Radio frequency coil temperature tuning apparatus, semiconductor process apparatus, and control method

Abstract

The application provides a radio frequency coil temperature adjusting device, a semiconductor process equipment and a control method, adopts a temperature detection module to obtain a real-time temperature distribution diagram of a radio frequency coil, realizes temperature distribution visualization through the real-time temperature distribution diagram, a temperature adjusting module pre-stores a reference temperature distribution diagram and a temperature-wind speed mapping relationship, calculates temperature differences of corresponding positions in the real-time temperature distribution diagram and the reference temperature distribution diagram, adjusts wind speed of the position according to the temperature difference of the position and the temperature-wind speed mapping relationship when the temperature difference of the position exceeds a preset temperature difference threshold range, compared with single-point temperature measurement, can comprehensively capture problems such as local overheating and uneven heat dissipation of the radio frequency coil, provides reliable data support for accurate temperature control, and avoids the missing detection hidden danger existing in the traditional temperature measurement mode.

Description

Technical Field

[0001] This invention relates to the field of semiconductor process equipment technology, and in particular to a radio frequency coil temperature control device, semiconductor process equipment and control method. Background Technology

[0002] In plasma process equipment, radio frequency coils are the core components that generate high-frequency electromagnetic fields to excite process gases to form plasma.

[0003] When the RF coil is working, it generates significant Joule heating and induced eddy current heating through the high-frequency alternating current. This causes the surface temperature to rise rapidly, which in turn leads to a decrease in process stability. Specifically, the temperature change of the RF coil affects the uniformity of its electromagnetic field distribution, which in turn leads to uneven plasma density and energy distribution, ultimately causing the deterioration of key process indicators such as etching rate and film thickness uniformity.

[0004] The current solution is to place a high-power fan near the RF coil to force cooling through forced convection. However, the fan is usually always on and will continue to run during the idle period of the RF coil. This results in the RF coil being too cold when it is restarted after being idle, which leads to a very obvious first-wafer effect during the process (i.e., after the plasma process equipment is idled, cleaned or maintained, the process results of the first or first few wafers are significantly and systematically deviated from the steady-state mass production). Furthermore, it is difficult to accurately control the operating temperature of the RF coil during the process.

[0005] Therefore, it is necessary to provide a novel radio frequency coil temperature control device, semiconductor process equipment, and control method to solve the above-mentioned problems existing in the prior art. Summary of the Invention

[0006] The purpose of this invention is to provide a radio frequency coil temperature control device, semiconductor process equipment and control method to reduce the first-chip effect and improve the accuracy of temperature control.

[0007] To achieve the above objectives, the radio frequency coil temperature control device of the present invention includes: A temperature detection module is used to acquire a real-time temperature distribution map of the RF coil; and, The temperature regulation module has a pre-stored reference temperature distribution map and temperature-wind speed mapping relationship. It is used to calculate the temperature difference between the real-time temperature distribution map and the corresponding positions in the reference temperature distribution map. When the temperature difference at any position exceeds the preset temperature difference threshold range, the wind speed at that position is adjusted according to the temperature difference at that position and the temperature-wind speed mapping relationship.

[0008] Optionally, the temperature regulation module includes a main cooling module and an auxiliary cooling module. The main cooling module includes at least one air supply unit, which is located above the RF coil and has its air outlet facing the top of the RF coil. This air supply unit forms a downward airflow with a temperature lower than the operating temperature of the RF coil, thereby achieving main cooling of the RF coil. The auxiliary cooling module includes several exhaust units, which are located in the same horizontal arrangement area as the RF coil and are arranged around the RF coil. The air inlets of each exhaust unit face the same circumferential position of the RF coil or different circumferential positions of the RF coil, respectively. These exhaust units independently exhaust air from different areas of the RF coil, discharging the airflow that has absorbed heat from the RF coil, thereby achieving auxiliary cooling of the RF coil.

[0009] Optionally, each of the exhaust units is provided with a guide pipe at its air inlet, and the air inlet of each guide pipe is respectively facing the weak heat dissipation area of ​​the radio frequency coil, and the radial cross-sectional area of ​​the guide pipe gradually decreases along the air outlet direction.

[0010] Optionally, the guide tube is provided with any one of the following: a porous rectification structure, an array rectification structure, a grid rectification structure, a honeycomb rectification structure, and a streamlined guide structure, to suppress airflow turbulence and avoid plasma disturbance.

[0011] Optionally, the temperature regulation module further includes a closed-loop control unit, which is connected to the temperature detection module, the air supply unit, and the exhaust unit. The closed-loop control unit is used to determine the reference temperature of each position of the RF coil according to the reference temperature distribution map and the real-time temperature of each position of the RF coil according to the real-time temperature distribution map, and calculate the temperature difference between the reference temperature and the real-time temperature at each position. When the temperature difference at any position exceeds a preset temperature difference threshold range, the control parameters of at least one of the air supply unit and the corresponding exhaust unit are adjusted according to the temperature difference at that position and the temperature-wind speed mapping relationship, so as to regulate the wind speed at that position.

