Temperature drop control method and temperature drop control system

Abstract

The invention discloses a temperature drop control method and a temperature drop control system. The temperature drop control method comprises the following steps: determining a temperature value of a to-be-cooled part; under the condition that the temperature value is larger than a first threshold value, a cooling device is controlled to work at preset power, and the first threshold value is larger than a preset value; under the condition that the temperature value is smaller than the first threshold value and larger than the preset value, the cooling device is controlled to be switched from the preset power to the first power to work, and the first power is smaller than the preset power; and under the condition that the temperature value is equal to or smaller than a preset value, controlling the cooling device to stop working. According to the temperature drop control method, the problem that the process effect of a part of silicon wafers is poor due to the fact that the temperature drop of the part of silicon wafers cannot meet the requirement when the current silicon wafers are all cooled based on the same cooling standard can be solved.

Description

Technical Field

[0001] This application belongs to the field of semiconductor processing technology, specifically relating to a temperature drop control method and a temperature drop control system. Background Technology

[0002] In the fabrication of semiconductor devices such as silicon wafers, the process temperature is typically relatively high. Therefore, after the process is complete, the silicon wafer generally needs to be cooled. Currently, fans are commonly used to provide air cooling for the silicon wafers. In this cooling process, it is generally assumed that the cooling is complete after the fan operates at its rated speed for a preset time. However, due to the different processing positions of the silicon wafers within the chamber, their processing temperatures often vary. For example, the processing temperature of silicon wafers located at the opening and tail of the chamber is usually lower than that of silicon wafers located in the middle of the chamber. Therefore, cooling silicon wafers at different processing positions under the same cooling standard can easily lead to some silicon wafers failing to meet the required temperature drop, resulting in poor processing performance for those wafers. Summary of the Invention

[0003] The purpose of this application is to provide a temperature drop control method and a temperature drop control system to solve the problem that current silicon wafers are all cooled based on the same cooling standard, which easily leads to some silicon wafers failing to meet the temperature drop requirements, resulting in poor process performance of these silicon wafers.

[0004] In a first aspect, embodiments of this application disclose a temperature drop control method, which includes: Determine the temperature value of the component to be cooled; When the temperature value is greater than a first threshold, the cooling device is controlled to operate at a preset power, wherein the first threshold is greater than the preset value; When the temperature value is less than the first threshold and greater than the preset value, the cooling device is controlled to switch from the preset power to the first power, wherein the first power is less than the preset power; When the temperature value is equal to or less than the preset value, the cooling device is controlled to stop working.

[0005] Secondly, this application discloses a temperature drop control system, which includes a support frame, a cooling device, a temperature detection device, and a controller. The cooling device includes a fan, and both the fan and the temperature detection device are mounted on the support frame. The component to be cooled can be supported on the support frame, and the fan is positioned facing the component to be cooled. The temperature detection device is used to detect the temperature of the component to be cooled, and both the fan and the temperature detection device are connected to the controller. The controller uses the above-mentioned temperature drop control method to control the fan.

[0006] This application discloses a temperature drop control method. In the temperature drop control process, the temperature value of the component to be cooled is first determined. Then, based on the specific conditions of the determined temperature value, the actual operation of the cooling device is controlled accordingly. Specifically, when the temperature of the component to be cooled is relatively high, specifically greater than or equal to a first threshold, the cooling device can be controlled to operate at a preset power to efficiently and rapidly reduce the temperature of the component. As the temperature of the component continues to decrease, if the temperature of the component is lower than the first threshold but still greater than the preset value, the cooling device can be controlled to switch from the preset power to the first power to reduce the operating efficiency of the cooling device. This ensures that the cooling device can still provide normal cooling to the component while reducing energy consumption. Then, when the temperature of the component to be cooled is equal to or less than the preset value, it is considered that the temperature of the component has met the cooling requirements. At this point, the cooling device can be controlled to stop operating, and subsequent processes can begin.

[0007] As described above, in the temperature drop control method disclosed in this application embodiment, the temperature of the component to be cooled can be detected, and if the temperature of the component to be cooled meets the wafer removal temperature requirement, the cooling operation on the component to be cooled will no longer continue. This ensures that even if there are differences in temperature at different locations in the process cavity after the process is completed, the cooling of each silicon wafer can still meet the requirements. At the same time, in the process of controlling the temperature of the component to be cooled using the temperature drop control method disclosed in this application embodiment embodiment, the power and other operating parameters of the cooling device can be controlled according to the temperature of the component to be cooled. This ensures that the cooling device can provide the required cooling effect while making the energy consumption of the cooling device relatively lower, thereby reducing the overall cost of the cooling process. Attached Figure Description

[0008] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic flowchart of the temperature drop control method disclosed in the embodiments of this application; Figure 2 This is a schematic diagram of the temperature drop control system disclosed in the embodiments of this application; Figure 3 This is a schematic diagram of the temperature drop control system disclosed in an embodiment of this application from another direction; Figure 4 This is a schematic diagram of a portion of the structure of the temperature drop control system disclosed in the embodiments of this application.

[0009] Figure label: 110-Bearing frame, 120-First mounting frame, 130-Second mounting frame, 210-Fan, 220-Flow detection element, 230-Pressure detection element, 240-Infrared camera, 300-Gas collection cylinder, 410-Silicon boat, 420-Silicon wafer, 510-First rheostat, 520-Second rheostat, 611-First drive motor, 612-Second drive motor, 621-First connecting block, 622-Second connecting block, 631-First lead screw, 632-Second lead screw. Detailed Implementation

[0010] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0011] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0012] like Figure 1 As shown in the embodiments of this application, a temperature drop control method is disclosed. During the cooling process of a silicon wafer 420 that has completed the process, the temperature drop control method disclosed in this application can be used to control the equipment used to cool the silicon wafer 420. Specifically, the aforementioned equipment can be a temperature drop control system. To facilitate the introduction of the temperature drop control method disclosed in the embodiments of this application, this article first introduces the structure and composition of the aforementioned temperature drop control system.

