Radio frequency source device, impedance matching method thereof and semiconductor process equipment

Abstract

The invention provides a radio frequency source device which is applied to semiconductor process equipment and comprises a first radio frequency unit, a second radio frequency unit and a controller, and the first radio frequency unit and the second radio frequency unit are used for loading radio frequency power signals to a process chamber of the semiconductor process equipment. The radio frequency power signal is a pulse signal with a plurality of stages in each period; and the controller is used for controlling the first radio frequency unit and the second radio frequency unit to perform impedance matching in each stage, and enabling an impedance matching mode adopted by the first radio frequency unit in each stage to be different from an impedance matching mode adopted by the second radio frequency unit in the corresponding stage. According to the scheme, the problem that in the prior art, when two radio frequency power supplies adopt frequency sweeping matching at the same time or two matchers adopt matcher matching at the same time to carry out impedance matching, mutual interference exists, and the reflection power is high can be solved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor manufacturing, and in particular, to a radio frequency source device, an impedance matching method thereof, and a semiconductor process equipment. Background Art

[0002] In recent years, with the rapid development of the microelectronics industry and the continuous reduction of the feature size of semiconductor devices, higher requirements have been put forward for the plasma processing technology in the industry. The dual frequency capacitively coupled plasma (DF-CCP) can not only generate a large-area uniform plasma, but also independently control the plasma density and the ion energy bombarding the electrode plate, so it has been widely used in the semiconductor manufacturing process. The inductively coupled plasma (ICP) can obtain a high-density plasma at a relatively low working pressure, and has a simple structure and low cost, and can also independently control the plasma density and the particle energy incident on the wafer. The electron cyclotron resonance plasma (ECR) can obtain a high-density plasma at a relatively low working pressure. At present, the above various types of plasma sources are all applied in the semiconductor industry.

[0003] With the further development of integrated circuits and the wide application of etching processes of 20 nm and below, the pulsed plasma technology has many advantages compared with the continuous wave plasma technology, such as reducing plasma-induced damage (PID), enhancing plasma chemical etching characteristics, increasing etching selectivity, improving the process adjustment window, and so on. The commonly used pulsed discharge is modulated by the periodic change of the fed power, and the pulse is usually in the form of a square wave, and the period of the pulse signal ranges from dozens of microseconds to dozens of milliseconds. Compared with the continuous wave discharge, the pulsed discharge can obtain a wider and more independent control of the plasma parameters; it can effectively reduce the damage caused by the plasma to the surface to be processed. By modulating the pulsed discharge, a higher aspect ratio, a greater etching selectivity, less surface damage caused by the plasma, and a greater etching yield can be obtained.

[0004] In the process of radio frequency energy transmission, the output impedance of the radio frequency power supply is generally 50 ohms, while the input impedance of the process chamber is generally a non-50 ohm impedance value with a real part impedance and an imaginary part impedance. Therefore, if the energy is directly transmitted to the process chamber, due to the impedance mismatch of the transmission path, the reflection of the radio frequency energy may occur, resulting in the inability to normally excite the plasma in the process chamber. Therefore, a matching device needs to be connected between the radio frequency power supply and the process chamber to make the input impedance at the back end of the matching device 50 ohms, which is convenient for the normal transmission of energy.

[0005] Conventional matching methods used in the prior art include, for example, sweep matching and matcher matching. However, these two matching methods are currently only applicable to single-frequency plasma systems. For a dual-frequency plasma system, that is, a situation where two RF power supplies with different frequencies simultaneously output RF power signals through two matchers, when sweep matching is simultaneously used for the two RF power supplies or matcher matching is simultaneously used for the two matchers for impedance matching, there is mutual interference, resulting in a relatively high reflected power. Summary of the Invention

[0006] The present invention aims to solve at least one of the technical problems existing in the prior art, and provides a RF source device, its impedance matching method, and a semiconductor process equipment, which can solve the problem in the prior art that when sweep matching is simultaneously used for two RF power supplies or matcher matching is simultaneously used for two matchers for impedance matching, there is mutual interference, resulting in a relatively high reflected power.

[0007] To achieve the object of the present invention, there is provided a RF source device applied to a semiconductor process equipment, including a first RF unit, a second RF unit, and a controller. The first RF unit and the second RF unit are used to load RF power signals into a process chamber of the semiconductor process equipment, and the RF power signal is a pulse signal having multiple phases in each period;

[0008] The controller is used to control the first RF unit and the second RF unit to perform impedance matching in each of the phases, and make the impedance matching mode adopted by the first RF unit in each of the phases different from the impedance matching mode adopted by the second RF unit in the corresponding phase.

[0009] Optionally, both the first RF unit and the second RF unit include a power supply module and an impedance matcher module. The power supply module is used to load the RF power signal into the process chamber through the impedance matching module;

[0010] The impedance matching mode includes a sweep matching mode and a matcher matching mode;

[0011] In the sweep matching mode, the controller is used to control the power supply module to adjust the frequency of the RF power signal to achieve impedance matching between the power supply module and the process chamber;

[0012] In the matcher matching mode, the controller is used to control an actuator of the impedance matcher module to adjust the impedance value of the impedance matching network to achieve impedance matching between the power supply module and the process chamber.

[0013] Optionally, the controller is further configured to control the first radio frequency unit to adopt the swept-frequency matching mode in at least one of multiple phases within each of the cycles, and control the second radio frequency unit to adopt the swept-frequency matching mode in at least one of the multiple phases within each of the cycles, and the phases in which the first radio frequency unit and the second radio frequency unit adopt the swept-frequency matching mode are different.

[0014] Optionally, the power values of the radio frequency power signals loaded by the first radio frequency unit and the second radio frequency unit are non-zero in each of the phases;

[0015] The controller is further configured to control both the first radio frequency unit and the second radio frequency unit to switch from one of adopting the swept-frequency matching mode and adopting the matcher matching mode to the other at the switching moment between two adjacent phases.

[0016] Optionally, when the power value of the radio frequency power signal loaded by the first radio frequency unit is zero, the controller is configured to control the first radio frequency unit not to perform impedance matching; and / or, when the power value of the radio frequency power signal loaded by the second radio frequency unit is zero, the controller is configured to control the second radio frequency unit not to perform impedance matching.

[0017] Optionally, one of two adjacent phases within each of the cycles is a first phase and the other is a second phase; the power value of the radio frequency power signal loaded by the first radio frequency unit is non-zero in the first phase and zero in the second phase;

[0018] The power value of the radio frequency power signal loaded by the second radio frequency unit is non-zero in the first phase and zero in the second phase; or, the power value of the radio frequency power signal loaded by the second radio frequency unit is zero in the first phase and non-zero in the second phase.

