Optical measurement system for a semiconductor growth apparatus

Abstract

The utility model provides a kind of optical measuring system for semiconductor growth equipment, including light source piece, substrate, heating device, power supply circuit, heating control circuit, control signal generating device, including second temperature sensor's software over-temperature protection circuit, and including temperature switch piece's hardware over-temperature protection circuit;Light source piece and heating device are all located substrate;Power supply circuit connects heating device to constitute power supply circuit, and including on-off control device;Heating control circuit includes first temperature sensor, main control device and drive control device;The input end of control signal generating device is electrically connected with the output end of main control device and the output end of hardware over-temperature protection circuit, and the output end of control signal generating device is electrically connected with drive control device, and the input end of main control device is electrically connected with software over-temperature protection circuit;First temperature sensor, second temperature sensor and temperature switch piece are located between heating device and light source piece.This application is favorable to improve the measurement precision of reflectivity.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor growth equipment technology, and in particular to an optical measurement system for semiconductor growth equipment. Background Technology

[0002] Semiconductor growth equipment is used to grow semiconductor material layers. During the reaction process, process gases are introduced into the reaction chamber, where the reaction takes place on the substrate to generate the desired thin film material. In the process of controlling material growth in semiconductor growth equipment, the measurement and control system is one of the core components. It provides process quality detection and feedback control for the growth process and is a key device for material production quality control. Measuring reflectivity and temperature are common methods in optical measurement.

[0003] Taking reflectivity measurement as an example, the purpose of reflectivity measurement in semiconductor growth equipment is to calculate the change in the thickness of the grown thin film through the reflectivity curve. The principle is to continuously measure the periodic change in the overall reflectivity caused by multiple reflections and interferences of light of a certain wavelength between the layers of the grown thin film material, thereby calculating the thickness of the grown thin film. Since the detector cannot directly measure the reflectivity, it can only directly measure the reflected power (energy), and the reflectivity is calculated by the ratio of reflected energy to incident energy. Therefore, the measurement accuracy of this system is directly related to the stability of the light source's emission power.

[0004] Currently, semiconductor growth equipment typically uses high-power LEDs as the light source. However, the spectral power curve of LEDs often drifts with temperature, and this drift can significantly impact measurement accuracy in narrow-spectrum light source systems. Current optical measurement systems for semiconductor growth equipment do not yet consider the temperature-dependent peak power drift of LEDs or semiconductor laser sources. This is primarily because semiconductor growth equipment is often required to operate in a constant-temperature environment, with controlled ambient temperature variations. While cleanroom temperatures are generally controlled, this control precision is set based on the overall environmental requirements of the semiconductor growth equipment, failing to meet the temperature stability requirements of optical measurement systems, thus affecting measurement accuracy. Utility Model Content

[0005] The purpose of this invention is to provide an optical measurement system for semiconductor growth equipment, which is beneficial to improving the measurement accuracy of the reflectivity of the substrate in semiconductor growth equipment.

[0006] To achieve the above objectives, the optical measurement system for semiconductor growth equipment of this utility model includes a light source, a substrate, a heating device, a power supply circuit, a heating control circuit, a control signal generation device, a software over-temperature protection circuit including a second temperature sensor, and a hardware over-temperature protection circuit including a temperature switch. The light source is disposed on the substrate and is used to generate and emit a measurement beam. The heating device is disposed on the substrate to heat the light source. The power supply circuit is connected to the heating device to form a power supply loop and includes an on / off control device. The heating control circuit includes a first temperature sensor, a main control device electrically connected to the first temperature sensor, and a drive control device electrically connected to the output terminal of the main control device and the input terminal of the on / off control device. The input terminal of the control signal generation device is electrically connected to the output terminal of the main control device and the output terminal of the hardware over-temperature protection circuit, the output terminal of the control signal generation device is electrically connected to the drive control device, and the software over-temperature protection circuit is electrically connected to the input terminal of the main control device. The first temperature sensor, the second temperature sensor, and the temperature switch are disposed between the heating device and the light source.

[0007] Preferably, the heating device includes a thermally conductive insulating component and a PTC heating element, wherein the PTC heating element is embedded in the thermally conductive insulating component, and the thermally conductive insulating component is attached to the bottom of the substrate.

[0008] Preferably, the thermally conductive insulating component includes a thermally conductive insulating layer, a thermally conductive heat storage layer, and a thermally conductive outer shell, wherein the thermally conductive outer shell, the thermally conductive heat storage layer, and the thermally conductive insulating layer are sequentially arranged from the outside to the inside, and the PTC heating element is embedded in the thermally conductive insulating layer; the thermally conductive heat storage layer includes a thermally conductive skeleton and a heat storage medium filled in the thermally conductive skeleton.

[0009] Preferably, thermally conductive adhesive is provided between the thermally conductive insulating layer and the thermally conductive heat storage layer, and between the thermally conductive heat storage layer and the thermally conductive outer shell.

[0010] Preferably, the first temperature sensor, the second temperature sensor, and the temperature switch are located in the same area and close to the light source.