[0013] like Figures 2-4 As shown, the temperature drop control system includes a support frame 110, cooling devices, a temperature detection device, and a controller. The support frame 110 is used to support the silicon wafer 420 to be cooled. Of course, the support frame 110 can also serve as the mounting base for other components in the temperature drop control system. The specific structure and dimensions of the support frame 110 can be flexibly selected according to the actual situation, and this paper does not impose any restrictions on them.

[0014] Meanwhile, to improve the efficiency of the processing and cooling processes, multiple silicon wafers 420 can typically be carried together on a silicon boat 410. This allows for simultaneous processing and cooling of the multiple silicon wafers 420 on the silicon boat 410 during the processing and cooling processes. Therefore, during the cooling process, the silicon boat 410 can be supported on a support frame 110, and the silicon boat 410 can carry multiple silicon wafers 420. The multiple silicon wafers 420 carried on the same silicon boat 410 are distributed sequentially and at intervals along the length of the silicon boat 410. Of course, the structure and dimensions of the support frame 110 can be designed so that the support member 110 can support one or more silicon boats 410 together. As for the arrangement of multiple silicon boats 410 on the support frame 110, in a specific embodiment of this application, the multiple silicon boats 410 can be distributed in a direction perpendicular to their own length direction, which facilitates the assembly of multiple silicon boats 410 on the support frame 110. Alternatively, the multiple silicon boats 410 can be arranged in other ways on the support frame 110. This is not limited in this document.

[0015] In this embodiment, the temperature difference range of the multiple silicon wafers 420 carried on the same silicon boat 410 can be used to determine whether to cool all the silicon wafers 420 carried on the same silicon boat 410 simultaneously. For example, when the temperature difference between different silicon wafers 420 carried on the same silicon boat 410 is relatively small, all the silicon wafers 420 carried on the same silicon boat 410 can be cooled simultaneously, so that multiple silicon wafers 420 on the same silicon boat 410 correspond to the same or the same group of cooling devices. Conversely, when the temperature difference between different silicon wafers 420 carried on the same silicon boat 410 is relatively large, the multiple silicon wafers 420 carried on the same silicon boat 410 can be assigned to different cooling devices, or the multiple silicon wafers 420 can be cooled in batches. Accordingly, when there are multiple silicon boats 410, the temperature difference range of the silicon wafers 420 on the multiple silicon boats 410 can also be used to determine whether to cool each silicon wafer 420 on the multiple silicon boats 410 simultaneously.

[0016] The cooling device in the temperature reduction control system includes a fan 210, which uses the airflow generated by the fan 210 to remove heat from the silicon wafer 420, thereby cooling the silicon wafer 420. The temperature detection device can be an infrared thermometer. Taking the silicon wafer 420 as an example, the temperature detection device detects the temperature of the silicon wafer 420 to be cooled. During the assembly of the temperature reduction control system, both the fan 210 and the temperature detection device can be mounted on the support frame 110. As mentioned above, the silicon wafer 420 to be cooled can also be supported on the support frame 110. In this case, by directing the fan 210 towards the silicon wafer 420, the fan 210 can continuously replace the air around the silicon wafer 420, thereby cooling the silicon wafer 420.

[0017] Meanwhile, the temperature detection device can detect the temperature of the silicon wafer 420 waiting to be cooled, and both the fan 210 and the temperature detection device are connected to the controller, so that the controller can control the temperature detection device and the fan 210, and then the controller controls the operating parameters of the fan 210 according to the temperature value detected by the temperature detection device based on the temperature drop control method disclosed in the embodiments of this application.

[0018] Based on the above, such as Figure 1 As shown, the temperature drop control method disclosed in this application includes: S1. Determine the temperature value of the component to be cooled; as above, the component to be cooled can be silicon wafer 420, and the temperature drop control system includes a temperature detection device. Therefore, the temperature detection device can be used to detect the temperature of silicon wafer 420, the component to be cooled.

[0019] After determining the temperature value of the component to be cooled, the operation of the cooling device can be determined and controlled accordingly based on the actual temperature of the component. Specifically, after step S1 above, the temperature drop control method further includes: S2. When the temperature value is greater than or equal to the first threshold, control the cooling device to work at a preset power, wherein the first threshold is greater than the preset value; S3. When the temperature value is less than the first threshold and greater than the preset value, control the cooling device to switch from the preset power to the first power, wherein the first power is less than the preset power; S4. When the temperature value is equal to or less than the preset value, control the cooling device to stop working.

[0020] That is, in the temperature drop control method disclosed in this application, a temperature threshold can be preset. The preset temperature threshold includes a preset value and a first threshold. When the temperature of the component to be cooled is equal to or less than the preset value, it is considered that the temperature of the component to be cooled meets the requirements for wafer removal. In this case, cooling of the component to be cooled can be stopped, and subsequent wafer removal processes can be performed. However, when the temperature of the component to be cooled is greater than the preset value, it is considered that the component to be cooled still needs to continue the cooling process. During this process, the power and other operating parameters of the cooling device can be determined based on the actual temperature of the component to be cooled.