[0012] Optionally, the temperature regulation module further includes a partitioning unit, which is used to divide the real-time temperature distribution map into a central region and an annular region surrounding the central region, and to divide the annular region into several fan-shaped annular regions to respectively characterize the real-time temperature of the region corresponding to the radio frequency coil, and the air inlet of at least one of the exhaust units faces the position of the radio frequency coil corresponding to the fan-shaped annular region. When the temperature difference between the real-time temperature represented by the central region and the reference temperature at the corresponding position on the reference temperature distribution map exceeds a preset temperature difference threshold range, the closed-loop control unit adjusts the control parameters of the air supply unit according to the temperature difference at that position and the temperature-wind speed mapping relationship, or adjusts the control parameters of the air supply unit and the control parameters of all the exhaust units. When the temperature difference between the real-time temperature represented by the fan-shaped annular region and the reference temperature at the corresponding position on the reference temperature distribution map exceeds a preset temperature difference threshold range, the closed-loop control unit adjusts the control parameters of the exhaust unit corresponding to the fan-shaped annular region based on the temperature difference at that position and the temperature-wind speed mapping relationship.

[0013] Optionally, the temperature regulation module further includes a start-up control unit, which has a preset temperature rise curve. The start-up control unit is used to adjust the control parameters of the air supply unit and the control parameters of each of the exhaust units according to the temperature rise curve.

[0014] Optionally, the air supply unit includes a bladeless fan with an annular air outlet for forming a smooth and uniform downward airflow toward the central region of the radio frequency coil, and the exhaust unit includes a bladed fan.

[0015] Optionally, the temperature detection module includes at least one infrared temperature imaging unit, the bladeless fan is disposed between the infrared temperature imaging unit and the radio frequency coil, and the optical path of the infrared temperature imaging unit passes through the annular opening formed by the air outlet of the bladeless fan.

[0016] Optionally, the RF coil temperature control device further includes a heat-insulating and light-transmitting sheet, which is disposed between the temperature detection module and the RF coil.

[0017] The present invention also provides a semiconductor process apparatus, including the radio frequency coil temperature control device and the radio frequency coil.

[0018] The present invention also provides a control method for the radio frequency coil temperature control device, comprising the following steps: The temperature detection module acquires a real-time temperature distribution map of the RF coil; The temperature regulation module calculates the temperature difference between the real-time temperature distribution map and the corresponding position in the reference temperature distribution map. When the temperature difference at any position exceeds the preset temperature difference threshold range, the wind speed at that position is adjusted according to the temperature difference at that position and the temperature-wind speed mapping relationship.

[0019] The beneficial effects of this invention are as follows: A temperature detection module is used to obtain a real-time temperature distribution map of the RF coil, which visualizes the temperature distribution. The temperature adjustment module has a pre-stored reference temperature distribution map and a temperature-wind speed mapping relationship. It calculates the temperature difference between the real-time temperature distribution map and the reference temperature distribution map at each corresponding position. When the temperature difference at any position exceeds the preset temperature difference threshold range, the wind speed at that position is adjusted according to the temperature difference and the temperature-wind speed mapping relationship. Compared with single-point temperature measurement, it can comprehensively capture problems such as local overheating and uneven heat dissipation of the RF coil, providing reliable data support for accurate temperature control and avoiding the missed detection risks of traditional temperature measurement methods. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the radio frequency coil temperature control device in some embodiments of the present invention; Figure 2 This is a schematic diagram showing the positional relationship between the radio frequency coil and the exhaust unit in some embodiments of the present invention; Figure 3 This is a schematic diagram of the partitioning of the real-time temperature distribution map in some embodiments of the present invention; Figure 4 This is a comparison chart showing the changes in etching rate during continuous processing of several wafers under different temperature control methods in plasma etching processes.

[0021] Explanation of reference numerals in the attached figures: 10. Temperature detection module; 11. Central area; 12. Annular area; 20. Main cooling module; 30. Auxiliary cooling module; 31. Exhaust unit; 40. Closed-loop control unit; 50. Radio frequency coil; 60. Heat-insulating and light-transmitting sheet. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention 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 invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art. 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 do not exclude other elements or objects.

[0023] In existing technologies, most RF coil cooling solutions employ high-power fans for forced air cooling. These fans operate continuously, leading to over-cooling of the RF coil during extended periods of idle time. The temperature drops significantly below the process adaptation range, resulting in a noticeable first-piece process effect during production, severely impacting product consistency and yield. Furthermore, existing solutions rely on single-point temperature detection, failing to cover the entire temperature distribution of the RF coil. This makes it difficult to detect hidden problems such as localized overheating and uneven heat dissipation, resulting in a lack of comprehensive data support for temperature control decisions and extremely poor control accuracy. Even with fan-temperature linked control, the partial temperature measurement and delayed control can easily lead to uncontrolled coil temperatures, either too low or too high, failing to reliably match the process temperature control requirements of the RF coil.

