A down radio frequency control device and semiconductor equipment

Abstract

This application discloses a lower radio frequency (RF) control device and semiconductor equipment, including a voltage sensor, a reference voltage circuit, an RF control switch, and a voltage comparison circuit. The voltage sensor detects the actual voltage signal on the electrostatic chuck; the reference voltage circuit outputs a reference voltage signal according to a preset safety withstand voltage for the electrostatic chuck; the voltage comparison circuit controls the RF control switch to close when the actual voltage signal is less than or equal to the reference voltage signal, enabling the lower RF power supply to output RF power; when the actual voltage signal is greater than the reference voltage signal, it controls the RF control switch to open, cutting off the RF output of the lower RF power supply. Therefore, the lower RF control device can cut off the RF output of the lower RF power supply when the voltage on the electrostatic chuck is too high, aiming to cut off RF power that may cause arcing; moreover, the lower RF control device is implemented using hardware circuitry, resulting in a fast response speed and timely cutting off RF power that may cause arcing, thus preventing equipment damage.

Description

Technical Field

[0001] This application relates to the field of semiconductor processes, and more particularly to a radio frequency control device and semiconductor equipment. Background Technology

[0002] Semiconductor equipment includes a lower electrode and a lower radio frequency (RF) power supply fed to the lower electrode. The lower electrode includes an electrostatic chuck for holding the wafer, and the electrostatic chuck has a riser hole for the riser pins of the riser mechanism to pass through. During semiconductor manufacturing processes, a certain amount of charge accumulates on the electrostatic chuck. Furthermore, to achieve better wafer etching accuracy and deeper etching depth, higher power RF conditions are often used during wafer processing, increasing the amount of charge accumulated on the electrostatic chuck. This can easily lead to arcing around the riser hole, causing damage to the electrostatic chuck or the riser mechanism, thus altering the process chamber environment and affecting the normal operation of the equipment. Summary of the Invention

[0003] The purpose of this application is to provide a lower radio frequency control device and a semiconductor device. The lower radio frequency control device can cut off the radio frequency output of the lower radio frequency power supply when the voltage on the electrostatic chuck is too high, so as to cut off the radio frequency power that may cause arcing. Moreover, the lower radio frequency control device is implemented by hardware circuit, which has a fast response speed and can cut off the radio frequency power that may cause arcing in time to avoid damage to the equipment.

[0004] To address the aforementioned technical problems, this application provides a lower radio frequency (RF) control device applied to a semiconductor device. The semiconductor device includes: a lower electrode comprising an electrostatic chuck, and a lower RF power supply fed to the lower electrode; the lower RF control device includes:

[0005] A voltage sensor, connected to the electrostatic chuck, is used to detect the actual voltage signal on the electrostatic chuck;

[0006] A reference voltage circuit is used to output a reference voltage signal according to a preset safety withstand voltage for the electrostatic chuck;

[0007] An RF control switch is connected in series on the signal transmission line where the RF output signal used to control the lower RF power supply is located;

[0008] A voltage comparison circuit is connected to the voltage sensor, the reference voltage circuit, and the radio frequency control switch, respectively. When the actual voltage signal is less than or equal to the reference voltage signal, the circuit controls the radio frequency control switch to close so that the lower radio frequency power supply can output radio frequency; when the actual voltage signal is greater than the reference voltage signal, the circuit controls the radio frequency control switch to open so as to cut off the radio frequency output of the lower radio frequency power supply.

[0009] Optionally, the reference voltage circuit includes:

[0010] DC regulated power supply;

[0011] A variable resistor, wherein the first terminal of the variable resistor is connected to the DC regulated power supply, the middle terminal is connected to the voltage comparison circuit, and the second terminal is grounded, is used to adjust the magnitude of the reference voltage signal input to the voltage comparison circuit to the safe withstand voltage.

[0012] Optionally, the voltage comparison circuit includes:

[0013] A voltage comparator, wherein the positive input terminal of the voltage comparator is connected to the reference voltage circuit, the inverting input terminal is connected to the voltage sensor, and the output terminal is connected to the radio frequency control switch, is used to output a level signal to the radio frequency control switch to close the radio frequency control switch when the voltage of the positive input signal is greater than or equal to the voltage of the inverting input signal; and does not output a level signal to the radio frequency control switch to open the radio frequency control switch when the voltage of the positive input signal is less than the voltage of the inverting input signal.

