Suspension electrode circuit and apparatus capable of graphite boat cleaning

Abstract

The application provides a floating electrode circuit and equipment capable of being applied to graphite boat cleaning, and relates to the technical field of graphite boat cleaning. The floating electrode circuit comprises a first electrode, a second electrode, a plurality of detection circuits, a control circuit and a power supply circuit. The first electrode is arranged on a first side. The second electrode is arranged on a second side. The plurality of detection circuits are arranged at a plurality of positions in a chamber. The detection circuits are used for detecting the plasma concentration in the chamber and output corresponding detection signals. The control circuit is electrically connected with the plurality of detection circuits. The controlled end of the power supply circuit is connected with the output end of the control circuit. The first output end of the power supply circuit is connected with the first electrode. The second output end of the power supply circuit is connected with the second electrode. The control circuit is used for receiving the detection signals and controlling the power supply circuit to increase the current of the first electrode and the second electrode in the case that the detection signal of any detection circuit received is less than a target signal. The application can improve the cleaning uniformity and stability.

Description

Technical Field

[0001] This application relates to the field of graphite boat cleaning technology, and in particular to a suspended electrode circuit and a device applicable to graphite boat cleaning. Background Technology

[0002] In the field of graphite boat cleaning equipment, plasma cleaning technology has been widely used because it can efficiently remove contaminants such as deposited carbides or metal residues from the surface of graphite boats, thus ensuring the reusability of graphite boats in semiconductor or photovoltaic manufacturing. Traditional equipment typically includes a sealed chamber with opposing electrodes to generate plasma. A plasma atmosphere is formed by applying a high-frequency power supply to excite gas, achieving the cleaning effect. However, due to limitations in the chamber structure, uneven gas flow, or unstable power output, inconsistent cleaning results can easily occur, potentially leading to incomplete cleaning in certain areas. This can result in batch-to-batch fluctuations in cleaning quality, increasing product defect rates, shortening equipment maintenance cycles, and raising production costs. Utility Model Content

[0003] The main purpose of this invention is to provide a suspended electrode circuit, which aims to improve the uniformity of graphite boat cleaning.

[0004] To achieve the above objectives, this utility model provides a suspended electrode circuit for use in equipment capable of cleaning graphite boats. The equipment includes a chamber with a first side and a second side disposed opposite to each other on its inner wall. The suspended electrode circuit includes: A first electrode is disposed on the first side; The second electrode is disposed on the second side; Multiple detection circuits are arranged at multiple locations in the chamber. The detection circuits are used to detect the plasma concentration in the chamber and output corresponding detection signals. A control circuit, which is electrically connected to the plurality of detection circuits; A power supply circuit, wherein the controlled terminal of the power supply circuit is connected to the output terminal of the control circuit, the first output terminal of the power supply circuit is connected to the first electrode, and the second output terminal of the power supply circuit is connected to the second electrode; The control circuit is used to receive the detection signal, and when the detection signal received by any detection circuit is less than the target signal, control the power supply circuit to increase the current of the first electrode and the second electrode.

[0005] Optionally, the detection circuit includes: A plasma concentration sensor, used to detect the concentration signal in the chamber; A current detection circuit is provided, wherein the input terminal of the current detection circuit is connected in series between the first output terminal of the plasma concentration sensor and ground, and the output terminal of the current detection circuit is connected to the first input terminal of the control circuit. The current detection circuit is used to output a corresponding current detection signal according to the concentration signal. A voltage detection circuit is provided, wherein the first input terminal of the voltage detection circuit is connected to the first output terminal of the plasma concentration sensor, the second input terminal of the voltage detection circuit is connected to the second output terminal of the plasma concentration sensor, and the output terminal of the voltage detection circuit is connected to the second input terminal of the control circuit. The voltage detection circuit is used to output a corresponding voltage detection signal according to the concentration signal.

[0006] Optionally, the current detection circuit includes: A first resistor, the first end of which is connected to the first output terminal of the plasma concentration sensor, and the second end of which is grounded; The first operational amplifier chip has a second resistor connected in series between its inverting input and the first end of the first resistor, a third resistor connected in series between its non-inverting input and the second end of the first resistor, a fourth resistor connected in parallel between its output and inverting input, and its output connected to the first input of the control circuit.

[0007] Optionally, the voltage detection circuit includes: The second operational amplifier chip has a fifth resistor connected in series between its inverting input and the first output of the plasma concentration sensor, a sixth resistor connected in series between its non-inverting input and the second output of the plasma concentration sensor, a seventh resistor connected in parallel between the output and inverting inputs of the second operational amplifier chip, and its output connected to the second input of the control circuit.

[0008] Optionally, the power supply circuit includes: An impedance matching circuit, wherein the power input terminal of the impedance matching circuit is used to connect to an external power source; A switching circuit, wherein the input terminal of the switching circuit is connected to the output terminal of the impedance matching circuit, and the controlled terminal of the switching circuit is connected to the output terminal of the control circuit, the switching circuit being used to control the magnitude of the current output by the first electrode and the second electrode according to the control signal output by the control circuit; An isolation converter circuit is provided, wherein the first input terminal of the isolation converter circuit is connected to the output terminal of the switching circuit, the second input terminal of the isolation converter circuit is grounded, the first output terminal of the isolation converter circuit is connected to the first electrode, and the second output terminal of the isolation converter circuit is connected to the second electrode.

[0009] Optionally, the impedance matching circuit includes: The first inductor has a first terminal connected to an external power source. A first capacitor is connected in parallel between the first terminal of the first inductor and ground. A second capacitor is connected in parallel between the second terminal of the first inductor and ground. An eleventh resistor is connected in parallel between the second terminal of the first inductor and ground. The second terminal of the first inductor is connected to the input terminal of the switching circuit. The isolation conversion circuit includes: A transformer, wherein the first end of the primary winding of the transformer is connected to the output terminal of the switching circuit, the second end of the primary winding of the transformer is grounded, the first end of the secondary winding of the transformer is connected to the first electrode, and the second end of the secondary winding of the transformer is connected to the second electrode.

[0010] Optionally, the first electrode is a metal electrode with a mesh structure, a fence structure, or a plate structure, and the second electrode is a metal electrode with a plate structure, with the first electrode and the second electrode arranged parallel to each other.

