Inductive coupling device and semiconductor process equipment comprising same

Abstract

The invention provides an inductive coupling device and semiconductor process equipment comprising the same, the inductive coupling device comprises a radio frequency coil arranged on the outer side of a dielectric window, the surface of the radio frequency coil is provided with a silver coating, and the inductive coupling device further comprises a sealing assembly and a gas path assembly; a sealing space is formed between the sealing assembly and the dielectric window so as to accommodate the radio frequency coil in the sealing space, and the sealing assembly is provided with an air inlet port and an air outlet port; the gas circuit assembly is communicated with the gas inlet port and the gas outlet port, and is used for introducing protective gas into the sealed space through the gas inlet port so as to replace air in the sealed space, and enabling the protective gas to circularly flow in the sealed space when the radio frequency coil works; wherein the protective gas does not react with the silver plating layer. The method can solve the problems that the plasma density is reduced, the uniformity is deteriorated and the process stability is reduced.

Description

Technical Field

[0001] This invention relates to the field of semiconductor process equipment technology, and more particularly to an inductive coupling device and semiconductor process equipment including the device. Background Technology

[0002] Plasma technology plays a crucial role in semiconductor manufacturing, applicable to various semiconductor processes such as etching, resist stripping, and thin-film deposition. ICP (Inductively Coupled Plasma) equipment uses a radio frequency (RF) power supply connected to an RF coil to generate an alternating magnetic field within the reaction chamber. This induces a ring current, ionizing the gas within the process chamber and producing high-density plasma.

[0003] However, after a period of use, the stability and uniformity of plasma distribution in existing ICP equipment tend to decrease, and the plasma density also tends to decrease even when conditions such as RF power supply and process gas remain unchanged. Summary of the Invention

[0004] To address the problems of decreased plasma density, deteriorated uniformity, and reduced process stability, this invention provides an improved inductive coupling device and a semiconductor process apparatus incorporating the device.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: The first aspect of the present invention provides an inductive coupling device for coupling radio frequency energy into a process chamber of a semiconductor process equipment through a dielectric window, so as to ionize the process gas in the process chamber into plasma. The inductive coupling device includes a radio frequency coil disposed outside the dielectric window, the surface of the radio frequency coil is provided with a silver plating layer, and the inductive coupling device further includes a sealing component and a gas path component. A sealed space is formed between the sealing assembly and the medium window to house the radio frequency coil within the sealed space, and the sealing assembly is provided with an air inlet port and an air outlet port. The gas path assembly is connected to the air inlet port and the air outlet port, and is used to introduce protective gas into the sealed space through the air inlet port to displace the air in the sealed space, and to make the protective gas circulate in the sealed space when the radio frequency coil is working. The protective gas does not react with the silver plating layer to prevent corrosion of the silver plating layer. The air intake direction of the air intake port is aligned with the central axis of the medium window, tangent to the outer peripheral surface of the medium window, or aligned with the surface of the radio frequency coil.

[0006] Furthermore, the air circuit assembly is controlled by a control assembly and includes an intake pipe, an exhaust pipe, and a recirculation pipe; The output end of the intake pipe is connected to the intake port, and the input end of the intake pipe is connected to the protective gas source. The inlet of the exhaust pipe is connected to the exhaust port; The two ends of the circulation pipeline are respectively connected to the air inlet port and the air outlet port; The control component is configured to control the opening of the intake pipe and the exhaust pipe to introduce the protective gas into the sealed space to displace the air in the sealed space, and to control the closing of the intake pipe and the exhaust pipe after the displacement is completed.

[0007] Furthermore, the circulation pipeline is provided with a circulation drive component for driving the protective gas to circulate in the loop formed by the circulation pipeline and the sealed space; The control component is further configured to control the start and stop of the cycle drive component according to the operating state of the radio frequency coil.

[0008] Furthermore, the output end of the intake pipe is connected to the first branch point of the circulation pipe; The input end of the exhaust pipe is connected to the second branch point of the circulation pipe.

[0009] Furthermore, valves are provided in the intake pipe and the exhaust pipe, wherein the valve in the intake pipe is connected to the control component, and the valve in the exhaust pipe is a one-way valve, the inlet of which is connected to the input end of the exhaust pipe; And / or, the circulation pipeline is provided with a cooling component for cooling the protective gas in the circulation pipeline.

[0010] Furthermore, the inductive coupling device also includes a temperature sensor connected to the control component and used to detect temperature sensing information of the radio frequency coil. The control component is also configured to control the power of the circulating drive component based on the temperature sensing information so that the temperature of the radio frequency coil is maintained within a target temperature range.