[0014] Optionally, the lower radio frequency control device further includes:

[0015] A signal filtering circuit is connected in series on the transmission line from the voltage sensor to the voltage comparison circuit to transmit the actual voltage signal. It is used to filter the actual voltage signal output by the voltage sensor and transmit the filtered actual voltage signal to the voltage comparison circuit.

[0016] Optionally, the radio frequency control switch is specifically connected in series on the signal transmission line where the interlock signal of the lower radio frequency power supply is located.

[0017] Optionally, the radio frequency control switch is a relay.

[0018] Optionally, the lower radio frequency control device further includes:

[0019] The lower-level computer is connected in series on the transmission line from the reference voltage circuit to the voltage comparison circuit to transmit the reference voltage signal, and is also connected to the upper-level computer. It is used to determine whether the reference voltage signal has drifted according to a preset voltage drift determination strategy. If not, the reference voltage signal is output to the voltage comparison circuit; if so, an alarm signal indicating that the reference voltage signal has drifted is thrown to the upper-level computer.

[0020] Optionally, the lower-level computer is also connected to the lower-level RF power supply and is used to send an alarm signal to the upper-level computer to indicate that the RF output of the lower-level RF power supply has been cut off when the RF output of the lower-level RF power supply is detected to be cut off.

[0021] Optionally, the lower-level machine is specifically used to determine the relationship between DR and (V) ref -V refi ) / V refi Calculate the drift rate and determine whether the drift rate is greater than a preset drift threshold. If it is, determine that the reference voltage signal has drifted; if not, determine that the reference voltage signal has not drifted.

[0022] Wherein, DR represents the drift rate; V ref This represents the reference voltage signal actually output by the reference voltage circuit; V refi This indicates the initial setting value of the reference voltage signal.

[0023] To address the aforementioned technical problems, this application also provides a semiconductor device, comprising:

[0024] Lower electrode; the lower electrode includes an electrostatic chuck;

[0025] The lower radio frequency power supply is fed to the lower electrode;

[0026] The above-mentioned radio frequency control device.

[0027] This application provides a lower radio frequency (RF) control device, including a voltage sensor, a reference voltage circuit, an RF control switch, and a voltage comparison circuit. The voltage sensor detects the actual voltage signal on the electrostatic chuck; the reference voltage circuit outputs a reference voltage signal according to a preset safety withstand voltage for the electrostatic chuck; the RF control switch is connected in series on the signal transmission line containing the signal used to control the RF output of the lower RF power supply; the voltage comparison circuit controls the RF control switch to close when the actual voltage signal is less than or equal to the reference voltage signal, enabling the lower RF power supply to output RF signals; and controls the RF control switch to open when the actual voltage signal is greater than the reference voltage signal, cutting off the RF output of the lower RF power supply. Therefore, the lower RF control device can cut off the RF output of the lower RF power supply when the voltage on the electrostatic chuck is too high, aiming to cut off RF power that may cause arcing; moreover, the lower RF control device is implemented using hardware circuitry, resulting in a fast response speed and timely cutting off RF power that may cause arcing, thus preventing equipment damage.

[0028] This application also provides a semiconductor device that has the same beneficial effects as the radio frequency control device described above. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the structure of a lower radio frequency control device provided in an embodiment of this application;

[0031] Figure 2 A timing comparison diagram of software response time and hardware response time provided for embodiments of this application;

[0032] Figure 3 This is a schematic diagram of the specific structure of a lower radio frequency control device provided in an embodiment of this application. Detailed Implementation

[0033] The core of this application is to provide a lower radio frequency control device and a semiconductor device. The lower radio frequency control device can cut off the radio frequency output of the lower radio frequency power supply when the voltage on the electrostatic chuck is too high, with the purpose of cutting off the radio frequency power that may cause arcing. Moreover, the lower radio frequency control device is implemented by hardware circuit, with a fast response speed, so as to cut off the radio frequency power that may cause arcing in time and avoid damage to the equipment.

