Radio frequency power supply and semiconductor process equipment

Abstract

The invention provides a radio frequency power supply and semiconductor process equipment, and the radio frequency power supply comprises a main controller which is used for providing a frequency control signal and target power; the first power supply circuit is used for providing first direct-current electric energy and a power supply signal; the power amplification circuit is used for amplifying the frequency control signal under the action of the first direct-current electric energy so as to obtain and output a corresponding radio-frequency signal; the measuring circuit is used for measuring the current power of the radio frequency signal; the proportional-integral controller is used for determining a proportional-integral control quantity according to the current power and the target power; and the proportional-integral-differential controller is used for determining a proportional-integral-differential control quantity according to the proportional-integral control quantity and the power supply signal of the power amplification circuit, and outputting the proportional-integral-differential control quantity to the power amplification circuit, so that the power of the radio frequency signal is close to and reaches the target power. According to the scheme of the invention, the dynamic response speed and the anti-interference capability of the radio frequency power supply can be effectively improved, and the radio frequency output is more stable.

Description

Technical Field

[0001] The present application relates to the field of semiconductor manufacturing, and in particular to a radio frequency power supply and semiconductor process equipment. Background Art

[0002] RF power supply is one of the core components of semiconductor process equipment and is used to provide energy to semiconductor process equipment. The circuit used to complete the closed-loop control process in the RF power supply includes a proportional integral controller (PI controller) and a power amplifier circuit. The PI controller determines the proportional integral control amount based on the deviation between the current power of the RF signal output by the power amplifier circuit and the target power, and outputs the proportional integral control amount to the power amplifier circuit to achieve proportional integral control of the power amplifier circuit, so that the power of the RF signal output by the power amplifier circuit approaches and reaches the target power. However, since the proportional integral controller can only achieve first-level PI closed-loop control, the dynamic response and anti-interference capabilities of the RF power supply are poor, resulting in low stability of the RF output. Summary of the Invention

[0003] The present application provides a radio frequency power supply and semiconductor process equipment to solve the problem of low radio frequency output stability caused by the radio frequency power supply adopting only one-level PI closed-loop control in the related art.

[0004] In a first aspect, the present application provides a radio frequency power supply, comprising: a main controller for providing a frequency control signal and a target power; a first power supply circuit for providing a first direct current power and a power supply signal; a power amplifier circuit for amplifying the frequency control signal under the action of the first direct current power to obtain and output a corresponding radio frequency signal; a measurement circuit for measuring the current power of the radio frequency signal; a proportional-integral controller for determining a proportional-integral control amount based on the current power and the target power; a proportional-integral-differential controller for determining a proportional-integral-differential control amount based on the proportional-integral control amount and the power supply signal, and outputting the proportional-integral-differential control amount to the power amplifier circuit so that the power of the radio frequency signal approaches and reaches the target power.

[0005] In one embodiment, the main controller pre-stores multiple temperature information and multiple correction coefficients, and the multiple temperature information and multiple correction coefficients correspond one to one; the measurement circuit also includes a temperature sampling circuit, which is used to collect temperature information of the current environment; the main controller is also used to determine the corresponding correction coefficient based on the temperature information, and correct the target power based on the correction coefficient.

[0006] In one embodiment, the measurement circuit includes a filter amplifier circuit connected between the power amplifier circuit and the proportional-integral controller; the filter amplifier circuit has a plurality of different amplification factors, the plurality of amplification factors corresponding one-to-one to the plurality of power intervals, and the plurality of amplification factors are inversely correlated with the power values ​​of the plurality of power intervals;

[0007] The main controller determines the corresponding amplification factor as the target amplification factor of the filter amplifier circuit according to the power range in which the target power is located, and adjusts the amplification factor of the filter amplifier circuit to the target amplification factor, so that the filter amplifier circuit filters the current power and amplifies it to the target amplification factor before transmitting it to the proportional-integral controller.

[0008] In one embodiment, a filter amplifier circuit includes multiple sub-filter amplifier circuits and multiple controllable switches, and the amplification factors of the multiple sub-filter amplifier circuits are different; the input ends of the multiple sub-filter amplifier circuits are connected to the output end of the power amplifier circuit, the output ends of the multiple sub-filter amplifier circuits are connected to the first ends of the multiple controllable switches in a one-to-one correspondence, the second ends of the multiple controllable switches are connected to the proportional-integral controller, and the control ends of the multiple controllable switches are connected to the main controller; the main controller is used to determine the corresponding target sub-filter amplifier circuit from the multiple sub-filter amplifier circuits according to the target amplification factor, and control the controllable switch of the branch where the target sub-filter amplifier circuit is located to close, so that the current power is transmitted to the proportional-integral controller after passing through the target sub-filter amplifier circuit.

[0009] In one embodiment, the filtering and amplifying circuit includes a first filter and a signal amplifier, the signal amplifier includes an operational amplifier, an adjustable potentiometer and a first resistor; the first filter is connected between the output end of the power amplifier circuit and the non-inverting input end of the operational amplifier; the inverting input end of the operational amplifier is connected to the output end through the adjustable potentiometer and is grounded through the first resistor, and the control end of the adjustable potentiometer is connected to the main controller; the main controller is used to adjust the resistance value of the adjustable potentiometer according to the target amplification factor so that the amplification factor of the signal amplifier reaches the target amplification factor.

[0010] In one embodiment, the power amplifier circuit includes a driving circuit and a power amplifier filter circuit; the driving circuit is used to amplify and output the frequency control signal; the power amplifier filter circuit is used to amplify the amplified frequency control signal again and filter it to obtain and output the radio frequency signal.

[0011] In one embodiment, the measurement circuit also includes a signal sampling circuit, a second filter and a multiplier; the signal sampling circuit is used to sample the power of the radio frequency signal into a voltage signal, and the voltage signal is used to characterize the power of the radio frequency signal; the second filter is used to filter the voltage signal and then transmit it to the multiplier; the multiplier is used to perform a square operation on the voltage signal to obtain the current power.