[0011] Furthermore, the inductive coupling device also includes a pressure sensing element connected to the control component, which is further configured to control the air pressure within the sealed space based on the detection result of the pressure sensing element.

[0012] Furthermore, the sealing assembly is provided with a plurality of air inlet ports and a plurality of circulation pipes that are connected to each of the air inlet ports in a one-to-one correspondence, and the plurality of air inlet ports are evenly distributed around the radio frequency coil.

[0013] Furthermore, the air intake port and the air exhaust port are respectively located on opposite sides of the sealed space.

[0014] A second aspect of the present invention provides a semiconductor process apparatus, including a process chamber and an inductive coupling device for coupling radio frequency energy into the process chamber through a dielectric window of the process chamber, wherein the inductive coupling device is an inductive coupling device as described above.

[0015] By adopting the above technical solution, the present invention has the following advantages over the prior art: This invention recognizes that one of the fundamental reasons for the decline in plasma density, stability, and uniformity in existing technologies is the irreversible sulfidation and oxidation corrosion of the silver plating layer of the RF coil due to long-term exposure to air. Based on this, this invention constructs a sealed space surrounding the RF coil and designs a gas path assembly to introduce protective gas into the sealed space to displace the air. After displacement, the protective gas circulates within the sealed space, achieving a closed-loop circulation of the protective gas. This ensures the RF coil is completely within the protective gas environment, preventing the silver plating layer from being exposed to the atmosphere, thereby inhibiting sulfidation and oxidation of the silver plating layer. This ensures efficient and stable coupling of RF energy into the process chamber, maintaining the plasma density at its initial high level during long-term operation. Simultaneously, it avoids the problem of uneven plasma density distribution caused by non-uniform corrosion of the silver plating layer, which leads to distortion of the electromagnetic field generated by the coil.

[0016] Moreover, the flowing protective gas helps to remove the heat generated by the radio frequency coil during operation, thus playing the role of actively cooling the coil. Therefore, there is no need to set up an additional fan, eliminating the problem of electromagnetic field disturbances and instantaneous fluctuations in plasma caused by vibration during fan cooling, and further enhancing the overall stability and repeatability of the plasma generation process.

[0017] Furthermore, the present invention has a simple and compact structure, low modification cost compared to existing technologies, and is easy to implement. It not only ensures the establishment of a pure protective atmosphere, but also greatly reduces the continuous consumption of protective gas, thereby improving the system's economy. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of conventional semiconductor process equipment; Figure 2 This is a schematic diagram of one embodiment of the semiconductor process equipment in this invention; Figure 3 This is a schematic diagram of another embodiment of the semiconductor process equipment in this invention. Detailed Implementation

[0019] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0020] It should be noted that the illustrations provided in the embodiments are only schematic representations of the basic concept of the present invention. Although the illustrations only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation, the shape, quantity, positional relationship and proportion of each component in the actual implementation can be changed at will under the premise of realizing the technical solution of the present invention, and the layout of the components may also be more complex.

[0021] like Figure 1 As shown, conventional semiconductor process equipment typically includes a process chamber 20 and an inductive coupling device for coupling radio frequency energy into the process chamber 20 through a dielectric window 21.

[0022] The process chamber 20 is connected to a vacuum device (not shown) via a vacuum channel 22 to evacuate the process chamber 20. A stage 23 for carrying the workpiece 10 to be processed (e.g., a wafer) is disposed inside the process chamber 20 and is connected to the lower electrode RF power supply 24 as the lower electrode. The top of the process chamber 20 is provided with a top plate 25, which includes a central region and an extension 251 surrounding the central region. The central region is provided with an air inlet structure 252, through which process gas can enter the process chamber 20. The dielectric window 21 is cylindrical, with its top sealed to the bottom surface of the central region of the top plate 25 and its bottom sealed to the inner ring of the annular cover plate 26 of the process chamber 20.

[0023] The core of the inductive coupling device is the radio frequency coil 31 outside the dielectric window 21. The radio frequency coil 31 is connected to the upper-stage radio frequency power supply 32 via a matching unit (not shown) to excite and maintain plasma within the process chamber 20. When the radio frequency coil is energized, due to the "skin effect" of the high-frequency radio frequency current, the current will concentrate on the surface of the coil conductor. Therefore, the key to radio frequency transmission lies in the surface of the coil. In order to improve conductivity, reduce radio frequency loss, and reduce cost, the radio frequency coil 31 is usually made of copper and its surface is silver-plated to form a silver plating layer.