[0034] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0035] Semiconductor equipment includes a bottom electrode and a BRF (Bottom Radio Frequency) power supply fed to the bottom electrode. The bottom electrode includes an ESC (Electrostatic Chuck) for holding the wafer. The electrostatic chuck has a riser / faller hole for the riser / faller pins of the riser / faller mechanism to pass through. During the semiconductor manufacturing process, a certain amount of charge accumulates on the ESC. Moreover, to achieve better wafer etching accuracy and deeper wafer etching depth, higher-power bottom radio frequency conditions are often used during wafer processing. This increases the amount of charge accumulated on the ESC, making it prone to arcing around the riser / faller hole. (Specifically, in a radio frequency environment, the electrostatic chuck acts as a field source when high voltage is applied. Since the bottom of the riser / faller hole structure is a grounded structure, the direction of the field strength when high voltage is applied is along the electrostatic chuck towards the riser / faller mechanism. When the high voltage exceeds the withstand capability of the riser / faller hole structure, arcing will occur.) This damages the ESC or the riser / faller mechanism, thereby altering the process chamber environment and affecting the normal operation of the equipment.

[0036] To address the aforementioned technical problems, this application provides a lower radio frequency control device applied to semiconductor equipment. Please refer to... Figure 1 , Figure 1 This is a schematic diagram of a lower radio frequency control device provided in an embodiment of this application. Figure 1 As shown, the lower radio frequency control device includes:

[0037] Voltage sensor 1, connected to the electrostatic chuck, is used to detect the actual voltage signal on the electrostatic chuck;

[0038] Reference voltage circuit 2 is used to output a reference voltage signal according to the preset safety withstand voltage for the electrostatic chuck;

[0039] RF control switch 3 is connected in series on the signal transmission line where the RF output signal used to control the RF power supply is located;

[0040] The voltage comparison circuit 4 is connected to the voltage sensor 1, the reference voltage circuit 2, and the radio frequency control switch 3 respectively. When the actual voltage signal is less than or equal to the reference voltage signal, it controls the radio frequency control switch 3 to close so that the lower radio frequency power supply can output radio frequency; when the actual voltage signal is greater than the reference voltage signal, it controls the radio frequency control switch 3 to open so as to cut off the radio frequency output of the lower radio frequency power supply.

[0041] In this embodiment, the preset safety withstand voltage for the electrostatic chuck is a voltage that the electrostatic chuck can withstand without arcing, which is obtained based on actual measurements. Specifically, an insulation tester can be used to perform a withstand voltage test on the electrostatic chuck, testing the withstand voltage of the lifting pinhole structure of the electrostatic chuck to ground. This withstand voltage is used as the preset safety withstand voltage for the electrostatic chuck.

[0042] In specific applications, voltage sensor 1 is a bias voltage sensor (BVC sensor), used to detect the actual voltage signal (DC bias voltage signal) on the electrostatic chuck, and transmit the detected actual voltage signal on the electrostatic chuck to voltage comparison circuit 4.

[0043] The reference voltage circuit 2 is used to generate a reference voltage signal according to the preset safety withstand voltage for the electrostatic chuck. Specifically, it generates a reference voltage signal with the same magnitude as the safety withstand voltage and transmits the generated reference voltage signal to the voltage comparison circuit 4.

[0044] The input signal of the lower RF power supply includes a signal (called the target signal) used to control the RF output of the lower RF power supply. That is, when the target signal is normally input, the lower RF power supply can output RF signals; when the target signal is cut off from the input, the lower RF power supply cannot output RF signals. Based on this, the RF control switch 3 is connected in series with the signal transmission line containing the target signal of the lower RF power supply to control the on / off state of this signal transmission line. It can be understood that when the RF control switch 3 is closed, the signal transmission line containing the target signal of the lower RF power supply is in a connected state, and the target signal of the lower RF power supply can be normally input; when the RF control switch 3 is open, the signal transmission line containing the target signal of the lower RF power supply is in a disconnected state, and the target signal of the lower RF power supply is cut off from the input.