[0011] Preferably, the software over-temperature protection circuit further includes a first voltage divider resistor, the second temperature sensor and the first voltage divider resistor are connected in series, and the input terminal of the main control device is electrically connected between the second temperature sensor and the first voltage divider resistor.

[0012] Preferably, the hardware over-temperature protection circuit further includes a second voltage divider resistor and a hysteresis comparator, wherein the second voltage divider resistor and the temperature switch are connected in series, and the hysteresis comparator is electrically connected between the second voltage divider resistor and the temperature switch.

[0013] Preferably, the temperature switching device is a temperature-sensitive switch.

[0014] Preferably, the on / off control device is a MOSFET.

[0015] Preferably, the control signal generating device is an AND gate.

[0016] The beneficial effects of the optical measurement system for semiconductor growth equipment described in this utility model are as follows: (1) By adding a heating device and heating control circuit to the light source to control the temperature of the light source, the overall radiation power amplitude decrease caused by the temperature drift of the light source is avoided, as well as the energy loss caused by the right shift of the radiation spectrum, which leads to the reflectivity error. This solves the problem of the peak emission power of the light source drifting with temperature, which helps to reduce or avoid the influence of temperature drift on the reflectivity measurement accuracy and improves the measurement accuracy of the reflectivity of the substrate in the semiconductor growth equipment.

[0017] (2) This application uses a single heating device to generate heat, which is transferred to the light source through the substrate to heat the light source. Compared with the traditional method of using both heating and cooling to control the temperature, the temperature control of the light source in this application is simpler and less expensive.

[0018] (3) This application forms a dual over-temperature protection system including a software over-temperature protection circuit and a hardware over-temperature protection circuit. Through the redundant design of the software over-temperature protection circuit and the hardware over-temperature protection circuit, the risk of "single point of failure" is eliminated, and the system has high reliability. Even if the main control device of the software over-temperature protection circuit or the heating control circuit fails, the hardware over-temperature protection circuit can still provide safety protection.

[0019] (4) The first temperature sensor of the heating control circuit, the second temperature sensor of the software over-temperature protection circuit, and the temperature switch of the hardware over-temperature protection circuit are all located between the heating device and the light source, which can ensure the accuracy of the temperature judgment by the software over-temperature protection circuit and the hardware over-temperature protection circuit. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the beam path of an optical measurement system for a semiconductor growth apparatus according to an embodiment of the present invention.

[0021] Figure 2 This is a schematic diagram of the structure of the first temperature sensor in the optical measurement system for semiconductor growth equipment in some embodiments of the present invention, which is disposed in the heating device.

[0022] Figure 3This is a schematic diagram of the structure of a first temperature sensor, a second temperature sensor, and a temperature switch in an optical measurement system for a semiconductor growth equipment, as shown in some embodiments of the present invention, with the components disposed on a substrate.

[0023] Figure 4 This is a schematic diagram of the circuit connection structure of an optical measurement system for a semiconductor growth equipment in some embodiments of the present invention.

[0024] Figure 5 This is a schematic diagram of the circuit connection structure of the software over-temperature protection circuit and the hardware over-temperature protection circuit in the optical measurement system for semiconductor growth equipment in some embodiments of this utility model.

[0025] Figure 6 This is a schematic diagram showing the relationship between the normalized emission power of the light source and the casing temperature in an optical measurement system for a semiconductor growth equipment according to some embodiments of the present invention.

[0026] Explanation of reference numerals in the attached figures: 1. Light source module; 11. Light source component; 12. Substrate; 13. Heating device; 131. PTC heating element; 132. Thermally conductive insulating component; 14. First temperature sensor; 15. Main control device; 16. Drive control device; 17. Control signal generation device; 1701. Software over-temperature protection circuit; 1702. Hardware over-temperature protection circuit; 171. Second temperature sensor; 172. Temperature switch component; 173. Hysteresis comparator; 174. First voltage divider resistor; 175. Second voltage divider resistor; 18. Power supply circuit; 181. On / off control device; 182. DC power supply; 2. Detection module; 21. Photodetector; 22. Filter; 3. Reaction chamber; 31. Substrate; 32. Window; 33. Base. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art to which this utility model pertains. The terms "comprising" and similar expressions used herein mean that the element or object preceding the word covers the element or object listed following the word and its equivalents, but does not exclude other elements or objects.

[0028] To overcome the problems existing in the prior art, this utility model provides an optical measurement system for semiconductor growth equipment, which is beneficial to improving the measurement accuracy of the reflectivity of the substrate in semiconductor growth equipment.

