Variable reactance device with isolated gate driving power supply

Abstract

The invention relates to a switching circuit of a variable reactance matching network, which can be used in a plasma generation system that utilizes plasma for semiconductor processing. The switching circuit can be used in a hybrid matching network, and the hybrid matching network is provided with a first-stage switching matching network and a second-stage mechanical tuning matching network. The switching circuit may also be used for variable reactance to match in telecommunications applications, plasma laser cutting applications, and / or radar / lidar applications. The switching circuit includes an independent isolated power source powered by a main power source. An independent isolated power supply receives induced electricity from a primary power supply loop powered by a primary power supply. The inductive coupling provides an isolated power loop for driving a single switching circuit. Multiple instances of the isolation switch circuit are used to receive digital signals from a connected controller.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] The present invention claims priority to U.S. non-provisional patent application US17 / 712801 filed on April 4, 2022, having the same inventors and invention names as the present invention, the contents of which are incorporated herein by reference. The present invention claims all available rights, including priority. Background Art

[0003] In semiconductor manufacturing, plasma processing chambers use radio frequency (RF) energy to generate plasma. Plasma is typically generated and sustained by RF alternating current at a certain RF frequency, during which a source gas used in the plasma chamber is excited and ionized. Plasma processing chambers can be used in industrial processes such as, but not limited to, surface treatment of materials or plasma etching during semiconductor manufacturing. In order to achieve efficient energy transfer between the RF generator and the plasma load, an impedance matching network is typically used to match the load impedance to the source impedance (e.g., 50 ohms).

[0004] The electrical impedance present in a plasma chamber may change greatly and rapidly. The output impedance of the RF energy generator should be closely matched to the rapidly changing load impedance of the plasma chamber to avoid damage caused by energy reflection back to the output circuit of the RF power generator, which may occur when the impedance is mismatched. Impedance matching devices (such as matching networks) are used to match the load impedance of the plasma processing chamber to the output impedance of the RF power generator. For rapidly changing load impedances, the matching network must dynamically match the impedance accordingly.

[0005] In some plasma chamber embodiments, low frequency solid state capacitors are matched using symmetrical silicon carbide MOSFET (metal oxide semiconductor field effect transistor) switches connected to a logic controller. Other types of transistors may also be used in addition to or in place of the MOSFET. The switches act as elements (e.g., capacitors) to introduce and remove reactive components from the circuit. These switches and reactive elements are arranged in a binary parallel arrangement, where actuation of certain of these devices causes tuning of the device. The arrangement of the isolated gate drive power supply disclosed in the present invention is improved over previously known embodiments of such switches.

[0006] It should be understood that the above-mentioned background technology is helpful for understanding the content of the present invention, but any content in the background technology part should not be construed as a determination of the prior art related to the embodiments described in the present invention. Summary of the invention

[0007] In one embodiment of the present invention, a switch circuit is provided, which includes providing an isolated power supply for each switch in the circuit. When used in a matching network, such as a variable reactance matching network, the use of multiple isolated power supplies improves the function of the switch, wherein each isolated power supply is powered separately using a magnetic inductor from a main power supply.

[0008] Various aspects of the present invention will be described in more detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a block diagram of a hybrid matching network of the present invention;

[0010] Figure 2A is a schematic diagram of a hybrid matching network topology of the present invention;

[0011] Figure 2B It is a schematic diagram of a primary part in a hybrid matching network topology of the present invention; wherein the hybrid matching network topology has a variable reactance device of an isolated gate drive power supply;

[0012] Figure 2C yes Figure 2B An enlarged view of a single switch portion of a variable reactance device is shown;

[0013] Figure 3 is a schematic diagram of a plasma processing apparatus according to some embodiments of the present invention. DETAILED DESCRIPTION

[0014] Various embodiments and aspects of the present invention will be described with reference to the accompanying drawings. The following description and drawings are only for exemplary illustration of the present invention and should not be construed as limiting the scope of protection of the present invention. A large number of specific details are disclosed to provide a thorough understanding of various embodiments of the present invention. However, in some cases, well-known or traditional details are not described so that the embodiments disclosed in the present invention are briefly discussed. As a standard practice for providing drawings, the drawings do not necessarily have to scale with each other, and the same elements are given the same reference numbers in different views.