[0011] Optionally, the detection circuit further includes: A temperature detection circuit is provided, the output of which is connected to the third input of the control circuit. The temperature detection circuit includes a temperature sensor located in the chamber. The temperature detection circuit is used to acquire the temperature of the chamber and output a corresponding temperature signal to the control circuit.

[0012] Optionally, the temperature detection circuit includes: A temperature sensor connection terminal, which is used to connect the temperature sensor; The third operational amplifier chip has an eighth resistor connected in series between its inverting input and the third terminal of the temperature sensor connection terminal; a ninth resistor connected between its non-inverting input and the second terminal of the temperature sensor connection terminal; a tenth resistor connected in parallel between its output terminal and its inverting input; and its output terminal connected to the third input terminal of the control circuit.

[0013] In addition, to achieve the above objectives, this utility model also provides a device that can be applied to the cleaning of graphite boats, including the suspended electrode circuit described above.

[0014] The suspended electrode circuit of this invention is applied to a device capable of cleaning graphite boats. This device includes a chamber with a first side and a second side disposed opposite to each other on the inner wall. The suspended electrode circuit comprises a first electrode on the first side of the inner wall and a second electrode on the second side. Multiple detection circuits are arranged at multiple locations within the chamber to detect the plasma concentration and output corresponding detection signals. A control circuit is electrically connected to each of the detection circuits. Finally, a power supply circuit is provided, with its controlled terminal connected to the output terminal of the control circuit. The first output terminal of the power supply circuit is connected to the first electrode, and its second output terminal is connected to the second electrode. The control circuit receives the detection signals and, if the received detection signal from any of the detection circuits is less than the target signal, controls the power supply circuit to increase the current of the first and second electrodes. Thus, by using multiple detection circuits to monitor the plasma concentration in different areas within the chamber in real time and automatically increasing the electrode current when the concentration is insufficient, the cleaning uniformity and stability are improved, reducing the possibility of uneven plasma distribution. Attached Figure Description

[0015] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a circuit block diagram of a floating electrode circuit according to an embodiment of the present invention; Figure 2 This is a circuit block diagram of a floating electrode circuit according to another embodiment of the present invention; Figure 3 for Figure 2 Schematic diagram of the connection terminal circuit of the plasma concentration sensor in the image; Figure 4 for Figure 2 The circuit diagram of the current detection circuit in the image; Figure 5 for Figure 2 The circuit diagram of the voltage detection circuit in the image; Figure 6 This is a circuit block diagram of a floating electrode circuit according to another embodiment of the present invention; Figure 7 for Figure 6 The circuit diagram of the power supply circuit in the image; Figure 8 This is a circuit block diagram of a floating electrode circuit according to another embodiment of the present invention; Figure 9 for Figure 8 The circuit diagram of the temperature detection circuit in the image.

[0018] Explanation of icon numbers:

[0019] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Well-known modules, units, and their connections, links, communications, or operations are not shown or described in detail. Furthermore, the described features, architectures, or functions can be combined in any way in one or more embodiments. Those skilled in the art should understand that the various embodiments described below are only for illustrative purposes and are not intended to limit the scope of protection of the present invention.

[0021] In the field of graphite boat cleaning equipment, plasma cleaning technology has been widely used because it can efficiently remove contaminants such as deposited carbides or metal residues from the surface of graphite boats, thus ensuring the reusability of graphite boats in semiconductor or photovoltaic manufacturing. Traditional equipment typically includes a sealed chamber with opposing electrodes to generate plasma. A plasma atmosphere is formed by applying a high-frequency power supply to excite gas, achieving the cleaning effect. However, due to limitations in the existing chamber structure, uneven gas flow, or unstable power output, inconsistent cleaning results can easily occur, potentially leading to incomplete cleaning in certain areas. This can result in batch-to-batch cleaning quality fluctuations, increased product defect rates, shortened equipment maintenance cycles, and higher production costs.

[0022] The main solution of this application embodiment is: a suspended electrode circuit is applied to a device capable of cleaning graphite boats. The device includes a chamber with a first side and a second side disposed opposite to each other on the inner wall of the chamber. The suspended electrode circuit has a first electrode on the first side of the inner wall of the chamber and a second electrode on the second side of the inner wall of the chamber. Multiple detection circuits are arranged at multiple positions in the chamber. The detection circuits are used to detect the plasma concentration in the chamber and output corresponding detection signals. A control circuit is provided and electrically connected to the multiple detection circuits respectively. Finally, a power supply circuit is provided, and the controlled terminal of the power supply circuit is connected to the output terminal of the control circuit. The first output terminal of the power supply circuit is connected to the first electrode, and the second output terminal of the power supply circuit is connected to the second electrode. The control circuit is used to receive detection signals, and when the detection signal received by any detection circuit is less than the target signal, the power supply circuit is controlled to increase the current of the first electrode and the second electrode.

[0023] This application provides a solution that uses multiple detection circuits to monitor the plasma concentration in different areas of the chamber in real time, and automatically increases the electrode current when the concentration is insufficient, thereby improving the uniformity and stability of cleaning and reducing the possibility of uneven plasma distribution.

[0024] In existing technologies, plasma cleaning technology is widely used in graphite boat cleaning equipment. Traditional equipment generates plasma through opposing electrodes within a sealed chamber and uses a high-frequency power supply to excite gas to achieve the cleaning effect. However, the uneven distribution of plasma concentration within the chamber and the lack of a real-time control mechanism lead to inconsistent cleaning results. Especially in industrial production scenarios, factors such as differences in chamber structure, gas flow disturbances, or power supply fluctuations can easily cause insufficient plasma concentration in local areas, resulting in decreased cleaning efficiency and increased batch-to-batch variations.

[0025] To address the aforementioned issues, analysis revealed that the fixed power output parameters of existing equipment prevented parameter adjustment based on plasma concentration data at different locations within the chamber. Therefore, the proposed solution involves deploying detection units at multiple locations within the chamber, feeding the detection signals back to the control circuit to adjust the electrode current output. A closed-loop control system is then established to achieve dynamic compensation through multi-point monitoring.

