Monitoring system for remote plasma sources, remote plasma sources, methods, and reaction product generation apparatus.

Abstract

This application discloses a monitoring system, a remote plasma source, a method, and a reaction product generation apparatus for a remote plasma source, relating to the field of semiconductor processing technology. It includes: a signal acquisition component for detecting characteristic parameters of free radicals generated by the remote plasma source to obtain target characteristic values ​​of the free radicals; and a signal processing component connected to the signal acquisition component for generating a control signal based on the target characteristic values ​​transmitted by the signal acquisition component and transmitting the control signal to a controller. The control signal is used by the controller to maintain the characteristic parameter values ​​of the free radicals generated by the remote plasma source within a preset threshold range, thereby achieving precise control of the stability of the free radicals and meeting the actual needs of various semiconductor process scenarios.

Description

Technical Field

[0001] This application relates to the field of semiconductor processing technology, and in particular to a monitoring system for a remote plasma source, a remote plasma source, a method, and a reaction product generation apparatus. Background Technology

[0002] In semiconductor manufacturing, deposition is an essential process used to deposit thin film materials on wafer surfaces to form wiring films or insulating films. Common deposition processes include chemical vapor deposition (CVD), physical vapor deposition (PVD), and atomic layer deposition (ALD). However, during the deposition process, unwanted deposits or oxide layers may form on the inner walls of the process reaction chamber and on the wafer surface. Therefore, periodic chamber cleaning and wafer surface reduction treatments are necessary. Remote plasma sources (RPS) can generate plasma via transformer coupling, dissociating the introduced process gas into low-energy neutral free radicals, which are then transported to the process reaction chamber for cleaning or wafer surface treatment.

[0003] With the development of semiconductor technology, current processes have increasingly stringent requirements for chamber cleanliness and wafer surface uniformity, placing extremely high demands on the control precision of plasma reaction products. The control of plasma directly impacts process yield. However, current control of plasma reaction products is indirect, achieved through primary-side current and power, or even further, by controlling the power transferred to the plasma. This control method, however, has poor precision in controlling the reaction products within the process chamber, easily leading to deviations between the final reaction products and the expected values, thus affecting process yield. Summary of the Invention

[0004] This application discloses a remote plasma source, a monitoring system and method for the remote plasma source, and a reaction product generation device, which are used to solve the problem that the current plasma control methods have poor control accuracy of reaction products in the process reaction chamber.

[0005] In a first aspect, this application provides a monitoring system for a remote plasma source, comprising: a signal acquisition component for detecting characteristic parameters of free radicals generated by the remote plasma source and obtaining target characteristic values ​​of the free radicals; a signal processing component connected to the signal acquisition component for generating a control signal based on the target characteristic values ​​transmitted by the signal acquisition component and transmitting the control signal to a controller; the control signal is used to maintain the characteristic parameter values ​​of the free radicals within a preset threshold range.

[0006] In this scheme, remote plasma source monitoring is achieved through signal acquisition and signal processing components. The signal acquisition component can directly detect the characteristic parameters of free radicals generated by the remote plasma source and obtain target characteristic values. The signal processing component generates control signals based on the target characteristic values ​​and transmits them to the controller. Finally, the controller stabilizes the free radical characteristic parameters within a preset threshold range. The signal acquisition component enables direct and real-time detection of free radical characteristic parameters, solving the core problem of mismatch between input power and actual reaction product concentration. It can provide reliable data for controlling the stability of free radicals, enabling precise control of the stability of free radicals, and thus improving the control accuracy of reaction products in the process reaction chamber.

[0007] In one possible implementation, the signal acquisition component is deployed at a first preset location; the first preset location is any one of the following: inside the process reaction chamber, in a transmission pipe, in the gas dissociation chamber of the remote plasma source, or at the outlet of the process reaction chamber; the transmission pipe is a pipe used to transmit the free radicals generated by the remote plasma source to the process reaction chamber.

[0008] In this embodiment, the signal acquisition component is located at a first preset installation position, which covers the processes of free radical generation, transport, reaction, and discharge. This includes the process reaction chamber, the transport pipe from the RPS to the process reaction chamber, the gas dissociation chamber of the RPS, and the outlet of the process reaction chamber. This allows for monitoring of each step in the free radical reaction process, thereby determining the loss during free radical transport and the actual reaction concentration in the process reaction chamber. The first preset position can be determined according to different process requirements, adapting to various semiconductor equipment scenarios.

[0009] In one possible implementation, the signal acquisition component is used to detect the characteristic parameters at the first preset location to obtain the target characteristic value; the characteristic parameters include any one or more of the concentration, temperature, pressure, dissociation rate, and flow rate of the free radical. In this implementation, the characteristic parameters detectable by the signal acquisition component include any one or more of concentration, temperature, pressure, dissociation rate, and flow rate, enabling the detection of multi-dimensional parameters. Currently, only power and current parameters are monitored, which cannot comprehensively determine the multi-dimensional parameters affecting the stability of free radicals. Thus, by monitoring the state of free radicals in multiple dimensions, the control accuracy of the reaction products in the process reaction chamber can be improved.

[0010] In one possible implementation, when the signal acquisition component is deployed at a second preset location, it is further used to detect the gas pressure and / or gas flow rate of the process gas at the second preset location; the second preset location is the chamber inlet of the gas dissociation chamber of the remote plasma source. In this embodiment, the signal acquisition component can also be deployed at the second preset location, i.e., the chamber inlet of the RPS gas dissociation chamber. In this case, it can detect the gas pressure and / or gas flow rate of the process gas at the inlet end. Compared to the current method, which can only correct for deviations in free radical parameters and suffers from control lag, this method enables feedforward detection at the inlet end, allowing for early prediction of the impact of sudden changes in inlet gas on free radical parameters, thus significantly improving the stability of the RPS plasma.

[0011] In one possible implementation, the signal processing component is further configured to generate a feedforward signal based on the gas pressure and / or gas flow rate transmitted by the signal acquisition component, and transmit the feedforward signal to the controller. The feedforward signal is used in conjunction with the control signal to maintain the parameter values ​​of the characteristic parameters of the free radicals generated by the remote plasma source within a preset threshold range; wherein the controller is a feedback controller. In this embodiment, the signal processing component can generate a feedforward signal based on the gas pressure / flow rate at the inlet, and transmit the feedforward signal and the control signal synchronously to the feedback controller to achieve stable control of the free radical parameters. Through a closed-loop control architecture, the feedforward signal determines the inlet interference, and the feedback signal corrects the deviation of the characteristic parameters, thereby improving the dynamic stability of the characteristic parameters of the free radicals.

[0012] Secondly, this application provides a remote plasma source, comprising: a plasma generation device for generating free radicals; and a controller for receiving control signals transmitted by the aforementioned monitoring system and, based on the control signals, maintaining the parameter values ​​of the characteristic parameters of the free radicals within a preset threshold range. In this solution, the remote plasma source includes a plasma generation device and a controller. The controller receives control signals from the monitoring system and controls the characteristic parameters of the free radicals generated by the plasma generation device based on these signals. This ensures the stability of the free radical parameters at the hardware level, avoiding the shortcomings of traditional indirect control schemes such as current control and power control, which cannot achieve precise control, and can improve the consistency of the process.

[0013] In one possible implementation, the remote plasma source (RPS) is directly connected to the process reaction chamber, or connected to the process reaction chamber via a transmission pipeline. In this embodiment, the RPS and the process reaction chamber can be directly connected, or connected via a transmission pipeline. Therefore, in the case of a pipeline connection, a monitoring system can capture losses during the transmission process, thereby ensuring the control accuracy of the process products.

[0014] In one possible implementation, the controller is configured to generate a voltage regulation signal based on the control signal and transmit the voltage regulation signal to the plasma generation device. This allows the plasma generation device to generate a corresponding voltage based on the voltage regulation signal, thereby dissociating the process gas to produce free radicals and maintaining the characteristic parameters of the free radicals within the preset threshold range. In this implementation, the controller can generate a voltage regulation signal based on the control signal from the monitoring system and transmit it to the plasma generation device. By adjusting the output voltage, the dissociation process of the process gas is controlled, ultimately maintaining the characteristic parameters of the free radicals within the preset threshold range. Current RPS systems cannot dynamically adjust the energy input based on the actual state of the free radicals. Therefore, this implementation uses the actual parameters of the free radicals for voltage regulation, thereby achieving parameter correction and improving the control efficiency of the process products through voltage regulation, which can significantly improve the control accuracy of the free radicals.

[0015] In one possible implementation, the plasma generation device includes: a power supply module for converting a three-phase AC voltage into a target AC voltage that meets preset gas dissociation conditions, and powering a gas dissociation chamber using the target AC voltage; and a gas dissociation chamber for dissociating the process gas using the target AC voltage to generate the free radicals. In this embodiment, the plasma generation device includes a power supply module and a gas dissociation chamber. The power supply module can convert a three-phase AC voltage into a target AC voltage that meets the gas dissociation conditions to power the chamber; the gas dissociation chamber uses the target AC voltage to dissociate the process gas to generate free radicals. In this way, the power supply module can directly receive voltage regulation signals and dynamically adjust the target AC voltage, thereby controlling the reaction products.