[0015] A variable reactance device is disclosed having an isolated gate drive power supply in the form of an isolated inductive power supply loop. Since the switch is directly connected in series with the reactance element, it is necessary to provide an isolated portion of the power supply to some extent. Isolation is also required in the construction process of symmetrical switches. In the design disclosed in the present invention, the gate driver of each bit is completely isolated from each other and from the main power supply. The gate and source connections of each field effect transistor (FET) are driven with a high degree of current and electromagnetic isolation to prevent the state of one switch from affecting the state of any other nearby switches (e.g., through electrical interference).

[0016] In some conventional solutions, isolation can be achieved by isolating the gate drive circuit from the switch and coupling the gate drive energy to the MOSFET or FET using a transformer or other method. In contrast, the isolation technology involved in the present invention provides an isolated power supply for each switch to locally provide energy to the gate drive circuit of the variable reactance device.

[0017] The switch circuit disclosed in the present invention is used for a variable reactance device to achieve high power impedance matching. The switch circuit is composed of several fixed reactance elements connected in parallel, which can be connected or disconnected according to the change of the total reactance of the device. In some embodiments of the present invention, each isolation circuit is composed of a reactance element and a switch. The reactance element is usually a fixed capacitor, but it can also be an inductor or a resistor.

[0018] The implementation of the switch circuit can be constructed using symmetric silicon carbide MOSFET circuits, or other types of transistors in a similar isolation arrangement. In the plasma generation system (described in detail below), the switch circuit is connected in series with the reactive element and is essentially suspended on the input RF signal. The gate driver of each switch should be galvanically isolated and electromagnetically isolated to prevent the drive of any switch or switch group from affecting the state of the other switches.

[0019] In order to help provide isolation between the individual switch parts of the total switch circuit described in the present invention, the present invention provides a set of isolated power supplies so that the gate driver of each switch can be independently powered and driven. In order to achieve the above isolation, a constant current source transmits an alternating current (AC) current through a single main power loop. In turn, the above main power loop is electromagnetically coupled to each set of gate drive circuits by inductive coupling to the isolated switch power loop. This forms a transformer in which a single loop is the primary coil of the transformer, and the number of secondary networks (i.e., secondary coils) is multiple, which is the same as the number of switches. Each secondary coil provides rectified and filtered energy to form positive (+) and negative (-) voltage rails for gate drive. In some embodiments, the configuration can be set to provide a positive rail and ground (GND), or a positive rail and a negative rail. These power rails are applied to the gate drive circuit, which includes an isolator and a buffer amplifier to provide high current to quickly sweep the charge out of the gate and provide low output impedance to reduce the impact of Miller capacitance feedback from the device.

[0020] The disclosed embodiments of the present invention provide for the use of an independent isolated power supply, which makes the gate drive circuit (built into the aforementioned independent switch) as simple and robust as possible. In general, the isolation requirements provide guidance for the design of the gate drive transformer with additional circuitry to drive the primary winding of the transformer, and with an additional circuit to generate the required rectangular pulses at the secondary winding out of the AC signal coupled to the primary winding input.

[0021] Designing compact transformers and their associated necessary circuitry at high switching speeds is challenging due to the size constraints of most designs and the parasitics of such circuits. Further complicating this problem is that the switches under consideration may be suspended at high frequency radio frequencies of hundreds or thousands of volts. As a result, a large amount of feedback may be generated through the Miller capacitance, which must be handled by the gate drive circuitry. By suspending the entire gate drive circuitry (as shown in the illustrated embodiments of the present invention), no transformer or any type of complex circuitry is required. In some embodiments, a simple isolator that obtains the input signal and couples it to the gate and a buffer amplifier that amplifies the current applied to the gate can be operated from the rails of an isolated power supply.

[0022] The present invention discusses implementations of variable gate reactance devices with isolated gate drive power supplies in the context of plasma processing systems. Other uses are possible, which should be apparent to those skilled in the art in light of the present disclosure. Specifically, any industry or application area that uses variable reactance network circuits may benefit from the techniques disclosed in the present invention, to name a few industries that may benefit: telecommunication applications, laser cutting applications, and radar / laser radar (RADAR / LIDAR) implementation areas.