[0024] To address the problems existing in the prior art, embodiments of the present invention provide a radio frequency coil temperature control device. (Refer to...) Figure 1 and Figure 2 The radio frequency coil temperature control device includes a temperature detection module and a temperature adjustment module. The temperature detection module is used to acquire a real-time temperature distribution map of the radio frequency coil. The temperature adjustment module has a pre-stored reference temperature distribution map and a temperature-wind speed mapping relationship. It is used to calculate the temperature difference between the real-time temperature distribution map and the reference temperature distribution map at each corresponding position. When the temperature difference at any position exceeds a preset temperature difference threshold range, the wind speed at that position is adjusted according to the temperature difference at that position and the temperature-wind speed mapping relationship.

[0025] In this application, a temperature detection module 10 is used to collect the surface temperature of the radio frequency coil 50 and generate a real-time temperature distribution map to visualize the temperature distribution. The temperature adjustment module has a pre-stored reference temperature distribution map and a temperature-wind speed mapping relationship. It calculates the temperature difference between the real-time temperature distribution map and the reference temperature distribution map at each corresponding position. When the temperature difference at any position exceeds the preset temperature difference threshold range, the wind speed at that position is adjusted according to the temperature difference at that position and the temperature-wind speed mapping relationship. Compared with single-point temperature measurement, it can comprehensively capture problems such as local overheating and uneven heat dissipation of the radio frequency coil 50, providing reliable data support for accurate temperature control and avoiding the potential for missed detection in traditional temperature measurement methods.

[0026] Reference Figure 1 and Figure 2The temperature regulation module includes a main cooling module 20 and an auxiliary cooling module 30. The main cooling module 20 includes at least one air supply unit, which is located above the RF coil 50 and has its air outlet facing the top of the RF coil 50. This air supply unit forms a downward airflow with a temperature lower than the operating temperature of the RF coil 50 to achieve main cooling of the RF coil 50. The auxiliary cooling module 30 includes several exhaust units 31, which are located in the same horizontal arrangement area as the RF coil 50 and are arranged around the RF coil 50. The air inlets of each exhaust unit 31 face the same circumferential position of the RF coil 50 or different circumferential positions of the RF coil, so as to independently exhaust different areas of the RF coil 50 to discharge the airflow that has absorbed heat from the RF coil 50, thereby achieving auxiliary cooling of the RF coil 50.

[0027] By actively supplying air through the air supply unit located above the RF coil 50, and synchronously or asynchronously exhausting air through the exhaust units 31 around the RF coil 50, a three-dimensional air-cooling channel with top-down and circumferential airflow is formed. This overcomes the problem of airflow stagnation caused by single air supply or exhaust, accelerates the rapid discharge of hot air from the surface of the RF coil 50, and significantly improves the overall heat dissipation rate, adapting to the high-load and rapid-heating operating characteristics of the RF coil 50. The temperature regulation module, based on the temperature-wind speed mapping relationship and combined with the real-time temperature distribution map, dynamically adjusts the control parameters of the air supply unit and the exhaust unit 31 to adjust... The corresponding wind speed in the area enables on-demand air supply and precise temperature control. This avoids insufficient heat dissipation due to excessively low wind speed, while also preventing energy waste and airflow disturbances that could affect the operation of the RF coil 50 due to excessively high wind speed. This improves the accuracy of temperature control and ensures the operational stability of the RF coil 50. Furthermore, after the RF coil 50 stops working, based on the temperature-wind speed mapping relationship, the air supply unit and exhaust unit 31 will reduce the wind speed flowing through the RF coil 50, thereby reducing the cooling capacity and maintaining the RF coil 50 at a relatively high temperature. This reduces the first-piece effect during process operations.

[0028] In some embodiments, the temperature detection module is disposed on the upper side of the radio frequency coil to collect the operating temperature of the entire surface of the radio frequency coil, so as to form a real-time temperature distribution map characterizing the real-time temperature distribution of the radio frequency coil.

[0029] In some embodiments, the angle between the orientation of the air inlet of each exhaust unit and the tangent at the intersection point of the outermost RF coil may be the same or different. For example, all of them may be 90°, 85°, 30°, etc., or some may be 30° and some may be 40°, etc.

[0030] In some embodiments, the temperature-wind speed mapping relationship is pre-acquired and stored in the temperature control module through experimental calibration, simulation calculation, or data fitting. For example, by calibrating multiple times, the heating power of the RF coil is fixed, and the temperature change amplitude (i.e., temperature difference) of the RF coil after the wind speed changes (wind speed corresponds to the control parameters of the air supply unit and the air exhaust unit) is recorded, establishing a correspondence table between temperature and wind speed, i.e., the mapping relationship between temperature and wind speed; by modeling and analyzing the RF coil and the air-cooling system using fluid simulation software (such as Fluent) and thermal simulation software, the temperature change amplitude of the RF coil after the wind speed changes is obtained, forming a functional relationship or fitting curve between temperature and wind speed, i.e., the mapping relationship between temperature and wind speed.

[0031] In some embodiments, each of the exhaust units is provided with a guide pipe at its air inlet, and the air inlet of each guide pipe is respectively facing the weak heat dissipation area of ​​the radio frequency coil, and the radial cross-sectional area of ​​the guide pipe gradually decreases along the air outlet direction.

