Protection system for switches in direct drive circuits of substrate processing systems

Abstract

A direct drive system for providing RF power to a component of a substrate processing system includes a direct drive circuit including a switch and configured to supply RF power to the component, wherein a switch protection module is configured to monitor a load current and a load voltage in a processing chamber, calculate a load resistance based on the load current and the load voltage, compare the load resistance to a first predetermined load resistance, and adjust at least one of an RF power limit and an RF current limit of the direct drive circuit based on the comparison.

Description

[Technical field]

[0001] The present disclosure relates to substrate processing systems, and more particularly to drive circuits for supplying RF plasma power or RF bias in substrate processing systems. [Background technology]

[0002] The background description provided herein is intended to provide a general overview of the contents of the present disclosure. The work of the presently named inventors, as well as aspects of the specification that may not otherwise qualify as prior art at the time of filing, are not admitted, expressly or impliedly, as prior art to the present disclosure to the extent that they are described in this Background section.

[0003] Substrate processing systems are typically used to etch thin films on substrates, such as semiconductor wafers. Etching typically involves either wet chemical etching or dry etching. Dry etching may be performed using plasma generated by inductively coupled plasma (ICP). Inductively coupled plasma may be generated by a coil located outside the processing chamber adjacent to a dielectric window. Process gases flowing within the processing chamber are ignited, generating the plasma. In some applications, RF plasma power is output to one or more inductive coils located outside the processing chamber. RF bias power may also be supplied to an electrode on the substrate support.

[0004] The frequency of the RF plasma power or the RF bias power can be varied to provide additional process control. Additionally, the magnitude or level of the RF plasma power or RF bias power can be varied during processing to provide additional process control. Changing the RF plasma power or level and / or the RF bias power or level can change the impedance seen by the drive circuitry. An impedance mismatch between the load and the drive circuitry causes power to be reflected, which is inefficient. Summary of the Invention

[0005] A direct drive system for providing RF power to a component of a substrate processing system includes a direct drive circuit including a switch and configured to supply RF power to the component, wherein a switch protection module is configured to monitor a load current and a load voltage in a processing chamber, calculate a load resistance based on the load current and the load voltage, compare the load resistance to a first predetermined load resistance, and adjust at least one of an RF power limit and an RF current limit of the direct drive circuit based on the comparison.

[0006] In another feature, a voltage / current (VI) probe is disposed in the process chamber and configured to generate a load current and a load voltage. The first predetermined load resistance is selected based on a resistance in at least one non-plasma state. The at least one non-plasma state corresponds to a plasma not igniting. The at least one non-plasma state corresponds to a plasma being extinguished after process gas flow to the process chamber is stopped.

[0007] In other features, in response to the load resistance being less than or equal to a first predetermined load resistance, the switch protection module reduces at least one of an RF power limit and an RF current limit of the direct drive circuit. The switch protection module is configured to shut down the direct drive circuit in response to the load resistance being less than or equal to the first predetermined load resistance for a period of time greater than a predetermined period. In response to the load resistance being less than or equal to the first predetermined load resistance, the switch protection module increases at least one of an RF power limit and an RF current limit of the direct drive circuit.

[0008] In other features, the switch protection module is configured to shut down the direct drive circuit in response to the load resistance being less than or equal to a first predetermined load resistance for a period of time greater than a predetermined period.

[0009] In other features, a switch protection module selects at least one of a first RF power limit and a first RF current limit of the direct drive circuit in response to the load resistance being less than or equal to a first predetermined load resistance, and selects at least one of a second RF power limit and a second RF current limit of the direct drive circuit in response to the load resistance being greater than the first predetermined load resistance. At least one of the first RF power limit and the first RF current limit of the direct drive circuit is less than at least one of the second RF power limit and the second RF current limit of the direct drive circuit. The switch protection module is configured to shut down the direct drive circuit in response to the load resistance being less than or equal to the first predetermined load resistance for a period of time greater than a predetermined period of time.

[0010] In other features, a switch protection module selects at least one of a first RF power limit and a first RF current limit of the direct drive circuit in response to the load resistance being less than or equal to a first predetermined load resistance, and selects at least one of a second RF power limit and a second RF current limit of the direct drive circuit in response to the load resistance being greater than the first predetermined load resistance. At least one of the first RF power limit and the first RF current limit of the direct drive circuit is greater than at least one of the second RF power limit and the second RF current limit of the direct drive circuit. The switch protection module is configured to shut down the direct drive circuit in response to the load resistance being less than or equal to the first predetermined load resistance for a period of time greater than a predetermined period of time.

[0011] In other features, the switch protection module is configured to shut down the direct drive circuit in response to the load resistance being less than or equal to a first predetermined load resistance for a period of time greater than a predetermined period. The direct drive circuit includes a clock generator for generating a clock signal at a first frequency and a gate driver for receiving the clock signal. The bridge circuit includes a first switch having a control terminal connected to the gate driver, a first terminal, and a second terminal. The second switch has a control terminal connected to the gate driver, a first terminal connected to the second terminal of the first switch and to the output node, and a second terminal.

[0012] In other features, a current sensor senses a current at the output node to generate a current signal. A voltage sensor senses a voltage at the output node to generate a voltage signal. The controller includes a phase offset calculation module for calculating a phase offset between the voltage signal and the current signal and a clock adjustment module for adjusting the first frequency based on the phase offset. The component includes a coil disposed outside the process chamber.

