifier, a Boxcar averager, or a resonant amplifier, used to extract the intensity of the pulsed light from the signal of the second photodetector.

8. The pyrometer according to claim 2, characterized in that, The logic circuit includes an optoelectronic component module and an I / O and logic circuit module; The optoelectronic component module includes analog front-ends of the first photodetector and the second photodetector, used to receive optical signals and convert them into electrical signals; The I / O and logic circuit module is configured to calculate the temperature by comparing the pulse light intensity information received by the first photodetector and the second photodetector, and to implement a data communication interface with external devices and receive external configuration commands.

9. A method for measuring wafer temperature and emissivity using a pyrometer as described in any one of claims 1 to 8, comprising: The active emissivity measurement module is controlled to emit pulsed light toward the back of the wafer and the intensity of its reflected light is detected. The reflectivity of the wafer is calculated based on the intensity of the reflected light. And calculate the emissivity based on the reflectivity; The temperature measurement module detects the intensity of continuous light emitted by the wafer's thermal radiation. The temperature of the wafer is calculated using the blackbody radiation formula based on the emissivity and the continuous light intensity.

10. A semiconductor heat treatment apparatus, characterized in that, include: The system includes a reaction chamber, a heating lamp assembly for heating the wafer, a support mechanism for supporting and rotating the wafer, a main controller, and at least one pyrometer as described in any one of claims 1 to 8, wherein the main controller is communicatively connected to the pyrometer and is used to send configuration instructions to the pyrometer and receive wafer temperature and emissivity data from the pyrometer.

11. The semiconductor heat treatment apparatus according to claim 10, characterized in that, The heating lamp assembly is divided into multiple controllable heating zones, and multiple high-temperature gauges are provided, each corresponding to a wafer below one of the multiple heating zones for measurement. The device is configured to perform independent closed-loop temperature control on the corresponding heating zone based on the temperature measured by each pyrometer.

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