[0019] Optionally, the power value of the radio frequency power signal loaded by the first radio frequency unit remains unchanged or changes according to a first preset rule during the process of passing through each phase in sequence; and / or,

[0020] The power value of the radio frequency power signal loaded by the second radio frequency unit remains unchanged or changes according to a second preset rule during the process of passing through each phase in sequence.

[0021] Optionally, each of the cycles has two phases, namely a first phase and a second phase;

[0022] The first preset rule is that the power value of the radio frequency power signal loaded by the first radio frequency unit in the first phase is not equal to the power value in the second phase; and / or,

[0023] The second preset rule is that the power value of the radio frequency power signal loaded by the second radio frequency unit in the first stage is not equal to the power value in the second stage.

[0024] Optionally, the radio frequency source device further includes a first detection unit and a second detection unit, wherein,

[0025] The first detection unit is connected between the output end of the first radio frequency unit and the process chamber, and is used to detect the first phase information on the output end side of the first radio frequency unit in real time and send it to the controller;

[0026] The second detection unit is connected between the output end of the second radio frequency unit and the process chamber, and is used to detect the second phase information on the output end side of the second radio frequency unit in real time and send it to the controller;

[0027] The controller is further used to obtain the phase offset of the radio frequency power signals loaded by the first radio frequency unit and the second radio frequency unit according to the first phase information and the second phase information, and according to the phase offset, advance or delay the start time of the radio frequency power signals loaded by the first radio frequency unit and / or the second radio frequency unit in each stage, so that the phase offset is equal to zero.

[0028] Optionally, both the first phase information and the second phase information include the frequency of the radio frequency power signal;

[0029] The controller is further used to obtain the switching time between every two adjacent stages according to the change of the frequency of the radio frequency power signal in each stage, and calculate the difference between the switching times corresponding to the first radio frequency unit and the second radio frequency unit as the phase offset.

[0030] Optionally, the frequency of the power supply module in the first radio frequency unit is different from the frequency of the power supply module in the second radio frequency unit.

[0031] As another technical solution, the present invention further provides a semiconductor processing equipment, including a process chamber, and further including the above radio frequency source device provided by the present invention.

[0032] As another technical solution, the present invention further provides an impedance matching method for a radio frequency source device, including:

[0033] When the first radio frequency unit and the second radio frequency unit simultaneously load radio frequency power signals into the process chamber of the semiconductor process equipment, the radio frequency power signal is a pulse signal having multiple stages in each cycle; in each of the stages, the first radio frequency unit and the second radio frequency unit are controlled to perform impedance matching, and the impedance matching mode adopted by the first radio frequency unit in each stage is different from the impedance matching mode adopted by the second radio frequency unit in the corresponding stage.

[0034] The present invention has the following beneficial effects:

[0035] In the technical solution of the radio frequency source device, its impedance matching method, and the semiconductor process equipment provided by the present invention, the first radio frequency unit and the second radio frequency unit simultaneously load radio frequency power signals into the process chamber of the semiconductor process equipment, and the radio frequency power signal is a pulse signal having multiple stages in each cycle. The controller is used to control the first radio frequency unit and the second radio frequency unit to perform impedance matching in each stage, and the impedance matching mode adopted by the first radio frequency unit in each stage is different from the impedance matching mode adopted by the second radio frequency unit in the corresponding stage. In this way, in each stage, the impedance matching methods adopted by the first radio frequency unit and the second radio frequency unit can both play a normal impedance matching role without interference, thereby reducing the reflected power of the first radio frequency unit and the second radio frequency unit. Description of the Drawings

[0036] Figure 1 It is a structural block diagram of a radio frequency source device provided by an embodiment of the present invention;

[0037] Figure 2 It is a waveform diagram of the radio frequency power signals loaded by the first radio frequency unit and the second radio frequency unit adopted by an embodiment of the present invention;

[0038] Figure 3 It is a waveform diagram of the radio frequency power signals loaded by two radio frequency units and the reflected power in the related art;

[0039] Figure 4 It is a frequency spectrum diagram of the low-frequency radio frequency unit;

[0040] Figure 5 It is a structural block diagram of the first radio frequency unit and the second radio frequency unit adopted by an embodiment of the present invention;

[0041] Figure 6 It is a waveform diagram of the radio frequency power signals, the sweep control instruction, and the matching control instruction loaded by the first radio frequency unit and the second radio frequency unit adopted by an embodiment of the present invention;

[0042] Figure 7 It is a combined waveform diagram of four kinds of radio frequency power signals loaded by the first radio frequency unit and the second radio frequency unit adopted by an embodiment of the present invention;

[0043] Figure 8 Four other combined waveform diagrams of the radio frequency power signals loaded by the first radio frequency unit and the second radio frequency unit adopted in the embodiment of the present invention;

[0044] Figure 9 Another structural block diagram of the radio frequency source device provided by the embodiment of the present invention;

[0045] Figure 10 Waveform diagrams of the radio frequency power signals, frequencies, and actual pulse signals loaded by the first radio frequency unit and the second radio frequency unit adopted in the embodiment of the present invention;

[0046] Figure 11 Waveform diagrams of the basic signal, actual pulse signal, and the control signal after compensation by the second radio frequency unit loaded by the first radio frequency unit and the second radio frequency unit adopted in the embodiment of the present invention. Detailed implementation manners

[0047] To enable those skilled in the art to better understand the technical solutions of the present invention, the radio frequency source device, its impedance matching method, and semiconductor process equipment provided by the present invention will be described in detail below with reference to the accompanying drawings.

[0048] The embodiment of the present invention provides a radio frequency source device, which is applied to semiconductor process equipment, such as inductively coupled plasma (ICP) equipment, capacitively coupled plasma (CCP) equipment, microwave plasma equipment, electron cyclotron resonance plasma (ECR) equipment, etc.