[0024] In addition, the inductive coupling device also includes a protective cover 33 mounted on an annular cover 26 of the process chamber 20. This protective cover 33 is located outside the dielectric window 21 and forms a protective space with the dielectric window 21 to protect the RF coil 31 within that space. Figure 1In the device shown, the annular cover 26 seals the bottom of the protective space, and the extension 251 of the top plate 25 (which is disposed opposite to the annular cover 26) forms the top of the protective space. Since the radio frequency coil 31 generates heat during operation and needs to be dissipated, a fan 34 is also provided at the top of the protective space (i.e., the bottom surface of the extension 251). At the same time, through holes are provided on both the extension 251 and the protective cover 33 to allow the fan to generate airflow to remove the heat from the coil.

[0025] However, the inventors noted that after the above-mentioned equipment has been used for a period of time, the stability and uniformity of plasma distribution tend to decrease, and the plasma density tends to decrease even when the process conditions such as RF power supply and process gas remain unchanged.

[0026] Through extensive research, the inventors realized that one of the root causes of the above problems is that, in the aforementioned equipment, because air circulates within the protected space, the silver plating layer on the surface of the radio frequency coil 31 is constantly exposed to the air. This exposure results in a reaction with the combined effects of sulfides (such as hydrogen sulfide and sulfur dioxide), oxygen, and water vapor, generating compounds with high resistivity. Furthermore, due to the "skin effect" of high-frequency radio frequency current, the current concentrates on the surface of the coil. In other words, radio frequency transmission depends on the integrity of the silver plating layer on the coil surface. Once the silver plating layer is corroded, generating sulfides or oxides with even higher resistivity, the following problems will directly occur: (1) Decreased radio frequency energy transmission efficiency (most direct impact) High-frequency radio frequency (RF) current exhibits a "skin effect," meaning the current primarily flows on the surface of the coil. The resistivity of silver sulfide or silver oxide, formed by the corrosion of the silver plating, is much higher than that of pure silver. Therefore, the effective conductivity of the coil surface decreases sharply after corrosion. Consequently, a significant amount of RF power is lost as heat in the coil, rather than being effectively coupled into the process chamber for plasma excitation and maintenance. This directly manifests as reduced RF utilization, requiring higher power input to achieve the original plasma density.

[0027] (2) Decreased plasma density and stability The density and excitation efficiency of the plasma directly depend on the radio frequency energy coupled into the chamber. Due to the decrease in radio frequency energy transmission efficiency, the energy available for ionizing the process gas is reduced. Consequently, the generated plasma density decreases, leading to slower etching or deposition rates, longer process times, and reduced throughput. Furthermore, unstable energy coupling results in plasma instability, making the process uncontrollable and reducing repeatability.

[0028] (3) Process uniformity deteriorates The electromagnetic field distribution generated by the inductively coupled coil determines the uniformity of plasma spatial distribution within the cavity. However, the corrosion of the silver plating layer is often uneven, with areas of severe localized corrosion exhibiting higher resistance, resulting in weakened or distorted magnetic field strength in those areas. This leads to uneven electromagnetic field distribution within the cavity, consequently causing uneven plasma density distribution. On the wafer, this directly manifests as uneven etching or deposition thickness / rate, deterioration of on-wafer uniformity (WIWNU) indicators, and decreased product yield.

[0029] (4) Loss of process repeatability and consistency Semiconductor manufacturing demands extremely high run-to-run consistency in process results, but the etching of silver plating is a process that deteriorates continuously over time. This causes process parameters (such as rate and uniformity) to drift, making it impossible to maintain batch-to-batch consistency. This makes process windows difficult to control, requiring frequent equipment calibration and process verification, increasing maintenance costs and downtime.

[0030] (5) Reduced equipment reliability and increased maintenance costs Additional power loss causes the coil temperature to rise abnormally, which may accelerate the aging of other components (such as dielectric windows and sealing materials). At the same time, the changing coil impedance will put pressure on the RF matching network, causing the matching unit to be adjusted frequently or even fail, reducing system stability.

[0031] Furthermore, the use of fans for cooling generates vibrations, which are transmitted to the RF coils and dielectric windows, causing minute displacements or deformations. This results in slight changes in the coil's position relative to the dielectric window and process chamber, directly altering the spatial distribution of the generated electromagnetic field. Since plasma generation and maintenance are highly dependent on this electromagnetic field, instantaneous disturbances in the field distribution lead to synchronous, high-frequency fluctuations and localized inhomogeneities in the plasma density, further affecting the stability and uniformity of plasma generation.

[0032] To prevent the RF coil from being oxidized or sulfided, the inventors first thought of replacing the silver plating on the surface of the RF coil 31 with a more corrosion-resistant plating (such as a gold plating). However, this would greatly increase the cost and would still not completely eliminate the potential degradation in long-term complex environments, nor would it avoid the impact of fan vibration.