[0023] In the plasma processing process, the radio frequency (RF) generator transmits RF alternating current (AC) waves to the plasma processing chamber through RF transmission lines and networks. In order to achieve efficient energy transmission from the RF generator to the plasma processing chamber, a matching network is used to convert the time-varying impedance presented by the plasma chamber into the optimal load impedance of the RF generator.

[0024] Many RF matching networks have a variable capacitor and a control circuit with a microprocessor that controls the capacitance value of the variable capacitor. RF matching networks may have a variety of configurations. For purposes of the present invention, a vacuum variable capacitor may be defined as an electromechanical device having two concentric metal rings that move relative to each other to change capacitance. The value and size of the variable capacitor within the RF matching network may be determined by the energy handling capability, operating frequency, and impedance range of the plasma processing chamber.

[0025] Pulse frequency modulation (PFM) is a commonly used power transmission technique in plasma processing systems. In the present invention, pulse frequency modulation is a modulation method in which the amplitude of a carrier waveform varies between at least two discrete energy levels at certain frequencies with certain duty cycles. Therefore, the energy transmitted in a pulse waveform may affect the characteristics of the plasma, causing the electrical impedance of the plasma chamber to change with each pulse waveform. At the beginning of each pulse, a peak of reflected energy is generated. .

[0026] Many RF plasma generation systems use multi-stage pulsing to achieve a variety of different energy states. Each energy state may be associated with a specific impedance because the characteristics of the plasma can change depending on the energy delivered to the plasma chamber. In plasma processing, the plasma changes very quickly (e.g., at rates up to hundreds of kilohertz). Many matching networks, such as those with vacuum variable capacitors, typically react in hundreds or thousands of milliseconds.

[0027] Therefore, many of these matching networks are limited to locking into one of the multiple energy states (e.g., high amplitude or low amplitude). For example, for a two-level pulse, the matching network can lock into either the high amplitude or low amplitude state and hold position while the other state persists. This means that the system has optimal behavior in one state and suboptimal behavior in any other state.

[0028] According to the system and method disclosed in the present invention, Figure 1 1 is a block diagram of a hybrid matching network 100. Preferably, the hybrid matching network 100 disclosed in the present invention adopts a two-stage tunable matching network. Figure 1 As shown, the hybrid matching network 100 receives an RF input from an RF generator (not shown) at an RF input terminal 109, and a primary matching network 101 (e.g., a switch network), a secondary matching network 103 (e.g., a mechanically tuned matching network), a sensor element 102, and a plasma chamber (e.g., shown as a load 104) are all coupled to one or more transmission lines 105 to 108. In the present invention, the hybrid matching network 100 can be defined as a multi-stage matching network that can be operated simultaneously or sequentially to tune the load impedance to a target impedance (e.g., source impedance).

[0029] The primary matching network 101 is responsible for matching the high-speed changes in impedance at different stages of the RF waveform, and can utilize the variable reactance device with isolated gate drive power supply disclosed in the present invention. The secondary matching network 103 is responsible for high-Q impedance transformation. Therefore, in several embodiments of the present invention, for high-Q transformation, most of the impedance tuning is performed by the secondary matching network 103, while for low-Q transformation, the system impedance is tuned by the primary matching network 101, where the low-Q transformation is caused by the pulse waveform, chamber condition changes or other factors. In the present invention, high-speed changes are defined as impedance changes that exceed the control loop bandwidth associated with the secondary matching network.

[0030] The primary matching network may include a fixed capacitor and an electronic switch of a PIN diode, a silicon carbide field effect transistor (SiCFET), a metal oxide field effect transistor (MOSFET), an insulated gate bipolar transistor (IGBT), or a bipolar junction transistor (BJT), while the secondary matching network may include a vacuum variable capacitor or an air variable capacitor, a stepper motor, a brushed direct current (DC) motor, a brushless DC motor, or an AC motor.

[0031] Preferably, the hybrid matching system disclosed in the present invention can reduce the stress of a high-speed secondary matching network (eg, primary matching network 103 ), and can assist in adjusting the settings of the matching network to tune the plasma system to a target impedance.