[0012] In one embodiment, the RF power supply further includes an interface circuit, an analog-to-digital conversion circuit, and a first digital-to-analog conversion circuit; the interface circuit is used to receive a set power of the RF signal; the main controller is used to receive the set power from the interface circuit via the analog-to-digital conversion circuit, and to correct the set power to obtain a target power; the main controller is also used to transmit the target power to the proportional-integral controller via the first digital-to-analog conversion circuit.

[0013] In one embodiment, the RF power supply also includes a second digital-to-analog conversion circuit, which is connected between the main controller and the interface circuit; the main controller is also used to receive the current power through the analog-to-digital conversion circuit, and correct the current power to obtain feedback power; the main controller is also used to output feedback power to the interface circuit through the second digital-to-analog conversion circuit.

[0014] In one embodiment, the RF power supply further includes: a second power supply circuit for outputting a second DC power to the main controller, the proportional-integral controller, the proportional-integral-differential controller, and the power amplifier circuit; the voltage of the second DC power is lower than the voltage of the first DC power.

[0015] In a second aspect, the present application provides a semiconductor process equipment, characterized in that it includes: an RF power supply of any of the above-mentioned embodiments, at least one matcher, at least one RF electrode and a process chamber; the RF power supply loads an RF signal to the RF electrode through the matcher to generate plasma inside the process chamber.

[0016] In one embodiment, the RF power supply includes an upper RF power supply and a lower RF power supply, the matcher includes an upper matcher and a lower matcher, and the RF electrode includes an upper electrode and a lower electrode; the upper RF power supply loads an RF signal to the upper electrode through the upper matcher; and the lower RF power supply loads an RF signal to the lower electrode through the lower matcher.

[0017] The scheme of the present application has the following beneficial effects: the proportional-integral controller first determines the proportional-integral control amount based on the current power and target power of the RF signal and outputs it to the proportional-integral-differential controller; the proportional-integral-differential controller then determines the proportional-integral-differential control amount based on the proportional-integral control amount and the power supply signal of the first power supply circuit and outputs the PID control to the power amplifier circuit. In this way, the power supply signal of the power amplifier circuit can be introduced into the PID closed-loop control on the basis of the first-level PI closed-loop control, realizing the second-level PID closed-loop control. When the power supply signal of the power amplifier circuit fluctuates, the PID closed-loop control of the power amplifier circuit can be immediately performed on the power amplifier circuit to avoid the power supply signal from interfering with the RF power supply. This two-level nested closed-loop control method can effectively improve the dynamic response speed and anti-interference capability of the RF power supply, making the RF output more stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the description, serve to explain the principles of the present application. In addition, these drawings and the description are not intended to limit the scope of the concept of the present application in any way, but rather to illustrate the concept of the present application for those skilled in the art by reference to specific embodiments.

[0019] Figure 1 Shown is a structural schematic diagram of a radio frequency power supply in related technology.

[0020] Figure 2 FIG. 1 is a schematic structural diagram of a radio frequency power supply according to an embodiment of the present application.

[0021] Figure 3 Shown Figure 2 A structural diagram of .

[0022] Figure 4 Shown Figure 2 Another structural diagram of .

[0023] Figure 5 FIG. 1 is a schematic structural diagram of a semiconductor process equipment according to an embodiment of the present application.

[0024] Figure 6 Shown Figure 5 A structural diagram of . DETAILED DESCRIPTION

[0025] Hereinafter, only certain exemplary embodiments are briefly described. As will be appreciated by those skilled in the art, the described embodiments may be modified in various ways without departing from the spirit or scope of the present application. Therefore, the drawings and description are to be regarded as illustrative in nature and not restrictive.

[0026] Figure 1 Shown is a structural schematic diagram of a radio frequency power supply in related technology.

[0027] like Figure 1As shown, the RF power supply 10 of the related art is mainly composed of a main controller 11, a power amplifier circuit 12, a measurement circuit 13, a proportional-integral (PI) controller 14, a first power supply circuit 15, and a second power supply circuit 16. The main controller 11 and the proportional-integral controller 14 can be integrated into the same control circuit. The first power supply circuit 15 is used to provide a first DC power to the power amplifier circuit 12, and the second power supply circuit 16 is used to provide a second DC power to the control circuit, thereby powering the main controller 11, the power amplifier circuit 12, and the proportional-integral controller 14. The voltage of the second DC power is lower than the voltage of the first DC power. The RF power supply 10 operates as follows: a main controller 11 provides a preset frequency control signal to a power amplifier circuit 12, causing the power amplifier circuit 12 to amplify the frequency control signal, obtain a radio frequency signal, and output it. The frequency of the frequency control signal is the same as the frequency of the radio frequency signal. During the process of the power amplifier circuit 12 outputting the radio frequency signal, on the one hand, a measurement circuit 13 measures the current power of the radio frequency signal and transmits it to a proportional-integral controller 14. On the other hand, the main controller 11 also provides a target power to the proportional-integral controller 14, causing the proportional-integral controller 14 to perform a PI operation on the target power and the current power to determine a proportional-integral control variable for the power amplifier circuit 12. Specifically, the proportional-integral controller 14 first calculates the deviation between the target power and the current power, then linearly combines the proportion (P) and integral (I) of the deviation to form a proportional-integral control variable. The proportional-integral control variable is then output to the power amplifier circuit 12 to perform proportional-integral control on the power amplifier circuit 12, so that the power of the radio frequency signal output by the power amplifier circuit 12 approaches and reaches the target power. However, since the proportional-integral controller 14 can only implement first-level PI closed-loop control, the dynamic response and anti-interference capabilities of the RF power supply 10 are relatively poor, resulting in low stability of the RF output.

[0028] In view of this, the embodiments of the present application provide a radio frequency power supply and semiconductor process equipment that can effectively solve the problem of low radio frequency output stability caused by the use of only one-stage PI closed-loop control in radio frequency power supplies in related technologies. The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0029] Figure 2 FIG. 1 is a schematic structural diagram of a radio frequency power supply according to an embodiment of the present application.