[0032] In some embodiments, the weak heat dissipation areas of the RF coil include, but are not limited to, the gaps between the coil windings, the gaps between the coil and the housing, the back of the coil mounting bracket, the vicinity of the coil leads, and locations far from the exhaust unit. Specifically, the gaps between the coil windings, where the coils block each other, cause heat to easily accumulate and are difficult to dissipate, thus forming weak heat dissipation areas of the RF coil; the gaps between the coil and the housing make it difficult for airflow to enter effectively, resulting in a much lower heat dissipation capacity than the center of the coil or exposed areas, thus forming weak heat dissipation areas of the RF coil; the airflow is blocked by the bracket on the back of the coil mounting bracket, forming a low-speed vortex area where heat easily accumulates, thus forming weak heat dissipation areas of the RF coil; the vicinity of the coil leads, such as at the feed point, balun, matching capacitor, etc., has a complex structure that may block airflow and is often a heat source with high ohmic losses, resulting in a high-temperature area that is difficult to dissipate, thus forming weak heat dissipation areas of the RF coil; locations far from the exhaust unit, where the airflow is heated after passing through part of the coil, the temperature of the cooling gas obtained in the downstream area has increased, and the cooling efficiency has decreased, thus forming weak heat dissipation areas of the RF coil.

[0033] This embodiment precisely targets the weak heat dissipation area of ​​the RF coil through the air inlet of the guide tube, achieving directional airflow convergence and purging. This effectively solves the problems of uneven heat dissipation and localized heat accumulation, avoiding the risk of localized overheating of the RF coil. The radial cross-sectional area of ​​the guide tube gradually decreases along the air outlet direction, utilizing the Venturi effect to accelerate the airflow velocity (i.e., wind speed), enhancing the suction force and hot air exhaust rate, significantly improving the heat exchange efficiency of the weak area, and strengthening the local cooling effect. The directional flow guidance structure formed by the guide tube avoids disordered airflow diffusion, making it easier for cool air to concentrate on the parts to be cooled, reducing airflow loss, and reducing the interference of turbulence on the working stability of the RF coil, thus balancing heat dissipation efficiency and equipment operational reliability.

[0034] In some embodiments, the guide tube is provided with any one of a porous rectifying structure, an array-type rectifying structure, a grid-type rectifying structure, a honeycomb-type rectifying structure, and a streamlined guide structure to suppress airflow turbulence and avoid plasma disturbance. Specifically, the porous rectifying structure is any one of a porous sieve plate, a perforated plate, an open-cell foam metal, a foam ceramic, or a bundle tube rectifying structure; the array-type rectifying structure is any one of a regular polygonal honeycomb array, a circular array of rectifier plates, or a streamlined guide vane array; the grid-type rectifying structure is any one of a transverse grid, a longitudinal grid, a staggered grid, a multi-layered stacked grid, or a parallel flow channel structure formed by corrugated plates; the honeycomb rectifying structure is any one of a hexagonal honeycomb plate, a square honeycomb plate, or a rectangular honeycomb plate; and the streamlined guide structure is any one of a streamlined guide vane array, a honeycomb core structure, or a parallel flow channel structure formed by corrugated plates.

[0035] This embodiment effectively suppresses airflow turbulence by setting a rectification structure inside the guide tube, making the airflow through the guide tube more stable and uniform, improving the stability of the heat dissipation airflow and the heat exchange efficiency; the stable and regular airflow can avoid disturbing the plasma, ensuring the stability of the semiconductor process environment, preventing process parameter drift caused by airflow turbulence, and improving process consistency and product yield.

[0036] Reference Figure 1 The temperature regulation module further includes a closed-loop control unit 40. The closed-loop control unit 40 has a preset reference temperature distribution map and a temperature-wind speed mapping relationship. The closed-loop control unit 40 is connected to the temperature detection module 10, the air supply unit, and the exhaust unit 31. The closed-loop control unit is used to determine the reference temperature of each position of the RF coil according to the reference temperature distribution map and the real-time temperature of each position of the RF coil according to the real-time temperature distribution map. It also calculates the temperature difference between the reference temperature and the real-time temperature at each position. When the temperature difference at any position exceeds a preset temperature difference threshold range, the control parameters of at least one of the air supply unit and the corresponding exhaust unit 31 are adjusted according to the temperature difference at that position and the temperature-wind speed mapping relationship to regulate the wind speed at that position.

[0037] This embodiment employs a closed-loop control unit. Based on a real-time temperature distribution map, the real-time temperature of the RF coil is obtained. According to the temperature difference between the real-time temperature and the reference temperature, the control parameters of at least one of the air supply and exhaust units are dynamically adjusted to regulate the airflow speed in the corresponding area. This achieves precise closed-loop control of the RF coil temperature, ensuring that the RF coil's operating temperature remains stable within the required process range. It can adaptively adjust the cooling intensity (i.e., airflow speed) based on the temperature difference, preventing the RF coil temperature from becoming too high or too low, ensuring the stability and consistency of the plasma process, and effectively suppressing the first-chip effect. By flexibly adjusting the control parameters of at least one of the air supply and exhaust units to regulate the airflow speed in the corresponding area, the temperature control response speed and control accuracy are improved, enhancing the system's temperature control reliability and meeting the stringent requirements of semiconductor plasma equipment for RF coil temperature control.