[0033] The inventors discovered that providing a protective gas environment for the RF coil 31 can prevent its silver plating layer from reacting with sulfides, oxygen, water vapor, etc., in the air. Therefore, this invention overturns the existing coil protection approach by constructing a sealed space 30 around the RF coil 31 on a semiconductor process device, equipped with an air inlet and an exhaust port. A gas path assembly is designed to introduce protective gas into the sealed space 30 to displace the air inside. After displacement, the protective gas circulates within the sealed space 30, achieving a closed-loop circulation. This allows the sealed space to be replaced by a protective gas environment that is less likely to react with the silver plating layer. In this environment, because the silver plating layer loses the conditions for oxidation and sulfidation and does not react with the protective gas, corrosion is inhibited at its source, thus ensuring high efficiency of RF transmission and long-term stability of the equipment.

[0034] Most importantly, because the flowing protective gas itself has cooling properties, it can efficiently remove the heat generated when the RF coil 31 is energized while providing protection. This means that the present invention eliminates the need for fans in existing equipment to dissipate heat from the coil, thus completely abandoning the traditional solution that required the introduction of a corrosive medium (air) for heat dissipation. In other words, the flowing protective gas in the present invention simultaneously undertakes the dual tasks of isolating air and dissipating heat, perfectly resolving the inherent contradiction in traditional solutions where the cooling medium (i.e., air) itself is a source of corrosion. At the same time, omitting the fan avoids the adverse effects of mechanical vibration on the plasma, achieving two goals at once.

[0035] As can be seen, this invention achieves reliable protection of the silver plating layer through a disruptive design of "environmental reconstruction" and "functional integration," while avoiding the impact of fan vibration, thereby solving the problems of decreased plasma density, deteriorated uniformity, and reduced process stability. Furthermore, it has lower modification costs compared to existing semiconductor process equipment, requires no changes to the core coil and chamber design, is easy to implement, and the circulating protective gas ensures the establishment of a pure protective atmosphere while significantly reducing the continuous consumption of protective gas, thus improving system economy.

[0036] It should be noted that, in implementing the above-mentioned technical concept, this invention also innovatively proposes the following design: Firstly, by configuring the gas path assembly to include both intake and exhaust pipes, the air within the sealed space can be efficiently replaced with protective gas, ensuring the purity of the protective gas within the sealed space. After replacement, closing the intake and exhaust pipes and circulating the protective gas only through the recirculation pipe reduces protective gas consumption and lowers operating costs, while maintaining a positive pressure environment within the sealed space to prevent outside air from entering. Furthermore, by connecting the intake and exhaust pipes to two branch points of the recirculation pipe, intake, exhaust, and recirculation can be integrated within the recirculation pipe, reducing the number of individual interfaces penetrating the sealing assembly and lowering the sealing difficulty and leakage risk.

[0037] Secondly, a dynamic pressure closed-loop control system and / or temperature closed-loop control system are designed. By setting pressure detection elements and / or temperature sensors to be linked with the control components, the air pressure in the sealed space 30 can be maintained within the required air pressure range, and the radio frequency coil 31 can be maintained within the desired temperature range.

[0038] Thirdly, multiple air inlet ports are arranged around the RF coil 31, each connected to an exhaust port via a circulation pipe, ensuring that the protective gas flows through the sealed space 30 without any dead zones. The air inlet direction of each port can be set to align with the central axis of the dielectric window 21, forming an impinging jet that can quickly remove the heat generated by the RF coil 31. Alternatively, the air inlet direction of each port can be set to be tangential to the outer peripheral surface of the dielectric window 21. This design guides the airflow to rotate and flow near the outer surface of the dielectric window 21. This swirling flow can form a relatively stable and continuously renewed protective gas "sheath" on the coil surface, optimizing the uniformity of protection and heat dissipation. Furthermore, the air inlet ports can also be arranged along the extension direction of the RF coil 31, with the air inlet direction aligned with the surface of the RF coil 31, so that the protective gas flow can directly wash over the heated coil surface, achieving efficient cooling of the RF coil 31.

[0039] In summary, the core of this invention lies in constructing a dynamic, controllable, and cyclical protective gas environment, supplemented by precise closed-loop control and optimized flow field design, thereby achieving a comprehensive improvement in equipment reliability and process stability.

[0040] Based on the above inventive concept, the inductive coupling device and semiconductor process equipment including the device provided by the present invention will be described exemplarily below.