[0029] In some embodiments of this utility model, reference is made to Figures 1 to 5 The optical measurement system for semiconductor growth equipment includes a light source 11, a substrate 12, a heating device 13, a power supply circuit 18, a heating control circuit (not shown in the figure), a control signal generation device 17, a software over-temperature protection circuit 1701 including a second temperature sensor 171, and a hardware over-temperature protection circuit 1702 including a temperature switch 172. The light source 11 is disposed on the substrate 12 and is used to generate and emit a measurement beam. The heating device 13 is disposed on the substrate 12 to heat the light source 11. The power supply circuit 18 is connected to the heating device 13 to form a power supply loop, and the power supply circuit 18 includes an on / off control device 181. The heating control circuit (not shown in the figure) includes... The device includes a first temperature sensor 14, a main control device 15 electrically connected to the first temperature sensor 14, and a drive control device 16 electrically connected to the output terminal of the main control device 15 and the input terminal of the on / off control device 181; the input terminal of the control signal generation device 17 is electrically connected to the output terminal of the main control device 15 and the output terminal of the hardware over-temperature protection circuit 1702, the output terminal of the control signal generation device 17 is electrically connected to the drive control device 16, and the software over-temperature protection circuit 1701 is electrically connected to the input terminal of the main control device 15; the first temperature sensor 14, the second temperature sensor 171, and the temperature switch 172 are disposed between the heating device 13 and the light source 11.

[0030] The relationship between the emission power of the light source 11 and the ambient temperature is as follows: The peak emission wavelength of the light source 11 is based on room temperature. As the temperature of the outer casing of the light source 11 increases, the peak emission power of the light source 11 decreases, and the overall spectrum shifts to the right (e.g., ...). Figure 6 (As shown). During measurement, to ensure the uniformity of light wavelength and obtain a stable phase difference, a filter 22 is added to the front end of the photodetector 21 for filtering. Therefore, the reflectivity error caused by temperature increase consists of two parts: first, a decrease in the overall radiated power amplitude; and second, energy loss due to the rightward shift of the radiation spectrum. Generally, as the temperature shift increases, the second type of loss increases rapidly and non-linearly, becoming the main component of the measurement error.

[0031] In this application, the first temperature sensor 14 is used to acquire the first current operating temperature of the light source 11; the main control device 15 is connected to the first temperature sensor 14 and is used to acquire the first current operating temperature and send a temperature adjustment command based on the target temperature and the first current operating temperature; the drive control device 16 is electrically connected to the main control device 15 and the on / off control device 181 connected to the heating device 13, respectively, so that the drive control device 16 can control the heating device 13 to heat the light source 11 to the target temperature according to the temperature adjustment command. That is, this application increases the energy available for... The heating device and heating control circuit for heating the light source 11 control the temperature of the housing of the light source 11, so that the light source 11 is kept at a constant temperature or within a narrow temperature range when emitting the measurement beam to ensure the stability of the wavelength range of the output measurement beam. This avoids the decrease in the overall radiation power amplitude caused by the temperature drift of the light source 11, and the energy loss caused by the right shift of the radiation spectrum, which leads to the reflectivity error. It solves the problem of the peak emission power of the light source 11 drifting with temperature, which helps to reduce or avoid the impact of temperature drift on the reflectivity measurement accuracy and improves the measurement accuracy of the reflectivity of the substrate in the semiconductor growth equipment.

[0032] Furthermore, compared to existing technologies where the temperature of the light source 11 in an optical measurement system used in semiconductor growth equipment is controlled at 20ºC~28ºC, and where cooling and heating methods are used alternately, resulting in high system complexity, this application uses a single heating device 13 to generate heat, which is transferred to the light source 11 through the substrate 12 to heat the light source 11. Compared to the conventional method of simultaneously using heating and cooling methods for temperature control, the temperature control of the light source 11 in this application is simpler and less costly.

[0033] In some specific embodiments of this utility model, when the ambient temperature (room temperature) of the light source 11 is 20°C, the target temperature of the light source 11 is set to 25°C (i.e., higher than the ambient temperature). Before use, the heating device 13 operates, and the main control device 15 controls the output power of the drive control device 16 to heat the current operating temperature of the light source 11 (i.e., the outer shell temperature of the light source 11) to the set target temperature of 25°C. When the room temperature fluctuates, for example, if the room temperature drops from 20°C to 18°C, causing the outer shell temperature of the light source 11 to fall below 25°C, the main control device 15 sends a temperature adjustment command to the drive control device 16. The drive control device 16 adjusts the output power according to the temperature adjustment command to control the heating device 13 to heat the light source 11 to reach the set target temperature of 25°C. For example, if the room temperature rises from 20°C to 23°C... When the ambient temperature (the light source 11 itself also generates heat) causes the outer casing temperature of the light source 11 to exceed 25°C, the main control device 15 sends a temperature adjustment command to the drive control device 16. The drive control device 16 adjusts the output power according to the temperature adjustment command to control the heating device 13 to stop heating. Since the room temperature is lower than the outer casing temperature of the light source 11, the outer casing temperature of the light source 11 decreases through heat exchange with the ambient temperature until the set target temperature of 25°C is reached. Thus, constant temperature control of the light source 11 can be achieved using only a single heating device 13.