[0049] Please refer to Figure 1, The radio frequency source device includes a first radio frequency unit 1, a second radio frequency unit 2 and a controller 3. The first radio frequency unit 1 and the second radio frequency unit 2 each include a power supply module 11 and an impedance matcher module 12 for example. The power supply module 11 is used to load a radio frequency power signal into the process chamber 4 of the semiconductor process equipment through the impedance matcher module 12 connected thereto. Among them, the process chamber 4 of the semiconductor process equipment may specifically include a plasma generation chamber, in which a certain degree of vacuum can be maintained. The reaction gas introduced therein can be ionized under the action of the variable electric field excited by the first radio frequency unit 1 and the second radio frequency unit 2, thereby generating plasma. The power supply module 11 is used to provide a certain radio frequency (RF) power to be able to excite a variable electric field in the plasma generation chamber. The output impedance of the power supply module 11 is generally 50 ohms, while the input impedance of the process chamber 4 is generally a non-50 ohm impedance value with a real part impedance and an imaginary part impedance. To avoid the problem of high reflected power caused by impedance mismatch between the power supply module 11 and the process chamber 4, resulting in excessive power loss, an impedance matcher module 12 is coupled between the power supply module 11 and the process chamber 4 to achieve impedance matching between the power supply module 11 and the process chamber 4.

[0050] In some alternative embodiments, the frequency of the power supply module 11 in the first radio frequency unit 1 may be different from the frequency of the power supply module 11 in the second radio frequency unit 2. Such frequency is, for example, 400KHz, 13.56MHz, 40.68MHz, 60MHz, etc. Among them, the radio frequency power signal output by the power supply module 11 with a higher frequency (such as 40.68MHz, 60MHz) helps to obtain a high-density plasma. The radio frequency power signal output by the power supply module 11 with a lower frequency (such as 400KHz, 13.56MHz) helps to increase the energy of the plasma. By using two power supply modules 11 with different frequencies to load radio frequency power signals into the process chamber 4 simultaneously, the energy of the plasma can be increased on the basis of obtaining a high-density plasma.

[0051] The above-mentioned radio frequency power signals loaded by the first radio frequency unit 1 and the second radio frequency unit 2 are RF1 and RF2 respectively. Their waveform diagrams are as Figure 2 shown. Both RF1 Fwd and RF2 Fwd are pulse signals with multiple stages in each period T. By setting the specific values / modes of parameters such as power value, frequency, impedance matching mode, etc. of the pulse signal in each stage respectively, it helps to obtain a wider range of plasma parameters, and at the same time, the plasma parameters can be more independently regulated, so that at least one of the following effects can be obtained: effectively reducing the damage caused by the plasma to the surface of the workpiece to be processed; by modulating the pulse signal, a higher etching aspect ratio, a larger etching selectivity, a larger etching yield, etc. can be obtained.

[0052] For example, Figure 2 As shown, for a pulse signal having two phases (A, B) in each period T, one phase A is a high level phase, in which the pulse signal can have a larger power value, such as 1000 W, and the other phase B is a low level phase, in which the pulse signal can have a smaller power value, such as 600 W. Such a pulse signal is helpful for plasma ignition.

[0053] For another example, for a single RF unit, if an impedance matcher is used for impedance matching in both the High level stage and the Low level stage. In this case, if the impedance difference between the High level stage and the Low level stage is large, it is difficult to achieve impedance matching that meets the process requirements. Because it is necessary to constantly switch between the High level impedance matching position and the Low level impedance matching position, the motor response speed of the impedance matcher is far behind the impedance switching speed in the High level stage and the Low level stage, so that a balanced impedance point cannot be found for matching, so there is a risk of mismatch, which eventually manifests as oscillation or excessive reflection. In order to solve this problem, an impedance matching module 12 can be used for impedance matching and a power supply module 11 can be used for sweep frequency matching. Specifically, in the High level stage, one of the impedance matching module 12 and the power supply module 11 is used for impedance matching, and in the Low level stage, the impedance matching module 12 and the other of the power supply module 11 are used for impedance matching, which can effectively avoid the phenomenon of unstable matching and non-repetitive matching caused by too fast impedance changes during impedance matching, thereby achieving a larger process window and process stability.

[0054] However, the inventors have found through research that, for the case where two RF units simultaneously load RF power signals to the process chamber 4, if the impedance matching method used by the two RF units is the same, for example, Figure 3As shown, in the related art, for a pulse signal having two phases (A, B) in each period T, one phase A is the High level phase, and the other phase B is the Low level phase. And impedance matching is performed using an impedance matcher during the High level phase, while swept-frequency impedance matching is performed using the power supply module 11 during the Low level phase. In this case, when swept-frequency impedance matching is performed simultaneously on two radio frequency units, intermodulation distortion (IMD) will occur. IMD refers to non-linear distortion caused by the coexistence of two or more signals. Specifically, if the frequencies of the power supply modules in the two radio frequency units are different, and are 13.56 MHz and 40.68 MHz respectively, and the swept-frequency ranges of both are the center frequency f h ±5%, after the radio frequency power signals output by both are simultaneously applied to the process chamber and plasma ignition is achieved, the spectrogram of the power supply module with a frequency of 13.56 MHz is as shown in Figure 4 shown. This power supply module will generate a relatively high reflected power at f h ±nf l (n = 1, 2, 3,...). For example, at f h ±nf l (n = 3), the power supply module with a frequency of 13.56 MHz will generate harmonic power of about 40 MHz. This harmonic power will be detected by the power sensor in the power supply module with a frequency of 40.68 MHz, thus having a greater impact on the efficiency of the swept-frequency impedance matching of the power supply module with a frequency of 40.68 MHz. Moreover, due to the influence of the frequency change (changing at any time within the range of 12.88 MHz to 14 MHz) of the radio frequency power signal of the power supply module with a frequency of 13.56 MHz, there is an IMD frequency window for the power supply module with a frequency of 40.68 MHz. Compared with the case where the frequency is fixed at 13.56 MHz (that is, the frequency of the radio frequency power signal of the power supply module with a frequency of 13.56 MHz is fixed at 13.56 MHz), the frequency window expands a lot, resulting in a significant decrease in the swept-frequency success rate of the power supply module with a frequency of 40.68 MHz compared to when the frequency is fixed at 13.56 MHz, and even a situation where no matching can occur. In addition, for two radio frequency units with other frequencies, if the frequencies of the two satisfy mf h ±nf l (m, n are positive integers) at the frequency point, a relatively high reflected power will be generated in the process chamber at this frequency point. This is mainly because the frequency points around the center frequency will be detected by the power sensor in the power supply module, and the relatively high reflected power generated will affect the swept-frequency matching efficiency of this power supply module, thus having a greater impact on the swept-frequency matching of this power supply module.