[0032] In the present invention, high Q or low Q refers to high quality factor or low quality factor. The Q factor is defined as the ratio of energy stored in a system to the energy consumed in the system. The Q factor is a dimensionless unit, which is expressed as the ratio between the reactance of a component and its resistance for a single component. In a matching network, the minimum Q factor is the configuration that stores the least energy to complete the conversion.

[0033] In some embodiments, a high-Q impedance transformation is a transformation having a Q factor greater than 2, while a low-Q impedance transformation is a transformation having a Q factor less than 2.

[0034] Figure 2A Schematic diagram of a hybrid matching network 200 topology having the advantages of the variable reactance device disclosed in the present invention. The topology of the hybrid matching network 200 shows a primary matching network 201, a secondary matching network 202, and a sensor element 203 coupled thereto. In some embodiments, most of the tuning is performed by the secondary matching network 202, while the primary matching network 201 can be used to achieve "coarse tuning" for low-level and fast impedance changes. Figure 2A The hybrid matching network 200 topology shown in FIG. 1 does not show the isolated power supply of the switch terminal 210, which will be described below. Figure 2B-2C However, through Figure 2A The circuit and Figure 2B-2C By comparing the circuit of the present invention with that of the present invention, and combining the description of other components, and keeping the functions of the components relative to the overall matching network, a person of ordinary skill in the art should be able to fully understand the switch circuit disclosed in the present invention.

[0035] The voltage and current detected at the output of the primary matching network 201 (e.g., nodes 209 / 215) can be used to simultaneously guide the independently operated primary and secondary matching networks. RF energy is delivered from the RF generator to the system input node 208 and then delivered to the plasma chamber (not shown) through the hybrid matching network 200.

[0036] In the illustrated embodiment, the primary matching network 201 includes an impedance transformer 217 having groups 205, 206 of switch terminals 210 (e.g., switches connected to capacitors as reactive elements) on both sides of the impedance transformer 217. In general, the impedance transformer 217 and the groups 205, 206 of switch terminals 210 (e.g., switched capacitors) provide the primary matching network 201 with the flexibility to match impedance within a specified range. The impedance transformer 217 may include a lumped element π-shaped network or a distributed network such as a transmission line to achieve the desired impedance transformation. For example, the impedance transformer 217 may include a π-network portion to perform step-up and step-down impedance transformation to tune to a target impedance.

[0037] The specified range of a stage is a design choice that can be made based on the availability of the application and device at a given frequency and energy level. Selecting a narrower range may limit the stress of a stage at a given frequency and energy level, which will also limit the types of applications that use that stage. Selecting a wider range will have the opposite effect. In either case, the system will function similarly.

[0038] Thus, an impedance transformer 217 may be used in conjunction with the groups 205, 206 of switch terminals 210 (e.g., switched capacitors) to tune the impedance. The impedance transformer 217 may be implemented by inserting a section of transmission line having an appropriate electrical length and characteristic impedance. For example, a quarter-wavelength impedance transformer may be used to match a real impedance. However, by adding series or shunt reactive components, complex load impedances may also be converted to real impedances. Notably, a quarter-wavelength transformer may provide matching at a particular operating frequency and may provide acceptable matching over a bandwidth of one octave or less, depending on the quality factor Q of the conversion and application.

[0039] exist Figure 2AIn the embodiment shown, the impedance transformer 217 comprises a lumped element π network. The impedance transformer 217 performs the same impedance transformation as a transmission line or waveguide and can be made more compact at lower frequencies, but provides a more limited bandwidth. In one embodiment, the lumped element impedance transformer 217 consists of a capacitor 213 in a parallel network branch, a capacitor 214, and an inductor 216 in a series branch.

[0040] The groups 205, 206 of switches 212 each include independent (e.g., RF) switch terminals 210 (in each respective group 205, 206 of switches 212) that include switches 212 and reactance tuning elements 221 that allow the first stage to match a variety of load impedances. In some embodiments, the state of the switches 212 may be determined with reference to a lookup table stored in a storage element (not shown) of the hybrid matching network 200 to tune the first stage output impedance set to the complex conjugate of the calculated input impedance of the second stage matching network. Figure 2A In the illustrated embodiment, each of the groups 205 and 206 includes four switch terminals 210 of the switch 212, so there are eight switch terminals 210 to achieve impedance tuning. Figure 2B and Figure 2C Discussed in more detail, the circuitry for switch terminal 210 may be modified so that each instance of switch 212 has an isolated power source.