[0034] In this application, the software over-temperature protection circuit 1701 is electrically connected to the input terminal of the main control device 15, i.e., the second temperature sensor 171 is used to obtain the second current operating temperature of its area. The main control device 15 is connected to the second temperature sensor 171 to obtain the second current operating temperature. After the main control device 15 determines that the second current operating temperature exceeds the preset temperature threshold, it outputs a corresponding control signal to the control signal generation device 17, causing the control signal generation device 17 to output a low-level signal, thereby causing the drive control device 16 to respond and control the on / off control device 181 to disconnect, thus cutting off the power supply circuit of the heating device 13. The response speed is fast, and the preset temperature threshold can be flexibly set according to actual application requirements and ambient temperature, which can effectively prevent the heating device 13 from being damaged by large current, and realize software over-temperature protection for the heating device 13.

[0035] In this application, the main control system, composed of the first temperature sensor 14 and the main control device 15, is responsible for regulating the temperature of the heating device 13 to maintain a stable operating temperature of the light source 11. The software over-temperature protection circuit 1701, composed of the second temperature sensor 171 and the main control device 15, can avoid the risk of a "single point of failure" that may arise from the main control system and the software over-temperature protection circuit 1701 sharing a sensor. That is, if the first temperature sensor 14 is damaged, for example, short-circuited and continuously reports a low temperature, the main control system will incorrectly control the heating device 13 to continue heating. At this time, the second temperature sensor 171 can act as an independent "firewall". When the first temperature sensor 14 fails and causes the heating device 13 to continue heating but reports a low temperature, the temperature of the substrate 12 where the first temperature sensor 14 is located will rise abnormally. After the second temperature sensor 171 detects this temperature abnormality, it will activate the aforementioned software over-temperature protection.

[0036] In this application, the temperature switch 172 is an independent, passive mechanical or shape memory alloy switch (e.g., a normally closed thermal protector). The temperature switch 172 can be selected for use based on the desired preset temperature threshold. The temperature switch 172 is connected to the control signal generation device 17, the drive control device 16, the on / off control device 181, and the heating device 13. Specifically, the temperature switch 172 is connected to the power supply circuit of the heating device 13 to form a hard over-temperature protection system. This system is independent of software, power supply, or the main control device 15, and remains effective even if the main control system completely crashes, ensuring high safety. Furthermore, the structure is simple; detection and execution can be completed simultaneously with a single temperature switch 172, resulting in low cost and high reliability.

[0037] This application establishes dual over-temperature protection, including a software over-temperature protection circuit 1701 and a hardware over-temperature protection circuit 1702. The software over-temperature protection circuit 1701 is responsible for quickly handling abnormal temperature rises; the hardware over-temperature protection circuit 1702 can still handle overheating faults in the event of failure of the software over-temperature protection circuit 1701 or the main control device 15. Through the redundant design of the software over-temperature protection circuit 1701 and the hardware over-temperature protection circuit 1702, the risk of a "single point of failure" is eliminated, resulting in high reliability. Even if the software over-temperature protection circuit or the main control device of the heating control circuit fails, the hardware over-temperature protection circuit can still provide safety protection.

[0038] The first temperature sensor of the heating control circuit, the second temperature sensor of the software over-temperature protection circuit, and the temperature switch of the hardware over-temperature protection circuit in this application are all located between the heating device and the light source, which can ensure the accuracy of temperature judgment by the software over-temperature protection circuit and the hardware over-temperature protection circuit.

[0039] In some embodiments of this utility model, reference is made to Figures 2 to 4The light source 11 is disposed on the top of the substrate 12, and the heating device 13 is disposed on the bottom of the substrate 12.

[0040] In some embodiments of this utility model, reference is made to Figures 1 to 4 The optical measurement system for the semiconductor growth equipment further includes a detection module 2. The light source module 1, consisting of the light source 11, substrate 12, heating device 13, and heating control circuit, generates and emits a measurement beam onto the surface of the substrate 31 within the reaction chamber 3. The detection module 2 collects the light information fed back (reflected or scattered) by the measurement beam. The detection module 2 includes a photodetector 21 and a feedback optical path for the measurement beam, such that the feedback beam is received by the photodetector 21 after being emitted through a filter 22. The filter 22 is configured to allow light of a specific wavelength to pass through and be emitted to the photodetector 21. The photodetector 21 calculates the reflectivity and the growth rate of the thin film on the substrate surface based on the received feedback light information.

[0041] In some embodiments of this utility model, the heating device 13 includes a PTC heating element 131. The PTC heating device 13 has the advantages of low thermal resistance and high heat exchange efficiency. It is an automatic constant temperature and energy-saving electric heating device. Under any application conditions, it will not produce a "red" phenomenon on the surface like electric heating tubes, thereby avoiding safety hazards such as burns and fires.

[0042] In some embodiments of this utility model, the substrate 12 is a heat dissipation substrate.

[0043] In some embodiments of this utility model, the first temperature sensor 14, the second temperature sensor 171, and the temperature switch 172 are located in the same area and are positioned close to the light source 11.

[0044] In some embodiments of this utility model, the first temperature sensor 14, the second temperature sensor 171, and the temperature switch 172 are disposed on the heating device 13.

[0045] In some embodiments of this invention, the first temperature sensor 14, the second temperature sensor 171, and the temperature switch 172 are disposed on the substrate 12. Compared to disposing them within the heating device 13, this helps to avoid inaccurate temperature readings due to uneven heat conduction between the heating device 13 and the substrate 12.