[0038] In some embodiments, the reference temperature can be the average temperature of the current RF coil or a preset operating temperature. The reference temperature is 60°C to 150°C. For example, the reference temperature is 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, or 150°C, or any value between any two of the aforementioned temperature values.

[0039] In some specific embodiments, the preset temperature difference threshold range is -5℃ to 10℃.

[0040] In some embodiments, taking the reference temperature of the RF coil as 105°C as an example, when the real-time temperature of the RF coil is 160°C, the temperature difference is +45°C. Assuming that in the temperature-wind speed mapping relationship, when the temperature difference is +45°C, the wind speed of the air supply unit increases by 1 m / s, the closed-loop control unit adjusts the control parameters of the air supply unit to increase the wind speed from the original 1.5 m / s to 2.5 m / s.

[0041] In some embodiments, taking the reference temperature of the RF coil as 105°C as an example, when the real-time temperature of the RF coil is 165°C, the temperature difference is +50°C. Assuming that in the temperature-wind speed mapping relationship, when the temperature difference is +50°C, the wind speed of the exhaust unit increases by 0.5 m / s, and the closed-loop control unit increases the wind speed of the exhaust unit from the original 1 m / s to 1.5 m / s.

[0042] In some embodiments, taking a reference temperature of 105°C for the RF coil as an example, when the real-time temperature of the RF coil is 178°C, the temperature difference is +73°C. Assuming that in the temperature-wind speed mapping relationship, when the temperature difference is +73°C, the wind speed of the air supply unit increases by 1.5 m / s, the wind speed of the exhaust unit increases by 1 m / s, the closed-loop control unit increases the wind speed of the air supply unit from the original 1.5 m / s to 3 m / s, and the closed-loop control unit increases the wind speed of the exhaust unit from the original 1 m / s to 2 m / s.

[0043] In some embodiments, taking the reference temperature of the radio frequency coil as 105°C as an example, when the real-time temperature of the radio frequency coil is 50°C, the temperature difference is -55°C. Assuming that in the temperature-wind speed mapping relationship, when the temperature difference is -55°C, the wind speed of the air supply unit decreases by 1 m / s, the closed-loop control unit reduces the wind speed of the air supply unit from the original 2.5 m / s to 1.5 m / s. In some embodiments, taking the reference temperature of the radio frequency coil as 105°C as an example, when the real-time temperature of the radio frequency coil is 45°C, the temperature difference is -60°C. Assuming that in the temperature-wind speed mapping relationship, when the temperature difference is -60°C, the wind speed of the exhaust unit decreases by 0.5 m / s, and the closed-loop control unit reduces the wind speed of the exhaust unit from the original 1.5 m / s to 1 m / s. In some embodiments, taking a reference temperature of 105°C for the RF coil as an example, when the real-time temperature of the RF coil is 32°C, the temperature difference is -73°C. Assuming that in the temperature-wind speed mapping relationship, when the temperature difference is -73°C, the wind speed of the air supply unit decreases by 1.5 m / s, the wind speed of the exhaust unit decreases by 1 m / s, the closed-loop control unit reduces the wind speed of the air supply unit from the original 3 m / s to 1.5 m / s, and the closed-loop control unit reduces the wind speed of the exhaust unit from the original 2 m / s to 1 m / s.

[0044] In some embodiments, reference is made to Figure 3 The temperature regulation module further includes a partitioning unit, which is used to divide the real-time temperature distribution map into a central region 11 and an annular region 12 surrounding the central region 11, and further divide the annular region 12 into several fan-shaped annular regions (e.g., 16 fan-shaped annular regions, a1~a16) to respectively characterize the real-time temperature of the region corresponding to the RF coil, and the air inlet of at least one of the exhaust units faces the position of the RF coil corresponding to the fan-shaped annular region; when the temperature difference between the real-time temperature characterized by the central region 11 and the reference temperature at the corresponding position of the reference temperature distribution map exceeds a preset temperature difference threshold range, the closed-loop control unit adjusts the control parameters of the air supply unit according to the temperature difference at that position and the temperature-wind speed mapping relationship, or adjusts the control parameters of the air supply unit and the control parameters of all the exhaust units; when the temperature difference between the real-time temperature characterized by the fan-shaped annular region and the reference temperature at the corresponding position of the reference temperature distribution map exceeds a preset temperature difference threshold range, the closed-loop control unit adjusts the control parameters of the exhaust unit corresponding to that fan-shaped annular region according to the temperature difference at that position and the temperature-wind speed mapping relationship.