[0041] In addition, the switch actuator 204 is coupled to the corresponding switch terminal 210 by the group 205, group 206 with each switch terminal 210. In this embodiment, the switch actuator is defined as a part of the system that is responsible for bringing the switch terminal 210 into or out of the circuit by engaging (e.g., closing) or disengaging (e.g., opening) the switch 212 in the switch terminal 210. The switch actuator 204 can be coupled to the group 205, group 206 of the switch terminal 210 by electrical, magnetic, optical or mechanical means. In the embodiment shown, the switch actuator 204 is coupled to eight switches 212 in the group 205, group 206 of the switch terminal 210. In addition, the switch actuator 204 is coupled to the sensor element 203. The sensor element 203 can operate the switch actuator 204 to engage the primary matching network 201.

[0042] The states of the switches 212 of the groups 205 and 206 of the switch terminals 210 may be represented in binary format. For example, the first-stage matching network 201 and the groups 205 of the switches 212 are all closed, and the groups 206 of the switches 212 are all open, which is represented as [11110000]. Similarly, the first-stage matching network 201 and half of the groups 205 and 206 of the switches 212 are open, and the other half of the groups 205 and 206 of the switches 212 are closed, which may be represented as [0011 0011]. In one embodiment, a lookup table may be used to associate the correct configuration state of the switch terminals 210 with the readings from the sensor element 203. In this case, after receiving and processing the sensor data, the switch terminals 210 may be activated to a set of states to minimize the reflection coefficient (e.g., gamma) at the input node 208 of the first stage.

[0043] like Figure 2A As shown, the sensor element 203 is coupled to the input terminal 215 of the secondary matching network 202. The sensor element 203 can detect voltage and current, or forward and reflected coupled waves. The sensor element 203 can be a voltage and current sensor, or a bidirectional coupler that detects voltage, current, forward or reflected waveforms. Specifically, the sensor element 203 in this embodiment is used to measure voltage and current, and is used to calculate the relationship between the measured voltage and current in phase and amplitude. In addition, the sensor element 203 can detect the high-speed change of the plasma chamber impedance, and the impedance change caused by the high-speed change can be used to engage the primary matching network 201.

[0044] With the benefit of the present disclosure, it should be understood by those of ordinary skill in the art that the amplitude ratios and phase relationships of the voltage and current waveforms at specific nodes in the matching network can be used to guide the tunable elements in the automatic matching network. In this case, the aspects worth noting are the location of the sensors and the type of information they collect. The sensor elements 203 are present at the nodes in the system, and these large number of amplitude ratios and phase relationships at the above nodes enable the secondary matching network to be driven to match the network and simultaneously drive the switch terminals 210 in the primary matching network.

[0045] In this embodiment, the amplitude and phase are used to drive the tunable elements in the secondary matching network to match the network, and these values ​​are also used to calculate the input impedance of the secondary matching network, that is, the load impedance of the primary matching network. When calculating this impedance, the switch terminal 210 is driven so that the primary output impedance is the complex conjugate of the calculated load impedance. The above operations can occur simultaneously and independently.

[0046] As the secondary matching network 202 self-adjusts its tunable elements to minimize gamma entering its input 215, it constantly presents some load at the input of the first stage. Thus, in any case, the impedance of the input node 215 is approximately the complex conjugate of one of the available configurations of the switch terminal 210, and the first stage can minimize the gamma at the input node 208, which is the input of the hybrid matching system. As the secondary matching network continues to drive toward minimum gamma at node 215, the first stage can continue to drive the switch terminal 210 to maintain the best impedance match at the input node 208.

[0047] Figure 2A A schematic diagram of a secondary matching network 202 is also shown. In some embodiments, the secondary matching network 202 can be configured similarly to a conventional matching network. For example, the secondary matching network 202 can include one or more variable capacitors 218, variable capacitors 219, and inductors 220. The variable capacitors 218, 219 can be adjusted by, for example, a lead screw (not shown) in a mechanical device (e.g., using a motor 211) to transform the impedance presented by the plasma chamber (not shown) to match the target impedance (e.g., source impedance, typically 50 ohms).