[0030] like Figure 2As shown, the RF power supply 10 includes a main controller 11, a power amplifier circuit 12, a measurement circuit 13, a proportional-integral controller 14, a first power supply circuit 15, and a proportional-integral-differential controller (PID controller) 21. The main controller 11 is used to provide a frequency control signal and a target power. The first power supply circuit 15 is used to provide a first DC power and a power supply signal. The power amplifier circuit 12 is used to amplify the frequency control signal under the action of the first DC power to obtain and output a corresponding RF signal; wherein the frequency of the frequency control signal is the same as the frequency of the RF signal. The measurement circuit 13 is used to measure the current power of the RF signal. The proportional-integral controller 14 is used to determine a proportional-integral control variable (i.e., a PI control variable) based on the current power and target power of the RF signal. The proportional-integral-differential controller 21 is used to determine a proportional-integral-differential control variable based on the proportional-integral control variable and the power supply signal of the first power supply circuit 15, and output the proportional-integral-differential control variable to the power amplifier circuit 12, so that the power of the RF signal approaches and reaches the target power. The power of the RF signal is used to represent the amount of energy carried by the RF signal. The power of the RF signal can also be expressed as RF power.

[0031] Exemplarily, the main controller 11 has a first output terminal and a second output terminal, the power amplifier circuit 12 has a first power supply terminal, a first input terminal, a second input terminal and an output terminal, the measurement circuit 13 has an input terminal and an output terminal, the proportional-integral controller 14 has a first input terminal, a second input terminal and an output terminal, the first power supply circuit 15 has a power supply terminal and a sampling terminal, and the proportional-integral-differential controller 21 has a first input terminal, a second input terminal and an output terminal.

[0032] The first output terminal of the main controller 11 is connected to the first input terminal of the power amplifier circuit 12 to transmit a frequency control signal to the power amplifier circuit 12. The power supply terminal of the first power supply circuit 15 is connected to the first power supply terminal of the power amplifier circuit 12 to provide a first DC power to the power amplifier circuit 12. Powered by the first DC power, the power amplifier circuit 12 amplifies the frequency control signal to obtain and output a radio frequency signal. The first power supply circuit 15 can be an AC / DC circuit, wherein the input terminal of the first power supply circuit 15 is used to input AC power. The first power supply circuit 15 converts the AC power into a first DC power and outputs it through the power supply terminal.

[0033] The second output end of the main controller 11 is connected to the first input end of the proportional-integral controller 14 to transmit the target power to the proportional-integral controller 14; the input end of the measurement circuit 13 is connected to the output end of the power amplifier circuit 12, and the output end of the measurement circuit 13 is connected to the second input end of the proportional-integral controller to measure the current power of the radio frequency signal and transmit the current power to the proportional-integral controller, so that the proportional-integral controller determines the proportional-integral control amount (i.e., the PID control amount) of the power amplifier circuit 12 based on the current power and the target power.

[0034] The output end of the proportional-integral controller 14 is connected to the first input end of the proportional-integral-differential controller 21 to transmit the proportional-integral control variable to the proportional-integral-differential controller 21. The sampling end of the first power supply circuit 15 is connected to the second input end of the proportional-integral-differential controller 21 to transmit the power supply signal to the proportional-integral-differential controller 21. The output end of the proportional-integral-differential controller 21 is connected to the second input end of the power amplifier circuit 12. The proportional-integral-differential controller 21 determines the proportional-integral-differential control variable of the power amplifier circuit 12 based on the proportional-integral control variable and the power supply signal, and outputs the proportional-integral-differential control variable to the power amplifier circuit 12, so that the power of the RF signal output by the power amplifier circuit 12 approaches and reaches the target power, thereby achieving power control of the power amplifier circuit 12. The power supply signal can be a current signal collected from the sampling end of the first power supply circuit 15.

[0035] Exemplarily, the proportional-integral-differential control amount is determined by first calculating the deviation between the proportional-integral control amount and the power supply signal; then, the proportional-integral-differential control amount is linearly combined with the proportion (P), integral (I), and differential (D) of the deviation between the proportional-integral control amount and the power supply signal to form the proportional-integral-differential control amount. For example, the deviation between the proportional-integral-differential control amount and the proportional-integral-differential control amount and the power supply signal satisfies the following formula (1):

[0036]

[0037] Among them, u(t) represents the proportional integral differential control quantity, K P is the proportionality coefficient, K i is the integral coefficient, K d is the differential coefficient, e(t) is the deviation between the proportional integral control amount and the power supply signal, is the integral of the deviation between the proportional integral control quantity and the power supply signal, It is the differential of the deviation between the proportional integral control quantity and the power supply signal, and t represents the control time.

[0038] In the above scheme, the proportional-integral controller 14 first determines the proportional-integral control variable based on the current power and target power of the RF signal and outputs it to the proportional-integral-differential controller 21. The proportional-integral-differential controller 21 then determines the proportional-integral-differential control variable based on the proportional-integral control variable and the power supply signal from the first power supply circuit 15 and outputs the proportional-integral-differential control variable to the power amplifier circuit 12. This allows the power supply signal of the power amplifier circuit 12 to be introduced into the PID closed-loop control on the basis of the first-level PI closed-loop control, achieving second-level PID closed-loop control. When the power supply signal of the power amplifier circuit 12 fluctuates, PID closed-loop control can be immediately performed on the power amplifier circuit 12, preventing the power supply signal from interfering with the RF power supply 10. This two-level nested closed-loop control scheme can effectively improve the dynamic response speed and anti-interference capability of the RF power supply 10, making the RF output more stable.

[0039] In one embodiment, Figure 3 As shown, the main controller 11 pre-stores multiple temperature information and multiple correction coefficients, with each temperature information corresponding to each correction coefficient. The measurement circuit 13 also includes a temperature sampling circuit 13A. The temperature sampling circuit 13A is used to collect current ambient temperature information. The main controller 11 is used to determine the corresponding correction coefficient based on the temperature information and correct the target power based on the correction coefficient.