[0045] This embodiment divides the real-time temperature distribution map into a central region 11 and an annular region 12, which includes several fan-shaped annular regions, through partitioning units, achieving refined and regionalized monitoring of the RF coil temperature distribution. Differentiated control strategies are adopted for temperature anomalies in different regions. When the central region 11 is abnormal, the entire region is controlled, while when the fan-shaped annular regions are abnormal, individual control is applied. This achieves precise temperature control in different zones and eliminates local overheating at specific points, avoiding energy waste and temperature over-adjustment caused by uniform control across the entire region. The system can independently adjust the airflow speed of the corresponding exhaust unit according to the actual temperature requirements of each local region, significantly improving the targeting, response speed, and uniformity of temperature control. This effectively improves the temperature uniformity of the entire RF coil, ensuring the stability of the plasma process and product yield, while also suppressing the first-chip effect.

[0046] In some embodiments, the temperature regulation module further includes a start-up control unit. The start-up control unit has a preset temperature rise curve and is used to adjust the control parameters of the air supply unit and each of the exhaust units according to the temperature rise curve. By adjusting the wind speed according to the preset temperature rise curve, the start-up control unit can precisely control the heating rate and trajectory of the RF coil, ensuring that the RF coil temperature rises steadily and controllably to the reference temperature, avoiding sudden temperature increases or fluctuations. This achieves programmed and intelligent preheating control during the equipment startup phase, effectively solving the first-piece effect caused by uneven heating of the RF coil, and ensuring that the plasma process remains stable and consistent from the first piece. Dynamic matching of the air cooling intensity (i.e., wind speed) according to the temperature rise curve avoids excessive cooling or insufficient heat dissipation during startup, improving the response stability and process repeatability of the temperature control system, and enhancing the reliability of equipment operation.

[0047] In some embodiments, the temperature rise curve is pre-established and stored in the start-up control unit through experimental calibration, numerical simulation fitting, and equipment debugging verification. For example, during the equipment debugging phase, a gradually increasing steady-state power is applied to the RF coil, and the wind speed timing data required for the RF coil to smoothly rise to the reference temperature (60℃~150℃) under different initial temperatures and different load conditions are recorded. Based on multiple sets of experimental data, an ideal temperature rise trajectory curve, i.e., the temperature rise curve, is established to reflect the temperature change with the number of wafers, and a corresponding wind speed matching strategy is determined for different numbers of wafers. Another example is the use of fluid simulation software (such as Fluent) and thermal simulation tools to perform three-dimensional modeling of the RF coil, airflow, and heat dissipation structure. By applying a gradually increasing heat load, the temperature rise process under different wind speed combinations is simulated, and the optimal temperature rise rate, temperature rise slope, and wind speed at each stage are fitted to form a digital temperature rise curve model, i.e., the temperature rise curve.

[0048] In some specific embodiments, the temperature rise curve specifically includes three stages: the process stages of the first and second wafers, the process stages of the third and fourth wafers, and the process stages of the fifth and sixth wafers. The start-up control unit dynamically adjusts the airflow speed of the air supply unit and the exhaust unit in stages according to this temperature rise curve. Figure 4 Taking the third curve c as an example, the etching rates of the six wafers are similar, and the first-wafer effect is significantly improved. The specific process is as follows: During the process stages of the first and second wafers, the RF coil temperature is increased from 25°C to 60°C. During this stage, the airflow rate of the air supply unit is maintained at 0.3 m / s, and the airflow rate of the exhaust unit is maintained at 0.8 m / s to ensure that the RF coil heats up slowly, so that the etching rate of the first wafer is maintained at around 2072 and the etching rate of the second wafer is maintained at around 2076. During the process stages of the third and fourth wafers, the RF coil temperature is increased from 60°C to 140°C. According to the temperature rise curve, the start-up control unit increases the air velocity of the air supply unit from 0.3m / s to 1.2m / s at a constant speed, and the air velocity of the exhaust unit from 0.8m / s to 1.8m / s at a constant speed, so that the etching rate of the third wafer is maintained at around 2079 and the etching rate of the fourth wafer is maintained at around 2081. In the process stages of the fifth and sixth wafers, the RF coil temperature is increased from 140°C to 150°C. The start-up control unit controls the wind speed to be adjusted slowly. The wind speed of the air supply unit is finely adjusted from 1.2 m / s to 1.5 m / s, and the wind speed of the exhaust unit is finely adjusted from 1.8 m / s to 2.0 m / s. The etching rate of the fifth wafer is maintained at around 2082, and the etching rate of the sixth wafer is maintained at around 2084.

[0049] Furthermore, refer to Figure 4 The first curve (a) shows the change in inter-wafer etching rate among the six wafers when the fan is constantly running in the prior art. It can be seen that there are significant differences in the inter-wafer etching rates among the six wafers, and the first-wafer effect is very pronounced. The second curve (b) shows the change in inter-wafer etching rate among the six wafers when the fan and RF coil are simultaneously started and stopped in the prior art. It can be seen that there are significant differences in the inter-wafer etching rates among the six wafers. It can be seen that the third curve (c) in the technical solution of this invention significantly improves the inter-wafer etching rate among the six wafers, greatly mitigating the first-wafer effect.