[0045] The voltage comparison circuit 4 simultaneously receives the actual voltage signal on the electrostatic chuck detected by the voltage sensor 1 and the reference voltage signal output by the reference voltage circuit 2, and compares the simultaneously received actual voltage signal and reference voltage signal. When the actual voltage signal is less than or equal to the reference voltage signal (assuming there is no risk of arcing), the RF control switch 3 is closed, and the signal transmission line where the target signal of the lower RF power supply is located is in a connected state, the target signal of the lower RF power supply can be input normally, and the lower RF power supply can perform RF output. When the actual voltage signal is greater than the reference voltage signal (assuming there is a risk of arcing), the RF control switch 3 is opened, and the signal transmission line where the target signal of the lower RF power supply is located is in a disconnected state, the target signal of the lower RF power supply is cut off from input, and the lower RF power supply cannot perform RF output, so as to cut off the RF power that may cause arcing.

[0046] It should be noted that, as can be seen from the structure of the lower RF control device described above, the lower RF control device is implemented using hardware circuitry (composed of multiple connected electronic components). The reason for using hardware circuitry instead of software (controller programming) is that the action time of the hardware circuitry is only the action time of the electronic components, and the response time can be less than 20μs; while software, due to the large amount of data read and the long code execution time, can have a response time of hundreds of milliseconds. For example, the timing diagrams of the software and hardware responses when the voltage on the electrostatic chuck is too high are as follows: Figure 2 As shown, the response speed of the hardware circuit is significantly better than that of the software. Furthermore, the software implementation is prone to software crashes or system instability, potentially leading to misjudgments or uncontrolled RF power-off. The hardware circuit, on the other hand, is more stable. Therefore, the hardware circuit offers superior response speed and stability compared to the software.

[0047] The lower radio frequency control device provided in this application can cut off the radio frequency output of the lower radio frequency power supply when the voltage on the electrostatic chuck is too high, with the purpose of cutting off the radio frequency power that may cause arcing; moreover, the lower radio frequency control device is implemented by hardware circuit, with a fast response speed, so as to cut off the radio frequency power that may cause arcing in time and avoid equipment damage.

[0048] Based on the above embodiments:

[0049] Please refer to Figure 3 , Figure 3 This is a schematic diagram of the specific structure of a lower radio frequency control device provided in an embodiment of this application.

[0050] As an optional embodiment, the reference voltage circuit 2 includes:

[0051] DC regulated power supply 21;

[0052] The variable resistor R has its first terminal connected to the DC regulated power supply 21, its middle terminal connected to the voltage comparison circuit 4, and its second terminal grounded. It is used to adjust the magnitude of the reference voltage signal input to the voltage comparison circuit 4 to the safe withstand voltage.

[0053] In a specific application, the DC regulated power supply 21 outputs a first voltage signal V1. The first voltage signal V1 is adjusted by a variable resistor R to a second voltage signal V2 that is equal to the safe withstand voltage preset for the electrostatic chuck. The second voltage signal V2 is provided as a reference voltage signal to the voltage comparison circuit 4.

[0054] It should be noted that the variable resistor R has three terminals: a first terminal, a middle terminal, and a second terminal. The first and second terminals are fixed, while the middle terminal is adjustable. The variable resistor R can be considered as two resistors: a first resistor R1 located between the first and middle terminals, and a second resistor R2 located between the middle and second terminals. If the middle terminal is adjusted closer to the first terminal, the resistance of the first resistor R1 decreases, and the resistance of the second resistor R2 increases. Conversely, if the middle terminal is adjusted closer to the second terminal, the resistance of the first resistor R1 increases, and the resistance of the second resistor R2 decreases. Since V2 = V1 * R2 / (R1 + R2), and R1 + R2 = the total resistance of the variable resistor R, by adjusting the position of the middle terminal of the variable resistor R, the magnitude of the second voltage signal V2 can be made equal to the preset safety withstand voltage for the electrostatic chuck, that is, the magnitude of the reference voltage signal input to the voltage comparison circuit 4 is equal to the safety withstand voltage. In addition, the voltage source of the reference voltage signal is a DC regulated power supply 21, which can ensure the stability of the reference voltage signal.