[0026] Based on the above, referring to Figure 1 In one embodiment of this utility model, the suspended electrode circuit is applied to a device capable of cleaning graphite boats. This device includes a chamber with a first side and a second side disposed opposite to each other on the inner wall. The suspended electrode circuit includes a first electrode 10, a second electrode 20, multiple detection circuits 30, a control circuit 40, and a power supply circuit 50. The first electrode 10 is disposed on the first side; the second electrode 20 is disposed on the second side; a plurality of detection circuits 30 are arranged at multiple positions in the chamber, the detection circuits 30 are used to detect the plasma concentration in the chamber and output corresponding detection signals; the control circuit 40 is electrically connected to the plurality of detection circuits 30; the controlled terminal of the power supply circuit 50 is connected to the output terminal of the control circuit 40, the first output terminal of the power supply circuit 50 is connected to the first electrode 10, and the second output terminal of the power supply circuit 50 is connected to the second electrode 20; the control circuit 40 is used to receive the detection signals, and when the detection signal received by any detection circuit 30 is less than the target signal, control the power supply circuit 50 to increase the current of the first electrode 10 and the second electrode 20.

[0027] The first electrode 10 refers to a conductive structure disposed on one side of the chamber, which can be made of mesh or plate-like metal material, used to form an electric field distribution with the second electrode 20. The second electrode 20 refers to a conductor disposed opposite to the first electrode 10, typically using a plate-like metal structure to maintain electric field uniformity. The detection circuit 30 refers to a sensing unit capable of converting plasma concentration into an electrical signal, for example, by acquiring signals through dual-path detection of current and voltage. The control circuit 40 refers to an integrated circuit module with logic processing capabilities, used to analyze the detection signal and generate adjustment commands. The power supply circuit 50 refers to a power supply device with adjustable output characteristics, for example, using a combination of a switching circuit 52 and an isolation conversion circuit 53 to achieve current regulation.

[0028] In this configuration, there can be multiple first electrodes 10, and the number of second electrodes 20 corresponds one-to-one with the number of first electrodes 10. The number of first electrodes 10 and second electrodes 20 can match the number of detection circuits 30. A corresponding first electrode 10 and second electrode 20 are positioned at the location of each detection circuit 30 to achieve precise adjustment of the local current. Alternatively, there can be only one set of first electrodes 10 and second electrodes 20, while multiple detection circuits 30 perform distributed sampling of the plasma concentration in the chamber. If the plasma concentration in certain areas is too low, the current output of the first electrodes 10 and second electrodes 20 is increased, thereby avoiding a decrease in cleaning effect and efficiency due to insufficient plasma concentration in local areas.

[0029] Specifically, when the plasma concentration in a certain area of ​​the chamber falls below a preset threshold, the output signal of the corresponding detection circuit 30 weakens. Upon detecting the signal anomaly, the control circuit 40 sends a command to the power supply circuit 50 to increase the current between the first electrode 10 and the second electrode 20. This increased current leads to a higher electric field strength, thereby exciting more gas molecules to ionize and compensate for the plasma concentration in that area. The coordinated operation of multiple detection circuits 30 can cover different areas of the chamber, forming a multi-point feedback mechanism to ensure the dynamic balance of the overall concentration distribution.

[0030] Compared to existing technologies, traditional solutions rely on fixed-parameter power outputs and cannot respond to real-time changes in the plasma inside the chamber. This embodiment achieves dynamic adjustment of the electrode current by combining multi-point detection and closed-loop control. In existing technologies, both electrode position and current output are fixed, while this embodiment can adaptively adjust according to different operating conditions, effectively solving the problem of uneven concentration caused by gas flow or structural differences.

[0031] Through the above technical solution, this embodiment can monitor the plasma distribution inside the chamber in real time, automatically compensate for areas with insufficient local concentration, and significantly improve cleaning uniformity. This solution avoids the incomplete cleaning caused by concentration fluctuations in traditional equipment, while reducing the need for manual intervention and enhancing the stability and efficiency of the cleaning process.

[0032] Optionally, the first electrode 10 is a metal electrode with a mesh structure, a fence structure, or a plate structure, and the second electrode 20 is a metal electrode with a plate structure. The first electrode 10 and the second electrode 20 are arranged in parallel relative to each other.

[0033] Among them, the mesh structure refers to an electrode formed by cross-woven metal wires, which can be made of stainless steel or titanium alloy. Its pores allow gas flow while maintaining electric field uniformity. The fence structure refers to an electrode composed of multiple parallel metal strips, which can be made of copper or aluminum. The spacing between the metal strips can be adjusted to balance the electric field strength and gas diffusion requirements. The plate structure refers to a flat metal plate electrode, which can be made of nickel or tungsten. Its large-area coverage helps to stabilize the electric field distribution. Relative parallel arrangement means that the mounting planes of the first electrode 10 and the second electrode 20 are kept parallel. This can be achieved by fixing brackets on the inner wall of the cavity, ensuring that the electric field direction between the two electrodes is consistent and the intensity is uniform.

[0034] The first electrode 10, with a mesh, fence, or plate structure, is installed on the first side of the chamber, while the second electrode 20, with a plate structure, is installed on the second side. The two electrodes are arranged in parallel to form a symmetrical electric field region. When the power supply circuit 50 applies current, the first electrode 10 with different structures can be adapted to the gas flow state inside the chamber. For example, a mesh electrode is suitable for high-velocity regions to reduce resistance, a fence electrode is suitable for regions requiring localized enhancement of the electric field, and a plate electrode is suitable for scenarios requiring stable electric field output. The parallel arrangement of the two electrodes ensures a uniform distribution of electric field lines, avoiding plasma concentration differences caused by electrode misalignment.

[0035] Compared to existing technologies, traditional equipment typically employs a single-structure fixed electrode, such as a plate electrode, leading to obstructed gas flow or uneven electric field distribution. This embodiment, however, combines and arranges multiple selectable electrode structures in parallel, adapting to gas flow requirements under different operating conditions and suppressing local fluctuations in plasma concentration through a symmetrical electric field, thus solving the problem of inconsistent cleaning effects in traditional technologies. This embodiment allows for flexible selection of electrode structures based on the actual operating conditions inside the chamber, optimizing the synergistic effect of electric field distribution and gas flow, thereby improving the spatial uniformity of plasma concentration. The parallel electrode layout further reduces the risk of electric field distortion, ensuring consistent plasma forces across all areas of the graphite boat surface during cleaning, ultimately improving the stability of the cleaning effect and extending the lifespan of the graphite boat.