[0048] like Figure 2B and Figure 2C As shown, Figure 2B Schematic diagram of some variations of switch circuits that can be used in a primary (switch) matching network. Figure 2C for Figure 2B As mentioned above, by providing power isolation for the different switches within the variable reactance device, certain advantages can be achieved, such as Figure 2B Each of the power loops 262A-262D in the illustrated variable reactance device is isolated from each other.

[0049] Figure 2B The switching circuit 250 shown is connected to the controller 251 via a data bus 252. The controller 251 may be a processor, a digital signal processor (DSP), a microprocessor, or some other type of computer processor. As described above, the data signal between the switching circuit 250 and the controller 251 (via the data bus 252) may be a binary bit that forms an indication of the switching state of the gate within the variable reactance device. The above data signal may be provided by the controller 251 via the data bus 252 in the form of an electrical signal or an optical signal. If the data bus 252 is implemented optically, an optical breakpoint (e.g., a device that provides optical isolation) that converts the signal from an electrical signal to an optical signal may be provided somewhere in the data signal path. In some cases, if the data signal is an electrical signal, conversion to an optical signal may reduce further interference caused to the data signal, or reduce further interference caused by the data signal. Figure 2BThe controller 251 shown has the same functions as Figure 2A The combination of switch actuator 204 and sensor element 203 in FIG. 200 functions similarly. In effect, the set of individual leads 207 that go into switch actuator 204 is another representation of a data bus (eg, data bus 252).

[0050] like Figure 2B As shown, the switch circuit 250 is also connected to an isolated gate drive power supply unit (PSU) 260. Figure 2B As shown, the inductive circuit power loop 261 outputs from the isolated gate drive power supply unit 260 and provides inductive power, as shown by parallel lines 263, to indicate the magnetic coupling between the power loops. Figure 2B As shown, parallel lines 263 are adjacent to a series of inductive pickups that represent the secondary coil of the transformer, as shown by coil 264 in isolated power loop 262C. It is important to note that each of power loops 262A, 262B, 262C, and 262D is isolated from each other by physical separation and from the main power supply by inductive coupling. Therefore, each power loop 262A-262D powers a single (only one) switch 255 (i.e., switch (0), switch (1) ... switch (N-1), and switch (N)) of the plurality of switches shown in switch loop 250.

[0051] Associated with each switch 255 is a ground 256, a signal for a reactive element 254, a connection to a data bus 252, and a connection to an associated isolated power loop 262A-262D. In this embodiment, the reactive element 254 is a capacitor. However, in other embodiments, the reactive element may be an inductor, a resistor, or some other type of circuit. Each reactive element 254 is also connected to a node 253, which is shared by all existing reactive elements 254.

[0052] In use, the isolated gate drive power supply unit 260 generates a constant alternating current through a loop (e.g., power loop 261) that is magnetically coupled to each independent power loop (e.g., a corresponding one of power loops 262A-262D) in a series of independent switches 255. These switches 255 are in an open or closed state (e.g., based on receiving a 1 or 0 signal from the controller 251 via the data bus 252). It can be determined that when a single switch 255 may be floating up and down on a high voltage or the switch may be pulled to ground, it is advantageous to maintain independence across the power loops. In addition, higher differential voltages may exist between different switches. Specifically, the differential voltage from point 265A associated with switch (0) may be relatively higher relative to the differential voltage from point 265B associated with switch (1).

[0053] Figure 2C A schematic diagram showing a legend 275 (on a larger scale) showing the Figure 2B 255 is a single switch extracted from the switch circuit 250 shown in FIG. There are different components inside the switch 255 for performing rectification filtering, amplification, etc., which constitute the above-mentioned gate drive circuit. In this embodiment, the above-mentioned circuit drives the gate of the symmetrical FET (field effect transformer) switch. However, the internal structure of the switch 255 may be different depending on the implementation, so it will not be discussed further. It is worth noting that no matter how the internal structure of the switch 255 is, it is powered by an independent and isolated power loop 262, which receives power from the coil 264 and is connected to the parallel line 263. Each instance of the switch 255 can be set according to the instruction of the control signal from the controller 251.