[0021] Specifically, when the temperature of the component to be cooled is greater than or equal to a first threshold, it is considered that the temperature of the component to be cooled is still relatively high. In this case, it is necessary to ensure that the cooling device has a high cooling efficiency for the component to be cooled. For this purpose, the cooling device can be controlled to operate at a preset power. However, when the temperature of the component to be cooled is less than the first threshold but still greater than the preset value, since the temperature of the component to be cooled has already decreased and the temperature difference with the surrounding environment has decreased, a higher wind speed will not significantly improve the cooling efficiency of the component to be cooled per unit time compared to a lower wind speed. Therefore, in this embodiment, when the temperature of the component to be cooled is less than the first threshold but greater than the preset value, the power of the component to be cooled can be reduced to significantly reduce the power consumption of the cooling device while ensuring that the cooling device can still provide normal cooling and meet the required cooling efficiency. This also significantly reduces the energy waste of the cooling device, thereby significantly reducing the cost in the cooling process.

[0022] Specifically, this paper does not impose any restrictions on the specific selection values ​​of the first threshold and the preset value, as well as the preset power and the first power. Of course, it is necessary to ensure that the first threshold is greater than the preset value and the preset power is greater than the first power.

[0023] This application discloses a temperature drop control method. In the temperature drop control process, the temperature value of the component to be cooled is first determined. Then, based on the specific conditions of the determined temperature value, the actual operation of the cooling device is controlled accordingly. Specifically, when the temperature of the component to be cooled is relatively high, specifically greater than or equal to a first threshold, the cooling device can be controlled to operate at a preset power to efficiently and rapidly reduce the temperature of the component. As the temperature of the component continues to decrease, if the temperature of the component is lower than the first threshold but still greater than the preset value, the cooling device can be controlled to switch from the preset power to the first power to reduce the operating efficiency of the cooling device. This ensures that the cooling device can still provide normal cooling to the component while reducing energy consumption. Then, when the temperature of the component to be cooled is equal to or less than the preset value, it is considered that the temperature of the component has met the cooling requirements. At this point, the cooling device can be controlled to stop operating, and subsequent processes can begin.

[0024] As described above, in the temperature drop control method disclosed in this application embodiment, the temperature of the component to be cooled can be detected, and if the temperature of the component to be cooled meets the wafer removal temperature requirement, the cooling operation on the component to be cooled will no longer be continued. This ensures that even if there are differences in temperature after the completion of the process, the cooling of each silicon wafer 420 processed at different locations in the process cavity can meet the requirements. At the same time, in the process of controlling the temperature of the component to be cooled using the temperature drop control method disclosed in this application embodiment, the power and other operating parameters of the cooling device can be controlled according to the temperature of the component to be cooled. This ensures that the cooling device can provide the required cooling effect while making the energy consumption of the cooling device relatively lower, thereby reducing the overall cost of the cooling process.

[0025] To further balance the cooling efficiency and power consumption of the cooling device, in this embodiment, the temperature range between the preset value and the first threshold can be further finely divided. Specifically, the temperature threshold can also include a second threshold, which is greater than the preset value and less than the first threshold. Based on this, in the temperature drop control method disclosed in this embodiment, step S3 above may include: S31. When the temperature value is less than the first threshold and greater than the second threshold, control the cooling device to switch from the preset power to the first power.

[0026] When the temperature threshold includes the second threshold mentioned above, the temperature drop control method disclosed in this application embodiment may further include: S5. When the temperature value is less than or equal to the second threshold and greater than a preset value, the cooling device is controlled to switch from the first power to the second power, wherein the second power is less than the first power. That is, in this embodiment, the temperature range of the component to be cooled includes the range greater than or equal to the first threshold, the range between the first and second thresholds, the range between the second threshold and the preset value, and the range equal to or less than the preset value. Correspondingly, the operating states of the cooling device include preset power, first power, second power, and power of 0.

[0027] When adopting the embodiments of this application, the power and other operating parameters of the cooling device can be controlled more precisely according to the temperature of the component to be cooled, thereby preventing a large waste of power consumption of the cooling device.

[0028] Furthermore, in practical applications, the temperature threshold can be further divided into a third threshold, a fourth threshold, etc., depending on the specific difference between the first threshold and the preset value. Correspondingly, the power of the cooling device can also include a third power, a fourth power, etc., thereby further refining the temperature range of the cooling device and the operating parameters of the cooling device, and further optimizing the overall cooling efficiency of the cooling device and the overall power consumption of the cooling device.

[0029] As described above, in the temperature drop control method disclosed in this application embodiment, the power and other operating parameters of the cooling device can be controlled according to the temperature of the component to be cooled. Optionally, the fan 210 of the cooling device can be a device with speed adjustment capability. Considering that axial flow fans used in industry usually do not have speed adjustment capability, the temperature drop control system disclosed in this application embodiment can also include a variable resistance device, and the variable resistance device is connected in series with the fan 210. At the same time, the variable resistance device is connected to the controller, so that the controller can use the variable resistance device to control the current flowing into the fan 210, thereby achieving the purpose of controlling the power and speed of the fan 210.

[0030] Based on this, in the temperature drop control method disclosed in the embodiments of this application, step S3 above may include: S32. When the temperature value is less than a first threshold but greater than a preset value, the cooling device switches from a preset power to a first power by increasing the resistance of the variable resistor to a first preset resistance value. As mentioned above, since the voltage of the power supply connected to the cooling device cannot be changed, in this embodiment, to switch the cooling device to the first power, the current flowing through the fan 210 of the cooling device needs to be reduced. Therefore, in this embodiment, the resistance value in the entire circuit can be increased to reduce the current flowing through the fan 210 while keeping the voltage constant. Specifically, the variable resistor may include a sliding rheostat or other devices, and the variable resistor may be connected to a controller so that the controller can adjust the resistance value of the variable resistor connected to the circuit to control the power of the fan 210.