[0016] In one possible implementation, the power supply module includes an inverter module for acquiring the voltage regulation signal and adjusting the target AC voltage according to the voltage regulation signal to obtain a regulated voltage; and a gas dissociation chamber for dissociating the process gas using the regulated voltage to adjust the characteristic parameters of the free radicals and maintain the parameter values ​​of the characteristic parameters within a preset threshold range. In this embodiment, the power supply module mainly receives the voltage regulation signal through the inverter module and adjusts the target AC voltage so that the gas dissociation chamber can dissociate the process gas using the regulated voltage, dynamically correcting the characteristic parameters of the free radicals. In this way, dynamic adjustments can be made according to the actual state of the free radicals, effectively controlling the dissociation efficiency of the process gas, thereby achieving control of the free radicals.

[0017] In one possible implementation, the power module is further configured to generate a resonant voltage and maintain the target AC voltage; the resonant voltage is a voltage that satisfies the gas ignition condition; correspondingly, the gas dissociation chamber is configured to use the resonant voltage to excite the process gas and generate the free radicals. In this embodiment, the gas dissociation chamber can use the resonant voltage to excite the process gas to generate free radicals and maintain the target AC voltage, and the resonant voltage satisfies the ignition condition for gas dissociation, quickly realizing the excitation from gas to plasma, adapting to the needs of semiconductor processes, and improving the stability of free radical parameters by maintaining the target AC voltage.

[0018] In one possible implementation, the controller is further configured to acquire a target signal sent by a host computer, determine a target parameter value based on the target signal, and control the characteristic parameters of the free radicals generated by the remote plasma source based on the control signal and the target parameter value; the target parameter value is a parameter value within a preset threshold range. In this embodiment, the controller can acquire the target signal sent by the host computer, determine the target parameter value within a preset threshold range, and combine it with the control signal from the monitoring system to perform closed-loop control of the free radical characteristic parameters. In this way, the target parameters can be dynamically set according to different process requirements such as chamber cleaning and wafer processing, ensuring the implementation of semiconductor process requirements and helping to achieve precise control of reaction products.

[0019] Thirdly, this application provides a method for monitoring a remote plasma source, comprising: detecting characteristic parameters of free radicals generated by the remote plasma source through a signal acquisition component to obtain target characteristic values ​​of the free radicals; generating a control signal based on the target characteristic values ​​transmitted by the signal acquisition component through a signal processing component connected to the signal acquisition component, and transmitting the control signal to a controller; the control signal is used to maintain the parameter values ​​of the characteristic parameters of the free radicals within a preset threshold range.

[0020] Fourthly, this application provides a method for controlling the characteristic parameters of free radicals, comprising: receiving a control signal from a signal processing component, the control signal being generated based on a target characteristic value transmitted by a signal acquisition component, the target characteristic value being obtained by detecting the characteristic parameters of free radicals generated by a remote plasma source; and maintaining the parameter values ​​of the characteristic parameters of the free radicals within a preset threshold range based on the control signal.

[0021] Fifthly, this application provides a reaction product generation apparatus, comprising: the aforementioned remote plasma source; and a process reaction chamber connected to the remote plasma source, for realizing a process reaction based on free radicals transmitted by the remote plasma source to generate corresponding reaction products.

[0022] Sixthly, this application provides a control system for characteristic parameters of free radicals, including: the aforementioned monitoring system and the aforementioned remote plasma source.

[0023] In a seventh aspect, this application provides a computer-readable storage medium for storing a computer program that, when executed by a processor, implements the aforementioned method for controlling the characteristic parameters of free radicals.

[0024] Through the above technical solution, this application can use a signal acquisition component to detect the characteristic parameters of free radicals generated by a remote plasma source, obtain the target characteristic value of the free radicals, and then use a signal processing component connected to the signal acquisition component to generate a control signal based on the target characteristic value transmitted by the signal acquisition component, and transmit the control signal to the controller so that the controller can maintain the characteristic parameter value of the free radicals within a preset threshold range through the control signal.

[0025] This application enables remote monitoring of a plasma source via a signal acquisition component and a signal processing component. The signal acquisition component can directly detect the characteristic parameters of free radicals generated by the remote plasma source and obtain target characteristic values. The signal processing component generates control signals based on the target characteristic values ​​and transmits them to the controller. Finally, the controller stabilizes the free radical characteristic parameters within a preset threshold range. The signal acquisition component enables direct and real-time detection of free radical characteristic parameters, thereby directly acquiring real-time state data of the free radicals. This solves the core problem of mismatch between input power and actual reaction product concentration, providing reliable data for controlling the stability of free radicals. Furthermore, the signal processing component, connected to the acquisition component, converts the detected target characteristic values ​​into control commands, thereby directly adjusting the remote plasma source based on the actual state of the free radicals. This maintains the characteristic parameters of the free radicals within a preset threshold range, achieving precise control of the stability of the free radicals and improving the control accuracy of reaction products in the process reaction chamber. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 A schematic diagram of a monitoring system for a remote plasma source provided in an embodiment of this application; Figure 2 A schematic diagram of a control system structure for characteristic parameters of a free radical provided in an embodiment of this application; Figure 3 A schematic diagram of a closed-loop control process for free radical concentration provided in an embodiment of this application; Figure 4 This is a schematic diagram of the structure of a remote plasma source provided in an embodiment of this application; Figure 5 This is a flowchart illustrating a remote plasma source monitoring method provided in an embodiment of this application.

[0028] Explanation of reference numerals in the attached figures: 1- Monitoring system for remote plasma sources; 11-Signal acquisition component; 12-Signal processing component; 111-Detector; 112-Fiber optic cable; 113-Optical probe; 2-Remote plasma source; 21-Plasma generation device; 22-Controller; 211-Power supply module; 212-Gas dissociation chamber; 3-Transmission pipeline; 4-Process reaction chamber. Detailed Implementation

[0029] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0030] It should be noted that, in the description of this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. The terms "first," "second," etc., in this application are used to distinguish similar objects and are not used to describe a specific order or sequence.

[0031] Currently, the control of plasma reaction products is done indirectly, i.e., through primary-side current and power, or even further, by controlling the power transmitted to the plasma. However, this control method has poor accuracy in controlling the reaction products in the process reaction chamber, which can easily lead to deviations between the final reaction products and the expected values. This application can directly detect the characteristic parameters of free radicals generated by a remote plasma source through a signal acquisition component, and use a signal processing component to generate control signals and transmit them to the controller, stabilizing the characteristic parameters of free radicals within a preset threshold range. This achieves direct and real-time detection of the characteristic parameters of free radicals, greatly improving the accuracy of free radical parameter control, and thus improving the control precision of the reaction products in the process reaction chamber.

[0032] To enable those skilled in the art to better understand the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] First, it should be noted that the technical solution in this application achieves precise control of parameters such as the concentration and dissociation rate of free radicals generated by a remote plasma source (RPS) through direct detection of reaction products and corresponding closed-loop control. It is mainly applied to processes such as thin film deposition, wafer etching, chamber cleaning, and epitaxial growth in the semiconductor manufacturing field. It is particularly suitable for equipment in semiconductor production lines that uses low-energy free radicals to complete process reaction chamber cleaning, wafer surface treatment, and thin film modification / deposition, including but not limited to: PVD equipment, CVD equipment, ALD equipment, epitaxial deposition equipment (EPI, Epitaxy Equipment), etc., to dissociate gases. The generated plasma contains a large number of neutral radicals, which can be used for cleaning semiconductor chambers and processing wafers. It can overcome the control precision problem of traditional remote plasma sources and improve the accuracy and consistency of reaction product concentration / dissociation rate.

[0034] See Figure 1 As shown in the figure, this application discloses a monitoring system for a remote plasma source, including: Signal acquisition component 11 is used to detect the characteristic parameters of free radicals generated by the remote plasma source 2, and obtain the target characteristic value of the free radicals. The target characteristic value refers to the measured value of the specified characteristic parameter obtained by the signal acquisition component 11 after actually detecting the free radical (e.g., neutral radical) generated by the remote plasma source 2, such as the measured values ​​of free radical concentration, temperature, pressure, dissociation rate, and flow rate. For example, the signal acquisition component 11 deployed in the process reaction chamber 4 detects a concentration of F free radicals of 7.2 × 10⁻⁶. 15 cm -3 This value is the target characteristic value of the F free radical concentration; for example, when the signal acquisition component 11 deployed in the transmission pipeline 3 is a pressure sensor, the detected pressure of the free radical mixture gas is 1.2 Torr, and this value is the target characteristic value of the free radical pressure. The target characteristic value can be the measurement value of a single parameter, or it can be a combination of measurement values ​​of multiple parameters (such as simultaneously detecting concentration and temperature).