[0040] Exemplarily, the main controller 11 further includes a third input terminal connected to the output terminal of the temperature sampling circuit 13A to obtain temperature information collected by the temperature sampling circuit 13A. The temperature sampling circuit 13A can be a high-precision temperature sampling circuit, and the current environment is the environment in which the RF power supply 10 is located. By configuring the temperature sampling circuit 13A as a high-precision temperature sampling circuit, the sampling accuracy of the temperature information can be improved.

[0041] For example, the main controller 11 can correct the target power based on the correction coefficient by multiplying the target power by the corresponding correction coefficient, and taking the product of the two as the corrected target power. For example, the corresponding relationship between multiple temperature information and multiple correction coefficients is shown in Table 1 below.

[0042] Table 1 Temperature correction coefficient table

[0043]

[0044]

[0045] Among them, since the power is directly proportional to the square of the voltage, the voltage signal can be used to characterize the power of the radio frequency signal. For example, in the embodiment of the present application, a 1V voltage signal can be used to characterize the power of 1000W. In Table 1, when the target power is 1.5V, if the temperature sampling circuit 13A collects the temperature information of the current environment as 32°C, the main controller 11 multiplies 1.5V by the corresponding correction coefficient C according to the temperature correction coefficient table, and corrects the target power to 1.5×C(V). In the above Table 1, the values ​​of the multiple correction coefficients A, B, C, D, E, and F are different. Correspondingly, if the temperature information of the current environment collected is between 20℃ and 25℃, the main controller 11 multiplies the target power with the corresponding correction coefficient A; if the temperature information of the current environment collected is between 25℃ and 30℃, the main controller 11 multiplies the target power with the corresponding correction coefficient B; and so on,..., if the temperature information of the current environment collected is between 45℃ and 50℃, the main controller 11 multiplies the target power with the corresponding correction coefficient F.

[0046] It should be noted that in actual applications, the main controller 11, proportional-integral controller 14, proportional-integral-differential controller 21 and other controllers of the RF power supply 10, as well as the measurement circuit 13 and other circuits usually include components such as resistors, circuits, and transistors. These components will undergo parameter changes when the ambient temperature changes, resulting in temperature drift (i.e., temperature drift), which in turn causes the current power measured to change with changes in the ambient temperature, thereby reducing the stability of the RF output.

[0047] The above scheme utilizes temperature sampling circuit 13A to collect current ambient temperature information, and enables main controller 11 to correct the target power based on this temperature information and its corresponding correction coefficient, achieving temperature compensation for the target power. This allows the target power to change with ambient temperature to align with the current power variation pattern. This eliminates the effects of temperature drift on RF power supply 10 when the ambient temperature changes, allowing RF power supply 10 to maintain stable RF output under varying ambient temperatures, thereby improving RF output stability.

[0048] It should be noted that the RF power supply 10 can usually work normally when the ambient temperature range is 20° C. to 50° C., so the temperature compensation effect can be achieved by setting the pre-stored temperature information to be between 20° C. and 50° C.

[0049] In one embodiment, Figure 3As shown, the measurement circuit 13 includes a filter amplifier circuit 13B, which is connected between the power amplifier circuit 12 and the proportional-integral controller 14. For example, the measurement circuit 13 is connected between the output terminal of the filter amplifier circuit 13B and the second input terminal of the proportional-integral controller 14.

[0050] Filter amplifier circuit 13B has multiple amplification factors, each corresponding to a plurality of power intervals. The amplification factors are inversely correlated with the power values ​​within the power intervals. For example, a larger amplification factor corresponds to a smaller power value within the corresponding power interval; a smaller amplification factor corresponds to a larger power value within the corresponding power interval.

[0051] Exemplarily, the power interval in which the target power is located can be determined based on the rated power of the RF signal. For example, when the target power is less than 10% of the rated power, the target power is in the first power interval; when the target power is greater than or equal to 10% of the rated power, the target power is in the second power interval; the power value of the first power interval is less than the power value of the second power interval. It should be noted that the number of power intervals can be selected and adjusted according to actual needs. For example, the number of power intervals can be greater than or equal to two, and this embodiment of the present application does not limit this.

[0052] The main controller 11 is used to determine the corresponding amplification factor as the target factor of the filter amplifier circuit 13B according to the power range in which the target power is located, and adjust the amplification factor of the filter amplifier circuit 13B to the target amplification factor, so that the filter amplifier circuit 13B filters the current power and amplifies it to the target amplification factor before transmitting it to the proportional-integral controller 14.

[0053] In actual applications, the measurement circuit 13 has a measurement error. When the power of the RF signal output by the power amplifier circuit 12 is large, for example, the RF signal is a high-power signal, the measurement error accounts for a small proportion and can be ignored; when the power of the RF signal is small, for example, the RF signal is a low-power signal, the measurement error accounts for a large proportion, which will reduce the measurement accuracy, thereby worsening the accuracy of the RF output.

[0054] The above solution, by placing a filter amplifier circuit 13B between the power amplifier circuit 12 and the proportional-integral controller 14 and having the main controller 11 determine the corresponding amplification factor as the target amplification factor of the filter amplifier circuit 13B based on the power range in which the target power falls, can ensure that the target amplification factor of the filter amplifier circuit 13B is inversely correlated with the target power. Furthermore, because the power of the RF signal is typically close to or equal to the target power, the target amplification factor of the filter amplifier circuit 13B can be adapted to the RF output of the RF power supply 10. Thus, when the RF signal power is high, the target amplification factor of the filter amplifier circuit 13B is low, and since measurement errors are negligible, the RF power supply 10 can maintain high output accuracy. When the RF signal power is low, the target amplification factor of the filter amplifier circuit 13B is high, and the current power is amplified to a larger factor, which reduces the proportion of measurement errors, improves the measurement accuracy of the measurement circuit 13, and thus improves the RF output accuracy. In this way, the RF power supply 10 can maintain high output accuracy in all power ranges.

[0055] In an optional embodiment, as Figure 3 As shown, the filtering and amplifying circuit 13B includes a plurality of sub-filtering and amplifying circuits 131 and a plurality of controllable switches 132 , and the amplification factors of the plurality of sub-filtering and amplifying circuits 131 are all different.