[0055] The reason for choosing a variable resistor is that different types of electrostatic chucks have different safe withstand voltages, and therefore different reference voltage signals. A variable resistor allows adjustment of the reference voltage signal, enabling the RF control device to adapt to different types of electrostatic chucks and more varied process conditions. For example, when the electrostatic chuck in the semiconductor equipment is replaced with another type, the safe withstand voltage of the new chuck decreases compared to the original. In this case, the reference voltage signal can be decreased by adjusting the variable resistor, and vice versa.

[0056] As an optional embodiment, the voltage comparator circuit 4 includes:

[0057] Voltage comparator 41 has its positive input terminal connected to reference voltage circuit 2, its inverting input terminal connected to voltage sensor 1, and its output terminal connected to radio frequency control switch 3. It is used to output a level signal to radio frequency control switch 3 when the voltage of the positive input signal is greater than or equal to the voltage of the inverting input signal, so as to close radio frequency control switch 3; and not to output a level signal to radio frequency control switch 3 when the voltage of the positive input signal is less than the voltage of the inverting input signal, so as to open radio frequency control switch 3.

[0058] In practical applications, the reference voltage signal is input to the positive input terminal of the voltage comparator 41 (integrated within the voltage comparator chip), and the actual voltage signal on the electrostatic chuck detected by the voltage sensor 1 is input to the negative input terminal of the voltage comparator 41. When the reference voltage signal is greater than or equal to the actual voltage signal (assuming no risk of arcing), the voltage comparator 41 outputs a level signal to the RF control switch 3. In this case, the RF control switch 3 is closed, and the signal transmission line where the target signal of the lower RF power supply is located is in a connected state, the target signal of the lower RF power supply can be input normally, and the lower RF power supply can perform RF output. When the reference voltage signal is less than the actual voltage signal (assuming a risk of arcing), the voltage comparator 41 does not perform an output action, that is, it does not output a level signal to the RF control switch 3. In this case, the RF control switch 3 is open, and the signal transmission line where the target signal of the lower RF power supply is located is in a disconnected state, the target signal of the lower RF power supply is cut off from input, and the lower RF power supply cannot perform RF output, thereby cutting off the RF power that may cause arcing.

[0059] As an optional embodiment, the lower radio frequency control device further includes:

[0060] The signal filtering circuit 5 is connected in series on the transmission line from the voltage sensor 1 to the voltage comparison circuit 4 to transmit the actual voltage signal. It is used to filter the actual voltage signal output by the voltage sensor 1 and transmit the filtered actual voltage signal to the voltage comparison circuit 4.

[0061] In practical applications, the actual voltage signal on the electrostatic chuck detected by the voltage sensor 1 is first filtered by the signal filtering circuit 5 before being provided to the voltage comparison circuit 4, so as to avoid interference to the actual voltage signal input to the voltage comparison circuit 4 and thus improve the circuit stability.

[0062] As an optional embodiment, the radio frequency control switch 3 is specifically connected in series on the signal transmission line where the interlock signal of the lower radio frequency power supply is located.

[0063] In practical applications, the interlock signal of the lower RF power supply controls its RF output. When the interlock signal is normally input, the lower RF power supply can output RF signals; when the interlock signal is cut off, the lower RF power supply cannot output RF signals. Therefore, the RF control switch 3 is specifically connected in series with the signal transmission line where the interlock signal of the lower RF power supply is located, to control the on / off state of the signal transmission line. That is, when the RF control switch 3 is closed, the signal transmission line where the interlock signal of the lower RF power supply is located is connected, and the interlock signal of the lower RF power supply can be input normally; when the RF control switch 3 is open, the signal transmission line where the interlock signal of the lower RF power supply is located is open, and the interlock signal of the lower RF power supply is cut off.

[0064] As an optional embodiment, the radio frequency control switch 3 is a relay 31.

[0065] In specific applications, the radio frequency control switch 3 can be a relay or other controllable switching device, and this application does not limit it in this regard.