[0035] Specifically, in this embodiment, the signal acquisition component 11 is deployed at a first preset position; and the first preset position is any one of the following: inside the process reaction chamber 4, in the transmission pipe 3, in the gas dissociation chamber 212 of the remote plasma source 2, and at the outlet of the process reaction chamber 4. The transmission pipe 3 is used to transmit the free radicals generated by the remote plasma source 2 to the process reaction chamber 4. In this embodiment, the remote plasma source can be connected to or directly installed on the reaction chamber 4 via a pipe. It is understood that when the first preset position is the transmission pipe 3, the remote plasma source 2 is connected to the reaction chamber 4 via a pipe. Correspondingly, if the remote plasma source 2 is directly connected to the reaction chamber 4, then the signal acquisition component 11 will not be located in the transmission pipe 3. It should also be noted that the first preset position is any one of the following: inside the process reaction chamber 4, in the transmission pipe 3, in the gas dissociation chamber 212 of the remote plasma source 2, and at the outlet of the process reaction chamber 4. This embodiment does not limit the deployment of the signal acquisition component 11 to a single position; multiple signal acquisition components 11 can be installed simultaneously at multiple first preset positions. Furthermore, the signal acquisition component 11 can also be deployed at a second preset location, such as the chamber inlet of the gas dissociation chamber 212 of the remote plasma source 2. Therefore, multiple signal acquisition components 11 can be installed simultaneously at one or more first preset locations and the second preset location. Thus, multiple signal acquisition components 11 detect the target feature values ​​at their respective deployment locations and obtain multiple target feature values. Then, the signal processing component 12 can generate a control signal based on one or more target feature values, or it can simultaneously generate a feedforward signal based on the gas pressure and / or gas flow rate detected at the second preset location. The control signal and the feedforward signal are then transmitted to the controller 22 in combination to maintain the target feature values ​​of the free radicals generated by the remote plasma source 2 within a preset threshold range. In this way, the signal acquisition component 11 can be installed in any one or more of the following locations: inside the RPS cavity 21, on the transmission pipe 3 between the RPS2 and the process reaction cavity 4, on the process reaction cavity 4, or at the outlet of the process reaction cavity 4. By installing the signal acquisition component 11 in different locations, the detection of characteristic parameters can cover the processes of free radical generation, transmission, reaction, and discharge, thereby determining the loss of free radicals during transmission and the characteristic parameters participating in the process reaction. Therefore, this embodiment can monitor each process in the free radical reaction process through parameter detection at different locations, thereby determining the loss during transmission and the actual reaction concentration in the process reaction cavity 4. Furthermore, the corresponding preset location can be selected according to different process requirements to adapt to various semiconductor process scenarios.

[0036] In one embodiment, the signal acquisition component 11 can be used to detect characteristic parameters at a first preset location to obtain target characteristic values; wherein, the characteristic parameters include any one or more of the following: concentration of free radicals, temperature, pressure, dissociation rate, and flow rate. Thus, the concentration, temperature, and other multi-dimensional parameters affecting the stability of free radicals can be comprehensively determined, and the control accuracy of the reaction products in the process reaction chamber 4 can be improved by monitoring the state of free radicals in multiple dimensions. In one embodiment, the signal acquisition component 11 includes one or more detection modules. Exemplarily, the detection modules can be various detection instruments, specifically including, but not limited to, optical emission spectrometers (OES), absorption spectrometers, laser-induced fluorescence spectrometers, mass spectrometers, or other detection devices capable of detecting characteristic parameters of free radicals.

[0037] The monitoring system 1 for the remote plasma source 2 also includes a signal processing component 12 connected to the signal acquisition component 11, which generates a control signal based on the target feature value transmitted by the signal acquisition component 11 and transmits the control signal to the controller 22; wherein the control signal is used to maintain the parameter value of the feature parameter of the free radical within a preset threshold range.

[0038] As a specific implementation method, such as Figure 2As shown, an exemplary embodiment is illustrated where a signal acquisition component 11 is deployed in a gas dissociation chamber 212 to detect characteristic parameters of free radicals within the gas dissociation chamber 212. In this embodiment, the signal acquisition component 11, i.e., the detection module, can detect characteristic parameters of free radicals within the gas dissociation chamber 212. For example, the signal acquisition component 11 can be an emission spectrometer for detecting the concentration of free radicals, and the concentration of active radicals within the RPS or pipeline can be obtained using a non-invasive optical measurement method via the emission spectrometer. When the detection module is an OES, it may specifically include an optical probe 113, an optical fiber 112, and a detector 111. The optical probe 113 is the signal acquisition end of the detection module, used to acquire the plasma glow inside the gas dissociation chamber 212; the optical fiber 112 is the signal transmission part of the detection module, used to transmit the glow signal acquired by the optical probe 113 to the detector 111; the detector 111 is used to convert the received glow signal acquired by the optical probe 113 into a detection signal and transmit it to the signal processing component 12, so that the signal processing component 12 can generate a corresponding control signal based on the received detection signal. For example, the optical probe 113 in the OES can be composed of a quartz or sapphire transparent sealed window and collimating optical elements, used to detect the plasma glow spectrum from the gas dissociation chamber 212 and coupled to the optical fiber 112; the optical fiber 112 conducts the glow collected by the optical probe 113 to the detector 111 for analysis; the detector 111 can perform spectral dispersion and intensity detection of the plasma glow, obtain the spectral intensity of the target active group and other groups (i.e., detection signal), so that the signal processing component 12 can further use the scaling method or other spectral analysis methods to calculate the concentration of the target active group based on the detection signal, thereby generating a control signal and feeding it back to the controller 22. For example, when the signal processing component 12 calculates the concentration of the target active group, it can use emission spectroscopy to perform quantitative analysis based on the characteristic spectra emitted during excited-state atomic / molecular transitions in plasma, which is suitable for detecting common active groups such as F (703.7 nm), H (656.3 nm), and O (777.4 nm); or, it can use absorption spectroscopy to calculate the concentration by measuring the attenuation of light of a specific wavelength after passing through plasma; or, it can use laser-induced fluorescence to detect the fluorescence signal emitted by free radicals at specific energy levels excited by laser.

[0039] In one embodiment, the signal acquisition component 11 may include different types of detection modules, which are used to detect different types of characteristic parameters. These different types of detection modules can be installed in the same or different locations, and the signals detected by the detection modules are then aggregated to the signal processing component 12. Exemplarily, the characteristic parameters are divided into two categories: characteristic parameters at a first preset location, namely the concentration, temperature, pressure, dissociation rate, or flow rate of free radicals in the gas dissociation chamber 212, the transmission pipeline 3, the process reaction chamber 4, or the outlet of the process reaction chamber 4; and characteristic parameters at a second preset location, namely the gas pressure and / or gas flow rate of the process gas detected at the inlet of the gas dissociation chamber 212. Furthermore, different types of detection modules can detect corresponding characteristic parameters. For example, when it is necessary to detect the concentration of free radicals, the detection module can include optical detectors such as spectrometers. In this case, the detection module can be installed on the side wall of the process reaction chamber 4, the transmission pipe 3, or the outer wall of the RPS dissociation chamber through a quartz window. That is, a non-invasive installation method is adopted. The probe of the detection module is not directly inserted into the sealed gas dissociation chamber 212, the transmission pipe 3, or the process reaction chamber 4. Instead, the glow signal emitted by the plasma inside the chamber is collected through a quartz glass window pre-set on the cavity wall. This can avoid damaging the vacuum of the cavity, and then the corresponding concentration value can be determined based on the relationship between the characteristic peak intensity of the plasma glow spectrum and the concentration. For another example, when it is necessary to detect the temperature of free radicals, the detection module can include a spectrometer to calculate the gas temperature by analyzing the intensity distribution of the rotational spectral lines of free radical molecules. For yet another example, when it is necessary to detect the pressure of free radicals, the detection module can be a dedicated pressure sensor such as a capacitive pressure sensor directly installed on the wall of the process reaction chamber 4, the transmission pipe 3, or the RPS dissociation chamber. The pressure is calculated by measuring the impact force of gas molecules on the sensor diaphragm. In other words, the signal acquisition component 11 in this embodiment can include multiple types of detection modules, and multiple types of detection modules can be installed at the same location to detect multiple characteristic parameters at that location. For example, a spectrometer and a pressure sensor can be installed in the gas dissociation chamber 212 to detect the concentration of free radicals in the gas dissociation chamber 212 and the pressure in the chamber. Alternatively, different types of detection modules can be installed at different locations to detect characteristic parameters at different locations. For example, a spectrometer can be installed in the gas dissociation chamber 212 and a pressure sensor can be installed at the inlet of the gas dissociation chamber 212 to obtain the concentration of free radicals in the gas dissociation chamber 212 and the gas pressure at the inlet of the gas dissociation chamber 212, respectively.