[0056] The input ends of the multiple sub-filtering and amplifying circuits 131 are all connected to the output end of the power amplifying circuit 12. The output ends of the multiple sub-filtering and amplifying circuits 131 are connected in a one-to-one correspondence with the first ends of the multiple controllable switches 132. The second ends of the multiple controllable switches 132 are all connected to the proportional-integral controller 14. The control ends of the multiple controllable switches 132 are all connected to the main controller 11. For example, the second ends of the multiple controllable switches 132 are all connected to the second input end of the proportional-integral controller 14, and the control ends of the multiple controllable switches 132 are all connected to the second output end of the main controller 11.

[0057] The main controller 11 is used to determine the corresponding target sub-filter circuit from multiple sub-filter amplifier circuits 131 according to the target amplification factor, and control the controllable switch 132 of the branch where the target sub-filter circuit is located to close, so that the current power passes through the target sub-filter amplifier circuit and is transmitted to the proportional-integral controller 14.

[0058] For example, Figure 3As shown, the sub-filtering and amplifying circuit 131 is used as two for illustration. The sub-filtering and amplifying circuit 131 includes a first sub-filtering and amplifying circuit 131A and a second sub-filtering and amplifying circuit 131B. The amplification factor of the first sub-filtering and amplifying circuit 131A is 10X, and the amplification factor of the second sub-filtering and amplifying circuit 131B is X. Where X is a real number greater than 0, for example, X can be a decimal or an integer greater than 0. When the target power is within the first power range, the main controller 11 determines that the first sub-filtering and amplifying circuit 131A is the target sub-filtering and amplifying circuit and controls the first controllable switch 132A of the branch where the first sub-filtering and amplifying circuit 131A is located to close, so that the current power is filtered and amplified by 10X by the first sub-filtering and amplifying circuit 131A before being transmitted to the proportional-integral controller 14. When the target power is within the second power range, the main controller 11 determines that the second sub-filtering and amplifying circuit 131B is the target sub-filtering and amplifying circuit, and controls the second controllable switch 132B of the branch where the second sub-filtering and amplifying circuit 131B is located to close, so that the current power is filtered and amplified by a factor of X by the second sub-filtering and amplifying circuit 131B before being transmitted to the proportional-integral controller 14. Based on this, the amplification factor of the filtering and amplifying circuit 13B can be adjusted to the target amplification factor, so that the current power is filtered and amplified by the target amplification factor before being transmitted to the proportional-integral controller 14.

[0059] It should be noted that, since the radio frequency signal output by the power amplifier circuit 12 is usually a high-power signal, the current power measured by the measurement circuit 13 is a low-power signal, and the target power is also a low-power signal, but there may be a mismatch between the magnitude of the current power and the target power. In the above scheme, by setting X to a decimal less than 1, for example, setting X = 0.25, the target power is 1.5V, and the current power is 4V, the second sub-filter amplifier circuit 131B can reduce the current power by 1 / 4, that is, the current power is reduced to 1V, so that the magnitude of the current power matches the magnitude of the target power, which facilitates the proportional-integral controller 14 to process the current power and target power of the same level. Among them, the size of X can be selected and adjusted according to actual needs, and the embodiment of the present application does not limit it.

[0060] In another alternative embodiment, Figure 4 As shown, the filtering and amplifying circuit 13B includes a first filter 133 and a signal amplifier 134 . The signal amplifier 134 includes an operational amplifier OP, an adjustable potentiometer AR, and a first resistor R1 .

[0061] The first filter 133 is connected between the output of the power amplifier circuit 12 and the non-inverting input of the operational amplifier OP. For example, the first filter 133 includes a second resistor R2 and a capacitor C. The second resistor R2 is connected between the output of the power amplifier circuit 12 and the non-inverting input of the operational amplifier OP. The non-inverting input of the operational amplifier OP is also grounded via the capacitor C, allowing the first filter 133 to function as a low-pass filter. In this manner, the first filter 133 can be used to filter out harmonic signals carried by the current power.

[0062] The inverting input of the operational amplifier OP is connected to the output via an adjustable potentiometer AR and to ground via a first resistor R1. The output of the operational amplifier OP is also connected to the proportional-integral controller 14. The control end of the adjustable potentiometer AR is connected to the main controller 11. For example, the control end of the adjustable potentiometer AR is connected to the second output end of the main controller 11. The adjustable potentiometer AR can be a digital potentiometer. When the main controller 11 adjusts the resistance value of the adjustable potentiometer AR, the amplification factor of the signal amplifier 134 changes accordingly, thereby achieving adjustment of the amplification factor.

[0063] Furthermore, the main controller 11 is configured to adjust the resistance value of the adjustable potentiometer AR according to the target amplification factor, thereby enabling the amplification factor of the signal amplifier 134 to reach the target amplification factor. For example, when the target power is within the first power range, the main controller 11 adjusts the resistance value of the potentiometer AR to set the amplification factor of the signal amplifier to 10X. The current power is then filtered and amplified by 10X by the filter-amplifier circuit 13B before being transmitted to the proportional-integral controller 14. When the target power is within the second power range, the main controller 11 adjusts the resistance value of the potentiometer AR to set the amplification factor of the signal amplifier 134 to X. The current power is then filtered and amplified by X by the filter-amplifier circuit 13B before being transmitted to the proportional-integral controller 14.

[0064] In one embodiment, Figure 3 and Figure 4 As shown, the power amplifier circuit 12 includes a driving circuit 121 and a power amplifier and filter circuit 122. The driving circuit 121 is used to amplify and output the frequency control signal. The power amplifier and filter circuit 122 is used to further amplify and filter the amplified frequency control signal to obtain and output a radio frequency signal.

[0065] Exemplarily, the drive circuit 121 has an input and an output, and the power amplifier and filter circuit 122 has a first input and a second input. The input of the drive circuit 121 is connected to the first output of the main controller 11 to receive a frequency control signal, and the output of the drive circuit 121 is connected to the first input of the power amplifier and filter circuit 122 to amplify the frequency control signal and transmit it to the power amplifier and filter circuit 122. The second input of the power amplifier and filter circuit 122 is connected to the output of the proportional-integral-differential controller 21 to receive the proportional-integral-differential control variable. The input of the drive circuit 121 constitutes the first input of the power amplifier circuit 12, and the second input of the power amplifier and filter circuit 122 constitutes the second input of the power amplifier circuit 12.