[0031] In the above embodiments of this application, the temperature threshold may also include a second threshold, and the operation of the cooling device may be controlled accordingly based on the second threshold. Therefore, step S5 may include: S51. When the temperature value is less than or equal to the second threshold and greater than the preset value, the cooling device switches from the first power to the second power by increasing the resistance of the variable resistor to the second preset resistance value. Similarly, during the process of controlling the cooling device to switch to the second power, the total resistance in the circuit can be increased by correspondingly controlling the resistance value of the entire circuit through the variable resistor, thereby reducing the current flowing through the fan 210 and thus reducing the power of the fan 210 accordingly.

[0032] In addition, in the above embodiments, when the cooling device is switched to the first power, the above-mentioned variable resistor device can be used to achieve this purpose. In this process, the resistance of the variable resistor device is the first preset resistance value. Since the first power is greater than the second power, the second preset resistance value is greater than the first preset resistance value in this embodiment. Of course, the specific values ​​of the second preset resistance value and the first preset resistance value can be flexibly selected according to the actual situation, and this article does not limit them.

[0033] Accordingly, the temperature drop control system disclosed in this application embodiment can, based on the temperature drop control method disclosed in the above embodiment, enable the controller to control the variable resistor according to the temperature detection value, thereby changing the power of the fan 210.

[0034] Furthermore, in the temperature drop control system disclosed in this application embodiment, the variable resistor device includes a first variable resistor 510 and a second variable resistor 520. In order to reduce the difficulty of adjustment while improving the adjustment accuracy, in this application embodiment, the range of the first variable resistor 510 can be greater than the range of the second variable resistor 520, and the scale division of the second variable resistor 520 can be smaller than the scale division of the first variable resistor 510. Therefore, when the resistance value of the variable resistor device needs to be adjusted, the first variable resistor 510 and the second variable resistor 520 can be used simultaneously to adjust the resistance value. Of course, in the case of adopting this application embodiment, when the resistance value of the variable resistor device needs to be adjusted, it is usually necessary to control the resistance value of the first variable resistor 510 to change. For the second variable resistor 520, it is possible to select whether to control the resistance value of the second variable resistor 520 connected in the circuit according to the specific situation of the total resistance value to be adjusted.

[0035] More specifically, for mounting the variable resistor, the temperature drop control system disclosed in this application embodiment may further include a first mounting bracket 120 and a second mounting bracket 130, both mounted on the support frame 110. The first variable resistor 510 can be mounted on the first mounting bracket 120, and the second variable resistor 520 can be mounted on the second mounting bracket 130. Furthermore, as mentioned above, both the first variable resistor 510 and the second variable resistor 520 can be sliding rheostats. Based on this, in order for the controller to control the resistance changes of the first variable resistor 510 and the second variable resistor 520 according to actual needs, in this application embodiment, the temperature drop control system may further include a first drive motor 611 and a second drive motor 612, both of which can be linear motors. By connecting their respective drive rods to the sliders of the first variable resistor 510 and the second variable resistor 520 respectively, the controller can control the resistance changes of the first variable resistor 510 and the second variable resistor 520 by controlling the driving distance and direction of the first drive motor 611 and the second drive motor 612 respectively.

[0036] In another embodiment of this application, both the first drive motor 611 and the second drive motor 612 can be rotary motors. In this case, in order to achieve the purpose of changing the resistance values ​​of the first rheostat 510 and the second rheostat 520, the temperature drop control system may further include a first connecting block 621, a second connecting block 622, a first lead screw 631, and a second lead screw 632. The first lead screw 631 and the second lead screw 632 are respectively connected to the first drive motor 611 and the second drive motor 612, and the first lead screw 631 and the second lead screw 632 also form a helical engagement relationship with the first connecting block 621 and the second connecting block 622, so that when the first lead screw 631 and the second lead screw 632 rotate with the first drive motor 611 and the second drive motor 612, the first connecting block 621 and the second connecting block 622 can be driven to make linear motion. Based on this, by connecting the first connecting block 621 and the second connecting block 622 to the sliders of the first rheostat 510 and the second rheostat 520 respectively, it can be ensured that the first drive motor 611 and the second drive motor 612 can change the resistance value of the first rheostat 510 and the second rheostat 520 in the circuit by means of rotation drive.

[0037] As described above, the temperature drop control system includes a temperature detection device, which may specifically include an infrared thermometer. In the temperature drop control method disclosed in the above embodiments, the temperature measured by the infrared thermometer can be used as the temperature of the component to be cooled. Furthermore, in this embodiment, since the cooling device includes a fan 210, and the fan 210 causes a relatively high gas flow speed, and due to the relatively high temperature of the silicon wafer 420, the gas flow will have a certain impact on the temperature detection result of the infrared thermometer, resulting in a difference between the temperature measured by the infrared thermometer and the actual temperature of the silicon wafer 420. This will adversely affect the control accuracy of the temperature drop control method. Therefore, in this embodiment, the actual temperature of the component to be cooled can be determined by utilizing the temperature change.