[0040] In another example, a pressure sensor can be installed on the wall of the gas dissociation chamber 212, the transfer pipe 3, or the process reaction chamber 4 of the remote plasma source 2 to acquire the gas pressure of the active group mixture gas in the chamber or pipe in real time. This pressure sensor is an invasive or non-invasive gas dynamics detection element that obtains the pressure signal by directly sensing the force exerted by gas molecules on a sensitive diaphragm. Exemplarily, the pressure sensor can be a capacitive or piezoelectric pressure sensor, which internally includes a sensitive diaphragm and an electrode structure. When the active group mixture gas in the chamber or pipe acts on the sensitive diaphragm, the gas pressure causes a slight deformation of the diaphragm, thereby changing the capacitance value between the diaphragm and the electrode or generating a corresponding electrical signal. The pressure sensor converts this capacitance change or charge change into a standard voltage signal or digital signal and feeds this signal back to the controller 22. The controller 22 can then acquire the gas pressure value at the corresponding location based on this signal and use this gas pressure value as one of the characteristic parameters of the free radicals in closed-loop control.

[0041] Taking F radical concentration detection as an example, the optical probe 113 collects plasma glow through a quartz window and transmits it to the detector 111 via optical fiber 112. The detector 111 converts the light intensity of a preset characteristic wavelength into an analog voltage signal, which is then transmitted to the signal processing component 12. The signal processing component 12 calls a pre-calibrated light intensity-concentration curve to convert the voltage signal into a specific concentration value. The signal processing component 12 then compares the calculated actual concentration value with the preset target concentration value, calculates the deviation value (actual concentration - target concentration), and, based on the deviation value, calculates the required power supply change using a PID (proportional-integral-derivative) algorithm or other control algorithms. For example, if the deviation is -0.5 × 10⁻⁶, the power supply change must be adjusted. 15 cm -3 At this time, the power supply needs to be increased by 5%. Then, the signal processing component 12 converts the calculated power adjustment amount into a control signal recognizable by the controller 22, usually a digital command or analog voltage signal, and transmits the control signal to the controller 22 through a communication interface or analog interface. After receiving the control signal, the controller 22 converts it into a voltage adjustment signal executable by the power supply module 211, driving the inverter module to adjust the output power, thereby maintaining the concentration of the target active group within a preset threshold range. Furthermore, the aforementioned threshold range is specifically the allowable parameter fluctuation range (upper limit + lower limit) of the process, a pre-set allowable fluctuation range that can maintain the stability of the plasma process, which can be determined according to semiconductor process requirements, equipment design capabilities, experimental calibration data, etc. For example, the target free radical concentration is 7.0 × 10⁻⁶. 15 cm -3 The preset threshold range is 6.5 × 10. 15 ~7.5×10 15 cm-3 The target gas pressure is 1.2 Torr, with a preset threshold range of 1.0~1.4 Torr; the target gas temperature is 450K, with a preset threshold range of 420~480K. For different types of characteristic parameters, corresponding preset threshold ranges can be set independently. Each preset threshold range is determined independently based on process requirements, equipment capacity, and experimental calibration results, without interference. When the real-time detected value of any characteristic parameter exceeds its corresponding preset threshold range, the control system adjusts the parameter back to the threshold range by adjusting the power supply, voltage, or gas flow rate, ensuring that all characteristic parameters remain within their respective allowable ranges, thereby guaranteeing the stable operation of the remote plasma source 2 and the uniform production of free radicals. Figure 2 As shown, the signal processing component 12 connected to the acquisition component 11 can directly convert the detected target feature value into a control command through the controller 22, thereby directly adjusting the RPS based on the actual state of the free radical, maintaining the feature parameters of the free radical within a preset threshold range, maintaining the stability of the feature parameters, meeting the actual needs of semiconductor processes, and realizing precise control of the feature parameters of the free radical.

[0042] In one embodiment, when the signal acquisition component 11 is deployed at a second preset position, the signal acquisition component 11 is also used to detect the gas pressure and / or gas flow rate of the process gas at the second preset position; the second preset position is the chamber inlet of the gas dissociation chamber 212 of the remote plasma source 2. That is to say, in this embodiment, in addition to being deployed at the first preset positions such as inside the process reaction chamber 4, inside the transmission pipeline 3, inside the gas dissociation chamber 212 of the remote plasma source 2, and at the outlet of the process reaction chamber 4, the signal acquisition component 11 can also be deployed at the chamber inlet of the RPS gas dissociation chamber 212. At this time, variables at the RPS inlet, such as gas pressure or flow rate, can also be detected as feedforward inputs for RPS control. This allows for correction before the free radical parameters deviate, avoiding control lag, realizing feedforward detection at the inlet end, and predicting in advance the impact of sudden increases in inlet flow rate on the characteristic parameters of free radicals. In the event of sudden changes in gas conditions, this helps to achieve plasma stability inside the RPS and ensure a faster switching speed. In this embodiment, sensors in the signal acquisition component 11 can be deployed simultaneously at multiple locations. For example, an optical detector can be deployed at a first preset location to detect the concentration / temperature / pressure / flow rate of free radicals and generate a feedback signal; and / or a pressure / flow sensor can be deployed at a second preset location to detect the pressure / flow rate of undissociated process gas and generate a feedforward signal to predict concentration changes in advance. For example, a photodiode with a filter can be deployed in the transmission pipe 3 at a first preset position to detect the F radical concentration, and a capacitive pressure sensor can be deployed to detect the pressure of the radical mixed gas. Simultaneously, a thermal mass flow sensor can be deployed at the inlet of the RPS gas dissociation chamber at a second preset position to detect the inlet flow rate, and a pressure sensor can be deployed to detect the inlet pressure. Alternatively, a spectrometer can be installed in the gas dissociation chamber 212 to detect the F radical concentration, a capacitive pressure sensor can be installed on the transmission pipe 3 to detect the gas pressure, and a mass flow sensor can be installed at the inlet of the gas dissociation chamber 212 to detect the inlet flow rate. In this case, the signal processing component 12 can simultaneously receive the detection signals from the spectrometer, pressure sensor, and mass flow sensor. The detection signals from the pressure sensor and mass flow sensor are used to generate a feedforward compensation signal, and the detection signal from the spectrometer is used to generate a feedback control signal. For example, when the inlet flow rate suddenly increases by 20%, the feedforward control immediately increases the power by 6%, while the feedback control fine-tunes according to the actual concentration deviation detected by the spectrometer, ultimately controlling the fluctuation range of the F radical concentration within ±3%. Therefore, the aforementioned sensors together constitute the signal acquisition component 11, and all kinds of signals are uniformly collected to the signal processing component 12 to realize closed-loop control of various characteristic parameters such as free radical concentration.

[0043] Specifically, such as Figure 3As shown, the signal processing component 12 is also used to generate a feedforward signal F(s) based on the gas pressure and / or gas flow rate transmitted by the signal acquisition component 11, and transmit the feedforward signal to the controller 22. The controller 22, based on the control signal and the feedforward signal, adjusts the target characteristic value to a preset threshold range by adjusting the power supply, voltage, or gas flow rate, ensuring that all characteristic parameters remain within their respective allowable ranges. This guarantees the stable operation of the remote plasma source 2 and the uniform production of free radicals. The controller 22 is a feedback controller, such as a PI controller (Proportional-Integral Controller) or a PID controller (Proportional-Integral-Derivative Controller). Specifically, the signal acquisition component 11 acquires the target characteristic value of the free radicals and generates a raw measurement signal based on the target characteristic value, which is fed back to the analog input port of the RPS. This analog input port is the interface for connecting the raw measurement signal (e.g., the continuous voltage / current signal corresponding to the target characteristic value) to the signal processing component 12, allowing the raw measurement signal to be sent to the corresponding signal processing component 12 for calculation. For example, a photodiode detects light intensity and outputs a continuous voltage of 0-5V. The resulting voltage signal is the original measurement signal, which can be input to the signal processing component 12 via an analog input port. The signal processing component 12 then uses the voltage signal to generate a control signal and transmits it to the controller 22. The controller 22 then adjusts the operating frequency or voltage amplitude of the internal inverter in the power module 211 of the remote plasma source 2 based on the control signal, thereby stabilizing the concentration of active groups at a set level. Specifically, the signal processing component 12 can compare the target characteristic value, such as the measured concentration, with a preset target parameter value to obtain the corresponding deviation, and generate a control signal accordingly for feedback adjustment.