[0046] In some embodiments of this utility model, the main control device 15 and the drive control device 16 are disposed on the substrate 12.

[0047] In some embodiments of this invention, the target temperature is higher than the ambient temperature of the light source 11. By making the outer shell temperature of the light source 11, i.e., the target temperature when emitting the measurement beam, higher than the ambient temperature of the light source 11, it is made unaffected by the external ambient temperature, reducing the dependence of the light source 11 on room temperature, improving the stability of the measurement, and enabling this measurement system to be applicable to reflectivity measurement in a wider range of room temperature environments.

[0048] In some embodiments of this utility model, the second temperature sensor 171 is adjacent to the first temperature sensor 14.

[0049] In some embodiments of this invention, the second temperature sensor 171 is positioned close to the PTC heating element 131, enabling more accurate monitoring of whether the PTC heating element is overheating.

[0050] In other embodiments of this utility model, reference is made to Figure 3 The second temperature sensor 171 is disposed on the substrate 12 and close to the light source 11, which is beneficial for accurately obtaining the second current operating temperature of the light source 11.

[0051] In some embodiments of this utility model, reference is made to Figure 5 The software over-temperature protection circuit 1701 further includes a first voltage divider resistor 174. The second temperature sensor 171 and the first voltage divider resistor 174 are connected in series. The input terminal of the main control device 15 is electrically connected between the second temperature sensor 171 and the first voltage divider resistor 174, which helps to improve the temperature measurement accuracy.

[0052] In some embodiments of this utility model, the temperature switch 172 includes a temperature sensing part and a switching part. The temperature sensing part is in contact with the heating device 13 or the substrate 12. The switching part, i.e., the contact, consists of two electrical terminals (pins or leads) sealed in a housing. The temperature switch 172 is connected to the power supply circuit of the heating device 13. Specifically, the live wire of the main power supply circuit is first led to one electrical terminal of the temperature switch 172, and then a wire is led from the other electrical terminal of the temperature switch 172 to the heating device 13. This allows the current flowing to the heating device 13 to flow through the internal contact of the temperature switch 172. When the temperature exceeds a preset temperature threshold, the contact is opened, and the entire circuit is cut off. The temperature switch 172 does not rely on any electronic signals or programs. Regardless of the state of the main control device 15, as long as the temperature at the location of the temperature switch 172 reaches or exceeds its preset temperature threshold, the temperature switch 172 will automatically and forcibly disconnect the circuit connected in series with it using purely physical principles such as bimetallic strip deformation and shape memory alloy shrinkage. This disconnection is fundamental. Even if the main control device 15 crashes, the software has a bug, or the drive circuit of the drive control device 16 fails, the heating device 13 can still be powered off.

[0053] In some embodiments of this utility model, reference is made to Figure 5 The hardware over-temperature protection circuit 1702 also includes a hysteresis comparator 173, which is connected to the temperature switch 172 and the control signal generation device 17. The hysteresis comparator 173 effectively prevents system oscillation, improves stability, and avoids the vicious cycle of "protection-cooling-restart-reprotection" at the critical temperature point of the heating device 13. It eliminates the "jittering" phenomenon, which is beneficial for improving the protection of the heating device 13, the drive control device 16, and the entire power system, and can greatly extend the equipment's lifespan. The hysteresis comparator 173 forces the temperature control system to undergo a sufficient cooling process before restarting, ensuring that the root cause of the overheating fault (such as poor heat dissipation) has been eliminated, rather than just a temporary decrease in surface temperature, thus improving safety. Furthermore, the hysteresis comparator 173 upgrades a passive, automatically reset hardware over-temperature protection circuit 1702 into an intelligent over-temperature protection system with "memory" and "judgment" capabilities, reducing the burden on the main control device 15. The main control device 15 does not need to use complex software algorithms to determine when it is safe to restart; it only needs to follow the explicit instructions given by the hysteresis comparator 173, simplifying software design and improving response reliability. The specific structure and working principle of the hysteresis comparator 173 are common knowledge in the art and will not be described in detail here.

[0054] In this embodiment, the hysteresis comparator 173 sets upper and lower thresholds to ensure that once protection is triggered, the temperature must drop to a sufficiently low level before resetting, thus preventing the main control device 15 from repeatedly triggering protection, which could lead to system instability or even damage to the equipment. Specifically, the hysteresis comparator 173 monitors the state (on or off) of the temperature switch 172 and treats it as a digital signal. When the temperature switch 172 disconnects due to overheating, the system enters a protection state. At this time, even if the temperature of the heating device 13 or the substrate 12 drops, causing the temperature switch 172 to automatically reset and close, the hysteresis comparator 173 can still judge the current temperature situation. When the temperature drops sufficiently and stably to a "safe temperature" far below its operating point (i.e., crossing the entire hysteresis window of the hysteresis comparator 173), the hysteresis comparator 173 will change its output state. The main control device 15 will only send a command to the drive control device 16 to reconnect the power supply circuit of the heating device 13 after receiving a "safe" signal from the hysteresis comparator 173.