[0038] In detail, step S1 above includes: S11. Determine the temperature values ​​T1 and T2 of the component to be cooled at the first and second time points, respectively. Specifically, a temperature detection device can be used to detect the temperature of the component to be cooled to obtain the temperature values ​​of the component at the two time points. Of course, as mentioned above, the temperature values ​​obtained by the temperature detection device are measured values ​​and may differ from the actual temperature values. Therefore, in this application, step S1 further includes: S12. Determine the temperature change ΔT of the component to be cooled between the first and second time points to determine the temperature value T of the component, where T = 2T² - T₁ + ΔT. Specifically, ΔT is the true value of the temperature difference between the component to be cooled at the first and second time points. Furthermore, taking the measurement error of the temperature detection device between the first and second time points as Δδ as an example, the actual temperature value T at the second time point should be T² + Δδ. Correspondingly, since Δδ = T² - T₁ + ΔT, the actual temperature value T of the component to be cooled at the second time point should be 2T² - T₁ + ΔT.

[0039] As mentioned above, the main factor causing errors in the temperature measurement results of the temperature detection device on the cooling component is the gas flow. Therefore, in a specific embodiment of this application, the temperature change can be determined based on parameters such as gas flow rate. Specifically, step S12 may include: Based on the flow rate, pressure, cross-sectional area, mass, and volume of the gas downstream of the component to be cooled, determine the temperature change ΔT of the component to be cooled between the first and second time points.

[0040] Specifically, to determine the specific values ​​of the flow rate parameters of the gas downstream of the component to be cooled, the structure of the temperature drop control system can be further designed to make the flow rate and other parameters of the gas flowing through the component controllable and obtainable. More specifically, the temperature drop control system may include a gas collection cylinder 300, which can be installed on the support frame 110 and positioned on the side of the component to be cooled away from the fan 210. This allows the gas flowing through the component to flow outwards via the gas collection cylinder 300, enabling the gas collection cylinder 300 to collect the parameters of the gas flowing through the component. The gas downstream of the component to be cooled refers to the gas that flows through the component and into the gas collection cylinder 300.

[0041] More specifically, the projection of the gas collection cylinder 300 in a plane perpendicular to the axis of the fan 210 can be made to coincide with the cross section of the gas collection cylinder 300 cut by the plane. This makes the gas collected by the gas collection cylinder 300 more representative of the gas flowing through the component to be cooled. Thus, by using the corresponding parameters of the gas that has completed heat exchange with the component to be cooled and flows into the gas collection cylinder 300 located downstream of the component to be cooled, the temperature change ΔT of the component to be cooled between the first time point and the second time point can be determined.

[0042] As described above, any silicon boat 410 can carry multiple silicon wafers 420. Therefore, it is usually necessary to process multiple silicon wafers 420 on the silicon boat 410 together. In this case, in order to improve the cooling efficiency of the silicon wafers 420, in this embodiment of the application, a gas collection cylinder 300 can be used in conjunction with multiple components to be cooled (i.e., multiple silicon wafers 420), and the projections of the multiple components to be cooled corresponding to the gas collection cylinder 300 in the above-mentioned plane are all located inside the gas collection cylinder 300, so that the gas that has been overheated and exchanged with the multiple silicon wafers 420 can basically flow into the gas collection cylinder 300 after passing through the silicon wafers 420.

[0043] It should be noted that, firstly, multiple silicon wafers 420 mounted on the same silicon boat 410 can be simultaneously positioned with the same gas collection cylinder 300 and undergo a cooling process. If the temperature difference between multiple silicon wafers 420 at different positions on the same silicon boat 410 is relatively large, then the multiple silicon wafers 420 can also be positioned with different gas collection cylinders 300, or the multiple silicon wafers 420 can undergo a cooling process in batches. Secondly, when there are multiple silicon boats 410, if the temperature difference between all silicon wafers 420 on the multiple silicon boats 410 is relatively small, then the multiple silicon wafers 420 on each of the multiple silicon boats 410 can also be simultaneously positioned with the same gas collection cylinder 300. In this case, the projections of each component to be cooled on the multiple silicon boats 410 corresponding to the gas collection cylinder 300 in the aforementioned plane can all be located inside the gas collection cylinder 300.

[0044] When the temperature drop control system adopts the above structure, based on the following relationship between gas flow rate and temperature: Q = m × V × ΔT / (P × A), the value of the temperature change ΔT can be determined after measuring the relevant gas parameters. Here, Q represents the gas flow rate, m represents the gas mass, V represents the gas volume, P represents the gas pressure, and A represents the cross-sectional area of ​​the gas flow. Accordingly, in the temperature drop control system, a flow detection element 220 and a pressure detection element 230 can also be provided. Both are installed in the gas collection cylinder 300, and both the flow detection element 220 and the pressure detection element 230 are connected to the controller so that the controller can use the temperature drop control method disclosed in the above embodiments of this application to control the flow detection element 220 and the pressure detection element 230, so as to realize the purpose of detecting the flow rate and pressure of the gas flowing through the gas collection cylinder 300 with a known cross-sectional area and volume. In this way, the controller can determine the temperature change of the part to be cooled between the first time point and the second time point based on the type of gas introduced during the cooling process. Simply put, △T=(Q×P×A) / (m×V).

[0045] As described above, multiple silicon wafers 420 may be processed simultaneously in the same process. Therefore, during the cooling process, it may be necessary to cool the multiple silicon wafers 420 separately or in batches. Specifically, because the multiple silicon wafers 420 are located at different positions during the process, their temperatures may differ. Therefore, to ensure that the cooling accuracy of the multiple silicon wafers 420 is relatively high, as described above in the embodiments of this application, such as... Figure 4 As shown, the temperature control system can include multiple fans 210 to cool multiple silicon wafers 420 separately. It should be noted that one fan 210 can still cool at least two of the multiple silicon wafers 420. That is, the number of fans 210 does not necessarily need to be the same as the number of silicon wafers 420.