[0044] Simultaneously, the signal processing component 12 can generate a feedforward signal based on the RPS inlet gas pressure and / or flow rate to compensate for disturbances in advance. Then, the total adjustment amount is determined by the control signal and the feedforward signal. The controller 22 adjusts the operating frequency or voltage amplitude of the inverter in the power module 211 according to the total adjustment amount, thereby stabilizing the free radical concentration. For example, the concentration deviation is obtained based on the difference between the measured concentration and the preset target concentration (preset value), and a control signal is generated to determine the power adjustment amount. Furthermore, the advance compensation amount can be determined based on the feedforward signal, and the deviation correction amount is determined based on the control signal. Further, the total adjustment amount is the sum of the adjustment amount corresponding to the control signal (used for feedback adjustment offset) and the adjustment amount corresponding to the feedforward signal (used for advance compensation offset). The aforementioned adjustment amount is the adjustment parameter corresponding to the control signal and the feedforward signal, and their sum is the total adjustment amount. The controller 22 adjusts the operating frequency or voltage amplitude of the inverter according to the total adjustment amount, thereby maintaining the characteristic parameters of the free radicals within a preset threshold range. For example, when the signal acquisition component 11 detects a change in intake flow rate ΔQ or a change in pressure ΔF, it can calculate the power change ΔP that needs to be compensated in advance based on the preset flow-concentration or pressure-concentration characteristic curves, where K_Q and K_F are feedforward gain coefficients determined in advance through experiments; the feedback control uses a PID algorithm to correct the deviation of the feedforward prediction, and the total adjustment ΔP_total = ΔP + K_P × e + K_I × The formula is edt + K_D × de / dt, where e is the deviation between the target concentration and the measured concentration, and K_P, K_I, and K_D are the proportional, integral, and derivative gains, respectively. For example, if the target concentration is 100 and the measured concentration is 90, the deviation is -10. Since the concentration is low, +5% power is required. The signal processing component 12 generates a control signal for the +5% power, and the inlet flow suddenly increases. Based on this, it can be predicted that the concentration will be diluted, and the signal processing component 12 compensates for +3% power in advance, generating a feedforward signal for the +3% power. Therefore, the total adjustment is 5% + 3% = +8%, and based on this, the controller 22 commands the inverter to increase the voltage / frequency by 8%. In another scenario, the signal acquisition component 11 detects a decrease in inlet flow at the second preset position (inlet of the gas dissociation chamber 212) and outputs the corresponding original measurement signal. Based on this original measurement signal, the signal processing component 12 predicts that the free radical concentration will be too high and generates a feedforward signal for -2% power. At the same time, based on the original measurement signal at the first preset position, the signal processing component 12 calculates the target characteristic value (measured concentration), compares it with the preset target parameter value to obtain the deviation, and generates a control signal for +5% power. The controller 22 receives the control signal and feedforward signal transmitted by the signal processing component 12, adds the two together to obtain the total adjustment amount = 5% + (-2%) = +3%. Then, the controller 22 adjusts the operating frequency or voltage amplitude of the inverter in the power module 211 according to the total adjustment amount. In this way, based on the preset target parameter values ​​and the target characteristic values ​​such as the concentration, pressure, flow rate, and dissociation rate of free radicals fed back by the detection module, the controller 22 can realize closed-loop control of characteristic parameters such as the concentration of free radicals. Therefore, this embodiment can directly detect the concentration of free radicals or pressure, flow rate, dissociation rate, etc. through the detection module, and through the closed-loop control system, it can directly control the concentration of neutral radicals or pressure, flow rate, dissociation rate, etc., avoiding the shortcomings of traditional indirect control schemes such as current control and power control that cannot accurately control the process. It can directly take the direct determinants of process results such as the concentration of free radicals as the control target, and fundamentally solve the problem of stable parameters but unstable results. By stabilizing the overall concentration of free radicals in real time, it controls the differences in process effects such as etching rate, cleaning rate, and deposition thickness between the central and edge regions on the same wafer. Furthermore, by directly detecting the concentration of free radicals and performing closed-loop control, it reduces batch-to-batch deviation, thereby improving process consistency, reducing the differences in process effects at different locations on the same wafer, and reducing the differences in average process effects between different batches of wafers under the same process parameters.

[0045] Using the aforementioned monitoring system, this embodiment can directly detect the reaction products generated by RPS, i.e., the free radicals themselves, using the signal acquisition component 11. This allows for the direct acquisition of the true state data of the free radicals, solving the problems of mismatch between indirect parameters and the actual product state, as well as the inability to determine the losses caused by the free radicals in the transmission path. Furthermore, the signal processing component 12, connected to the acquisition component, directly converts the detected data into control commands, thereby directly adjusting the RPS based on the actual state of the free radicals. This maintains the parameter values ​​of the free radicals' characteristic parameters within a preset threshold range, achieving stable control of the free radicals' characteristic parameters, such as concentration, to meet the actual needs of semiconductor processes. Rather than controlling based on the input parameters of the RPS, this allows for direct and precise control of the free radical parameters. Additionally, the signal processing component 12 can generate a feedforward signal based on the gas pressure / flow rate at the inlet, and synchronously transmit the feedforward signal and control signal to the feedback controller 22 to achieve stable control of the free radical parameters. Through a closed-loop control architecture, the feedforward signal determines the inlet interference, and the feedback signal corrects the deviation of the characteristic parameters, improving the dynamic stability of the free radical parameters.

[0046] Based on the above embodiments, such as Figure 2 As shown, this embodiment provides a remote plasma source, including: Plasma generating device 21 for generating free radicals; the plasma generating device 21 is the device described in the foregoing embodiment that includes a power module 211 and a gas dissociation chamber 212, the power module 211 containing an inverter module. The controller 22 is used to receive the control signal transmitted by the monitoring system 1, and based on the control signal, maintain the parameter value of the characteristic parameter of the free radical within a preset threshold range; the controller 22 may be the feedback controller of the aforementioned embodiment, used to receive the control signal and the feedforward signal, and adjust the operating frequency or voltage amplitude of the inverter module.

[0047] For a detailed description of the structure and function of the monitoring system 1 in this embodiment, please refer to the relevant content of the foregoing embodiments, which will not be repeated here.

[0048] In this embodiment, the remote plasma source 2 includes a plasma generating device 21 and a controller 22. The controller 22 receives the control signal from the monitoring system 1 and controls the characteristic parameters of the free radicals generated by the plasma generating device 21 based on the signal. This ensures the stability of the free radical parameters from a hardware perspective and avoids the shortcomings of traditional indirect control schemes such as current control and power control, which cannot accurately control the process. This can improve the consistency of the process.

[0049] Based on the above embodiments, it can be seen that the remote plasma source 2 can be directly connected to the process reaction chamber 4, or connected to the process reaction chamber 4 through the transmission pipeline 3. In the case of pipeline connection, the loss during the transmission process can be captured by the monitoring system 1 to avoid the problem that the characteristic parameters of the monitored free radicals do not match the actual value due to the recombination of free radicals in the transmission pipeline 3 and the inability to obtain the specific recombination ratio. This ensures the control accuracy of the process product.

[0050] In one embodiment, when controlling the characteristic parameters of free radicals generated by the plasma generation device 21 based on a control signal, the controller 22 is specifically used to generate a voltage adjustment signal based on the control signal and transmit the voltage adjustment signal to the plasma generation device 21. This causes the plasma generation device 21 to generate a corresponding voltage or current based on the voltage adjustment signal, thereby dissociating the process gas to generate free radicals. When the voltage increases, the dissociation rate of the process gas increases, and the concentration of free radicals increases; when the voltage decreases, the dissociation rate of the process gas decreases, and the concentration of free radicals decreases. This maintains the parameter values ​​of the free radicals within a preset threshold range, achieving stable control of the free radicals. This embodiment can change the state of the plasma generation device 21 by adjusting the voltage, thereby changing the characteristic parameters of the free radicals. For example, voltage adjustment can be applied to actual characteristic values ​​such as the concentration of free radicals, thereby achieving parameter correction of the characteristic values ​​and maintaining them within a preset threshold range. Therefore, voltage adjustment can improve the control efficiency of the process products and significantly enhance the control accuracy of free radicals. Furthermore, in this embodiment, the controller 22 can adjust the operating frequency or voltage amplitude of the inverter module in the power module 211. Therefore, it can be understood that the voltage regulation signal in this embodiment can be a signal that directly or indirectly regulates the voltage output by the power module 211. For example, the controller 22 can directly generate a voltage regulation signal to adjust the output voltage amplitude of the inverter module; or it can generate a frequency regulation signal to adjust the operating frequency of the inverter module, thereby achieving the adjustment of the output voltage through the adjusted operating frequency of the inverter module.