[0041] Example 1 This embodiment provides an inductive coupling device disposed on a process chamber 20 and used to couple radio frequency energy into the process chamber 20 through a dielectric window 21. Figure 2 and Figure 3As shown, the inductive coupling device mainly includes a radio frequency coil 31 disposed outside the dielectric window 21. The radio frequency coil 31 is connected to the upper-stage radio frequency power supply 32 via a matching unit (not shown) to excite and maintain plasma within the process chamber 20. The main body of the radio frequency coil 31 is preferably made of copper. To improve conductivity under the "skin effect" of high-frequency radio frequency current, a silver plating treatment is performed on the surface of the copper coil to form a silver plating layer.

[0042] To prevent the silver plating of the coil from sulfiding and oxidizing in the air, such as Figure 2 and Figure 3 As shown, the inductive coupling device in this embodiment also includes a sealing assembly and a gas path assembly.

[0043] Specifically, a sealed space 30 is formed between the sealing assembly and the dielectric window 21 to house the RF coil 31 within the sealed space 30. The sealing assembly is provided with an inlet port and an exhaust port for air intake and exhaust. The gas path assembly is connected to the inlet and exhaust ports to introduce protective gas into the sealed space 30 through the inlet port, displacing the air within the sealed space 30. After displacing, the protective gas circulates within the sealed space 30 when the RF coil 31 is operating. The protective gas does not react with the silver plating layer to prevent corrosion. This isolates the RF coil 31 from the air, preventing corrosion of the silver plating layer by sulfides, oxygen, etc., thus maintaining the conductivity of the RF coil 31 and ensuring efficient and stable coupling of RF energy into the process chamber 20, thereby maintaining plasma density and process stability. Simultaneously, the circulating protective gas also carries away the heat generated by the RF coil 31 during operation, achieving active cooling and avoiding vibration problems caused by fan cooling, further improving the stability and uniformity of the plasma generation process.

[0044] In this embodiment, the gas path assembly is controlled by a control assembly (not shown) and specifically includes an intake pipe 36, an exhaust pipe 37, and a circulation pipe 38. The output end of the intake pipe 36 is connected to the intake port of the sealing assembly, and the input end of the intake pipe 36 is connected to a protective gas source (not shown) to introduce protective gas into the sealed space. The input end of the exhaust pipe 37 is connected to the exhaust port of the sealing assembly to discharge the gas within the sealed space (e.g., to a tail gas treatment device). The two ends of the circulation pipe 38 are connected to the intake port and exhaust port of the sealing assembly, respectively, to achieve the circulation of gas within the sealed space.

[0045] In this embodiment, in order to create a dynamic protective gas environment within the sealed space, the control component is configured to first open the intake pipe 36 and the exhaust pipe 37 for a period of time to introduce protective gas into the sealed space 30 and displace the air within the sealed space 30. After the displacement is completed, the intake pipe 36 and the exhaust pipe 37 are then closed so that the protective gas circulates within the sealed space 30 via the circulation pipe 38, thereby completely suppressing the oxidation and sulfidation reactions of the silver plating layer from the source.

[0046] In this embodiment, the protective gas is a gas that does not react with the silver plating layer to prevent the silver plating layer from being corroded. Specifically, one of the inert gases such as nitrogen, helium, and argon can be used. Considering cost and safety, nitrogen is the best choice.

[0047] exist Figure 2 In the illustrated implementation, by Figure 1 A sealing cover 35, covering the top plate 25 and the protective cover 33, is fixedly mounted on the annular cover 26 of the process chamber 20 as the aforementioned sealing assembly. The bottom of the sealing cover is sealed by the annular cover 26, and the extension 251 of the top plate 25 has a through hole, allowing gas to flow within the interior of the sealing cover (i.e., the sealed space 30 enclosed by the annular cover 26, the medium window 21, the central area of ​​the top plate 25, and the sealing cover 35). See again... Figure 2 As shown, the output end of the circulation pipeline 38 passes through the sealing cover 35 and the protective cover 33 in sequence to introduce protective gas into the sealed space 30.

[0048] exist Figure 3 In another embodiment shown, by... Figure 1 The top plate 25 and protective cover 33 of the process chamber 20 shown are formed as a sealed structure to serve as the aforementioned sealing assembly, thus eliminating the need for an additional sealing cover 35. In this case, the aforementioned protective space is formed as a sealed space 30.

[0049] Preferably, such as Figure 2 and Figure 3 As shown, the output end of the intake pipe 36 is connected to the first branch point P of the circulation pipe 38; the input end of the exhaust pipe 37 is connected to the second branch point Q of the circulation pipe 38. By connecting the intake pipe 36 and the exhaust pipe 37 to the two branch points of the circulation pipe 38 respectively, the intake, exhaust, and circulation paths are integrated on the circulation pipe 38, reducing the number of interfaces that individually penetrate the sealing assembly, and lowering the sealing difficulty and leakage risk.