[0050] In some embodiments, the air supply unit includes a bladeless fan with an annular outlet to create a smooth and uniform downward airflow to the central region of the RF coil. The use of an annular outlet bladeless fan in the air supply unit enables a smooth, uniform, and pulsation-free downward airflow to the central region of the RF coil, avoiding airflow disturbances and turbulence caused by traditional bladed fans, reducing interference with the plasma, and ensuring process stability. The uniform airflow to the central region, combined with the exhaust air from the peripheral bladed fans, forms a highly efficient heat dissipation flow field with coordinated vertical and directional airflow, improving overall heat dissipation efficiency and temperature uniformity. The reasonable combination of the bladeless and bladed fans balances overall heat dissipation in the central region with localized heat dissipation in the surrounding areas, ensuring effective heat dissipation while optimizing the structural layout and improving the reliability of the temperature control system.

[0051] In some embodiments, the exhaust unit includes a bladed fan. Using a bladed fan as the exhaust unit is simple and reliable in structure, provides stable exhaust, and can effectively achieve airflow extraction and delivery.

[0052] In some embodiments, when there is one air supply unit, the air supply unit is positioned directly above the center of the radio frequency coil; when there are two air supply units, the two air supply units are symmetrically arranged around the axis of the radio frequency coil; when there are three or more air supply units, one air supply unit is positioned directly above the center of the radio frequency coil, and the remaining air supply units are arranged at equal intervals around the axis of the radio frequency coil.

[0053] In some embodiments, the wind speed can be controlled by adjusting the rotation speed of the bladeless fan and the bladed fan; the correspondence between the wind speed and the fan rotation speed can be obtained and stored in the temperature control module through pre-experimental calibration.

[0054] In some embodiments, reference is made to Figure 1 The temperature detection module 10 includes at least one infrared temperature imaging unit. The bladeless fan is positioned between the infrared temperature imaging unit and the radio frequency coil 50, and the optical path of the infrared temperature imaging unit passes through the annular opening formed by the air outlet of the bladeless fan. By arranging the bladeless fan between the infrared temperature imaging unit and the radio frequency coil 50, infrared light passes through the annular opening of the bladeless fan, preventing the fan body from blocking the infrared temperature measurement path and avoiding interference from the heat of the bladeless fan itself on the infrared temperature imaging unit. This ensures that the infrared temperature imaging unit can clearly and completely acquire the temperature signal across the entire range of the radio frequency coil 50, ensuring accurate and reliable temperature measurement.

[0055] In some embodiments, the sampling frequency of the infrared temperature imaging unit is greater than or equal to 1 time / second.

[0056] In some embodiments, reference is made to Figure 1The radio frequency coil temperature control device further includes a heat-insulating and light-transmitting sheet 60, which is disposed between the infrared temperature imaging unit and the radio frequency coil 50. By placing the heat-insulating and light-transmitting sheet 60 between the infrared temperature imaging unit and the radio frequency coil 50, the high temperature and heat radiation generated when the radio frequency coil 50 is working are blocked, preventing high temperature damage to the infrared temperature imaging unit and improving the working stability and service life of the infrared temperature imaging unit. The heat-insulating and light-transmitting sheet 60 also has light-transmitting characteristics, which does not affect the normal penetration of infrared light, ensuring that the infrared temperature imaging unit can accurately collect the temperature signal of the radio frequency coil 50, taking into account both heat insulation protection and temperature measurement accuracy. It effectively isolates the high temperature environment in the process cavity from the influence of the infrared temperature imaging unit, improves the adaptability and reliability of the system under high temperature conditions, and ensures the long-term stable operation of the temperature control system.

[0057] In some specific embodiments, the heat-insulating and light-transmitting sheet is calcium fluoride. Transmitter, magnesium fluoride Translucent film, sapphire Transparent film, quartz glass (fused silica) transparent film, infrared grade zinc selenide Transparent sheet or infrared grade zinc sulfide Translucent film.

[0058] This invention also provides a semiconductor process apparatus, including the aforementioned radio frequency coil temperature control device and radio frequency coil. The remaining conventional structures of the semiconductor process apparatus can all adopt mature structural forms existing in the art, and will not be described in detail here.

[0059] The present invention also provides a control method for the radio frequency coil temperature control device, comprising the following steps: The temperature detection module acquires a real-time temperature distribution map of the RF coil; The temperature regulation module calculates the temperature difference between the real-time temperature distribution map and the corresponding position in the reference temperature distribution map. When the temperature difference at any position exceeds the preset temperature difference threshold range, the wind speed at that position is adjusted according to the temperature difference at that position and the temperature-wind speed mapping relationship.

[0060] While embodiments of the present invention 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 the invention as set forth in the claims. Furthermore, the invention described herein may have other embodiments and can be implemented or carried out in various ways.

Claims

1. A radio frequency coil temperature control device, characterized in that, include: The temperature detection module is used to obtain the real-time temperature distribution map of the RF coil; as well as, The temperature regulation module has a pre-stored reference temperature distribution map and temperature-wind speed mapping relationship. It is used to calculate the temperature difference between the real-time temperature distribution map and the corresponding positions in the reference temperature distribution map. When the temperature difference at any position exceeds the preset temperature difference threshold range, the wind speed at that position is adjusted according to the temperature difference at that position and the temperature-wind speed mapping relationship.