[0051] In one embodiment, taking a voltage regulation signal as an example, the plasma generation device 21 specifically includes: a power supply module 211, used to convert a three-phase AC voltage into a target AC voltage that meets the preset gas dissociation conditions for continuous dissociation of the process gas, and to power the gas dissociation chamber 212 through the target AC voltage; the gas dissociation chamber 212 is used to dissociate the process gas using the target AC voltage to generate free radicals. Figure 4As shown, the power supply module 211 comprises modules such as a rectifier module, an inverter module, a filter, and a start-up circuit. Specifically, the filter can be an electromagnetic interference filter (EMI filter); the rectifier module specifically includes a power factor correction (Boost PFC) module and a DC bus capacitor; the inverter module specifically includes a full-bridge inverter and a gate driver; and the resonant matching module specifically includes a resonant tank circuit and a transformer. The power supply module 211 is primarily responsible for converting the three-phase AC voltage into a 400kHz AC voltage, which provides energy to the chamber via the transformer. The chamber uses a transformer coupling scheme under the influence of a medium-frequency electric field to ionize and thermally dissociate process gases such as N2, O2, H2, and NF3 into free radicals, which are then transported to the process reaction chamber 4 for reaction. The heating module controls the chamber temperature to ensure that plasma generation and reaction occur within the required temperature range. The fan is used for equipment cooling, and its speed is adjusted by the controller 22. In this embodiment, the power supply module 211 directly receives voltage regulation signals to dynamically adjust the target AC voltage, thereby controlling the reaction products.

[0052] For example, the power module 211 includes an inverter module for acquiring a voltage regulation signal and adjusting the target AC voltage according to the voltage regulation signal to obtain the regulated voltage. Correspondingly, the gas dissociation chamber 212 is used to dissociate the process gas using the regulated voltage to adjust the characteristic parameters of the free radicals and maintain the parameter values ​​within a preset threshold range. In this embodiment, the power module 211 mainly receives the voltage regulation signal through the inverter module and adjusts the target AC voltage so that the gas dissociation chamber 212 can dissociate the process gas using the regulated voltage and dynamically correct the characteristic parameters of the free radicals. This allows for dynamic adjustment based on the actual state of the free radicals, effectively controlling the dissociation efficiency of the process gas and thus achieving control over the free radicals. Furthermore, the power module 211 is also used to generate a resonant voltage and maintain the target AC voltage; the gas dissociation chamber 212 is used to excite the process gas using the resonant voltage to generate free radicals, wherein the resonant voltage is the voltage that satisfies the gas ignition conditions. In this way, the gas dissociation chamber 212 can use the resonant voltage to excite the process gas to generate free radicals and maintain the target AC voltage. The resonant voltage meets the ignition conditions for gas dissociation, quickly realizing the excitation from gas to plasma, adapting to the needs of semiconductor processes, and improving the stability of free radical parameters by maintaining the target AC voltage.

[0053] In this embodiment, as Figure 4As shown, the rectifier module is the rectifier unit of the Boost PFC. Inside the Boost PFC, the three-phase AC power is directly converted into pulsating DC power through the rectifier bridge. The inverter module can be a full-bridge inverter. The full-bridge inverter receives stable DC power from the DC-Link and inverts it into 400kHz high-frequency AC power through the high-frequency switching of power switching transistors (such as FETs), providing high-frequency power to the subsequent transformer. The filters are divided into input-side electromagnetic filters and post-inverter resonant filters. The input-side filter can be an EMI filter to ensure the purity of the three-phase AC power input and avoid interference with subsequent rectification. The post-inverter resonant filter can be a resonant tank to perform resonant filtering and impedance matching on the 400kHz high-frequency AC power output from the full-bridge inverter, ensuring efficient transfer of high-frequency power to the transformer. The ignition circuit can include a resonant tank and a transformer, which can provide an initial high voltage to break down and ionize the gas in the chamber. Driven by the inverter power, the resonant tank generates a resonant high voltage, which is transmitted to the chamber through the transformer coupling, causing the process gas in the chamber to break down and ionize instantly, completing the "ignition" process, that is, the initial excitation from gas to plasma. The power module 211 also includes a maintenance circuit to maintain a stable discharge after plasma ignition, ensuring continuous and stable plasma generation.

[0054] Specifically, such as Figure 4 As shown, the electromagnetic interference filter (EMI filter) can suppress external electromagnetic noise from entering the power module 211 and the radiation of internal noise from the power module 211, ensuring the electromagnetic compatibility of the circuit and allowing the power module 211 to operate stably; the power factor correction (Boost PFC) module can improve the power factor, making the input current close to a sine wave and in phase with the voltage, reducing reactive power loss, and at the same time stabilizing the DC bus voltage through the boost structure, providing high-quality DC power for subsequent circuits; the DC bus capacitor (DC-Link Capacitor), i.e. Figure 4The capacitor following the Boost PFC stores electrical energy, stabilizes the DC bus voltage, and filters out voltage fluctuations, providing a stable DC input for the inverter. The full-bridge inverter converts the DC power from the DC bus into high-frequency AC power (e.g., 400kHz), providing suitable mid-frequency energy for plasma excitation to the subsequent resonant tank circuit and transformer. The resonant tank circuit, composed of inductors and capacitors, operates in a resonant state, improving inverter efficiency, reducing power loss, and matching the chamber impedance to ensure energy transfer to the chamber. The transformer uses electromagnetic induction to achieve voltage transformation, providing the voltage / current for ionizing the excitation gas in the chamber. In the plasma dissociation chamber, after the introduction of process gases (e.g., NF3, H2), the gas is ionized into plasma under the high-frequency energy excitation of the transformer, generating active groups such as F and H for semiconductor chamber cleaning and wafer surface treatment. The heating module... The module is used to control the temperature of the chamber or related components, ensuring that plasma generation and reaction occur within the temperature range required by the process. The flow switch is used to monitor the flow rate of the process gas, ensuring that the gas flow rate meets the process requirements. If the flow rate is abnormal, it can trigger an adjustment operation to maintain the stability of plasma generation. The inspection terminal, which is the interface connecting to the signal acquisition component 11, is used to detect the characteristic parameters of free radicals (such as the concentration and pressure of free radicals) in the chamber 4 / transmission pipe 3, providing feedback signals to the controller 22. The controller 22 is used to receive feedback from various sensors, such as DC bus current, inverter output current, transformer primary current, power transistor (FET) temperature, cooling fan speed, etc., and output signals to control the inverter, fan, and other components to achieve the goal of stabilizing the characteristic parameters of free radicals. The gate driver is used to receive the weak control signal from the controller 22, amplify it, and drive the switching devices of the full-bridge inverter to ensure the normal operation of the inverter. The DC bus sensor (DC-Link Sensor) is used to detect the voltage / current of the DC bus and feed it back to the controller 22 for bus status monitoring and voltage / current regulation. The DC current sensor (DC... The DC-side sensor is used to detect the DC-side current to achieve overcurrent protection; the inverter output current protection is used to detect the inverter output current to prevent excessive current from damaging the inverter; primary-side current detection and protection (Pri) are also provided.The Current Sensing and Protection module is used to detect the primary current of the transformer and monitor its operating status; the FET transistor over-temperature detection module is used to detect the temperature of power transistors (such as FETs) to prevent overheating damage; the fan speed feedback module is used to detect the fan speed, and the controller 22 adjusts the fan speed accordingly to ensure that the equipment operates within a safe temperature range.

[0055] For example, during plasma generation, the plasma dissociation chamber, under the influence of a mid-frequency electric field, dissociates gases such as N2 / O2 / H2 / NF3 into free radicals. Process gases (such as NF3 and H2) are introduced into the chamber through pipes. Then, a transformer transmits high-frequency electrical energy into the chamber, creating an electric field. This electric field accelerates the free electrons in the gas, causing high-energy electrons to collide with gas molecules. If the collision energy exceeds the gas ionization threshold (e.g., the ionization energy of NF3 is approximately 16 eV), electrons in the molecules detach from the atomic nucleus, forming plasma. Simultaneously, highly reactive free radicals are dissociated (e.g., NF3 dissociates into F free radicals, and H2 dissociates into H atoms), which are then transmitted to the process reaction chamber 4. Furthermore, when controlling the concentration of free radicals, taking the signal acquisition component 11 in the monitoring system 1 as an example (OES), such as... Figure 2 As shown, in the OES, optical probe 113 collects plasma glow (e.g., the characteristic glow wavelength of F radicals is 703.7 nm) from the chamber / pipe; optical fiber 112 transmits the glow signal to detector 111; detector 111 first filters stray light, then converts the characteristic wavelength glow into an electrical signal, and calculates the target radical concentration by comparing the glow intensity with a known concentration. In addition to detecting radical concentration, monitoring system 1 also monitors the gas pressure and flow rate at the RPS inlet, transmitting these parameters as feedforward signals to controller 22. If the gas pressure suddenly increases, controller 22 can adjust the inverter power in advance to avoid sudden changes in plasma concentration. In addition, the controller 22 adopts a PI / PID controller, which performs proportional-integral-derivative calculations on the deviation between the actual concentration and the given concentration, and outputs adjustment commands, such as increasing the inverter frequency by 5kHz or increasing the voltage amplitude by 10V. Then, the controller 22 amplifies the adjustment commands through the Gate Driver, drives the full-bridge inverter to change the switching frequency or duty cycle, so as to adjust the high-frequency electrical energy input to the transformer, thereby adjusting the plasma concentration in the chamber until the actual concentration is close to the given concentration.