[0036] The suspended electrode circuit of this embodiment is applied to a device capable of cleaning graphite boats. The device includes a chamber with a first side and a second side disposed opposite to each other on the inner wall of the chamber. The suspended electrode circuit has a first electrode 10 disposed on the first side of the inner wall of the chamber and a second electrode 20 disposed on the second side of the inner wall of the chamber. Multiple detection circuits 30 are arranged at multiple positions in the chamber. The detection circuits 30 are used to detect the plasma concentration in the chamber and output corresponding detection signals. A control circuit 40 is provided and electrically connected to the multiple detection circuits 30 respectively. Finally, a power supply circuit 50 is provided, and the controlled terminal of the power supply circuit 50 is connected to the output terminal of the control circuit 40. The first output terminal of the power supply circuit 50 is connected to the first electrode 10, and the second output terminal of the power supply circuit 50 is connected to the second electrode 20. The control circuit 40 is used to receive detection signals. When the detection signal received by any detection circuit 30 is less than the target signal, the power supply circuit 50 is controlled to increase the current of the first electrode 10 and the second electrode 20. In this way, multiple detection circuits 30 monitor the plasma concentration in different areas of the chamber in real time, and automatically increase the electrode current when the concentration is insufficient, thereby improving the uniformity and stability of cleaning and reducing the possibility of uneven plasma distribution.

[0037] Optionally, refer to Figures 2 to 5 Another embodiment of this utility model provides a floating electrode circuit, based on the above. Figure 1 In the embodiment shown, the detection circuit 30 includes a plasma concentration sensor 31, a current detection circuit 32, and a voltage detection circuit 33, wherein: The plasma concentration sensor 31 is used to detect the concentration signal in the chamber; the input terminal of the current detection circuit 32 is connected in series between the first output terminal of the plasma concentration sensor 31 and ground, and the output terminal of the current detection circuit 32 is connected to the first input terminal of the control circuit 40. The current detection circuit 32 is used to output a corresponding current detection signal according to the concentration signal; the first input terminal of the voltage detection circuit 33 is connected to the first output terminal of the plasma concentration sensor 31, the second input terminal of the voltage detection circuit 33 is connected to the second output terminal of the plasma concentration sensor 31, and the output terminal of the voltage detection circuit 33 is connected to the second input terminal of the control circuit 40. The voltage detection circuit 33 is used to output a corresponding voltage detection signal according to the concentration signal.

[0038] The plasma concentration sensor 31 is a device that converts plasma concentration into an electrical signal. It can be implemented using a sensor structure with an ion collecting electrode, such as a Langmuir probe, and reflects concentration changes by measuring the ion current intensity. The current detection circuit 32 converts the weak current signal output from the plasma concentration sensor 31 into a voltage signal. It can be implemented using a transimpedance amplifier composed of an operational amplifier and a resistor network. The resistor network converts the current into voltage, which is then amplified by the operational amplifier chip. The voltage detection circuit 33 measures the voltage difference across the sensor. It can be implemented using a differential amplifier structure. By setting the input impedance with corresponding resistors and adjusting the gain, a concentration-related voltage signal is output.

[0039] Existing technologies rely solely on a single electrical parameter to detect plasma concentration, such as measuring only current or voltage, which is prone to misjudgment due to sensor aging and environmental interference. This embodiment, however, establishes a composite correlation model between concentration and electrical parameters by simultaneously acquiring both current and voltage signals, effectively eliminating errors caused by single-signal drift and improving detection reliability. Furthermore, the current detection circuit 32 employs a transimpedance amplifier structure, which can linearly amplify weak currents, avoiding the limited current detection range problem in traditional solutions.

[0040] This embodiment achieves dual signal detection of plasma concentration, solving the problem of misjudgment caused by single parameter detection in traditional equipment. It ensures that the control circuit 40 can accurately identify the real changes in plasma concentration in the chamber, thereby providing a reliable basis for the dynamic adjustment of the power supply circuit 50, and ultimately improving the uniformity and stability of graphite boat cleaning.

[0041] Optionally, refer to Figure 3and Figure 4 Another embodiment of this utility model provides a floating electrode circuit, based on the above. Figure 2 In the embodiment shown, the current detection circuit 32 includes a first resistor R1 and a first operational amplifier chip U1.2, wherein: The first end of the first resistor R1 is connected to the first output terminal of the plasma concentration sensor 31, and the second end of the first resistor R1 is grounded; a second resistor R5 is connected in series between the inverting terminal of the first operational amplifier chip U1.2 and the first end of the first resistor R1; a third resistor R6 is connected in series between the non-inverting terminal of the first operational amplifier chip U1.2 and the second end of the first resistor R1; a fourth resistor R7 is connected in parallel between the output terminal and the inverting terminal of the first operational amplifier chip U1.2; and the output terminal of the first operational amplifier chip U1.2 is connected to the first input terminal of the control circuit 40.

[0042] In this circuit, the first resistor R1 is used to convert the current signal output by the plasma concentration sensor 31 into a voltage signal. It can be implemented using a metal film resistor with a resistance of 1kΩ to 10kΩ, forming a current loop and generating a voltage drop through grounding. The first operational amplifier chip U1.2 is used to amplify the voltage signal. It can be implemented using an LM358 chip, with its inverting and non-inverting inputs receiving the input signal and performing differential amplification. The second resistor R5 is a current-limiting element connected in series on the inverting input path. It can be implemented using a carbon film resistor with a resistance of 100Ω to 1kΩ, used to adjust the input impedance of the operational amplifier circuit. The third resistor R6 is a current-limiting element connected in series on the non-inverting input path. It can be implemented using a carbon film resistor with a resistance matching that of the second resistor R5, used to balance the impedance of the differential input. The fourth resistor R7 is a feedback element connected in parallel between the operational amplifier output and the inverting input. It can be implemented using a precision resistor with a resistance of 10kΩ to 100kΩ, used to set the amplification factor of the operational amplifier circuit.