[0055] Figure 3 The waveforms of the reflected frequencies corresponding to the two RF units when IMD exists are shown, which are the reflected power waveform RF1 Ref corresponding to the power module (RF1) with a frequency of 13.56 MHz and the reflected power waveform RF2 Ref corresponding to the power module (RF2) with a frequency of 40.68 MHz. When the RF power signal output by RF1 is a pulse signal including a High level phase and a Low level phase in each cycle, and the RF power signal output by RF2 is a pulse signal with a fixed power value, Figure 3 From the waveform of the reflected power RF1 Ref, it can be seen that when RF1 is controlled alone for swept-frequency impedance matching, the reflected power corresponding to the power module can be reduced. However, if RF2 is superimposed for swept-frequency impedance matching, the two will interfere with each other. Figure 3 From the reflected power waveform RF2 Ref, it can be seen that the reflected power corresponding to RF2 is too high. On this basis, when RF2 switches between frequency sweep matching and impedance matching, the motor response speed of the impedance matching device cannot keep up with the impedance switching speed because it needs to constantly switch between different impedance matching positions. This will also cause the reflected power corresponding to RF2 to be too high. In addition, RF1 will also have reflected power due to the large change in chamber impedance caused by the unstable matching of RF2.

[0056] In order to solve the above problem, the controller 3 is used to control the first RF unit 1 and the second RF unit 2 to perform impedance matching in each stage, and the impedance matching mode adopted by the first RF unit 1 in each stage is different from the impedance matching mode adopted by the second RF unit 2 in the corresponding stage. In this way, in each stage, the impedance matching mode adopted by the first RF unit 1 and the second RF unit 2 can play a normal impedance matching role without interference, thereby reducing the reflected power of the first RF unit 1 and the second RF unit 2. Take the example of having two stages (A, B) in each cycle T, such as Figure 2 As shown, the first RF unit 1 adopts the matching mode of the matcher in phase A and adopts the frequency sweeping matching mode in phase B; the second RF unit 2 adopts the frequency sweeping matching mode in phase A and adopts the matching mode of the matcher in phase B.

[0057] In some optional embodiments, the impedance matching mode includes a sweep frequency matching mode and a matcher matching mode. In the sweep frequency matching mode, the controller 3 is used to control the power module 11 to adjust the frequency of the RF power signal to achieve impedance matching between the power module 11 and the process chamber 4. Figure 5, the radio frequency power supply module 11 includes an oscillation generator 111, a power amplifier 112, a first power sensor 113, and a power supply controller 114. In the sweep matching mode, the controller 3 sends a sweep start instruction (i.e., the ON phase in the waveforms of the RF1 sweep control instruction and the RF2 sweep control instruction in Figure 6 ) and a target power value P1 to the power supply controller 114; when receiving the sweep start instruction, the power supply controller 114 executes a sweep program and sends a frequency control instruction to the oscillation generator 111; when receiving the frequency control instruction, the oscillation generator 111 outputs a pulse signal with a specified frequency F1 via the power amplifier 112; the first power sensor 113 is used to detect the incident power Pi1 and the reflected power Pr1 on the output side of the power amplifier 112 in real time and send them to the power supply controller 114; the power supply controller 114 adjusts the magnitude of the specified frequency F1 in real time within a certain frequency range (e.g., 38.64 MHz to 42.71 MHz) according to the incident power Pi1, the reflected power Pr1, and the above target power value P1. During this process, since the specified frequency F1 of the pulse signal output by the oscillation generator via the power amplifier 112 is changing in real time, the impedance value of the impedance matching network of the impedance matcher will also change accordingly until the reflected power Pr1 gradually decreases and approaches zero, that is, the impedance matching between the power supply module 11 and the process chamber 4 is achieved. Theoretically, when the impedance between the power supply module 11 and the process chamber 4 is matched, the radio frequency power from the power supply module 11 will be completely transmitted to the process chamber 4, and there will be no reflected power from the process chamber 4.

[0058] In the matcher matching mode, the controller 3 is used to control the actuating element of the impedance matcher module 12 to adjust the impedance value of the impedance matching network, so as to achieve impedance matching between the power supply module 11 and the process chamber 4. Specifically, the impedance matcher module 12 is, for example, a mechanical matcher, and specifically includes an impedance matching network, an actuating unit 121 (such as a motor driver), a matching controller 123, and a second power sensor 122. Among them, the impedance matching network may include impedance elements, such as capacitive impedance elements, inductive impedance elements, etc. The network formed by connecting these impedance elements is the impedance matching network. At least a part of these impedance elements may have a variable impedance configuration, so that the impedance matching network as a whole can present different impedance values. For example, the impedance matching network may include a variable capacitance element, and the variable capacitance element may include a rotatable part, such as a plate or a dielectric layer between the plates. By rotating the rotatable part, the capacitance value of the variable capacitance element can be changed. In practical applications, the type of the impedance matching network may be L-type, π-type, T-type, etc. The actuating unit 121 is used to adjust the impedance value of the impedance matching network. Specifically, taking the actuating unit 121 as a motor driver as an example, the motor driver can drive the rotatable part in the variable capacitance element to rotate, thereby changing the capacitance value of the variable capacitance element. The motor driver may be, for example, a servo motor.

[0059] In the matcher matching mode, the controller 3 sends a sweep shutdown command (i.e., the OFF phase in the waveforms of the RF1 sweep control command and the RF2 sweep control command in Figure 6 ), and a target power value P2 to the power supply controller 114; sends a matching start command (i.e., the ON phase in the waveforms of the RF1 matching control command and the RF2 matching control command in Figure 6 ) to the matching controller 123. When the matching controller 123 receives the matching start command, it sends a motor position command to the motor driver. When the motor driver receives the motor position command, it adjusts the impedance value of the impedance matching network by changing the motor position; the second power sensor 122 is used to detect the incident power Pi2 and the reflected power Pr2 on the output side of the impedance matcher in real time, and send them to the matching controller 123. The matching controller 123 controls the motor position of the motor driver in real time according to the incident power Pi2, the reflected power Pr2, and the target power value P2. During this process, the impedance value of the impedance matching network of the impedance matcher module 12 will change accordingly until the reflected power Pr2 gradually decreases and approaches zero, that is, impedance matching between the power supply module 11 and the process chamber 4 is achieved.