[0056] In one embodiment, the controller 22 is further configured to acquire a target signal sent by a host computer. This target signal is used to determine the target parameter values ​​required by the process. Therefore, the controller 22 can determine the target parameter values ​​based on the target signal, and control the characteristic parameters of the free radicals generated by the remote plasma source 2 based on the control signal and the target parameter values. The target parameter values ​​are within a preset threshold range. The controller 22 is also responsible for executing the start / stop commands issued by the machine and for uploading the internal operating status and fault information of the RPS to the machine. The controller 22 may include a control chip and industrial Ethernet, Serial Peripheral Interface (SPI), etc. In this embodiment, the controller 22 can acquire the target signal sent by the host computer, determine the target parameter values ​​within a preset threshold range, and, combined with the control signals provided by the monitoring system 1, perform closed-loop control of the free radical characteristic parameters. This allows for dynamic setting of target parameters according to different process requirements such as chamber cleaning and wafer processing, ensuring the implementation of semiconductor process requirements and facilitating precise control of reaction products.

[0057] An example is given of determining the target concentration value of free radicals based on a target signal, and controlling the concentration of free radicals based on the target concentration value and a control signal indicating the concentration of free radicals. Specifically, the controller 22 acquires the target signal sent by the host computer, which contains the free radical concentration value required by the process (e.g., 100). The controller 22 determines this value as the target parameter value for this process. Then, the signal acquisition component 11 detects the measured concentration (e.g., 90). The signal processing component 12 compares the measured concentration with the target parameter value (100) to obtain the concentration deviation (-10), and generates a control signal corresponding to a +5% power adjustment. At the same time, based on the original measurement signal of a sudden increase in inlet flow detected at the second preset position, the signal processing component 12 predicts that the concentration will be diluted and generates a feedforward signal corresponding to a +3% power adjustment. Then, the controller 22 superimposes the control signal and the feedforward signal to obtain the total adjustment (+8%), and adjusts the operating frequency or voltage amplitude of the inverter in the power module 211 accordingly, so that the free radical concentration rises to the target parameter value of 100.

[0058] In one specific implementation, the detection module can continuously collect the concentration of free radicals within the process reaction chamber 4 / transfer pipe 3 and convert it into an analog electrical signal recognizable by the controller 22, namely the feedback signal H(s). This feedback signal H(s) is an electrical signal output by the signal processing component 12 representing the measured free radical concentration. Then, based on the target signal sent by the host computer and adjusted based on the feedforward signal, the adjusted target signal is compared with the feedback signal H(s) to calculate the concentration deviation. Specifically, the control module can perform a difference calculation between the adjusted target signal and the feedback signal H(s) to obtain the deviation between the actual concentration and the target concentration. It is understood that in this implementation, the adjusted target signal does not simply indicate a given concentration, but rather the sum of the given concentration and the compensation amount of the feedforward signal F(s). For example, if the process requires a free radical concentration of 10¹⁰ F. 6 cm - ³, meaning a given concentration, but the detection module detects a sudden 20% increase in the RPS inlet flow rate, i.e., the feedforward signal F(s), the control module will adjust the target signal to 1.1×10¹ in advance. 6 cm - ³, we can assume the adjusted target signal corresponds to an electrical signal of 3V, i.e., the target concentration, and the feedback signal H(s) is 2.5V, meaning the actual concentration is low. Therefore, the deviation is calculated as 3V - 2.5V = 0.5V, indicating insufficient actual concentration and a need to increase generation. Next, the controller can perform proportional (P), integral (I), and derivative (D) operations on the concentration deviation signal based on a PI / PID algorithm, converting the voltage deviation into executable inverter adjustment commands, such as a frequency of +5kHz or a voltage amplitude of +10V. The power circuit then executes the commands, adjusting the inverter's output power. After receiving the adjustment commands from the controller 22, the power circuit (including the full-bridge inverter, resonant tank circuit, and transformer) changes the high-frequency power parameters output to the RPS chamber, such as frequency or voltage. For example, if the command is a voltage amplitude of +10V, the controller 22 will adjust the FET's on-time using pulse width modulation (PWM) to increase the inverter's output voltage and enhance the power transmitted to the transformer. At this point, electrical energy is transferred to the chamber, which can adjust the concentration of free radicals. The adjusted high-frequency electrical energy is coupled to the RPS chamber through a transformer, changing the electric field strength of the chamber and thus adjusting the gas ionization efficiency, so that the concentration of free radicals is adjusted to a given concentration.

[0059] Through the above technical solution, the signal acquisition component 11 can directly detect the reaction products generated by RPS, i.e., the free radicals themselves, thereby obtaining the real state data of the free radicals. The signal processing component 12 connected to the acquisition component directly converts the detected data into control commands, thereby directly adjusting the RPS based on the actual state of the free radicals and maintaining the characteristic parameters of the free radicals within a preset threshold range to meet the actual needs of semiconductor processes. Furthermore, the signal processing component 12 can generate a feedforward signal based on the gas pressure / flow rate at the inlet end, and transmit the feedforward signal and control signal synchronously to the feedback controller to achieve stable control of the free radical parameters. Through a closed-loop control architecture, the feedforward signal is used to determine the inlet interference, and the feedback signal is used to correct the deviation of the characteristic parameters, thereby improving the dynamic stability of the characteristic parameters of the free radicals.

[0060] Based on any of the foregoing embodiments, the remote plasma source and its monitoring system, such as Figure 5 As shown, this embodiment provides a method for monitoring a remote plasma source. The method includes: Step S11: The monitoring system detects the characteristic parameters of the free radicals generated by the remote plasma source through the signal acquisition component, and obtains the target characteristic value of the free radicals.

[0061] Step S12: The monitoring system generates a control signal based on the target feature value transmitted by the signal acquisition component through the signal processing component connected to the signal acquisition component, and transmits the control signal to the controller in the remote plasma source.

[0062] Step S13: The controller in the remote plasma source maintains the parameter values ​​of the characteristic parameters of the free radical within a preset threshold range based on the control signal, thereby controlling the stability of the free radical.

[0063] It is understood that all optional implementations in the aforementioned device embodiments can be directly applied to this method embodiment. For example, the signal processing component can also generate a feedforward signal based on the process gas pressure or flow rate collected at the second preset location, and transmit the feedforward signal and the control signal together to the controller. The controller then obtains the total adjustment amount and executes the adjustment control to improve the system's response speed. The controller can use a PI / PID algorithm to generate adjustment commands. The signal acquisition component can use various detection instruments such as emission spectrometers and absorption spectrometers to achieve non-invasive detection of free radical concentrations. For a detailed description of each step in this method, please refer to the functional descriptions of the relevant hardware and software in the aforementioned device embodiments, which will not be repeated here.

[0064] In this embodiment, remote plasma source monitoring can be achieved through a signal acquisition component and a signal processing component. The signal acquisition component directly detects the characteristic parameters of free radicals generated by the remote plasma source and obtains the target characteristic values. The signal processing component generates control signals based on the target characteristic values ​​and transmits them to the controller. Finally, the controller stabilizes the characteristic parameters of free radicals within a preset threshold range. This addresses the current problem of indirect control based solely on RPS primary-side current and input power, which cannot directly perceive the actual state of free radicals and cannot cope with transmission pipeline losses, resulting in insufficient control precision. This embodiment achieves direct and real-time detection of free radical characteristic parameters, solving the core problem of mismatch between input power and actual reaction product concentration. It provides reliable data for controlling the stability of free radicals, enabling precise control of free radical stability and thus improving the control precision of reaction products in the process reaction chamber.

[0065] This application also provides a reaction product generation apparatus, and the technical features, implementation methods, and technical effects disclosed in all the foregoing embodiments regarding the remote plasma source, remote plasma source monitoring system, and monitoring method are all applicable to the reaction product generation apparatus of this embodiment. The reaction product generation apparatus provided in this embodiment includes: Remote plasma source; The process reaction chamber connected to the remote plasma source is used to realize the process reaction based on the free radicals transmitted by the remote plasma source to generate the corresponding reaction products.

[0066] In this embodiment, the reaction product generation device uses a remote plasma source with real-time concentration control to stably maintain the characteristic parameters of free radicals within the preset threshold range required by the process, thereby achieving precise control over the stability of free radicals and improving the control accuracy of reaction products in the process reaction chamber.

[0067] This application also provides a control system for the characteristic parameters of free radicals, comprising: a monitoring system as described in any of the foregoing embodiments, i.e., the monitoring system in the foregoing embodiments that includes a signal acquisition component and a signal processing component, responsible for detecting the characteristic parameters of free radicals and the process gas parameters, and generating control signals; and a remote plasma source as described in any of the foregoing embodiments, i.e., the RPS device in the foregoing embodiments that includes a plasma generation device and a controller, responsible for receiving control signals and generating stable free radicals. The reaction product generation device in the above embodiments can use the above control system to control the characteristic parameters of free radicals transmitted to the process reaction chamber, thereby improving the control accuracy of the reaction products in the process reaction chamber.