[0043] The plasma concentration sensor 31 is located within the chamber, and its output ion current intensity changes with the plasma concentration. The current detection circuit 32 converts the ion current into a voltage signal via a first resistor R1. The input bias is set via second resistors R5 and R6, and a fourth resistor R7 forms a negative feedback network with the first operational amplifier chip U1.2, amplifying the microampere-level current into a volt-level voltage signal. The voltage detection circuit 33 differentially samples the potential across the sensor via fifth resistors R2 and sixth resistors R3. A seventh resistor R4 and the second operational amplifier chip U1.1 provide proportional amplification, outputting a concentration-related voltage value. The control circuit 40 simultaneously receives both current and voltage detection signals and accurately determines the actual state of the plasma concentration through dual-parameter cross-validation.

[0044] In this circuit, the current signal output by the plasma concentration sensor 31 flows through the first resistor R1, generating a voltage signal. This voltage signal is then input to the inverting input of the first operational amplifier chip U1.2 via the second resistor R5, while the third resistor R6 stabilizes the potential of the non-inverting input at the ground reference point. The first operational amplifier chip U1.2 amplifies the input signal through a negative feedback loop formed by the fourth resistor R7, ultimately outputting a current detection signal connected to the control circuit 40. By adjusting the resistance ratios of the second, third, and fourth resistors R5, the amplification factor of the operational amplifier circuit can be precisely controlled, thereby adapting to different plasma concentration detection requirements.

[0045] Compared with existing technologies, this embodiment achieves high-precision, low-drift current signal conversion by combining an operational amplifier chip with a multi-stage resistor network. Simultaneously, the differential input structure effectively suppresses common-mode interference, ensuring the authenticity and stability of the detection signal. This embodiment can accurately convert the weak current signal output by the plasma concentration sensor 31 into a standard voltage signal, and adapt to different detection requirements under various operating conditions through adjustable amplification. This circuit effectively avoids signal distortion and noise introduction, providing reliable input data for the control circuit 40, thereby ensuring the timeliness and accuracy of power supply current adjustment, and ultimately maintaining a uniform distribution of plasma concentration within the chamber.

[0046] Optionally, refer to Figure 5 Another embodiment of this utility model provides a floating electrode circuit, based on the above. Figure 2 In the embodiment shown, the voltage detection circuit 33 includes a second operational amplifier chip U1.1, wherein: A fifth resistor R2 is connected in series between the inverting input of the second operational amplifier chip U1.1 and the first output terminal of the plasma concentration sensor 31. A sixth resistor R3 is connected in series between the non-inverting input of the second operational amplifier chip U1.1 and the second output terminal of the plasma concentration sensor 31. A seventh resistor R4 is connected in parallel between the output terminal and the inverting input of the second operational amplifier chip U1.1. The output terminal of the second operational amplifier chip U1.1 is connected to the second input terminal of the control circuit 40.

[0047] In this circuit, the second operational amplifier chip U1.1 refers to an operational amplifier integrated circuit, which can be implemented using a differential input operational amplifier. The second operational amplifier chip U1.1 is used to amplify the differential voltage signal output by the plasma concentration sensor 31. The fifth resistor R2 is a resistor connected between the sensor's first output terminal and the operational amplifier's inverting input. It can be implemented using a precision metal film resistor. The fifth resistor R2 is used to transmit the voltage signal output by the sensor to the operational amplifier's inverting input terminal. The sixth resistor R3 is a resistor connected between the sensor's second output terminal and the operational amplifier's non-inverting input. It can be implemented using a resistor with the same parameters as the fifth resistor R2. The sixth resistor R3 is used to balance the input impedance and match the signal transmission path. The seventh resistor R4 is a feedback resistor connected between the operational amplifier's output terminal and its inverting input. It can be implemented using an adjustable resistor and is used to set the operational amplifier's closed-loop gain and stabilize the amplification factor.

[0048] The plasma concentration sensor 31 outputs two differential voltage signals, which are input to the inverting and non-inverting inputs of the second operational amplifier chip U1.1 via resistors R2 (fifth) and R3 (sixth), respectively. Resistor R4, along with the internal circuitry of the operational amplifier, forms a negative feedback loop, amplifying the differential voltage at the input by a preset gain and generating a voltage detection signal corresponding to the plasma concentration at the output. This signal is transmitted via a wire to the second input of the control circuit 40, serving as the basis for determining whether the plasma concentration meets the standard. Due to the use of a differential amplification structure, common-mode interference signals are effectively suppressed, retaining only the effective differential signal output by the sensor, thereby improving detection accuracy.

[0049] Compared to existing technologies, this embodiment eliminates common-mode noise during signal transmission through a differential input structure and a matching resistor network. Simultaneously, it precisely controls the amplification factor via feedback resistors, preventing signal attenuation or distortion during transmission. This embodiment accurately acquires the raw voltage signal output by the plasma concentration sensor 31 and generates a stable detection signal through high-precision differential amplification. This helps the control circuit 40 monitor the plasma distribution within the chamber in real time, adjust the electrode current promptly to maintain consistent cleaning results, and solve the problem of uneven cleaning caused by voltage detection errors in traditional equipment.

[0050] Optionally, refer to Figure 6 In another embodiment of this utility model, a floating electrode circuit is provided, based on the above. Figure 1 In the embodiment shown, the power supply circuit 50 includes an impedance matching circuit 51, a switching circuit 52, and an isolation conversion circuit 53, wherein: The power input terminal of the impedance matching circuit 51 is used to connect to an external power source; the input terminal of the switching circuit 52 is connected to the output terminal of the impedance matching circuit 51, and the controlled terminal of the switching circuit 52 is connected to the output terminal of the control circuit 40. The switching circuit 52 is used to control the current output of the first electrode 10 and the second electrode 20 according to the control signal output by the control circuit; the first input terminal of the isolation conversion circuit 53 is connected to the output terminal of the switching circuit 52, the second input terminal of the isolation conversion circuit 53 is grounded, the first output terminal of the isolation conversion circuit 53 is connected to the first electrode 10, and the second output terminal of the isolation conversion circuit 53 is connected to the second electrode 20.