[0050] Preferably, the circulation pipeline 38 is provided with a circulation drive component 381 connected to the control component, which drives the protective gas to flow in the loop formed by the circulation pipeline 38 and the sealed space 30. The control component can be configured to control the start and stop of the circulation drive component 381 according to the operating state of the RF coil 31, so that the protective gas circulates when the RF coil 31 is working and stops circulating when the RF coil 31 is not working, thereby reducing energy consumption. For example, the circulation drive component 381 can be a fan or a circulation pump, providing controllable power for the continuous circulation of the protective gas in the sealed space, ensuring that the coil surface is always covered with fresh protective gas and maintaining long-term stable heat dissipation efficiency. At the same time, by adjusting the operating power (such as the rotation speed) of the circulation drive component 381, the gas flow rate can be directly controlled, thereby adjusting the convective heat transfer intensity of the protective gas and providing conditions for achieving closed-loop control of the coil temperature.

[0051] Preferably, the circulation pipe 38 is provided with a cooling element (not shown) to cool the protective gas in the circulation pipe 38, thereby achieving active cooling of the circulating protective gas and further enhancing the ability of the protective gas to remove heat from the coil, ensuring stable operation of the equipment for a long time under high RF power. It should be understood that if the circulation pipe 38 is not provided with a cooling element, the length of the circulation pipe 38 should be set to ensure that the circulating protective gas is sufficiently cooled in the circulation pipe 38.

[0052] Preferably, valves are provided in the intake pipe 36 and the exhaust pipe 37. For example, a first valve 361 is provided in the intake pipe 36 and a second valve 371 is provided in the exhaust pipe 37, thereby accurately controlling the opening and closing of the intake pipe 36 and the exhaust pipe 37. The first valve 361 is connected to a control component, and its opening and closing are controlled by the control component; the second valve 371 is preferably a one-way valve, with its inlet connected to the input end of the exhaust pipe 37. This prevents gas backflow, ensuring that the gas in the sealed space 30 can only be discharged through the exhaust pipe 37 and cannot flow back in, thus maintaining the purity of the gas in the sealed space 30.

[0053] Specifically, the control component first controls the opening of the first valve 361, and the intake pipe 36 begins to supply protective gas until the air pressure in the sealed space 30 is greater than atmospheric pressure (i.e., 760 Torr) and the pressure difference with atmospheric pressure reaches the opening pressure difference of the check valve (e.g., 5 Torr-10 Torr, depending on the actual specifications of the check valve). At this point, the check valve is triggered to open automatically, and the exhaust pipe 37 begins to discharge air. After a period of time (3~600 seconds) to empty the air in the sealed space 30, the first valve 361 is closed, and the air pressure in the sealed space 30 will gradually decrease. When the air pressure in the sealed space 30 decreases to the point where the pressure difference with atmospheric pressure is lower than the opening pressure difference of the check valve, the check valve will close automatically. The sealed space 30 and the circulation pipe 38 form a closed loop. Then, the control component determines whether the radio frequency coil 31 is in working condition. If it is, the circulation drive component 381 is turned on, so that the protective gas in the sealed space can circulate in the circulation pipe 38 to cool the radio frequency coil 31. Otherwise, the circulation drive component 381 is turned off to save energy.

[0054] When determining whether the RF coil 31 is in operation, the control component can determine whether the RF coil 31 is working based on the excitation signal of the upper RF power supply 32, or it can determine whether the RF coil 31 is working by detecting the spectral intensity signal of the characteristic wavelength after the process gas in the process chamber is excited into plasma.

[0055] In this embodiment, the inductive coupling device may further include a pressure sensing element (not shown), which is connected to the control component to implement dynamic closed-loop air pressure control of the sealed space 30. That is, the control component controls the air pressure within the sealed space based on the detection results of the pressure sensing element. For example, when exhaust gas needs to be released to the outside, the air pressure within the sealed space should be greater than atmospheric pressure, and the pressure difference with atmospheric pressure should reach the opening pressure difference of the one-way valve. When circulating protective gas is required, the air pressure within the sealed space should be slightly greater than atmospheric pressure, but the pressure difference with atmospheric pressure should be lower than the opening pressure difference of the one-way valve. The pressure sensing element can be used to monitor the actual air pressure within the sealed space. The pressure sensing element can be a pressure sensor for real-time air pressure detection, or a lower-cost ATM switch can be used to detect whether the air pressure within the sealed space reaches the opening pressure of the one-way valve. This embodiment does not impose any specific limitations on this.