[0066] As an optional embodiment, the lower radio frequency control device further includes:

[0067] The lower-level machine 6 is connected in series on the transmission line from the reference voltage circuit 2 to the voltage comparison circuit 4 to transmit the reference voltage signal, and is also connected to the upper-level machine. It is used to determine whether the reference voltage signal has drifted according to the preset voltage drift determination strategy. If not, the reference voltage signal is output to the voltage comparison circuit 4; if so, an alarm signal indicating that the reference voltage signal has drifted is sent to the upper-level machine.

[0068] In practical applications, considering that the reference voltage signal output by the reference voltage circuit 2 may drift due to hardware or interference problems, once drift occurs, the lower radio frequency control device needs to be removed to adjust the variable resistor R to recalibrate the reference voltage signal. If the variable resistor R also fails to calibrate the reference voltage signal back to its original setting value, the DC regulated power supply 21 needs to be replaced. Based on this, a lower-level machine 6 is set on the transmission line from the reference voltage circuit 2 to the voltage comparator circuit 4 (specifically, the input terminal of the lower-level machine 6 is connected to the middle terminal of the variable resistor R, and the output terminal of the lower-level machine 6 is connected to the positive input terminal of the voltage comparator 41). The lower-level machine 6 determines whether the reference voltage signal has drifted according to a preset voltage drift judgment strategy. If it determines that the reference voltage signal has not drifted, it outputs the reference voltage signal to the voltage comparator circuit 4; if it determines that the reference voltage signal has drifted, it does not output the reference voltage signal to the voltage comparator circuit 4, and instead sends a relevant alarm signal to the upper-level machine to remind the operator to adjust the variable resistor R to recalibrate the reference voltage signal.

[0069] As an optional embodiment, the lower-level computer 6 is also connected to the lower-level RF power supply and is used to send an alarm signal to the upper-level computer to indicate that the RF output of the lower-level RF power supply has been cut off when the RF output of the lower-level RF power supply is detected to be cut off.

[0070] In practical applications, the lower-level computer 6 is also connected to the lower-level RF power supply, which can detect whether the RF output of the lower-level RF power supply is cut off. If it is cut off, it will send a relevant alarm signal to the upper-level computer to remind the staff that the voltage on the electrostatic chuck is too high and there is a risk of arcing. If it is not cut off, no action will be taken.

[0071] As an optional embodiment, the lower-level machine 6 is specifically used to determine DR = (V ref -V refi ) / Vrefi Calculate the drift rate and determine whether the drift rate is greater than the preset drift threshold. If it is, the reference voltage signal is determined to have drifted; otherwise, the reference voltage signal is determined not to have drifted.

[0072] Where DR represents the drift rate; V ref This represents the actual reference voltage signal output by the reference voltage circuit; V refi This indicates the initial setting value of the reference voltage signal, which is the preset safe withstand voltage of the electrostatic chuck.

[0073] In this embodiment, the determination principle of the preset voltage drift determination strategy is as follows: the determination relationship (V ref -V refi ) / V refi >DR h (DR h This indicates whether the preset drift threshold (which can be 5% or other values) is met. If it is met, the reference voltage signal is determined to have drifted; if it is not met, the reference voltage signal is determined not to have drifted.

[0074] In addition to using the hardware circuit of the lower radio frequency control device to solve the arcing problem, the structure of the electrostatic chuck can be upgraded so that its lifting pin structure can withstand higher bias voltage; or, the lower radio frequency control device can also be implemented in software, but the software communication architecture needs to be upgraded so that the software signal transmission has a faster response speed.

[0075] This application also provides a semiconductor device, including:

[0076] Lower electrode; the lower electrode includes an electrostatic chuck;

[0077] The lower radio frequency power supply is fed to the lower electrode;

[0078] The above-mentioned radio frequency control device.

[0079] For a description of the semiconductor device provided in this application, please refer to the above-described embodiments of the radio frequency control device; further details will not be repeated here.

[0080] As will be known to those skilled in the art, with the development of technology and the emergence of new scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0081] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms are interchangeable where appropriate; this is merely a way of distinguishing objects with the same attributes in the embodiments of this application. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion, so that a process, method, system, product, or apparatus that comprises a series of elements is not necessarily limited to those elements, but may include other elements not explicitly listed or inherent to those processes, methods, products, or apparatuses.