[0051] Impedance matching circuit 51 is a unit used to match the impedance between the external power supply and subsequent circuits. It can be implemented using a filter network composed of inductors, capacitors, and resistors. Its function is to eliminate voltage fluctuations and noise interference at the power input terminal, ensuring a stable power supply to subsequent circuits. Switching circuit 52 is a power unit that regulates current output through control signals. It can be implemented using a chopper circuit built with field-effect transistors or insulated-gate bipolar transistors. Its function is to dynamically adjust the electrode current based on real-time plasma concentration detection results, thereby maintaining stable plasma generation conditions. Isolation conversion circuit 53 is a unit that achieves electrical isolation and voltage conversion. It can be implemented using a combination of a high-frequency transformer T1 and a rectifier circuit. Its function is to convert the electrical energy output from switching circuit 52 into high-frequency AC power suitable for electrode operation, while avoiding direct electrical connection between the electrodes and the power supply, thus improving system safety.

[0052] When the control circuit 40 detects that the plasma concentration in a certain area of ​​the chamber is lower than a set threshold, it sends a control signal to the switching circuit 52 to enhance the current. At this time, the impedance matching circuit 51 filters and matches the AC power input from the external power source, eliminating high-frequency harmonics and voltage fluctuations. After receiving the control signal, the switching circuit 52 adjusts the duty cycle or frequency to transfer the matched electrical energy to the isolation conversion circuit 53. The isolation conversion circuit 53 couples the electrical energy from the primary side to the secondary side through the transformer T1, generating a high-frequency AC current matched to the electrodes, driving the first electrode 10 and the second electrode 20 to generate an enhanced electric field, thereby increasing the plasma concentration.

[0053] Existing equipment uses a fixed power output parameter, which cannot be dynamically adjusted according to changes in plasma distribution. However, this embodiment, through the synergistic effect of the switching circuit 52 and the isolation conversion circuit 53, can adjust the electrode current intensity in real time. At the same time, the impedance matching circuit 51 eliminates power supply interference, making the electrical energy output by the electrodes more stable and effectively solving the problem of uneven plasma concentration caused by power supply fluctuations or load changes.

[0054] This embodiment can quickly adjust the electrode current output based on the plasma concentration detection results in different areas of the chamber, ensuring the uniformity of plasma distribution during the cleaning process. The electrical isolation characteristics provided by the isolation conversion circuit 53 avoid potential interference between the electrodes and the power supply, while the impedance matching circuit 51 improves the stability of the power supply output, thereby significantly improving the consistency of graphite boat cleaning and the reliability of equipment operation.

[0055] Optionally, refer to Figure 7 Another embodiment of this utility model provides a floating electrode circuit, based on the above. Figure 6 In the embodiment shown, the impedance matching circuit 51 includes a first inductor L1, wherein: The first end of the first inductor L1 is used to connect to an external power source. A first capacitor C1 is connected in parallel between the first end of the first inductor L1 and ground. A second capacitor C2 is connected in parallel between the second end of the first inductor L1 and ground. An eleventh resistor R11 is connected in parallel between the second end of the first inductor L1 and ground. The second end of the first inductor L1 is connected to the input terminal of the switching circuit 52.

[0056] The isolation conversion circuit 53 includes a transformer T1, wherein: The first end of the primary winding of the transformer T1 is connected to the output end of the switching circuit 52, the second end of the primary winding of the transformer T1 is grounded, the first end of the secondary winding of the transformer T1 is connected to the first electrode 10, and the second end of the secondary winding of the transformer T1 is connected to the second electrode 20.

[0057] In this circuit, the first inductor L1 is an inductive element used to suppress high-frequency interference. L1 can be implemented using an air-core coil or a magnetic core coil, and its inductive characteristics suppress the conduction of high-frequency noise from the power input to subsequent circuits. The first capacitor C1 and the second capacitor C2 are capacitive elements used to filter out high-frequency interference, and can be implemented using ceramic capacitors or film capacitors. They are connected in parallel between the power input and ground to form a low-pass filter structure. The eleventh resistor R11 is a current-limiting element used to discharge residual charge. R11 can be implemented using a metal film resistor or a carbon film resistor to prevent the storage of charge in the capacitors from causing safety hazards after power failure. The transformer T1 is an electromagnetic device used to achieve electrical isolation and voltage transformation. Transformer T1 can be implemented using a ferrite core wound with a double-winding structure. The output voltage is adjusted by the turns ratio of the primary and secondary windings, while simultaneously blocking the transmission of DC components.

[0058] After the external power supply is connected, high-frequency noise is suppressed by the first inductor L1. The first capacitor C1 and the second capacitor C2 connected in parallel further filter out high-frequency interference signals. The eleventh resistor R11 guides the residual charge to the ground to eliminate safety hazards. The filtered power signal is transmitted to the switching circuit 52 for power regulation, and then the energy is transferred to the secondary winding through the primary winding of transformer T1. The AC signal output from the secondary winding is connected to the first electrode 10 and the second electrode 20 respectively, forming a floating electric field to excite plasma. There is no direct electrical connection between the primary winding and the secondary winding of transformer T1, effectively blocking the interference of DC components on the electrodes.

[0059] Compared to existing technologies, this embodiment uses a combination of inductors and capacitors to construct a filter network to suppress power supply interference, resistors to eliminate residual charge, and transformer T1 to achieve electrical isolation, resulting in a more stable and reliable electrode power supply. This embodiment effectively reduces the interference of high-frequency noise introduced by external power supplies on the plasma excitation process, preventing uneven discharge of the electrodes due to voltage fluctuations. The isolation structure blocks the transmission of DC components, preventing leakage current paths between the electrodes and the cavity, and improving the safety of equipment operation. Impedance matching design optimizes the energy transfer efficiency between the power input and the load, ensuring a stable current supply to the electrodes to maintain a uniform plasma distribution.

[0060] Optionally, refer to Figure 8 Another embodiment of this utility model provides a floating electrode circuit, based on the above. Figure 1 In the embodiment shown, the detection circuit 30 further includes a temperature detection circuit 34, wherein: The output terminal of the temperature detection circuit 34 is connected to the third input terminal of the control circuit 40. The temperature detection circuit 34 includes a temperature sensor, which is located in the chamber. The temperature detection circuit 34 is used to acquire the temperature of the chamber and output a corresponding temperature signal to the control circuit 40.