[0056] In addition, the inductive coupling device may also include a temperature sensor (not shown), which is also connected to the control component and is used to detect the temperature sensing information of the RF coil 31. When the RF coil 31 is energized, the control component can control the gas flow rate in the circulation pipeline 38 according to the temperature sensing information (e.g., by adjusting the power of the circulation drive component 381) so that the temperature of the RF coil 31 is maintained within the target temperature range (e.g., 100~120°C).

[0057] Preferably, the temperature sensor is a non-contact sensor, such as an infrared sensor, to avoid coupling between the sensor body and the radio frequency coil 31, which would interfere with the transmission of radio frequency energy.

[0058] In this embodiment, the sealing assembly may be provided with multiple air inlet ports, each of which is connected to an exhaust port through a corresponding circulation pipe 38. The multiple air inlet ports are evenly distributed around the radio frequency coil 31 to eliminate dead zones in the airflow within the sealed space 30, and to avoid insufficient local protection or uneven cooling of the coil due to uneven distribution of protective gas.

[0059] In this embodiment, the dielectric window 21 is cylindrical, and the radio frequency coil 31 is a three-dimensional coil surrounding the dielectric window 21. The air intake direction of each air intake port can be aligned radially with the central axis of the dielectric window 21, tangent to the outer peripheral surface of the dielectric window 21, or aligned with the surface of the radio frequency coil 31. When the air intake direction is aligned with the central axis of the dielectric window 21, an impinging jet can be formed, which can quickly remove the heat generated by the radio frequency coil 31. When the air intake direction is tangent to the outer peripheral surface of the dielectric window 21, the airflow can be guided to rotate and flow near the outer surface of the dielectric window 21. This swirling flow can form a relatively stable and continuously renewed protective gas protection on the coil surface, optimizing the uniformity of protection and the heat dissipation effect. When the air intake direction is aligned with the surface of the radio frequency coil 31, the gas flow can directly wash over the heated coil surface, achieving efficient cooling of the radio frequency coil 31.

[0060] In this embodiment, the air inlet port and the exhaust port are respectively located on opposite sides of the sealed space 30. For example, the air inlet port is located at the bottom of the sealed space 30, and the exhaust port is located at the top of the sealed space 30; or conversely, the air inlet port is located at the top of the sealed space 30, and the exhaust port is located at the bottom of the sealed space 30. This ensures that the protective gas, after entering from one end, flows through almost the entire sealed space 30 before being extracted from the other end. This maximizes the contact path and time between the gas and the coil, significantly improving the overall coverage efficiency and heat dissipation performance of the protective gas on the coil surface, while avoiding waste caused by gas flowing out directly before reaching the coil area.

[0061] It should be noted that although this embodiment only illustrates the case of the RF coil 31 as a three-dimensional coil, it should be understood that the present invention is also applicable to semiconductor process equipment where the RF coil 31 is planar. When the RF coil 31 is a planar coil, it can be placed directly on the outer surface (usually the top surface) of the dielectric window 21, and the sealing assembly is configured to cover the outer side of the dielectric window and form a sealed space with the dielectric window 21.

[0062] Example 2 This embodiment provides a semiconductor process apparatus, including a process chamber 20 and an inductive coupling device for coupling radio frequency energy into the process chamber 20 through a dielectric window 21, wherein the inductive coupling device is the inductive coupling device provided in Embodiment 1.

[0063] like Figure 2 and Figure 3 As shown, in this embodiment, the process chamber 20 is connected to a vacuum device (such as a vacuum pump) via a vacuum channel 22 to evacuate the process chamber 20; the stage 23 is disposed inside the process chamber 20 to support the workpiece 10 to be processed, and is connected to the lower electrode RF power supply 24 as the lower electrode; the top of the process chamber 20 is provided with a top plate 25, which includes a central region and an extension 251 surrounding the central region, and the central region is provided with an air intake structure 252, through which process gas can enter the interior of the process chamber 20.

[0064] During the process, the upper-stage RF power supply provides RF current to the RF coil 31 through the matching unit. The RF current generates an alternating electromagnetic field under the action of the RF coil 31. This alternating electromagnetic field penetrates the dielectric window 21 and ionizes the process gas delivered to the process chamber 20 by the gas inlet structure 252.

[0065] When using the inductive coupling device of Example 1, the protective gas is first replaced by opening the intake pipe 36 and exhaust pipe 37 until the original air in the sealed space 30 is emptied. Then, the circulation pipe 38 is used to switch to pure circulation mode, realizing a closed-loop circulation of the protective gas. This completely inhibits the oxidation and sulfidation reaction of the silver plating layer from the source. Moreover, the circulation pipe 38 not only ensures the establishment of a pure protective atmosphere, but also greatly reduces the continuous consumption of protective gas, improving the system's economy.