[0060] In some alternative embodiments, in the swept-frequency matching mode, the position of the actuating element 121 of the impedance matcher module 12 remains fixed. Specifically, when switching from the matcher matching mode to the swept-frequency matching mode, the controller 3 sends a swept-frequency start command and a target power value P1 to the power controller 114, and at the same time sends a matching shutdown command (i.e., the OFF phase in the waveforms of the RF1 matching control command and the RF2 matching control command in Figure 6 ). When the matching controller 123 receives this matching shutdown command, it sends a motor position command to the actuating element 121 (such as a motor driver), and the motor position remains fixed, that is, a fixed value. In this case, the impedance value of the impedance matching network also remains fixed, which is a fixed value. The motor position of the above impedance matcher module 12 is a fixed value in the swept-frequency matching mode.

[0061] In the matcher matching mode, the frequency of the radio frequency power signal remains fixed. Specifically, when switching from the swept-frequency matching mode to the matcher matching mode, the controller 3 sends a swept-frequency shutdown command and a target power value P2 to the power controller 114. When the power controller 114 receives this swept-frequency shutdown command, it sends a frequency control command to the oscillation generator 111. When the oscillation generator 111 receives this frequency control command, it outputs a pulse signal with a specified frequency F2 via the power amplifier 112, and this specified frequency F2 remains fixed, that is, a fixed value, and can be, for example, a preset process empirical value.

[0062] In some alternative embodiments, the above controller 3 can be integrated with the power controller 114 and the matching controller 123, or can also be set separately.

[0063] In some alternative embodiments, the controller 3 is further configured to control the first radio frequency unit 1 to adopt the swept-frequency matching mode in at least one of multiple stages within each period T, and control the second radio frequency unit 2 to adopt the swept-frequency matching mode in at least one of multiple stages within each period T, and the stages in which the first radio frequency unit 1 and the second radio frequency unit 2 adopt the swept-frequency matching mode are different. That is to say, there are stages in which the first radio frequency unit 1 and the second radio frequency unit 2 adopt the swept-frequency matching mode within each period T, but the first radio frequency unit 1 and the second radio frequency unit 2 do not adopt the swept-frequency matching mode in the same stage. Specifically, it can be a combination of the swept-frequency matching mode and the matcher matching mode, or a combination of the swept-frequency matching mode and no impedance matching (the power value of the radio frequency power signal is zero). In this way, since there is the swept-frequency matching mode within each period T, the fast matching advantage of swept-frequency matching can be utilized, and impedance matching can be achieved even when the load impedance changes rapidly.

[0064] In some alternative embodiments, the power values of the radio frequency power signals loaded by the first radio frequency unit 1 and the second radio frequency unit 2 are non-zero in each stage. In this case, the controller 3 is further configured to control both the first radio frequency unit 1 and the second radio frequency unit 2 to switch from one of the frequency sweep matching mode and the matcher matching mode to the other at the switching moment between two adjacent stages. Specifically, as Figure 2 shown, taking a pulse signal having two stages (A, B) in each period T as an example, both the first radio frequency unit 1 and the second radio frequency unit 2 are set to: in stage A, impedance matching is performed using one of the impedance matcher module 12 and the power supply module 11; in stage B, impedance matching is performed using the other of the impedance matcher module 12 and the power supply module 11. This can effectively avoid the phenomena of unstable and non-repetitive matching caused by too rapid impedance change during the impedance matching process, thereby enabling a larger process window and process stability. On this basis, by making the impedance matching mode adopted by the first radio frequency unit 1 in each stage different from the impedance matching mode adopted by the second radio frequency unit 2 in the corresponding stage, in each stage, the impedance matching methods respectively adopted by the first radio frequency unit 1 and the second radio frequency unit 2 can both play a normal impedance matching role without interference, thereby reducing the reflected power of the first radio frequency unit 1 and the second radio frequency unit 2. In addition, since there is a frequency sweep matching mode in each period, the fast matching advantage of frequency sweep matching can be utilized, and impedance matching can be achieved even when the load impedance changes rapidly.

[0065] In some alternative embodiments, the controller 3 is further configured to control the first radio frequency unit 1 not to perform impedance matching when the power value of the radio frequency power signal loaded by the first radio frequency unit 1 is zero; and / or to control the second radio frequency unit 2 not to perform impedance matching when the power value of the radio frequency power signal loaded by the second radio frequency unit 2 is zero. Further optionally, one of each adjacent two phases within each period is the first phase and the other is the second phase; the power value of the radio frequency power signal loaded by the first radio frequency unit is non-zero in the first phase and zero in the second phase; the power value of the radio frequency power signal loaded by the second radio frequency unit is non-zero in the first phase and zero in the second phase; or, the power value of the radio frequency power signal loaded by the second radio frequency unit is zero in the first phase and non-zero in the second phase. Specifically, at the switching moment between each adjacent two phases within each period, the power value of the radio frequency power signal loaded by the first radio frequency unit switches between zero and non-zero, and it can switch from zero to non-zero or from non-zero to zero. On this basis, the power value of the radio frequency power signal loaded by the second radio frequency unit can also switch between zero and non-zero, and it can switch from zero to non-zero or from non-zero to zero, and when the power value of the radio frequency power signal loaded by the first radio frequency unit is zero, the power value of the radio frequency power signal loaded by the second radio frequency unit can be zero or non-zero.

[0066] In some alternative embodiments, the power value of the radio frequency power signal loaded by the first radio frequency unit 1 remains unchanged or changes according to a first preset rule during the process of sequentially passing through each phase; and / or the power value of the radio frequency power signal loaded by the second radio frequency unit 2 remains unchanged or changes according to a second preset rule during the process of sequentially passing through each phase. Specifically, taking a pulse signal having two phases within each period, the two phases being the first phase and the second phase as an example, the power value of the radio frequency power signal loaded by the first radio frequency unit 1 remains unchanged during the process of sequentially passing through the first phase and the second phase, that is, the power value of the radio frequency power signal loaded by the first radio frequency unit 1 in the first phase is equal to that in the second phase, so that the radio frequency power signal originally being a pulse signal can be simulated to form a continuous wave signal. The second radio frequency unit similarly simulates to form a continuous wave signal by keeping the power value of the loaded radio frequency power signal unchanged during the process of sequentially passing through the first phase and the second phase.

[0067] Alternatively, the power value of the radio frequency power signal loaded by the first radio frequency unit 1 changes according to a first preset rule during the process of passing through each stage in turn. The first preset rule is, for example: the power value of the radio frequency power signal loaded by the first radio frequency unit 1 in the first stage is not equal to the power value in the second stage; and / or, the power value of the radio frequency power signal loaded by the second radio frequency unit 2 changes according to a second preset rule during the process of passing through each stage in turn. The second preset rule is: the power value of the radio frequency power signal loaded by the second radio frequency unit 2 in the first stage is not equal to the power value in the second stage.