[0061] The temperature detection circuit 34 is a circuit module used to acquire the temperature signal of the chamber. It can be implemented using a signal conditioning circuit built with an operational amplifier and a resistor network. This circuit amplifies the weak signal from the temperature sensor and converts it into a standard voltage signal. The temperature sensor is a physical device that can sense temperature changes; it can be implemented using a thermocouple or a thermistor. Its installation location can be placed on the inner wall of the chamber or near the electrodes. The third input terminal of the control circuit 40 is the interface specifically used to receive the temperature signal. The temperature signal can be converted into a digital quantity for processing using an analog-to-digital converter.

[0062] The temperature detection circuit 34 monitors the temperature changes within the chamber in real time using a temperature sensor and transmits the temperature signal to the control circuit 40. When the chamber temperature fluctuates due to plasma discharge or external environmental factors, the temperature signal output by the temperature detection circuit 34 changes synchronously. The control circuit 40 combines the plasma concentration detection signal and the temperature signal to comprehensively analyze the relationship between the plasma generation state and the thermal environment. For example, when an increase in temperature leads to a decrease in gas ionization efficiency, the control circuit 40 can adjust the output current of the power supply circuit 50 in advance to compensate for the decrease in plasma concentration caused by temperature changes, thereby maintaining the stability of the cleaning process. The control circuit 40 can pre-set the mapping relationship between the temperature signal and the plasma concentration signal in the chip and output corresponding level signals for control based on the acquired temperature and plasma concentration signals.

[0063] Compared to existing technologies, traditional equipment relies solely on adjusting power output with fixed parameters, neglecting the impact of temperature on plasma generation efficiency. This embodiment, however, introduces a temperature detection function to dynamically sense changes in the chamber's thermal environment, preventing uncontrolled plasma concentration due to temperature fluctuations. The localized cleaning failures caused by temperature increases in existing technologies can be effectively suppressed in this embodiment through joint control of temperature and concentration signals. This embodiment overcomes the technical deficiency of traditional cleaning equipment where plasma concentration is unstable due to temperature changes, achieving dual monitoring of the chamber's thermal environment and plasma state. This ensures uniform cleaning results even under complex operating conditions while reducing the risk of equipment failure due to abnormal temperatures.

[0064] Optionally, refer to Figure 9 Another embodiment of this utility model provides a floating electrode circuit, based on the above. Figure 8 In the embodiment shown, the temperature detection circuit 34 includes a temperature sensor connection terminal H2 and a third operational amplifier chip U2.2, wherein: The temperature sensor connection terminal H2 is used to connect the temperature sensor; an eighth resistor R8 is connected in series between the inverting terminal of the third operational amplifier chip U2.2 and the third terminal of the temperature sensor connection terminal H2; a ninth resistor R9 is connected between the non-inverting terminal of the third operational amplifier chip U2.2 and the second terminal of the temperature sensor connection terminal H2; a tenth resistor R10 is connected in parallel between the output terminal and the inverting terminal of the third operational amplifier chip U2.2; and the output terminal of the third operational amplifier chip U2.2 is connected to the third input terminal of the control circuit 40.

[0065] Among them, temperature sensor connection terminal H2 refers to the interface component used for physical connection of the temperature sensor. It can be implemented using a three-terminal terminal block, with the third and second terminals connected to the signal output terminal and common terminal of the temperature sensor, respectively, to realize the transmission of the temperature signal. The third operational amplifier chip U2.2 refers to the operational amplifier device, which can be implemented using a differential amplifier circuit structure. Through the resistance configuration of the eighth resistor R8, the ninth resistor R9, and the tenth resistor R10, the weak voltage signal output by the temperature sensor is linearly amplified and impedance matched, thereby forming a stable temperature detection signal output to the control circuit 40. The eighth resistor R8 and the ninth resistor R9 are current-limiting components used to set the input bias current path of the operational amplifier. They can be implemented using metal film resistors with an accuracy of 1%, and their resistance range can be, for example, 1kΩ to 10kΩ, to balance the signal attenuation at the input terminal. The tenth resistor R10 is the feedback resistor of the operational amplifier, which can be implemented using an adjustable resistor, and its resistance range can be, for example, 10kΩ to 100kΩ, to adjust the gain of the amplifier circuit and ensure that the temperature detection signal matches the input voltage range of the control circuit 40.

[0066] A temperature sensor is positioned within the chamber, and its output is electrically connected to the third operational amplifier chip U2.2 via temperature sensor connection terminal H2. When the chamber temperature changes, the temperature sensor generates a corresponding voltage signal change. This signal is input to the inverting and non-inverting inputs of the third operational amplifier chip U2.2 via the eighth resistor R8 and the ninth resistor R9. The third operational amplifier chip U2.2 amplifies the input signal based on the gain set by the tenth resistor R10, and outputs a detection signal linearly related to the temperature to the control circuit 40. The control circuit 40, based on the received temperature signal and the plasma concentration detection signal, comprehensively determines whether to adjust the output current of the power supply circuit 50. For example, when the temperature exceeds a preset threshold, the control circuit 40 can reduce the electrode current to prevent overheating of the equipment while maintaining the stability of the plasma concentration.

[0067] In some specific implementations, the temperature sensor can be a thermocouple or a thermistor, and the pin layout of its connection terminals can be adjusted according to the sensor type. The eighth resistor R8 and the ninth resistor R9 can be fixed or adjustable to accommodate the output characteristics of different temperature sensors. The resistance value of the tenth resistor R10 can be automatically adjusted through a preset algorithm, for example, dynamically optimizing the gain of the amplifier circuit based on changes in the chamber temperature.

[0068] Existing technical solutions either lack integrated temperature detection functionality or employ only simple voltage divider circuits for temperature acquisition, resulting in low signal accuracy and poor anti-interference capabilities. This embodiment constructs a differential amplifier circuit using an operational amplifier, combined with a precision resistor network, effectively improving the detection accuracy and stability of the temperature signal. Simultaneously, it achieves coordinated control of temperature parameters and plasma concentration, resolving the issue of uneven plasma distribution caused by chamber temperature fluctuations.