2. The radio frequency coil temperature control device according to claim 1, characterized in that, The temperature regulation module includes a main cooling module and an auxiliary cooling module. The main cooling module includes at least one air supply unit, which is located above the RF coil and has its air outlet facing the top of the RF coil. This air supply unit forms a downward airflow with a temperature lower than the operating temperature of the RF coil, thereby achieving main cooling of the RF coil. The auxiliary cooling module includes several exhaust units, which are located in the same horizontal arrangement area as the RF coil and are arranged around the RF coil. The air inlets of each exhaust unit face the same circumferential position of the RF coil or different circumferential positions of the RF coil, respectively. These exhaust units independently exhaust air from different areas of the RF coil, discharging the airflow that has absorbed heat from the RF coil, thereby achieving auxiliary cooling of the RF coil.

3. The radio frequency coil temperature control device according to claim 2, characterized in that, Each of the exhaust units is provided with a guide pipe at its air inlet. The air inlet of each guide pipe is directly opposite to the weak heat dissipation area of ​​the radio frequency coil, and the radial cross-sectional area of ​​the guide pipe gradually decreases along the air outlet direction.

4. The radio frequency coil temperature control device according to claim 3, characterized in that, The guide tube is equipped with any one of the following: a porous rectification structure, an array rectification structure, a grid rectification structure, a honeycomb rectification structure, and a streamlined guide structure, to suppress airflow turbulence and avoid plasma disturbance.

5. The radio frequency coil temperature control device according to claim 2, characterized in that, The temperature regulation module further includes a closed-loop control unit, which is connected to the temperature detection module, the air supply unit, and the exhaust unit. The closed-loop control unit is used to determine the reference temperature of each position of the RF coil according to the reference temperature distribution map and the real-time temperature of each position of the RF coil according to the real-time temperature distribution map, and to calculate the temperature difference between the reference temperature and the real-time temperature at each position. When the temperature difference at any position exceeds a preset temperature difference threshold range, the control parameters of at least one of the air supply unit and the corresponding exhaust unit are adjusted according to the temperature difference at that position and the temperature-wind speed mapping relationship, so as to regulate the wind speed at that position.

6. The radio frequency coil temperature control device according to claim 5, characterized in that, The temperature regulation module further includes a partitioning unit, which is used to divide the real-time temperature distribution map into a central region and an annular region surrounding the central region, and to divide the annular region into several fan-shaped annular regions to respectively characterize the real-time temperature of the region corresponding to the radio frequency coil, and the air inlet of at least one of the exhaust units faces the position of the radio frequency coil corresponding to the fan-shaped annular region. When the temperature difference between the real-time temperature represented by the central region and the reference temperature at the corresponding position on the reference temperature distribution map exceeds a preset temperature difference threshold range, the closed-loop control unit adjusts the control parameters of the air supply unit according to the temperature difference at that position and the temperature-wind speed mapping relationship, or adjusts the control parameters of the air supply unit and the control parameters of all the exhaust units. When the temperature difference between the real-time temperature represented by the fan-shaped annular region and the reference temperature at the corresponding position on the reference temperature distribution map exceeds a preset temperature difference threshold range, the closed-loop control unit adjusts the control parameters of the exhaust unit corresponding to the fan-shaped annular region based on the temperature difference at that position and the temperature-wind speed mapping relationship.

7. The radio frequency coil temperature control device according to claim 2, characterized in that, The temperature regulation module also includes a start-up control unit, which has a preset temperature rise curve. The start-up control unit is used to adjust the control parameters of the air supply unit and the control parameters of each of the exhaust units according to the temperature rise curve.

8. The radio frequency coil temperature control device according to claim 2, characterized in that, The air supply unit includes a bladeless fan with an annular air outlet for forming a smooth and uniform downward airflow toward the central area of ​​the radio frequency coil. The exhaust unit includes a bladed fan.

9. The radio frequency coil temperature control device according to claim 8, characterized in that, The temperature detection module includes at least one infrared temperature imaging unit. The bladeless fan is disposed between the infrared temperature imaging unit and the radio frequency coil, and the optical path of the infrared temperature imaging unit passes through the annular opening formed by the air outlet of the bladeless fan.

10. The radio frequency coil temperature control device according to claim 9, characterized in that, It also includes a heat-insulating and light-transmitting sheet, which is disposed between the temperature detection module and the radio frequency coil.

11. A semiconductor process apparatus, characterized in that, It includes the radio frequency coil temperature control device and the radio frequency coil as described in any one of claims 1 to 10.

12. A control method for the radio frequency coil temperature control device as described in any one of claims 1 to 10, characterized in that, Includes the following steps: The temperature detection module acquires a real-time temperature distribution map of the RF coil; The temperature regulation module calculates the temperature difference between the real-time temperature distribution map and the corresponding position in the reference temperature distribution map. When the temperature difference at any position exceeds the preset temperature difference threshold range, the wind speed at that position is adjusted according to the temperature difference at that position and the temperature-wind speed mapping relationship.

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