[0066] In practical applications, the frequency control signal generated by the main controller 11 is typically a low-power signal on the order of mW (milliwatts), while the frequency control signal required by the power amplifier and filter circuit 122 is on the order of W (watts). If the frequency control signal is directly transmitted to the power amplifier and filter circuit 122, the power amplifier and filter circuit 122 will not be able to operate. By amplifying the frequency control signal using the driver circuit 121, a high-power drive signal on the order of W required by the power amplifier and filter circuit 122 can be obtained. Furthermore, when the amplified frequency control signal is transmitted to the power amplifier and filter circuit 122, the power amplifier and filter circuit 122 can be driven to further amplify the amplified frequency control signal to obtain a radio frequency signal on the order of kW (kilowatts). The frequencies of the frequency control signal, the amplified frequency control signal, and the radio frequency signal are all the same. Furthermore, harmonics are generated during the power amplification process. By configuring the power amplifier circuit 12 to include the power amplifier and filter circuit 122, the radio frequency signal can be filtered and outputted to remove unwanted harmonic components, leaving only the desired fundamental component in the output radio frequency signal.

[0067] Exemplarily, the drive circuit 121 further has a first power supply terminal, and the power amplification and filtering circuit 122 has a power supply terminal. The first power supply terminal of the drive circuit 121 and the power supply terminal of the power amplification and filtering circuit 122 are both connected to the power supply terminal of the first power supply circuit 15, so that the first power supply circuit 15 provides the first DC power to the drive circuit 121 and the power amplification and filtering circuit 122, respectively. The first power supply terminal of the drive circuit 121 and the power supply terminal of the power amplification and filtering circuit 122 constitute the first power supply terminal of the power amplification circuit 12.

[0068] In one embodiment, Figure 3 and Figure 4As shown, the measurement circuit 13 also includes a signal sampling circuit 13C, a second filter 13D, and a multiplier 13E. The input of the signal sampling circuit 13C is connected to the output of the power amplifier circuit 12, and is used to sample the power of the RF signal into a voltage signal; this voltage signal is used to represent the power of the RF signal. For example, the power of the RF signal is generally a high-power signal, while the voltage signal is a low-power signal. By using the signal sampling circuit 13C to sample the power of the RF signal into a voltage signal, the power of the RF signal can be represented using a low-power signal.

[0069] The output of signal sampling circuit 13C is connected to the input of second filter 13D to transmit the voltage signal to second filter 13D. The output of second filter 13D is connected to the input of multiplier 13E, which filters the voltage signal and transmits it to multiplier 13E. Multiplier 13E is configured to perform a multiplication and square operation on the voltage signal to obtain the current power. The squaring operation performed by multiplier 13C on the voltage signal may be performed on a scalar of the voltage signal, so that the calculated current power remains a low-power voltage signal, consistent with the target power signal type. Furthermore, the output of multiplier 13E is also connected to the input of filter amplifier circuit 13B to transmit the current power to filter amplifier circuit 13B.

[0070] In the above scheme, since the power of the RF signal is proportional to the square of its voltage signal, signal sampling circuit 13C first samples the RF signal power as a voltage signal. This low-power voltage signal can then be used to characterize the power of the RF signal. Multiplier 13E then performs a square operation on this voltage signal to obtain the current power proportional to the power of the RF signal, thereby achieving current power measurement. Furthermore, since sampling the power of the RF signal using signal sampling circuit 13C introduces harmonics, causing the voltage signal to carry harmonics, a second filter 13D is provided between signal sampling circuit 13C and multiplier 13E to filter out the harmonics carried by the voltage signal before transmitting it to multiplier 13E, further improving measurement accuracy.

[0071] In one embodiment, Figure 3 and Figure 4 As shown, the RF power supply 10 further includes an interface circuit 31 , an analog-to-digital conversion circuit 32 and a first digital-to-analog conversion circuit 33 .

[0072] The interface circuit 31 is used to receive a set power of a radio frequency signal. The set power may be sent to the interface circuit 31 by a semiconductor process device.

[0073] The main controller 11 is configured to receive a set power from the interface circuit 31 via the analog-to-digital conversion circuit 32, and to correct the set power to obtain a target power. The main controller 11 is also configured to transmit the target power to the proportional-integral controller 14 via the first digital-to-analog conversion circuit 33. For example, the main controller 11 may also include a transceiver, which is connected to the interface circuit 31 via the analog-to-digital conversion circuit 32 to receive the set power. A second output terminal of the main controller 11 is connected to a first input terminal of the proportional-integral controller 14 via the first digital-to-analog conversion circuit 33 to transmit the target power to the proportional-integral controller 14.

[0074] For example, the set power is typically an analog signal, the main controller 11 is typically configured to process digital signals, and the proportional-integral controller 14 is typically configured to process analog signals. The set power is first converted to digital by the analog-to-digital conversion circuit 32 before being output to the main controller 11. This ensures that the signal type of the set power matches the processing type of the main controller 11. The main controller 11 then performs digital-to-analog conversion on the target power using the first digital-to-analog conversion circuit 33 before outputting it to the proportional-integral controller 14. This ensures that the signal type of the target power matches the processing type of the proportional-integral controller 14. Furthermore, using the main controller 11 to calibrate the set power to obtain the target power improves the accuracy of the target power.

[0075] For example, Figure 3 As shown, the analog-to-digital conversion circuit 32 is also connected between the temperature sampling circuit 13A and the transceiver end of the main controller 11, and is used to perform analog-to-digital conversion on the temperature information collected by the temperature sampling circuit 13A and transmit it to the main controller 11, so that the type of the temperature information conforms to the processing type of the main controller 11.