[0055] In some embodiments of this utility model, reference is made to Figure 5 The hardware over-temperature protection circuit 1702 also includes a second voltage divider resistor 175, which is connected in series with the temperature switch 172. The hysteresis comparator 173 is electrically connected between the second voltage divider resistor 175 and the temperature switch 172, which helps to improve the accuracy of temperature measurement.

[0056] In some embodiments of this utility model, the temperature switch 172 is a temperature-sensitive switch.

[0057] In some embodiments of this utility model, reference is made to Figure 1 The incident light generated and emitted by the light source 11 in the light source module 1 enters the surface of the substrate 31 inside the reaction cavity 3 through the window 32. The substrate 31 is placed on the base 33 inside the reaction cavity 3. The light beam is reflected by the surface of the substrate 31, and the reflected light passes through the window 32 of the reaction cavity 3 and then through the filter 22. Finally, the light signal of a specific wavelength band after passing through the filter 22 is detected by the photodetector 21. The photodetector 21 calculates the reflectivity based on the ratio of the reflected energy of the reflected light to the incident energy of the incident light. Specifically, the photodetector 21 detects the reflected light and obtains the reflectivity, which is a conventional technique in the art and will not be elaborated here. The filter 22 is used to allow specific wavelengths to pass through, which greatly suppresses strong background thermal radiation interference and ensures that the photodetector 21 measures an effective reflected signal.

[0058] In some embodiments of this invention, the center wavelength of the filter 22 is adapted to the emission wavelength of the light source 11 at the target temperature, which helps to improve the accuracy of the reflected light detected by the photodetector 21 and improves the signal-to-noise ratio of the measuring device.

[0059] In this embodiment, as the current operating temperature of the light source 11, i.e., the casing temperature, increases, the peak emission power of the light source 11 decreases, and the overall spectrum shifts to the right (e.g., ...). Figure 6 As shown, in order to make the light source 11 unaffected by the external ambient temperature, the dependence of the light source 11 on room temperature is reduced, or the outer casing temperature of the light source 11 during operation, i.e., the target temperature, is set higher than the ambient temperature where the light source 11 is located. Therefore, the center wavelength of the filter 22 is adapted to the emission wavelength of the light source at the target temperature, so as to ensure the accuracy of the reflected light detected by the photodetector 21.

[0060] In some embodiments of this invention, the center wavelength of the filter 22 is consistent with the emission wavelength of the light source at the target temperature, which helps to improve the accuracy of the reflected light detected by the photodetector 21.

[0061] In some embodiments of this invention, the filter 22 is a narrowband filter. Specifically, the bandwidth of the filter 22 is set according to the target temperature of the light source 11, etc. If the bandwidth of the bandpass filter is too wide, it is easy to introduce more noise and affect the measurement accuracy. Under high-temperature measurement, the intensity of thermal radiation is high enough, limiting the bandwidth of the filter 22 to a suitable narrow range can ensure that the emitted effective light signal is sufficient and minimize or avoid the influence of noise. If the operating wavelength range of the photodetector 21 is too narrow, it is not easy to fully utilize the effective signal transmitted by the filter 22, thereby affecting the measurement accuracy.

[0062] In some embodiments of this utility model, the light source 11 includes an LED lamp or a semiconductor laser.

[0063] In some embodiments of this utility model, the substrate 12 is a circuit board, and the circuits of the main control device 15 and the drive control device 16 are all disposed on the circuit board and electrically connected.

[0064] In some embodiments of this utility model, the PTC heating element 131 is composed of a PTC ceramic heating element and an aluminum tube, and the PTC ceramic heating element is made of PTC (Positive Temperature Coefficient) material.

[0065] In some embodiments of this utility model, reference is made to Figures 2 to 4The heating device further includes a thermally conductive insulating component 132, in which the PTC heating element 131 is embedded. The thermally conductive insulating component 132 is attached to the bottom of the substrate 12. This improves the heating effect and heat transfer efficiency of the PTC heating element 131 on the light source 11, and reduces heat loss.

[0066] In some embodiments of this utility model, the heating device 13 further includes an electrode plate, which is disposed on both sides of the PTC heating element 131, and the electrode plate and the PTC heating element 131 are enclosed in the thermally conductive insulating member 132.

[0067] In some embodiments of this invention, the light source 11 is located within the orthographic projection structure of the substrate 12, where the heating device 13 is located. That is, the heating device 13 is located directly below the light source 11, which improves the heating effect and heat transfer efficiency of the heating device 13 on the light source 11 and reduces heat loss.

[0068] In some embodiments of this utility model, reference is made to Figure 4 The power supply circuit 18 further includes a DC power supply 182, the two ends of which are respectively connected to one of the electrode plates of the PTC heating element 131 and one end of the on / off control device 181, and the other end of the on / off control device 181 is connected to the other electrode plate of the PTC heating element 131.