[0069] Through the above technical solution, this embodiment can monitor chamber temperature changes in real time and dynamically adjust electrode current through a closed-loop control mechanism to avoid equipment performance degradation or plasma instability caused by excessive temperature. The coordinated processing of temperature detection signals and plasma concentration signals further improves the uniformity and controllability of the cleaning process, ensuring efficient removal of contaminants from the graphite boat surface and extending the service life of key equipment components.

[0070] This invention also proposes a device applicable to the cleaning of graphite boats, the device including the control device as described in the above embodiments.

[0071] It is worth noting that since the equipment for cleaning graphite boats can be applied to this utility model is based on the above-mentioned control device, the embodiments of the equipment for cleaning graphite boats can include all the technical solutions of all the embodiments of the above-mentioned control device, and the technical effects achieved are exactly the same, so they will not be repeated here.

[0072] The above are merely preferred embodiments of this utility model and do not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the description and drawings of this utility model, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A suspended electrode circuit, applied to a device capable of cleaning graphite boats, the device comprising a chamber having a first side and a second side disposed opposite to each other on the inner wall of the chamber, characterized in that... The floating electrode circuit includes: A first electrode is disposed on the first side; The second electrode is disposed on the second side; Multiple detection circuits are arranged at multiple locations in the chamber. The detection circuits are used to detect the plasma concentration in the chamber and output corresponding detection signals. A control circuit, which is electrically connected to the plurality of detection circuits; A power supply circuit, wherein the controlled terminal of the power supply circuit is connected to the output terminal of the control circuit, the first output terminal of the power supply circuit is connected to the first electrode, and the second output terminal of the power supply circuit is connected to the second electrode; The control circuit is used to receive the detection signal, and when the detection signal received by any detection circuit is less than the target signal, control the power supply circuit to increase the current of the first electrode and the second electrode.

2. The floating electrode circuit as described in claim 1, characterized in that, The detection circuit includes: A plasma concentration sensor, used to detect the concentration signal in the chamber; A current detection circuit is provided, wherein the input terminal of the current detection circuit is connected in series between the first output terminal of the plasma concentration sensor and ground, and the output terminal of the current detection circuit is connected to the first input terminal of the control circuit. The current detection circuit is used to output a corresponding current detection signal according to the concentration signal. A voltage detection circuit is provided, wherein the first input terminal of the voltage detection circuit is connected to the first output terminal of the plasma concentration sensor, the second input terminal of the voltage detection circuit is connected to the second output terminal of the plasma concentration sensor, and the output terminal of the voltage detection circuit is connected to the second input terminal of the control circuit. The voltage detection circuit is used to output a corresponding voltage detection signal according to the concentration signal.

3. The floating electrode circuit as described in claim 2, characterized in that, The current detection circuit includes: A first resistor, the first end of which is connected to the first output terminal of the plasma concentration sensor, and the second end of which is grounded; The first operational amplifier chip has a second resistor connected in series between its inverting input and the first end of the first resistor, a third resistor connected in series between its non-inverting input and the second end of the first resistor, a fourth resistor connected in parallel between its output and inverting input, and its output connected to the first input of the control circuit.

4. The floating electrode circuit as described in claim 2, characterized in that, The voltage detection circuit includes: The second operational amplifier chip has a fifth resistor connected in series between its inverting input and the first output of the plasma concentration sensor, a sixth resistor connected in series between its non-inverting input and the second output of the plasma concentration sensor, a seventh resistor connected in parallel between the output and inverting inputs of the second operational amplifier chip, and its output connected to the second input of the control circuit.

5. The floating electrode circuit as described in claim 1, characterized in that, The power supply circuit includes: An impedance matching circuit, wherein the power input terminal of the impedance matching circuit is used to connect to an external power source; A switching circuit, wherein the input terminal of the switching circuit is connected to the output terminal of the impedance matching circuit, and the controlled terminal of the switching circuit is connected to the output terminal of the control circuit, the switching circuit being used to control the magnitude of the current output by the first electrode and the second electrode according to the control signal output by the control circuit; An isolation converter circuit is provided, wherein the first input terminal of the isolation converter circuit is connected to the output terminal of the switching circuit, the second input terminal of the isolation converter circuit is grounded, the first output terminal of the isolation converter circuit is connected to the first electrode, and the second output terminal of the isolation converter circuit is connected to the second electrode.

6. The floating electrode circuit as described in claim 5, characterized in that, The impedance matching circuit includes: The first inductor has a first terminal connected to an external power source. A first capacitor is connected in parallel between the first terminal of the first inductor and ground. A second capacitor is connected in parallel between the second terminal of the first inductor and ground. An eleventh resistor is connected in parallel between the second terminal of the first inductor and ground. The second terminal of the first inductor is connected to the input terminal of the switching circuit. The isolation conversion circuit includes: A transformer, wherein the first end of the primary winding of the transformer is connected to the output terminal of the switching circuit, the second end of the primary winding of the transformer is grounded, the first end of the secondary winding of the transformer is connected to the first electrode, and the second end of the secondary winding of the transformer is connected to the second electrode.

7. The floating electrode circuit as described in claim 1, characterized in that, The first electrode is a metal electrode with a mesh structure, a fence structure, or a plate structure, and the second electrode is a metal electrode with a plate structure. The first electrode and the second electrode are arranged parallel to each other.

8. The floating electrode circuit as described in claim 1, characterized in that, The detection circuit further includes: A temperature detection circuit is provided, the output of which is connected to the third input of the control circuit. The temperature detection circuit includes a temperature sensor located in the chamber. The temperature detection circuit is used to acquire the temperature of the chamber and output a corresponding temperature signal to the control circuit.

9. The floating electrode circuit as described in claim 8, characterized in that, The temperature detection circuit includes: A temperature sensor connection terminal, which is used to connect the temperature sensor; The third operational amplifier chip has an eighth resistor connected in series between its inverting input and the third terminal of the temperature sensor connection terminal; a ninth resistor connected between its non-inverting input and the second terminal of the temperature sensor connection terminal; a tenth resistor connected in parallel between its output terminal and its inverting input; and its output terminal connected to the third input terminal of the control circuit.

10. A device applicable to cleaning graphite boats, characterized in that, Includes the floating electrode circuit as described in any one of claims 1 to 9.

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