[0068] It should be noted that in practical applications, the power values corresponding to the first radio frequency unit 1 and the second radio frequency unit 2 can each be freely selected to be fixed or to change according to a preset rule, and the power change modes of the first radio frequency unit 1 and the second radio frequency unit 2 can be freely combined.

[0069] The following exemplarily lists eight combinations of the power change modes of the first radio frequency unit 1 and the second radio frequency unit 2. Specifically, as Figure 7 shown in Figures (1) to (4) in. In Figures (1) to (4), the power value of the radio frequency power signal RF1 Fwd loaded by the first radio frequency unit 1 is not zero in stage A and is zero in stage B. Therefore, the first radio frequency unit 1 does not perform impedance matching in stage B. On this basis, in Figure (1), the power value of the radio frequency power signal RF2 Fwd loaded by the second radio frequency unit 2 is not zero in stage A and is zero in stage B. Therefore, the first radio frequency unit 1 does not perform impedance matching in stage B. In Figure (2), the power value of the radio frequency power signal RF2 Fwd loaded by the second radio frequency unit 2 is zero in stage A and is not zero in stage B. Therefore, the second radio frequency unit 2 does not perform impedance matching in stage A. In Figure (3), the power value of the radio frequency power signal RF2 Fwd loaded by the second radio frequency unit 2 is not zero in both stage A and stage B, and the power value of RF2 Fwd in stage A is greater than the power value in stage B. In Figure (4), the power value of the radio frequency power signal RF2 Fwd loaded by the second radio frequency unit 2 is not zero in both stage A and stage B, and the power value of RF2 Fwd in stage A is equal to the power value in stage B.

[0070] As Figure 8As shown in Figures (1) to (4), in Figures (1) to (3), the power value of the RF power signal RF1 Fwd loaded by the first RF unit 1 is non-zero in both stage A and stage B, and the power value of RF1 Fwd in stage A is greater than that in stage B. On this basis, in Figure (1), the power value of the RF power signal RF2 Fwd loaded by the second RF unit 2 is non-zero in both stage A and stage B, and the power value of RF2 Fwd in stage A is less than that in stage B. In Figure (2), the power value of the RF power signal RF2 Fwd loaded by the second RF unit 2 is non-zero in stage A and zero in stage B. Therefore, the second RF unit 2 does not perform impedance matching in stage B. In Figure (3), the power value of the RF power signal RF2 Fwd loaded by the second RF unit 2 is zero in stage A and non-zero in stage B. Therefore, the second RF unit 2 does not perform impedance matching in stage A. In Figure (4), the power value of the RF power signal RF1 Fwd loaded by the first RF unit 1 is non-zero in both stage A and stage B, and the power value of RF1 Fwd in stage A is equal to that in stage B. On this basis, the power value of the RF power signal RF2 Fwd loaded by the second RF unit 2 is non-zero in both stage A and stage B, and the power value of RF2 Fwd in stage A is less than that in stage B.

[0071] Preferably, the power value of the RF power signal loaded by the first RF unit 1 remains unchanged, that is, a continuous wave signal is simulated, and the power value of the RF power signal loaded by the second RF unit 2 is greater in the first stage than in the second stage, and the power value in the second stage is zero. By making the power value of the RF power signal loaded by the second RF unit 2 zero in the second stage, the problem of relatively high reflected power in the plasma ignition stage can be avoided.

[0072] In practical applications, due to factors such as the control error existing in the controller 3 itself, the differences in the models of the two RF power supplies, the length, material, and power of the transmission cables, there is often a phase difference between the RF power signals loaded by the first RF unit 1 and the second RF unit 2. For the situation where, at the switching moment between adjacent two stages, both the first RF unit 1 and the second RF unit 2 switch from one of the frequency sweep matching mode and the matcher matching mode to the other, if there is a phase difference, there will inevitably be a period during which the two RF power supplies perform frequency sweep matching simultaneously or the two impedance matchers perform impedance matching simultaneously, resulting in problems such as relatively large reflected power or slow matching speed during this period.

[0073] To solve the above problems, please refer to Figure 9, the radio frequency source device further includes a first detection unit 5 and a second detection unit 6. Among them, the first detection unit 5 is connected between the output end of the first radio frequency unit 1 and the process chamber 4, and is used to detect the first phase information on the output end side of the first radio frequency unit 1 and send it to the controller 3; the second detection unit 6 is connected between the output end of the second radio frequency unit 2 and the process chamber 4, and is used to detect the second phase information on the output end side of the second radio frequency unit 2 and send it to the controller 3; the controller 3 is further used to obtain the phase offset of the radio frequency power signals loaded by the first radio frequency unit 1 and the second radio frequency unit 2 according to the first phase information and the second phase information, and according to the phase offset, advance or delay the start time of each stage of the radio frequency power signals loaded by the first radio frequency unit 1 and / or the second radio frequency unit 2, so that the phase offset is equal to zero, thereby avoiding the situation that two radio frequency power supplies perform frequency sweep matching at the same time or two impedance matchers perform impedance matching at the same time during a certain period. In practical applications, the first detection unit 5 and the second detection unit 6 can detect in real time or detect once every fixed time period.

[0074] There are various ways to obtain the above-mentioned phase offset of the radio frequency power signal. For example, both the first phase information and the second phase information include the frequency of the radio frequency power signal; the controller 3 is further used to obtain the switching moments of each adjacent two stages according to the change of the frequency of the radio frequency power signal in each stage, and calculate the difference between the switching moments corresponding to the first radio frequency unit 1 and the second radio frequency unit 2 as the above-mentioned phase offset. For the switching moments of each adjacent two stages, in the case where both the first radio frequency unit 1 and the second radio frequency unit 2 are controlled to switch from one of the frequency sweep matching mode and the matcher matching mode to the other, during the process of passing through each stage in sequence, the frequency of the radio frequency power signal alternates between a fixed value and a changing value. In this case, the switching moments of each adjacent two stages can be determined by recording the time points when the frequency of the radio frequency power signal alternates between a fixed value and a changing value. Of course, in practical applications, the above-mentioned method for obtaining the phase offset of the radio frequency power signal can also be applied to other situations where the frequency of the radio frequency power signal changes between each adjacent two stages. For example, at the switching moments of each adjacent two stages, both the first radio frequency unit 1 and the second radio frequency unit 2 are controlled to switch from one of the frequency sweep matching mode (or matcher matching mode) and no impedance matching to the other, so that during the process of passing through each stage in sequence, the frequency of the radio frequency power signal alternates between a fixed value and zero.