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A lower radio frequency control device, applied to a semiconductor device, the semiconductor device comprising: The device comprises a lower electrode of an electrostatic chuck and a lower radio frequency power supply fed to the lower electrode; characterized in that the lower radio frequency control device includes: A voltage sensor, connected to the electrostatic chuck, is used to detect the actual voltage signal on the electrostatic chuck; A reference voltage circuit is used to output a reference voltage signal according to a preset safety withstand voltage for the electrostatic chuck; An RF control switch is connected in series on the signal transmission line where the RF output signal used to control the lower RF power supply is located; A voltage comparison circuit is connected to the voltage sensor, the reference voltage circuit, and the radio frequency control switch, respectively. When the actual voltage signal is less than or equal to the reference voltage signal, the circuit controls the radio frequency control switch to close so that the lower radio frequency power supply can output radio frequency; when the actual voltage signal is greater than the reference voltage signal, the circuit controls the radio frequency control switch to open so as to cut off the radio frequency output of the lower radio frequency power supply.

2. The lower radio frequency control device as described in claim 1, characterized in that, The reference voltage circuit includes: DC regulated power supply; A variable resistor, wherein the first terminal of the variable resistor is connected to the DC regulated power supply, the middle terminal is connected to the voltage comparison circuit, and the second terminal is grounded, is used to adjust the magnitude of the reference voltage signal input to the voltage comparison circuit to the safe withstand voltage.

3. The lower radio frequency control device as described in claim 1, characterized in that, The voltage comparison circuit includes: A voltage comparator, wherein the positive input terminal of the voltage comparator is connected to the reference voltage circuit, the inverting input terminal is connected to the voltage sensor, and the output terminal is connected to the radio frequency control switch, is used to output a level signal to the radio frequency control switch to close the radio frequency control switch when the voltage of the positive input signal is greater than or equal to the voltage of the inverting input signal; and does not output a level signal to the radio frequency control switch to open the radio frequency control switch when the voltage of the positive input signal is less than the voltage of the inverting input signal.

4. The lower radio frequency control device as described in claim 1, characterized in that, The lower radio frequency control device further includes: A signal filtering circuit is connected in series on the transmission line from the voltage sensor to the voltage comparison circuit to transmit the actual voltage signal. It is used to filter the actual voltage signal output by the voltage sensor and transmit the filtered actual voltage signal to the voltage comparison circuit.

5. The lower radio frequency control device as described in claim 1, characterized in that, The radio frequency control switch is specifically connected in series on the signal transmission line where the interlock signal of the lower radio frequency power supply is located.

6. The lower radio frequency control device as described in claim 5, characterized in that, The radio frequency control switch is a relay.

7. The lower radio frequency control device according to any one of claims 1-6, characterized in that, The lower radio frequency control device further includes: The lower-level computer is connected in series on the transmission line from the reference voltage circuit to the voltage comparison circuit to transmit the reference voltage signal, and is also connected to the upper-level computer. It is used to determine whether the reference voltage signal has drifted according to a preset voltage drift determination strategy. If not, the reference voltage signal is output to the voltage comparison circuit; if so, an alarm signal indicating that the reference voltage signal has drifted is thrown to the upper-level computer.

8. The lower radio frequency control device as described in claim 7, characterized in that, The lower-level computer is also connected to the lower-level RF power supply and is used to send an alarm signal to the upper-level computer when the RF output of the lower-level RF power supply is detected to be cut off.

9. The lower radio frequency control device as described in claim 7, characterized in that, The lower-level machine is specifically used to determine DR = (V ref -V refi ) / V refi Calculate the drift rate and determine whether the drift rate is greater than a preset drift threshold. If so, determine that the reference voltage signal has drifted. If not, then it is determined that the reference voltage signal has not drifted; Wherein, DR represents the drift rate; V ref This represents the reference voltage signal actually output by the reference voltage circuit; V refi This indicates the initial setting value of the reference voltage signal.

10. A semiconductor device, characterized in that, include: Lower electrode; the lower electrode includes an electrostatic chuck; The lower radio frequency power supply is fed to the lower electrode; The lower radio frequency control device as described in any one of claims 1-9.

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