[0054] like Figure 3 As shown, Figure 3 Schematic diagram of a radio frequency plasma processing device 300 (which can be implemented using a switching circuit and a matching network according to the embodiments disclosed in the present invention). In this embodiment, the radio frequency plasma processing device 300 includes a radio frequency generator 305. The radio frequency generator 305 is configured to provide energy to the reaction chamber 310. The radio frequency generator 305 can provide radio frequency energy between about 400 KHz and about 150 MHz. In certain specific embodiments, a second radio frequency generator (not shown) may also exist in the radio frequency plasma processing device 300, and may provide the same, lower or higher radio frequency energy as the radio frequency generator 305.

[0055] The reaction chamber 310 may include various components for processing manufacturing operations, such as those associated with the semiconductor industry. The reaction chamber 310 may include one or more sensors (not shown) for measuring certain characteristics generated within the reaction chamber 310. The reaction chamber 310 may also include a pedestal (also not shown) on which a substrate to be manufactured may be placed during operation. The reaction chamber 310 may also include a coil or otherwise be connected to a coil (not separately shown), such as the coil discussed above, or a showerhead, etc.

[0056] The RF plasma processing apparatus 300 may also include a matching network 315 (one example of which is the matching network 200 discussed above). The matching network 315 may be located between the RF generator 305 and the reaction chamber 310. The matching network 315 may include a variable capacitor (not shown) and other components to balance the impedance between the RF generator 305 and the reaction chamber 310, as described in detail above. During operation, the matching network may be tuned, for example by adjusting the capacitor position, to provide a matching impedance.

[0057] During operation, when energy is supplied from the RF generator 305 to the plasma (not shown) within the reaction chamber 310, a problem may occur in which energy may be reflected from the reaction chamber 310. Such energy reflection may cause undesirable conditions, resulting in low processing efficiency, damage to the substrate, damage to components of the RF plasma processing device 300, etc. In order to solve the above problems and improve the operability of the RF processing device 300, a tuning module 337 of a programmable logic controller (PLC) 335 is provided, which can provide commands to the matching network 315 to adjust the capacitor position, thereby providing matching impedance to minimize energy reflection. The programmable logic controller 33 can be connected to a storage device 340 to store these commands or obtained data during operation.

[0058] During operation, the programmable logic controller 335 can identify capacitors within the matching network 315. The above identification can be performed automatically or controlled by an operator. In addition to identifying capacitors, the impedance of the entire matching network can also be measured. Measuring the impedance of the entire matching network 315 (for example, by using one or more sensors distributed throughout the matching network) includes measuring multiple impedance values ​​of one or more capacitors and / or other components within the matching network 315. Then, the capacitor can be driven from a zero step value (representing the minimum capacitance point in its usable range) to a higher step value to increase its capacitance, thereby tuning the network (for example, reducing power reflections).

[0059] Although the invention has been discussed with reference to the various embodiments disclosed in the present invention, it should be understood by those skilled in the art that any equivalent modifications and substitutions made to the present invention are also within the scope of the present invention for those skilled in the art. Therefore, equivalent transformations and modifications made without departing from the spirit and scope of the present invention should be included in the scope of the present invention. That is, the various exemplary embodiments and drawings disclosed in the present invention are merely specific embodiments to help understand the various aspects disclosed in the present invention, and are not intended to limit the scope of protection of the present invention. For example, the specific order of steps can be modified or changed without departing from the scope of the present invention. Therefore, the scope of protection of the present invention is not limited by the detailed description of the present invention, but by the attached claims, and all differences within the scope should be understood to be included in the scope of protection of the present invention.

Claims

1. A switching circuit, characterized in that: The switch circuit comprises: a plurality of switch elements, each switch element receiving an output signal from a controller; a plurality of reactance elements, each reactance element being connected to a corresponding one of the plurality of switch elements; and, A main power supply is inductively coupled to a plurality of independent isolated power loops, each of which is connected to a corresponding one of the plurality of switch elements.

2. The switch circuit according to claim 1, characterized in that: The output signal is provided by the controller via a data bus.

3. The switch circuit according to claim 2, characterized in that: The data bus is an optical data bus.

4. The switch circuit according to claim 3, characterized in that: The switch circuit further comprises: An optical isolation connection portion is provided between each of the plurality of switch elements and a data bus, wherein the data bus is used to connect the plurality of switch elements to a controller.