[0046] Correspondingly, there are multiple gas collection tubes 300, flow detection devices 220 and pressure detection devices 230. Multiple gas collection tubes 300 are set up one-to-one with multiple fans 210. Each gas collection tube 300 is equipped with a flow detection device 220 and a pressure detection device 230 to detect the flow rate and pressure in the corresponding gas collection tube 300.

[0047] In this case, multiple fans 210, multiple flow sensors 220, and multiple pressure sensors 230 are all connected to the controller to input the detected flow and pressure values ​​in each gas collection cylinder 300 to the controller. The controller, based on the detection values ​​of the flow sensors 220 and pressure sensors 230 corresponding to each gas collection cylinder 300, controls the power and speed of the fan 210 corresponding to each gas collection cylinder 300 by controlling the resistance value of the variable resistor connected to the corresponding fan 210 according to the temperature drop control method disclosed in the above embodiments of this application, thereby ensuring that the cooling accuracy of one or more silicon wafers 420 corresponding to each gas collection cylinder 300 is relatively high.

[0048] Considering that infrared temperature measuring devices can typically only measure the specific temperature value at a single point on the component to be cooled, and that the temperature at different locations on the same silicon wafer 420 may differ due to the influence of the process environment, this embodiment of the application can measure the temperature at multiple locations on the silicon wafer 420 and use the average temperature of these multiple locations on the same component to be cooled as the temperature measurement value of the component at a certain point in time, thereby further improving the temperature drop control accuracy. Therefore, in the temperature drop control method disclosed in this embodiment of the application, the above step S11 may include: S111. Determine the average temperature of multiple target locations on the component to be cooled at a first time point as T1, and determine the average temperature of multiple target locations on the component to be cooled at a second time point as T2. Of course, to obtain the temperature values ​​of multiple target locations on the component to be cooled, the temperature reduction control system disclosed in this application embodiment can be equipped with multiple temperature detection devices, and these multiple temperature detection devices can be used to detect the temperature of each of the multiple target locations on the component to be cooled. Correspondingly, multiple temperature detection devices can be connected to a controller, so that the controller can obtain the temperature measurement values ​​of each of the multiple temperature detection devices, and control the operation of the cooling device accordingly based on the average value of the multiple temperature measurement values.

[0049] In order to make the temperature measurement value closer to the actual temperature value of the component to be cooled, in the embodiments of this application, the above step S111 may include: S1111: Acquire infrared images of the component to be cooled at the first and second time points, respectively; S1112. Based on the proportional relationship of gray values ​​between pixels in each infrared image and the temperature detection value of at least one pixel in each infrared image corresponding to the position on the component to be cooled, determine the average values ​​T1 and T2 of the temperatures of multiple target positions on the component to be cooled at the first time point and the second time point, wherein the multiple target positions include the positions corresponding to each pixel in the infrared image of the component to be cooled on the component to be cooled.

[0050] That is, in the embodiments of this application, an infrared image of the entire component to be cooled can be captured, and based on the grayscale contrast relationship between each pixel in the image, the equivalent temperature value at each pixel in the entire infrared image can be determined using the known measured temperature values ​​of one or more pixels. Then, the average temperature value at each pixel of the component to be cooled in the infrared image can be used as the temperature measurement value of the entire component to be cooled, which can further improve the ability of the measured temperature value to characterize the overall temperature of the component to be cooled.

[0051] Of course, in this embodiment of the application, in order to obtain an infrared image of the component to be cooled, the temperature detection device in the temperature drop control system disclosed in this embodiment of the application may include an infrared camera 240 and a temperature detection element. The infrared camera 240 is capable of capturing an overall infrared image of the component to be cooled, and the temperature detection element may specifically be an infrared thermometer, which can measure the specific temperature value of a certain point on the component to be cooled. During assembly, both the infrared camera 240 and the temperature detection element can be mounted on the support frame 110, with the infrared camera 240 facing the component to be cooled supported on the support frame 110. More precisely, the infrared camera 240 can be facing the position or area on the support frame 110 used to support the component to be cooled, so that when the component to be cooled is supported on the support frame 110, the infrared camera 240 has the ability to capture an infrared image of the component to be cooled. Meanwhile, both the infrared camera 240 and the temperature detection device are connected to the controller, so that the controller can control the infrared camera 240 and the temperature detection device using the temperature drop control method disclosed in the above embodiments of this application. The controller can also determine the equivalent temperature value at each pixel in the image captured by the infrared camera 240 according to the detection position and detection temperature of the temperature detection device, and then determine the average temperature value of the part to be cooled at a certain time point.

[0052] It should be noted that in the above embodiments, if the component to be cooled is a silicon wafer 420, multiple silicon wafers 420 are usually cooled simultaneously during the cooling process. In this case, the average of the average temperatures of the multiple silicon wafers 420 corresponding to the same fan 210 can be used as the standard value for whether the operating parameters of the cooling device need to be changed. Of course, in this case, there may be cases where the average temperature of a certain silicon wafer 420 is greater than or less than the temperature value used as the standard for changing the operating parameters of the cooling device. However, since the multiple silicon wafers 420 on the silicon boat 410 corresponding to the same fan 210 are basically in roughly the same position during the process, the temperature differences of the aforementioned multiple silicon wafers 420 are usually relatively small. Therefore, even if the average temperature of a certain silicon wafer 420 is greater than or less than the temperature value used as the standard, it will not have an adverse effect on the performance of the silicon wafer 420, and it will not cause a significant increase in the power consumption of the cooling device.