[0076] In one embodiment, Figure 3 and Figure 4 As shown, the RF power supply 10 further includes a second digital-to-analog conversion circuit 34, which is connected between the main controller 11 and the interface circuit 31. For example, the main controller 11 further has a third output terminal, and the second digital-to-analog conversion circuit 34 is connected between the third output terminal of the main controller 11 and the interface circuit 31.

[0077] The main controller 11 is also configured to receive the current power via the analog-to-digital conversion circuit 32 and correct the current power to obtain feedback power. For example, the analog-to-digital conversion circuit 32 is connected between the filter amplifier circuit 13B and the main controller 11. It is configured to perform analog-to-digital conversion on the current power output by the filter amplifier circuit 13B and transmit the result to the main controller 11, ensuring that the current power type conforms to the processing type of the main controller 11. This allows the main controller 11 to correct the current power to obtain feedback power. The main controller 11 is also configured to output the feedback power to the interface circuit 31 via the second digital-to-analog conversion circuit 34, so that the feedback power is transmitted to the semiconductor process equipment via the interface circuit 31, allowing the semiconductor process equipment to display the feedback power. Based on this, the RF power supply 10 can output the current power to the semiconductor process equipment by outputting the feedback power, thereby enabling the semiconductor process equipment to display the feedback power. This facilitates a visual display of the current power and facilitates timely observation of the control results of the RF power supply 10 by the user.

[0078] In practical applications, at least two of the main controller 11, the proportional-integral controller 14, the proportional-integral-differential controller 21, the analog-to-digital conversion circuit 32, the first digital-to-analog conversion circuit 33, and the second digital-to-analog conversion circuit 34 can be integrated into the same control circuit. The embodiments of the present application do not limit the manner in which they are integrated.

[0079] In one embodiment, Figure 3 and Figure 4 As shown, the RF power supply 10 also includes a second power supply circuit 16. The second power supply circuit 16 is used to convert AC power into a second DC power and output it to the main controller 11, the proportional-integral controller 14, the proportional-integral-differential controller 21, and the power amplifier circuit 12 to provide power supply; the voltage of the second DC power is lower than the voltage of the first DC power. Exemplarily, the second power supply circuit 16 outputs the second DC power to the power amplifier circuit 12 by outputting the second DC power to the second power supply terminal of the drive circuit 121, thereby enabling the drive circuit 121 to operate. The second power supply terminal of the drive circuit 121 can constitute the second power supply terminal of the power amplifier circuit 12.

[0080] Figure 5 FIG. 1 is a schematic structural diagram of a semiconductor process equipment according to an embodiment of the present application.

[0081] like Figure 5 As shown, the semiconductor processing equipment 100 includes an RF power supply 10 according to any of the above embodiments, at least one matching unit 20, at least one RF electrode 30, and a process chamber 40. The RF electrode 30 is located inside the process chamber 40. The RF power supply 10 applies an RF signal to the RF electrode 30 through the matching unit 20 to excite the process gas inside the process chamber 40 to generate plasma.

[0082] The matcher 20 is used to achieve impedance matching between the RF power supply 10 and the process chamber 40 , so that the RF energy provided by the RF power supply 10 is transferred to the process chamber 40 to the maximum extent.

[0083] During operation of the process chamber 40, the RF output stability and accuracy of the RF power supply 10 directly affect the process quality. For example, in a film coating process, when the RF output stability and accuracy of the RF power supply 10 are low, the stress distribution of the coating formed on the surface of the workpiece to be plated is uneven, resulting in poor adhesion of the coating; furthermore, the process consistency between different batches of workpieces to be plated is poor. Since the RF output stability and accuracy of the RF power supply 10 of the embodiment of the present application are high, applying the RF power supply 10 of the embodiment of the present application to the semiconductor process equipment 100 is beneficial to improving process quality. For example, in a film coating process, it can effectively improve the uniformity of the stress distribution of the coating and the process consistency between different batches of workpieces to be plated.

[0084] In one embodiment, Figure 6 As shown, the RF power source 10 includes an upper RF power source 10A and a lower RF power source 10B, the matching box 20 includes an upper matching box 20A and a lower matching box 20B, and the RF electrode 30 includes an upper electrode 30A and a lower electrode 30B. The upper RF power source 10A applies an RF signal to the upper electrode 30A via the upper matching box 20A, while the lower RF power source 10B applies an RF signal to the lower electrode 30B via the lower matching box 20B.

[0085] For example, the semiconductor processing equipment 100 is described as a plasma etching device. The upper electrode 30A can be a radio frequency coil. The upper radio frequency power supply 10A applies a radio frequency signal to the radio frequency coil through the upper matching device 20A to provide upper electrode power, so that the radio frequency coil excites the process gas inside the process chamber 40 to generate plasma. The lower electrode 30B can be the lower electrode of the wafer carrier. The lower radio frequency power supply 10B applies a radio frequency signal to the lower electrode 30B of the wafer carrier through the lower matching device 20B to provide lower electrode power, so that the lower electrode 30 of the wafer carrier provides a radio frequency bias to attract the plasma above and bombard the object to be etched 50. The semiconductor processing equipment 100 also includes an air inlet assembly 30C for introducing process gas into the process chamber 40.

[0086] The semiconductor process equipment 100 of the embodiment of the present application can be an inductively coupled plasma (ICP) etching device or a capacitively coupled plasma (CCP) etching device. The semiconductor process equipment 100 can also be a physical vapor deposition (PVD) device or other semiconductor process equipment that requires an RF power supply 10. The embodiment of the present application does not limit the type of semiconductor process equipment 100.

[0087] It should be noted that, since the semiconductor process equipment 100 adopts all technical solutions of all embodiments of the above-mentioned RF power supply 10, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be described one by one here.