[0075] In some alternative embodiments, the first detection unit and the second detection unit are further configured to respectively and real-time detect at least one of voltage, current, and pulse duty cycle on the output side of the first radio frequency unit 1 and the second radio frequency unit 2, and send the detected information to the controller 3. The controller 3 is further configured to process the detected information to obtain the actual pulse signal of the radio frequency power signal loaded by the first radio frequency unit 1 and the second radio frequency unit 2. As Figure 10 shown, the actual pulse signals of RF1 and RF2 can be processed into a square wave signal as shown in Figure 10 (this waveform is the equivalent extraction waveform of the pulse component of the actual pulse signal waveform). For the switching moment between two adjacent stages, when controlling both the first radio frequency unit 1 and the second radio frequency unit 2 to switch from one of the frequency sweep matching mode and the matcher matching mode to the other, during the process of passing through each stage in sequence, the frequency of the radio frequency power signal alternates between a fixed value and a varying value. In this case, taking a pulse signal with two stages in each cycle, the two stages being the first stage A and the second stage B as an example, the power value of the radio frequency power signal loaded by the first radio frequency unit 1 in the first stage A is greater than the power value in the second stage B, and the power value of the radio frequency power signal loaded by the second radio frequency unit 2 in the first stage A is equal to the power value in the second stage B. Moreover, the controller 3 controls the first radio frequency unit 1 to perform impedance matching in the matcher matching mode in the first stage A. In this first stage A, the frequency of the radio frequency power signal loaded by the first radio frequency unit 1 is a fixed value F2a; the controller 3 controls the first radio frequency unit 1 to perform impedance matching in the frequency sweep matching mode in the second stage B. In this second stage B, the frequency of the radio frequency power signal loaded by the first radio frequency unit 1 is a varying value F1a. Thus, the frequency of the radio frequency power signal alternates between the fixed value F2a and the varying value F1a. The time point when the frequency of the radio frequency power signal switches from the fixed value F2a to the varying value F1a can be recorded as the rising edge of the square wave, and the time point when the frequency of the radio frequency power signal switches from the varying value F1a to the fixed value F2a can be recorded as the falling edge of the square wave. Therefore, the actual pulse signal of RF1 loaded by the first radio frequency unit 1 can be processed into a square wave signal as shown in Figure 10 .

[0076] Similarly, the controller 3 controls the second RF unit 2 to perform impedance matching in the sweep matching mode during the first stage A. During this first stage A, the frequency of the RF power signal loaded by the second RF unit 2 is a variable value F1b. The controller 3 controls the second RF unit 2 to perform impedance matching in the matcher matching mode during the second stage B. During this second stage B, the frequency of the RF power signal loaded by the second RF unit 2 is a fixed value F2b. In this way, the frequency of the RF power signal alternates between the variable value F1b and the fixed value F2b. The time point when the frequency of the RF power signal switches from the variable value F1b to the fixed value F2b can be recorded as the rising edge of the square wave, and the time point when the frequency of the RF power signal switches from the fixed value F2b to the variable value F1b can be recorded as the falling edge of the square wave. Thus, the actual pulse signal of RF2 loaded by the second RF unit 2 can be processed into a square wave signal as shown in Figure 10 shown.

[0077] The controller 3 compares the square wave signals of the first RF unit 1 and the second RF unit 2. If there is a time difference △t, that is, a phase offset, between the two, then the start time of the RF power signal loaded by the first RF unit 1 and / or the second RF unit 2 in each stage is advanced or delayed to make △t equal to zero. Specifically, as shown in Figure 10 shown, if the square wave signal of the second RF unit 2 lags behind the square wave signal of the first RF unit 1 by △t, then the controller 3 can control the start time of the RF power signal loaded by the second RF unit 2 in each stage to be △t ahead of the start time of the RF power signal loaded by the first RF unit 1 in each stage to compensate for the above time difference △t. Specifically, the controller 3 can achieve the above compensation by adjusting the time when the matching start command is sent to the matching controller 123 and / or the time when the sweep start command is sent to the power controller 114. For example, as shown in Figure 11As shown, the initial moments of the base signals of RF1 and RF2 can be used as a reference to compare with the initial moments of the actual pulse signals of RF1 and RF2 respectively, so as to obtain the differences (Δt1, Δt2) between the initial moments of the actual pulse signals of RF1 and RF2 and the initial moments of the base signals of RF1 and RF2. Specifically, the initial moment of the actual pulse signal of RF1 lags behind the initial moments of the base signals of RF1 and RF2 by Δt1, and the initial moment of the actual pulse signal of RF2 lags behind the initial moments of the base signals of RF1 and RF2 by Δt2, and Δt2 > Δt1. In this case, the initial moment of the base signal of RF2 can be advanced by (Δt2 - Δt1) relative to the initial moments of the base signals of RF1 and RF2 to achieve the above compensation. The initial moment of the base signal of RF1 remains unchanged. It should be noted that in practical applications, it is also possible to keep the initial moment of the base signal of RF2 unchanged and lag the initial moment of the base signal of RF2 by (Δt2 - Δt1) relative to the initial moments of the base signals of RF1 and RF2, which can also achieve the above compensation. Additionally, taking Figure 10 as an example, if the initial moment of the base signal of RF1 is kept unchanged, the controller 3 can control the initial moment of the base signal of RF2 by controlling the moment when the matching start instruction is sent to the matching controller 123. If the initial moment of the base signal of RF2 is kept unchanged, the initial moment of the base signal of RF1 can be controlled by controlling the moment when the frequency sweep start instruction is sent to the power supply controller 114.

[0078] As another technical solution, an embodiment of the present invention further provides a semiconductor process equipment, including a process chamber and the above radio frequency source device provided by the embodiment of the present invention.

[0079] The semiconductor process equipment provided by the embodiment of the present invention can solve the problem of high reflection power caused by mutual interference when impedance matching is performed by simultaneously using frequency sweep matching for two radio frequency power supplies or using matcher matching for two matchers in the prior art by adopting the above radio frequency source device provided by the embodiment of the present invention.

[0080] As another technical solution, an embodiment of the present invention further provides an impedance matching method for a radio frequency source device, including:

[0081] When the first radio frequency unit and the second radio frequency unit simultaneously load radio frequency power signals into the process chamber of the semiconductor process equipment, the radio frequency power signals are pulse signals having multiple stages in each period; in each stage, control the first radio frequency unit and the second radio frequency unit to perform impedance matching, and make the impedance matching mode adopted by the first radio frequency unit in each stage different from the impedance matching mode adopted by the second radio frequency unit in the corresponding stage.