[0053] More specifically, a floating-point algorithm can be used to determine the grayscale value Y of each pixel in the infrared image, where Y = wr*Mr + wg*Mg + wb*Mb, where w is the weight of different color channels, M is the matrix of extracted different color channels, and r, g, and b represent the red, green, and blue channels, respectively. The typical weights for each color are wr = 0.299, wg = 0.587, and wb = 0.114. Furthermore, the location of the temperature sensor can be flexibly selected based on the actual situation; for example, a specific location within the central region of the component to be cooled can be chosen.

[0054] In another embodiment of this application, considering that the temperature drop control system typically converts infrared images to grayscale images relatively quickly, in order to maximize the accuracy of determining the equivalent temperature values ​​of each pixel in the infrared image, the temperature at the location corresponding to the position with the highest and lowest grayscale value in the grayscale image can be detected. These two locations should ideally represent the highest and lowest temperatures in the component to be cooled. Based on the temperature measurements at these two locations and the grayscale image, the accuracy of the determined average temperature of the component to be cooled is relatively high. Of course, to further improve the accuracy of the temperature measurement results for the component to be cooled, the measurement accuracy of the temperature detection device used can be relatively high.

[0055] Therefore, step S1112 above may further include: S11121. Based on the proportional relationship of gray values ​​between pixels in each infrared image, and the temperature detection value of the position corresponding to the largest and smallest gray values ​​in each infrared image on the part to be cooled, determine the average temperature T1 and T2 of multiple target positions on the part to be cooled at the first time point and the second time point.

[0056] Of course, in this embodiment, since it is necessary to first acquire an infrared image, and then determine the specific location for temperature measurement on the component to be cooled based on the maximum and minimum grayscale values ​​in the grayscale image converted from the infrared image, and finally determine the average temperature value of the component to be cooled based on the measured temperature value and the grayscale image, the acquisition time points of the infrared image and the specific temperature value do not absolutely coincide. However, since the temperature drop control system processes infrared images relatively quickly, the time interval between acquiring the infrared image and the specific temperature is relatively small. This will not significantly affect the accuracy of the equivalent temperature value of each pixel in the infrared image determined by using the temperature detection values ​​of the locations corresponding to the maximum and minimum grayscale values ​​on the component to be cooled. Therefore, the average value of the aforementioned equivalent temperature value can be considered as the average temperature value of the component to be cooled at the acquisition time of the infrared image.

[0057] As mentioned above, the temperature of the silicon wafer 420 awaiting cooling is usually relatively high after the process is completed, while the cooling environment, i.e., the ambient temperature of the temperature control system, is usually close to or basically close to room temperature. This results in a relatively large temperature difference between the component to be cooled and its surrounding environment. Consequently, when the component to be cooled is first transferred to the temperature control system, determining its temperature using temperature change within a short period of time will lead to a large deviation in the measured temperature value. Therefore, in this embodiment, step S1111 may include: After the component to be cooled is transferred to the temperature drop control system and the cooling device operates for a preset time, infrared images of the component to be cooled are acquired at the first and second time points. In this case, after the component to be cooled is transferred to the temperature drop control system, the temperature of the gas around the component can be made basically uniform after the fan 210 blows on the component for a period of time. Under these circumstances, the accuracy of measuring the temperature of the component to be cooled by measuring the temperature change is relatively high.

[0058] It should be noted that, compared to the time required for the entire cooling process of the component to be cooled, the preset duration is usually relatively small, specifically less than 30 seconds. In a specific embodiment of this application, the preset duration can be 10 seconds. In this case, the temperature difference between the gas surrounding the component to be cooled and the temperature of the component to be cooled can be ensured to no longer be too large, thereby improving the measurement accuracy of the temperature of the component to be cooled. At the same time, even if the fan 210 is controlled to work for the aforementioned preset duration before the temperature detection device detects the temperature of the component to be cooled, it will not significantly hinder the subsequent cooling process of the component to be cooled, and will not significantly reduce the cooling efficiency or significantly increase the power consumption of the cooling device.

[0059] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0060] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A method for controlling temperature drop, characterized in that, include: Determine the temperature value of the component to be cooled; When the temperature value is greater than or equal to a first threshold, the cooling device is controlled to operate at a preset power, wherein the first threshold is greater than the preset value; When the temperature value is less than the first threshold and greater than the preset value, the cooling device is controlled to switch from the preset power to the first power, wherein the first power is less than the preset power; When the temperature value is equal to or less than the preset value, the cooling device is controlled to stop working.

2. The temperature drop control method according to claim 1, characterized in that, In the temperature drop control method, the step of controlling the cooling device to switch from the preset power to the first power when the temperature value is less than the first threshold and greater than the preset value includes: When the temperature value is less than the first threshold and greater than the second threshold, the cooling device is controlled to switch from the preset power to the first power, wherein the first threshold is greater than the second threshold and the second threshold is greater than the preset value; The temperature drop control method also includes: When the temperature value is less than or equal to the second threshold and greater than the preset value, the cooling device is controlled to switch from the first power to the second power, wherein the second power is less than the first power.

3. The temperature drop control method according to claim 1, characterized in that, In the temperature drop control method, the step of controlling the cooling device to switch from the preset power to the first power when the temperature value is less than the first threshold and greater than the preset value includes: When the temperature value is less than the first threshold and greater than the preset value, the cooling device switches from the preset power to the first power by controlling the resistance of the variable resistor to increase to the first preset resistance value.

4. The temperature drop control method according to claim 2, characterized in that, In the temperature drop control method, the step of controlling the cooling device to switch from the first power to the second power when the temperature value is less than or equal to the second threshold and greater than the preset value includes: When the temperature value is less than or equal to the second threshold and greater than the preset value, the cooling device switches from the first power to the second power by controlling the resistance of the variable resistor to increase to the second preset resistance value.