[0069] In some embodiments of this utility model, the thermally conductive insulating component 132 includes a thermally conductive insulating layer, a thermally conductive heat storage layer, and a thermally conductive outer shell. The thermally conductive outer shell, the thermally conductive heat storage layer, and the thermally conductive insulating layer are sequentially arranged from the outside to the inside. The PTC heating element 131 is embedded in the thermally conductive insulating layer, so that the heat generated by the PTC heating element 131 is transferred to the light source component 11 in sequence through the thermally conductive insulating layer, the thermally conductive heat storage layer, the thermally conductive outer shell, and the substrate 12.

[0070] In this embodiment, the thermally conductive insulating layer is used to efficiently transfer heat while maintaining electrical insulation. The thermally conductive and heat-storage layer has high thermal conductivity and high heat storage capacity, meaning it can quickly transfer heat generated by the PTC heating element 131 to the light source 11, and also absorb and store a large amount of heat, releasing it slowly when needed. This thermally conductive and heat-storage layer helps solve the time-space mismatch problem of heat generated by the PTC heating element 131, achieving temperature smoothing, thermal management, and energy recovery. For example, when the power of the PTC heating element 131 is greater than its heat dissipation power or there is excess heat, the layer absorbs and stores the excess heat, preventing a sharp rise in the temperature of the light source 11. When the power of the PTC heating element 131 decreases or there is insufficient heat, the layer releases the stored heat, preventing a sharp drop in the temperature of the light source 11. The thermally conductive outer shell provides support for the heating device 13 and provides a rapid heat conduction path. This application helps ensure the efficient transfer of heat generated by the PTC heating element 131 to the light source 11, thereby improving the heating effect and heat transfer efficiency of the heating device 13 on the light source 11 and reducing heat loss.

[0071] In some embodiments of this invention, the thermally conductive and heat-storing layer includes a thermally conductive framework and a heat-storing medium filled within the framework. The heat-storing medium includes a phase change material, paraffin wax, or fatty acid. The thermally conductive framework provides a rapid heat conduction path, i.e., quickly transferring heat in and out, while the phase change material or heat-storing medium provides a high heat storage capacity, i.e., absorbing and releasing heat.

[0072] In some embodiments of this utility model, the thermally conductive skeleton is made of metal or high thermal conductivity non-metallic material. The metal can be aluminum or copper foam or fin structure, and the high thermal conductivity non-metal can be graphene, carbon nanotubes, expanded graphite, aluminum nitride (AlN), etc.

[0073] In some embodiments of this utility model, the heat-conducting outer shell, the heat-conducting heat storage layer, and the heat-conducting insulating layer are all hollow rectangular or tubular structures. Each of these structures includes a receiving cavity, and the PTC heating element 131 is disposed within the receiving cavity of the heat-conducting insulating layer. Specifically, the radial width of the inner wall of the heat-conducting outer shell matches the radial width of the outer wall of the heat-conducting heat storage layer, the radial width of the inner wall of the heat-conducting heat storage layer matches the radial width of the outer wall of the heat-conducting insulating layer, and the radial width of the inner wall of the heat-conducting insulating layer matches the radial width of the outer wall of the PTC heating element 131.

[0074] In some embodiments of this utility model, the thermally conductive shell is made of metal or a high thermal conductivity non-metallic material; the metal can be aluminum or copper, and the high thermal conductivity non-metal can be graphene, carbon nanotubes, expanded graphite, aluminum nitride (AlN), etc.

[0075] In some embodiments of this utility model, the thermally conductive insulating layer includes a thermally conductive silicone tube, a thermally conductive ceramic tube, a polymer composite tube, or a high thermal conductivity tube, etc.; the thermally conductive silicone tube is made of thermally conductive silicone, the thermally conductive ceramic tube is made of thermally conductive ceramic, the polymer composite tube is made of materials such as polyimide, and the high thermal conductivity tube is made of materials such as alumina ceramic or aluminum nitride ceramic.

[0076] In some embodiments of this invention, thermally conductive adhesive is provided between the thermally conductive insulating layer and the thermally conductive heat storage layer, and between the thermally conductive heat storage layer and the thermally conductive outer shell. This facilitates the efficient transfer of heat generated by the PTC heating element 131 to the light source 11, thereby improving the heating effect and heat transfer efficiency of the heating device 13 on the light source 11 and reducing heat loss.

[0077] In some specific embodiments of this utility model, the first temperature sensor 14 is disposed between the thermally conductive and heat-storing layer and the thermally conductive outer shell, and is disposed on the side close to the light source 11, which helps to avoid the influence of environmental factors on the collected first current working temperature.

[0078] In some other embodiments of this utility model, the first temperature sensor 14 includes a temperature sensor M117W. The temperature sensor M117W has an accuracy of ±0.1°C in the range of 20°C to 70°C, which can accurately track temperature changes and is beneficial to improving measurement accuracy.

[0079] In some embodiments of this utility model, the on / off control device 181 is a MOS transistor, and the main control device 15 includes an MCU main control device. The MCU main control device contains a PWM generator, which enables the output power of the MOS transistor to control the heating of the PTC heating element 131 through the PWM generator, thereby realizing real-time control of the current operating temperature of the light source 11. At the same time, when the external ambient temperature changes slowly, this device can also achieve a temperature control accuracy of ±0.1ºC.