[0088] Furthermore, in this application, unless otherwise expressly specified or limited, terms such as "connected," "connected," and "stacked" should be interpreted broadly. For example, they may refer to fixed connections, detachable connections, or integration; they may refer to direct connections or indirect connections through an intermediate medium; they may refer to internal communication between two elements or interaction between two elements. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0089] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A radio frequency power supply, characterized in that: include: A main controller, configured to provide a frequency control signal and a target power; A first power supply circuit, configured to provide a first DC power and a power supply signal; a power amplifier circuit, configured to amplify the frequency control signal under the action of the first DC power to obtain and output a corresponding radio frequency signal; A measuring circuit, configured to measure the current power of the radio frequency signal; a proportional-integral controller, configured to determine a proportional-integral control amount according to the current power and the target power; A proportional-integral-differential controller is used to determine a proportional-integral-differential control amount based on the proportional-integral control amount and the power supply signal, and output the proportional-integral-differential control amount to the power amplifier circuit so that the power of the radio frequency signal approaches and reaches the target power.

2. The radio frequency power supply according to claim 1, characterized in that: The main controller pre-stores a plurality of temperature information and a plurality of correction coefficients, wherein the plurality of temperature information and the plurality of correction coefficients correspond one to one; The measurement circuit further includes a temperature sampling circuit, and the temperature sampling circuit is used to collect temperature information of the current environment; The main controller is further configured to determine a corresponding correction coefficient according to the temperature information, and correct the target power based on the correction coefficient.

3. The radio frequency power supply according to claim 1, wherein: The measurement circuit includes a filter amplifier circuit, which is connected between the power amplifier circuit and the proportional-integral controller; the filter amplifier circuit has a plurality of different amplification factors, the plurality of amplification factors correspond one-to-one to a plurality of power intervals, and the plurality of amplification factors are inversely correlated with the power values ​​of the plurality of power intervals; The main controller determines the corresponding amplification factor as the target amplification factor of the filter amplifier circuit according to the power range in which the target power is located, and adjusts the amplification factor of the filter amplifier circuit to the target amplification factor, so that the filter amplifier circuit filters the current power and amplifies it to the target amplification factor before transmitting it to the proportional-integral controller.

4. The radio frequency power supply according to claim 3, characterized in that: The filtering and amplifying circuit includes a plurality of sub-filtering and amplifying circuits and a plurality of controllable switches, and the amplification factors of the plurality of sub-filtering and amplifying circuits are different; The input ends of the plurality of sub-filter amplifier circuits are all connected to the output end of the power amplifier circuit, the output ends of the plurality of sub-filter amplifier circuits are connected in a one-to-one correspondence with the first ends of the plurality of controllable switches, the second ends of the plurality of controllable switches are all connected to the proportional-integral controller, and the control ends of the plurality of controllable switches are all connected to the main controller; The main controller is used to determine a corresponding target sub-filter amplifier circuit from the multiple sub-filter amplifier circuits according to the target amplification factor, and control the controllable switch of the branch where the target sub-filter amplifier circuit is located to close, so that the current power is transmitted to the proportional-integral controller after passing through the target sub-filter amplifier circuit.

5. The radio frequency power supply according to claim 3, characterized in that: The filtering and amplifying circuit includes a first filter and a signal amplifier, and the signal amplifier includes an operational amplifier, an adjustable potentiometer and a first resistor; The first filter is connected between the output terminal of the power amplifier circuit and the non-inverting input terminal of the operational amplifier; The inverting input terminal of the operational amplifier is connected to the output terminal through the adjustable potentiometer and is grounded through the first resistor, and the control terminal of the adjustable potentiometer is connected to the main controller; The main controller is used to adjust the resistance value of the adjustable potentiometer according to the target amplification factor, so that the amplification factor of the signal amplifier reaches the target amplification factor.

6. The radio frequency power supply according to claim 1, characterized in that: The power amplifier circuit includes a driving circuit and a power amplifier filter circuit; The driving circuit is used to amplify and output the frequency control signal; The power amplification and filtering circuit is used to amplify the amplified frequency control signal again and filter it to obtain and output the radio frequency signal.

7. The radio frequency power supply according to claim 1, characterized in that: The measurement circuit further includes a signal sampling circuit, a second filter and a multiplier; The signal sampling circuit is used to sample the power of the radio frequency signal into a voltage signal, and the voltage signal is used to represent the power of the radio frequency signal; The second filter is used to filter the voltage signal and then transmit the filtered signal to the multiplier; The multiplier is used to perform a square operation on the voltage signal to obtain the current power.

8. The radio frequency power supply according to claim 1, characterized in that: It also includes an interface circuit, an analog-to-digital conversion circuit, and a first digital-to-analog conversion circuit; The interface circuit is used to receive the set power of the radio frequency signal; The main controller is configured to receive the set power from the interface circuit via the analog-to-digital conversion circuit, and obtain the target power after correcting the set power; The main controller is further configured to transmit the target power to the proportional-integral controller through the first digital-to-analog conversion circuit.

9. The radio frequency power supply according to claim 8, characterized in that: Also includes: A second digital-to-analog conversion circuit is connected between the main controller and the interface circuit; The main controller is further configured to receive the current power through the analog-to-digital conversion circuit, and obtain feedback power after correcting the current power; The main controller is further configured to output the feedback power to the interface circuit via the second digital-to-analog conversion circuit, so as to send the feedback power to semiconductor process equipment via the interface circuit, so that the semiconductor process equipment displays the feedback power.

10. The radio frequency power supply according to claim 1, characterized in that: Also includes: a second power supply circuit, configured to output a second DC power to the main controller, the proportional-integral controller, the proportional-integral-differential controller, and the power amplifier circuit; The voltage of the second DC power is lower than the voltage of the first DC power.

11. A semiconductor process equipment, characterized in that: include: The radio frequency power supply, at least one matching device, at least one radio frequency electrode, and a process chamber according to any one of claims 1 to 10; The RF power supply applies a RF signal to the RF electrode through the matcher to generate plasma inside the process chamber.

12. The semiconductor process equipment according to claim 11, wherein: The radio frequency power supply includes an upper radio frequency power supply and a lower radio frequency power supply, the matching device includes an upper matching device and a lower matching device, and the radio frequency electrode includes an upper electrode and a lower electrode; The upper radio frequency power supply applies a radio frequency signal to the upper electrode through the upper matching device; The lower radio frequency power supply applies a radio frequency signal to the lower electrode through the lower matching device.

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