[0068] Furthermore, this application also discloses a computer-readable storage medium for storing a computer program; wherein, when the computer program is executed by a processor, it implements the aforementioned method for monitoring a remote plasma source. Specific steps of this method can be found in the corresponding content disclosed in the foregoing embodiments, and will not be repeated here.

[0069] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section.

[0070] Each of the above modules or units can be implemented through software, hardware, or a combination of both. In this application, "implemented through software" means that the processor reads and executes program instructions stored in memory to implement the functions corresponding to the above modules or units. The processor refers to a processing circuit capable of executing program instructions, including but not limited to at least one of the following: a central processing unit (CPU), a microprocessor, a digital signal processor (DSP), a microcontroller unit (MCU), or an artificial intelligence processor, etc., and other processing circuits capable of running program instructions. In some embodiments, the processor may also include circuits with other processing functions (such as hardware circuits for hardware acceleration, bus and interface circuits, etc.). Processors can be presented as integrated chips, for example, as integrated chips whose processing functions only include executing software instructions, or they can be presented as SoCs (system on a chip), that is, on a single chip, in addition to the processing circuits (usually called "cores") that can run program instructions, there are also other hardware circuits for implementing specific functions (of course, these hardware circuits can also be implemented separately based on ASICs or FPGAs). Correspondingly, in addition to executing software instructions, the processing functions can also include various hardware acceleration functions (such as AI calculations, encoding and decoding, compression and decompression, etc.).

[0071] In this application, "implemented in hardware" means that the functions of the above-mentioned modules or units are implemented through hardware processing circuits that do not have program instruction processing capabilities. These hardware processing circuits can be composed of discrete hardware components or integrated circuits. To reduce power consumption and size, integrated circuits are typically used. Hardware processing circuits can include ASICs (application-specific integrated circuits) or PLDs (programmable logic devices); PLDs can include FPGAs (field-programmable gate arrays), CPLDs (complex programmable logic devices), and so on. These hardware processing circuits can be a single packaged semiconductor chip (e.g., packaged as an ASIC); or they can be integrated with other circuits (e.g., CPUs, DSPs) and packaged into a single semiconductor chip. For example, multiple hardware circuits and a CPU can be formed on a silicon substrate and packaged into a single chip; this type of chip is also called a SoC. Alternatively, circuits for implementing FPGA functions and a CPU can be formed on a silicon substrate and encapsulated into a single chip; this type of chip is also called a SoPC (system on a programmable chip).

[0072] It should be noted that when this application is implemented through software, hardware, or a combination of both, different software or hardware can be used, and it is not limited to using only one type of software or hardware. For example, one module or unit can be implemented using a CPU, while another module or unit can be implemented using a DSP. Similarly, when implemented using hardware, one module or unit can be implemented using an ASIC, while another module or unit can be implemented using an FPGA. Of course, it is not limited to using the same software (e.g., all through a CPU) or the same hardware (e.g., all through an ASIC) to implement some or all modules or units. Furthermore, those skilled in the art will understand that software is generally more flexible but less performant than hardware, while hardware is the opposite. Therefore, those skilled in the art can choose software, hardware, or a combination of both based on actual needs.

Claims

1. A monitoring system for a remote plasma source, characterized in that, include: A signal acquisition component is used to detect the characteristic parameters of free radicals generated by a remote plasma source and obtain the target characteristic values ​​of the free radicals; A signal processing component connected to the signal acquisition component is used to generate a control signal based on the target feature value transmitted by the signal acquisition component, and transmit the control signal to the controller; the control signal is used to maintain the parameter value of the feature parameter of the free radical within a preset threshold range.

2. The monitoring system for a remote plasma source according to claim 1, characterized in that, The signal acquisition component is deployed at a first preset location; the first preset location is any one of the following: inside the process reaction chamber, in the transmission pipeline, in the gas dissociation chamber of the remote plasma source, and at the outlet of the process reaction chamber; the transmission pipeline is a pipeline used to transmit the free radicals generated by the remote plasma source to the process reaction chamber.

3. The monitoring system for a remote plasma source according to claim 2, characterized in that, The signal acquisition component is used to detect the feature parameters at the first preset position to obtain the target feature value; The characteristic parameters include any one or more of the following: concentration of the free radicals, temperature, pressure, dissociation rate, and flow rate.

4. The monitoring system for a remote plasma source according to any one of claims 1 to 3, characterized in that, The signal acquisition component is deployed at a second preset position, and the signal acquisition component is also used to detect the gas pressure and / or gas flow rate of the process gas at the second preset position; the second preset position is the chamber inlet of the gas dissociation chamber of the remote plasma source.

5. The monitoring system for a remote plasma source according to claim 4, characterized in that, The signal processing component is further configured to generate a feedforward signal based on the gas pressure and / or gas flow rate transmitted by the signal acquisition component, and transmit the feedforward signal to the controller. The feedforward signal is used in conjunction with the control signal to maintain the parameter values ​​of the characteristic parameters of the free radicals generated by the remote plasma source within a preset threshold range. The controller is a feedback controller.

6. A remote plasma source, characterized in that, include: A plasma generation device for producing free radicals; A controller is configured to receive a control signal transmitted from a monitoring system as described in any one of claims 1 to 5, and based on the control signal, maintain the parameter values ​​of the characteristic parameters of the free radical within a preset threshold range.

7. The remote plasma source according to claim 6, characterized in that, The remote plasma source is directly connected to the process reaction chamber, or connected to the process reaction chamber through a transmission pipeline.

8. The remote plasma source according to claim 6 or 7, characterized in that, The controller is configured to generate a voltage regulation signal based on the control signal and transmit the voltage regulation signal to the plasma generation device, so that after the plasma generation device generates a corresponding voltage based on the voltage regulation signal, it dissociates the process gas to generate free radicals, thereby maintaining the parameter values ​​of the characteristic parameters of the free radicals within the preset threshold range.

9. The remote plasma source according to claim 8, characterized in that, The plasma generation device includes: The power module is used to convert the three-phase AC voltage into a target AC voltage that meets the preset gas dissociation conditions, and to supply power to the gas dissociation chamber through the target AC voltage. A gas dissociation chamber is used to dissociate the process gas using the target AC voltage to generate the free radicals.

10. The remote plasma source according to claim 9, characterized in that, The power module includes an inverter module, used to acquire the voltage regulation signal and adjust the target AC voltage according to the voltage regulation signal to obtain the regulated voltage; The gas dissociation chamber is used to dissociate the process gas using the adjusted voltage, thereby adjusting the characteristic parameters of the free radicals and maintaining the parameter values ​​of the characteristic parameters within a preset threshold range.

11. The remote plasma source according to claim 10, characterized in that, The power module is also used to generate a resonant voltage and maintain the target AC voltage; the resonant voltage is the voltage that satisfies the gas ignition condition; Accordingly, the gas dissociation chamber is used to excite the process gas using the resonant voltage to generate the free radicals.

12. The remote plasma source according to any one of claims 6 to 11, characterized in that, The controller is also configured to acquire a target signal sent by a host computer, determine a target parameter value based on the target signal, and control the characteristic parameters of the free radicals generated by the remote plasma source based on the control signal and the target parameter value. The target parameter value is a parameter value within a preset threshold range.

13. A method for monitoring a remote plasma source, characterized in that, include: The characteristic parameters of the free radicals generated by the remote plasma source are detected by the signal acquisition component, and the target characteristic values ​​of the free radicals are obtained. A control signal is generated based on the target feature value transmitted by the signal acquisition component through a signal processing component connected to the signal acquisition component, and the control signal is transmitted to the controller; the control signal is used to maintain the parameter value of the feature parameter of the free radical within a preset threshold range.

14. A method for controlling characteristic parameters of free radicals, characterized in that, include: The system receives a control signal from a signal processing component, the control signal being generated based on a target feature value transmitted by a signal acquisition component, the target feature value being obtained by detecting the characteristic parameters of free radicals generated by a remote plasma source; Based on the control signal, the parameter values ​​of the characteristic parameters of the free radicals are maintained within a preset threshold range.

15. A reaction product generating apparatus, characterized in that, include: The remote plasma source as described in any one of claims 6 to 12; The process reaction chamber connected to the remote plasma source is used to realize the process reaction based on the free radicals transmitted by the remote plasma source to generate the corresponding reaction products.

16. A control system for characteristic parameters of free radicals, characterized in that, include: The monitoring system as described in any one of claims 1-5, and the remote plasma source as described in any one of claims 6-12.

17. A computer-readable storage medium, characterized in that, Used to store a computer program, which, when executed by a processor, implements the characteristic parameter control method for free radicals as described in claim 14.

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