[0080] In this embodiment, the MCU main control device can determine whether to generate a PWM wave with a target duty cycle based on the difference between the target temperature and the first current operating temperature, and control the heating device 13 to heat the light source 11 to the target temperature by switching the MOS transistor on and off under the action of the PWM wave with the target duty cycle.

[0081] In some embodiments of this invention, the control signal generating device is an AND gate.

[0082] In some embodiments of this utility model, the first temperature sensor 14, the second temperature sensor 171, and the temperature switch 172 are fixedly mounted on the heat-conducting outer shell of the heating device 13 or on the substrate 12 near the light source 11 by thermally conductive adhesive, fixing clamps, or screws. That is, a surface-fitting installation method is adopted, which is simple and convenient to install.

[0083] In some other embodiments of this utility model, a slot is provided on the heating device 13 or the substrate 12 near the light source 11, and the temperature sensing heads of the first temperature sensor 14, the second temperature sensor 171 and the temperature switch 172 are inserted into the slot. That is, the first temperature sensor 14, the second temperature sensor 171 and the temperature switch 172 are installed in an embedded manner to ensure the best heat conduction effect.

[0084] In some embodiments of this invention, the temperature control component further includes a power amplifier circuit integrated in the main control device 15 and connected to the first temperature sensor 14, the second temperature sensor 171, and the temperature switch 172. This amplifies the power of the electrical signals from the first temperature sensor 14, the second temperature sensor 171, and the temperature switch 172 without distorting the signals, thereby improving the accuracy of temperature information acquisition.

[0085] Although the embodiments of this utility model have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations fall within the scope and spirit of this utility model as described in the claims. Moreover, the utility model described herein may have other embodiments and can be implemented or realized in various ways.

Claims

1. An optical measurement system for semiconductor growth equipment, characterized in that, include: A substrate and a light source disposed on the substrate for generating and emitting a measurement beam; A heating device is disposed on the substrate to heat the light source component; A power supply circuit, connected to the heating device to form a power supply loop, and including an on / off control device; The heating control circuit includes a first temperature sensor, a main control device electrically connected to the first temperature sensor, and a drive control device electrically connected to the output terminal of the main control device and the input terminal of the on / off control device. The control signal generation device includes a software over-temperature protection circuit for a second temperature sensor and a hardware over-temperature protection circuit including a temperature switch. The input terminal of the control signal generation device is electrically connected to the output terminal of the main control device and the output terminal of the hardware over-temperature protection circuit. The output terminal of the control signal generation device is electrically connected to the drive control device. The software over-temperature protection circuit is electrically connected to the input terminal of the main control device. The first temperature sensor, the second temperature sensor, and the temperature switch are disposed between the heating device and the light source.

2. The optical measurement system for semiconductor growth equipment according to claim 1, characterized in that, The heating device includes a thermally conductive insulating component and a PTC heating element. The PTC heating element is embedded in the thermally conductive insulating component, which is attached to the bottom of the substrate.

3. The optical measurement system for semiconductor growth equipment according to claim 2, characterized in that, The thermally conductive insulating component includes a thermally conductive insulating layer, a thermally conductive heat storage layer, and a thermally conductive outer shell. The thermally conductive outer shell, the thermally conductive heat storage layer, and the thermally conductive insulating layer are sequentially arranged from the outside to the inside. The PTC heating element is embedded in the thermally conductive insulating layer. The thermally conductive and heat-storage layer includes a thermally conductive skeleton and a heat-storage medium filled within the thermally conductive skeleton.

4. The optical measurement system for semiconductor growth equipment according to claim 3, characterized in that, Thermal adhesive is provided between the thermally conductive insulating layer and the thermally conductive heat storage layer, and between the thermally conductive heat storage layer and the thermally conductive outer shell.

5. The optical measurement system for semiconductor growth equipment according to claim 1, characterized in that, The first temperature sensor, the second temperature sensor, and the temperature switch are located in the same area and are positioned close to the light source.

6. The optical measurement system for semiconductor growth equipment according to claim 1, characterized in that, The software over-temperature protection circuit also includes a first voltage divider resistor, the second temperature sensor and the first voltage divider resistor are connected in series, and the input terminal of the main control device is electrically connected between the second temperature sensor and the first voltage divider resistor.

7. The optical measurement system for semiconductor growth equipment according to claim 1, characterized in that, The hardware over-temperature protection circuit also includes a second voltage divider resistor and a hysteresis comparator. The second voltage divider resistor and the temperature switch are connected in series, and the hysteresis comparator is electrically connected between the second voltage divider resistor and the temperature switch.

8. The optical measurement system for semiconductor growth equipment according to claim 1, characterized in that, The temperature switch is a temperature-sensitive switch.

9. The optical measurement system for semiconductor growth equipment according to claim 1, characterized in that, The on / off control device is a MOS transistor.

10. The optical measurement system for semiconductor growth equipment according to claim 1, characterized in that, The control signal generation device is an AND gate.

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