5. The switch circuit according to claim 2, characterized in that: A plurality of switch elements receive a binary signal in common via a data bus.

6. The switch circuit according to claim 1, characterized in that: Each of the plurality of switching elements includes a drive circuit including: a rectifier; one or more filters; and an amplifier.

7. The switch circuit according to claim 1, characterized in that: The plurality of reactive elements include a plurality of capacitors.

8. The switch circuit according to claim 1, characterized in that: The plurality of reactive elements include a plurality of inductors, a plurality of resistors, or a combination of both.

9. The switch circuit according to claim 1, characterized in that: The switch circuit further comprises: A main power loop includes a primary coil powered by a power supply unit, the primary coil is inductively coupled to a plurality of secondary coils, each of the secondary coils is contained in an independent isolated power loop.

10. A hybrid matching network, characterized in that: The hybrid matching network comprises: A multi-stage tunable matching network, wherein the multi-stage tunable matching network includes a primary switch matching network and a secondary mechanical tuning matching network; a sensor electrically connected between the primary switch matching network and the secondary mechanical tuning matching network, the sensor being used to determine the phase and amplitude of the electrical signal; and, a load electrically connected to a secondary mechanical tuning and matching network; Wherein, the first-stage switch matching network includes a switch circuit, and the switch circuit includes: a plurality of switch elements, each switch element receiving an output signal from a controller; a plurality of reactance elements, each reactance element being connected to a corresponding one of the plurality of switch elements; and, A main power supply is inductively coupled to a plurality of independent isolated power loops, each of which is connected to a corresponding one of the plurality of switch elements.

11. The hybrid matching network according to claim 10, characterized in that: The output signal is provided by the controller via a data bus.

12. The hybrid matching network according to claim 11, characterized in that: A plurality of switch elements collectively receive a set of binary signals via a data bus.

13. The hybrid matching network according to claim 10, characterized in that: Each of the plurality of switching elements includes a drive circuit including: a rectifier; one or more filters; and an amplifier.

14. The hybrid matching network according to claim 10, characterized in that: The plurality of reactive elements include a plurality of capacitors.

15. The hybrid matching network according to claim 10, characterized in that: The plurality of reactive elements include a plurality of inductors, a plurality of resistors, or a combination of both.

16. The hybrid matching network according to claim 10, characterized in that: The hybrid matching network further includes: A main power loop includes a primary coil powered by a power supply unit, the primary coil is inductively coupled to a plurality of secondary coils, each of the secondary coils is contained in an independent isolated power loop.

17. A radio frequency plasma processing device, characterized in that: The radio frequency plasma processing device comprises: Reaction chamber; A radio frequency generator, the radio frequency generator is used to provide radio frequency power to the plasma in the reaction chamber; A multi-stage tunable matching network, wherein the multi-stage tunable matching network includes a primary switch matching network and a secondary mechanical tuning matching network; a sensor electrically connected between the primary switch matching network and the secondary mechanical tuning matching network, the sensor being used to determine the phase and amplitude of the electrical signal; and, A load, the load is from the reaction chamber, and the load is electrically connected to a second-stage mechanical tuning matching network; Wherein, the first-stage switch matching network includes a switch circuit, and the switch circuit includes: a plurality of switch elements, each switch element receiving an output signal from a controller; a plurality of reactance elements, each reactance element being connected to a corresponding one of the plurality of switch elements; and, A main power supply is inductively coupled to a plurality of independent isolated power loops, each of which is connected to a corresponding one of the plurality of switch elements.

18. The radio frequency plasma processing device according to claim 17, characterized in that: The output signal is provided by the controller via a data bus.

19. The radio frequency plasma processing device according to claim 17, characterized in that: Each of the plurality of switching elements includes a drive circuit including: a rectifier; one or more filters; and an amplifier.

20. The radio frequency plasma processing device according to claim 17, characterized in that: The switch circuit further comprises: A main power loop includes a primary coil powered by a power supply unit, the primary coil is inductively coupled to a plurality of secondary coils, each of the secondary coils is contained in an independent isolated power loop.

Images