[0066] Furthermore, the circulating protective gas not only provides protection but also efficiently removes the heat generated by the RF coil 31 during operation, achieving active cooling of the coil and eliminating the need for an additional fan. This eliminates the problem of electromagnetic field disturbances and instantaneous plasma fluctuations caused by vibrations during fan cooling, further enhancing the overall stability and repeatability of the plasma generation process.

[0067] It should be noted that the semiconductor process equipment in this embodiment may be, for example, a plasma etching equipment, a plasma resist stripping equipment, and a plasma deposition equipment, and this embodiment does not impose any specific limitations on it.

[0068] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. An inductive coupling device for coupling radio frequency energy into a process chamber of a semiconductor process apparatus through a dielectric window, thereby ionizing a process gas within the process chamber into plasma, wherein, The inductive coupling device includes a radio frequency coil disposed outside the dielectric window, the surface of the radio frequency coil being provided with a silver plating layer, characterized in that the inductive coupling device further includes a sealing assembly and a gas path assembly; A sealed space is formed between the sealing assembly and the medium window to house the radio frequency coil within the sealed space, and the sealing assembly is provided with an air inlet port and an air outlet port. The gas path assembly is connected to the air inlet port and the air outlet port, and is used to introduce protective gas into the sealed space through the air inlet port to displace the air in the sealed space, and to make the protective gas circulate in the sealed space when the radio frequency coil is working. The protective gas does not react with the silver plating layer to prevent corrosion of the silver plating layer. The air intake direction of the air intake port is aligned with the central axis of the medium window, tangent to the outer peripheral surface of the medium window, or aligned with the surface of the radio frequency coil.

2. The inductive coupling device as described in claim 1, characterized in that, The air circuit assembly is controlled by the control assembly and includes an intake pipe, an exhaust pipe, and a recirculation pipe; The output end of the intake pipe is connected to the intake port, and the input end of the intake pipe is connected to the protective gas source. The inlet of the exhaust pipe is connected to the exhaust port; The two ends of the circulation pipeline are respectively connected to the air inlet port and the air outlet port; The control component is configured to control the intake pipe and the exhaust pipe to open for a period of time to introduce the protective gas into the sealed space to displace the air in the sealed space, and to control the intake pipe and the exhaust pipe to close after the displacement is completed.

3. The inductive coupling device as described in claim 2, characterized in that, The circulation pipeline is equipped with a circulation drive component for driving the protective gas to circulate in the loop formed by the circulation pipeline and the sealed space. The control component is further configured to control the start and stop of the cycle drive component according to the operating state of the radio frequency coil.

4. The inductive coupling device as described in claim 2, characterized in that, The output end of the intake pipe is connected to the first branch point of the circulation pipe; The input end of the exhaust pipe is connected to the second branch point of the circulation pipe.

5. The inductive coupling device as described in claim 2, characterized in that, Valves are provided in the intake pipe and the exhaust pipe. The valve in the intake pipe is connected to the control component, and the valve in the exhaust pipe is a one-way valve. The inlet of the one-way valve is connected to the input end of the exhaust pipe. And / or, the circulation pipeline is provided with a cooling component for cooling the protective gas in the circulation pipeline.

6. The inductive coupling device as described in claim 3, characterized in that, The inductive coupling device further includes a temperature sensor connected to the control component and used to detect temperature sensing information of the radio frequency coil. The control component is also configured to control the power of the circulating drive component based on the temperature sensing information so that the temperature of the radio frequency coil is maintained within a target temperature range.

7. The inductive coupling device as described in claim 2, characterized in that, The inductive coupling device further includes a pressure sensing element connected to the control component, which is further configured to control the air pressure within the sealed space based on the detection result of the pressure sensing element.

8. The inductive coupling device as described in claim 2, characterized in that, The sealing assembly is provided with a plurality of air inlet ports and a plurality of circulation pipes that are connected to each of the air inlet ports in a one-to-one manner, and the plurality of air inlet ports are evenly distributed around the radio frequency coil.

9. The inductive coupling device as described in any one of claims 1-8, characterized in that, The air intake port and the air exhaust port are respectively located on opposite sides of the sealed space.

10. A semiconductor process apparatus, comprising a process chamber and an inductive coupling device for coupling radio frequency energy into the process chamber through a dielectric window of the process chamber, characterized in that, The inductive coupling device is the inductive coupling device according to any one of claims 1 to 9.

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