[0082] The impedance matching method of the radio frequency source device provided by the present invention controls the first radio frequency unit and the second radio frequency unit to perform impedance matching in each stage, and makes the impedance matching mode adopted by the first radio frequency unit in each stage different from the impedance matching mode adopted by the second radio frequency unit in the corresponding stage. In this way, the impedance matching methods adopted by the first radio frequency unit and the second radio frequency unit can both play a normal impedance matching role without interference, thereby reducing the reflection power of the first radio frequency unit and the second radio frequency unit.

[0083] It can be understood that the above embodiments are merely exemplary embodiments adopted to illustrate the principle of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also regarded as the protection scope of the present invention.

Claims

1. A radio frequency source device is applied to semiconductor process equipment, and is characterized in that, It includes a first radio frequency unit, a second radio frequency unit and a controller. The first radio frequency unit and the second radio frequency unit are used to load radio frequency power signals into the process chamber of the semiconductor process equipment, and the radio frequency power signals are pulse signals having multiple phases in each cycle; The controller is used to control the first radio frequency unit and the second radio frequency unit to perform impedance matching in each of the phases, and make the impedance matching mode adopted by the first radio frequency unit in each of the phases different from the impedance matching mode adopted by the second radio frequency unit in the corresponding phase.

2. The radio frequency source device according to claim 1, and is characterized in that, Both the first radio frequency unit and the second radio frequency unit include a power supply module and an impedance matcher module. The power supply module is used to load the radio frequency power signal into the process chamber through the impedance matching module; The impedance matching mode includes a frequency sweep matching mode and a matcher matching mode; In the frequency sweep matching mode, the controller is used to control the power supply module to adjust the frequency of the radio frequency power signal to achieve impedance matching between the power supply module and the process chamber; In the matcher matching mode, the controller is used to control the actuator of the impedance matcher module to adjust the impedance value of the impedance matching network to achieve impedance matching between the power supply module and the process chamber.

3. The radio frequency source device according to claim 2, and is characterized in that, The controller is further used to control the first radio frequency unit to adopt the frequency sweep matching mode in at least one of the multiple phases in each cycle, and control the second radio frequency unit to adopt the frequency sweep matching mode in at least one of the multiple phases in each cycle, and the phases in which the first radio frequency unit and the second radio frequency unit adopt the frequency sweep matching mode are different.

4. The radio frequency source device according to claim 2, and is characterized in that, The power values of the radio frequency power signals loaded by the first radio frequency unit and the second radio frequency unit are not zero in each phase; The controller is further used to control both the first radio frequency unit and the second radio frequency unit to switch from one of the frequency sweep matching mode and the matcher matching mode to the other at the switching moment between two adjacent phases.

5. The radio frequency source device according to claim 2, and is characterized in that, The controller is further used to control the first radio frequency unit not to perform impedance matching when the power value of the radio frequency power signal loaded by the first radio frequency unit is zero; and / or, control the second radio frequency unit not to perform impedance matching when the power value of the radio frequency power signal loaded by the second radio frequency unit is zero.

6. The radio frequency source device according to claim 5, and is characterized in that, One of each two adjacent phases in each cycle is the first phase, and the other is the second phase; the power value of the radio frequency power signal loaded by the first radio frequency unit is not zero in the first phase and is zero in the second phase; The power value of the radio frequency power signal loaded by the second radio frequency unit is not zero in the first phase and is zero in the second phase; or, the power value of the radio frequency power signal loaded by the second radio frequency unit is zero in the first phase and is not zero in the second phase.

7. The radio frequency source device according to claim 1, and is characterized in that, The power value of the radio frequency power signal loaded by the first radio frequency unit remains unchanged or changes according to a first preset rule during the process of passing through each stage in sequence; and / or, The power value of the radio frequency power signal loaded by the second radio frequency unit remains unchanged or changes according to a second preset rule during the process of passing through each stage in sequence.

8. The radio frequency source device according to claim 7, and is characterized in that, Each of the cycles has two stages, namely a first stage and a second stage; The first preset rule is: the power value of the radio frequency power signal loaded by the first radio frequency unit in the first stage is not equal to the power value in the second stage; and / or, The second preset rule is: the power value of the radio frequency power signal loaded by the second radio frequency unit in the first stage is not equal to the power value in the second stage.

9. The radio frequency source device according to any one of claims 1-8, and is characterized in that, The radio frequency source device further includes a first detection unit and a second detection unit, wherein, The first detection unit is connected between the output end of the first radio frequency unit and the process chamber, and is used to detect the first phase information on the output end side of the first radio frequency unit in real time and send it to the controller; The second detection unit is connected between the output end of the second radio frequency unit and the process chamber, and is used to detect the second phase information on the output end side of the second radio frequency unit in real time and send it to the controller; The controller is further used to obtain the phase offset of the radio frequency power signals loaded by the first radio frequency unit and the second radio frequency unit according to the first phase information and the second phase information, and advance or delay the start time of the radio frequency power signals loaded by the first radio frequency unit and / or the second radio frequency unit in each of the stages according to the phase offset, so that the phase offset is equal to zero.

10. The radio frequency source device according to claim 9, and is characterized in that, Both the first phase information and the second phase information include the frequency of the radio frequency power signal; The controller is further used to obtain the switching time of each adjacent two of the stages according to the change of the frequency of the radio frequency power signal in each stage, and calculate the difference between the switching times corresponding to the first radio frequency unit and the second radio frequency unit as the phase offset.

11. The radio frequency source device according to claim 2, and is characterized in that, The frequency of the power supply module in the first radio frequency unit is different from the frequency of the power supply module in the second radio frequency unit.

12. A semiconductor process equipment includes a process chamber, and is characterized in that, It also includes the radio frequency source device according to any one of claims 1-11.

13. An impedance matching method for a radio frequency source device, and is characterized in that, It includes: When the first radio frequency unit and the second radio frequency unit simultaneously load radio frequency power signals to the process chamber of the semiconductor processing equipment, the radio frequency power signal is a pulse signal having multiple stages in each cycle; in each of the stages, the first radio frequency unit and the second radio frequency unit are controlled to perform impedance matching, and the impedance matching mode adopted by the first radio frequency unit in each of the stages is different from the impedance matching mode adopted by the second radio frequency unit in the corresponding stage.

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