5. The temperature drop control method according to claim 1, characterized in that, In the temperature drop control method, determining the temperature value of the component to be cooled includes: The temperature values ​​T1 and T2 of the component to be cooled are determined at the first time point and the second time point, respectively. The temperature change ΔT of the component to be cooled between the first time point and the second time point is determined to determine the temperature value T of the component to be cooled, where T = 2T2 - T1 + ΔT.

6. The temperature drop control method according to claim 5, characterized in that, In the temperature drop control method, determining the temperature change ΔT of the component to be cooled between the first time point and the second time point includes: Based on the flow rate, pressure, cross-sectional area, mass, and volume of the gas downstream of the component to be cooled, the temperature change ΔT of the component to be cooled between the first time point and the second time point is determined.

7. The temperature drop control method according to claim 5, characterized in that, In the temperature drop control method, determining the temperature values ​​T1 and T2 of the component to be cooled at a first time point and a second time point, respectively, includes: The average temperature of the multiple target positions on the component to be cooled at the first time point is determined to be T1, and the average temperature of the multiple target positions on the component to be cooled at the second time point is determined to be T2.

8. The temperature drop control method according to claim 7, characterized in that, In the temperature drop control method, determining the average temperature of multiple target locations on the component to be cooled at a first time point as T1, and determining the average temperature of the multiple target locations on the component to be cooled at a second time point as T2, includes: Infrared images of the component to be cooled were acquired at the first and second time points, respectively. Based on the proportional relationship of grayscale values ​​between pixels in each infrared image, and the temperature detection value of at least one pixel in each infrared image corresponding to the position on the component to be cooled, the average values ​​T1 and T2 of the temperatures of multiple target positions on the component to be cooled at the first time point and the second time point are determined, wherein the multiple target positions include the positions corresponding to each pixel in the infrared image of the component to be cooled on the component to be cooled.

9. The temperature drop control method according to claim 8, characterized in that, The step of determining the average values ​​T1 and T2 of the temperatures at multiple target locations on the component to be cooled at a first time point and a second time point, based on the proportional relationship of grayscale values ​​between pixels in each infrared image and the temperature detection value of at least one pixel in each infrared image corresponding to the position on the component to be cooled, includes: Based on the proportional relationship of gray values ​​between pixels in each infrared image, and the temperature detection value of the position corresponding to the largest and smallest gray values ​​in each infrared image on the component to be cooled, the average values ​​T1 and T2 of the temperatures at multiple target positions on the component to be cooled at the first time point and the second time point are determined.

10. The temperature drop control method according to claim 8, characterized in that, The step of acquiring infrared images of the component to be cooled at the first time point and the second time point respectively includes: After the component to be cooled is transferred to the temperature drop control system and the cooling device is controlled to work for a preset time, infrared images of the component to be cooled are acquired at the first time point and the second time point, respectively.

11. A temperature drop control system, characterized in that, The temperature drop control system includes a support frame, a cooling device, a temperature detection device, and a controller. The cooling device includes a fan. Both the fan and the temperature detection device are mounted on the support frame. The part to be cooled can be supported on the support frame. The fan is oriented towards the part to be cooled. Both the fan and the temperature detection device are connected to the controller. The controller uses the temperature drop control method according to any one of claims 1, 2, 5, and 7 to control the temperature detection device and the fan.

12. The temperature drop control system according to claim 11, characterized in that, The temperature drop control system further includes a variable resistance device, which is connected in series with the fan and connected to the controller. The controller controls the variable resistance device using the temperature drop control method described in claim 3 or 4.

13. The temperature drop control system according to claim 12, characterized in that, The variable resistor device includes a first variable resistor and a second variable resistor, wherein the range of the first variable resistor is greater than the range of the second variable resistor, and the scale division of the second variable resistor is less than the scale division of the first variable resistor.

14. The temperature drop control system according to claim 11, characterized in that, The temperature drop control system further includes a gas collection tube, a flow detection device, and a pressure detection device. The gas collection tube is installed on the support frame and is located on the side of the component to be cooled away from the fan. The projection of the gas collection tube in a plane perpendicular to the axial direction of the fan coincides with the cross section of the gas collection tube cut by the plane. Both the flow detection element and the pressure detection element are installed in the gas collection cylinder and are connected to the controller. The controller uses the temperature drop control method described in claim 6 to control the flow detection element and the pressure detection element.

15. The temperature drop control system according to claim 14, characterized in that, One gas collection tube is used in conjunction with a plurality of cooling components, and the projections of the plurality of cooling components corresponding to the gas collection tube in the plane are all located inside the gas collection tube.

16. The temperature drop control system according to claim 14, characterized in that, The gas collection cylinders, flow sensors, and pressure sensors are arranged in multiple, one-to-one correspondence. Each gas collection cylinder is used to accommodate the component to be cooled, and each gas collection cylinder is correspondingly equipped with a fan. Each flow sensor, each pressure sensor, and each fan is connected to the controller, and the controller operates based on the detection values ​​of the flow sensor and pressure sensor corresponding to each gas collection cylinder. The temperature drop control method according to claim 6 controls the fan corresponding to each of the gas collection cylinders.

17. The temperature drop control system according to claim 11, characterized in that, The temperature detection device includes an infrared camera and a temperature detection element. Both the infrared camera and the temperature detection element are mounted on the support frame, and the infrared camera is positioned facing the part to be cooled. Both the infrared camera and the temperature detection element are connected to the controller. The controller controls the infrared camera and the temperature detection element using the temperature drop control method according to any one of claims 8-10.

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