[0013] A method for providing RF power to a component of a substrate processing system includes supplying RF power to the component using a direct drive circuit including a switch, monitoring a load current and a load voltage in a processing chamber, calculating a load resistance based on the load current and the load voltage, comparing the load resistance to a first predetermined load resistance, and adjusting at least one of an RF power limit and an RF current limit of the direct drive circuit based on the comparison.

[0014] In other features, the method includes disposing a voltage / current (VI) probe in the process chamber and generating a load current and a load voltage using the VI probe, the first predetermined load resistance being selected based on a resistance in at least one non-plasma state, the at least one non-plasma state corresponding to a plasma not igniting.

[0015] At least one of the non-plasma conditions corresponds to the plasma being extinguished after the flow of process gas to the processing chamber is stopped.

[0016] In other features, the method includes reducing at least one of an RF power limit and an RF current limit of the direct drive circuit in response to the load resistance being less than or equal to a first predetermined load resistance. The method includes shutting down the direct drive circuit in response to the load resistance being less than or equal to the first predetermined load resistance for a period of time greater than a predetermined period.

[0017] In other features, the method further includes increasing at least one of an RF power limit and an RF current limit of the direct drive circuit in response to the load resistance being less than or equal to a first predetermined load resistance. The method further includes shutting down the direct drive circuit when the load resistance is less than the first predetermined load resistance for a period of time greater than a predetermined period.

[0018] In other features, the method includes selecting at least one of a first RF power limit and a first RF current limit of the direct drive circuit in response to the load resistance being less than or equal to a first predetermined load resistance, and selecting at least one of a second RF power limit and a second RF current limit of the direct drive circuit in response to the load resistance being greater than the first predetermined load resistance. At least one of the first RF power limit and the first RF current limit of the direct drive circuit is less than at least one of the second RF power limit and the second RF current limit of the direct drive circuit. The method includes shutting down the direct drive circuit in response to the load resistance being less than the first predetermined load resistance for a period of time greater than the predetermined period.

[0019] In other features, the method includes selecting at least one of a first RF power limit and a first RF current limit of the direct drive circuit in response to the load resistance being less than or equal to a first predetermined load resistance, and selecting at least one of a second RF power limit and a second RF current limit of the direct drive circuit in response to the load resistance being greater than the first predetermined load resistance. At least one of the first RF power limit and the first RF current limit of the direct drive circuit is greater than at least one of the second RF power limit and the second RF current limit of the direct drive circuit. The method includes shutting down the direct drive circuit in response to the load resistance being less than or equal to the first predetermined load resistance for a period of time greater than the predetermined period.

[0020] Further areas of applicability of the present disclosure will become apparent from the detailed description, claims, and drawings. The detailed description and specific examples are for purposes of illustration only and are not intended to limit the scope of the present disclosure. [Brief description of the drawings]

[0021] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:

[0022] [Figure 1A] FIG. 1A is a functional block diagram of an example substrate processing system including one or more direct drive systems according to this disclosure.

[0023] [Figure 1B] FIG. 1B is a functional block diagram of an example direct drive system including a switch protection module and a switched direct drive circuit according to the present disclosure.

[0024] [Diagram 2] FIG. 2 is a functional block diagram of an example of a direct drive circuit including a switch according to the present disclosure.

[0025] [Diagram 3] FIG. 3 is a graph showing the output voltage as a function of time of the direct drive circuit of FIG.

[0026] [Figure 4] FIG. 4 is a functional block diagram of another example of the direct drive circuit.

[0027] [Diagram 5] FIG. 5 is a graph showing the output voltage as a function of time of the direct drive circuit of FIG.

[0028] [Figure 6] FIG. 6 is a functional block diagram of another example of the direct drive circuit.

[0029] [Figure 7] FIG. 7 is a flow chart of an example method for adjusting the frequency of a clock generator based on a phase offset. [Figure 8] FIG. 8 is a flow chart of an example method for adjusting the frequency of a clock generator based on a phase offset.

[0030] [Figure 9] FIG. 9 is a flow chart of an example of a method for protecting a switch of a direct drive circuit based on a load resistance according to the present disclosure.

[0031] [Figure 10] FIG. 10 is a flow chart of an example of a method for protecting a switch of a direct drive circuit based on a load resistance according to the present disclosure.

[0032] In the drawings, reference numbers may be reused to identify similar and / or identical elements. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] In some applications, the frequency of the RF source power supplied to the ICP coil and / or the RF bias to the electrode of the substrate support are switched between two or more frequencies and / or two or more pulse levels. In these systems, the impedance of the RF generator is matched to the load (such as the induction coil and plasma, or the electrode and plasma). However, the impedance of the load changes due to changes in plasma conditions, changes in pulse levels, and / or various other factors. When impedance mismatch occurs, power is reflected back to the load, which is inefficient. Tuning a circuit using a variable capacitor is difficult due to the amount of time required to change the value of the capacitance versus the switching period between frequency changes and / or level changes.

[0034] To overcome some of the problems identified above, direct drive circuits including switches have been used to provide RF power instead of an RF source and matching network. Examples of direct drive circuits and hybrid direct drive circuits are shown and described in commonly assigned U.S. Patent No. 10,515,781, which is incorporated herein by reference in its entirety. Direct drive circuits operate with low impedance, thus overcoming the matching problems discussed above.

[0035] The switches in the direct drive circuit may fail during non-plasma times, such as when the plasma does not ignite or when the plasma disappears after the gas flow is turned off. RF current and loss limits have been used to protect the direct drive circuit. However, RF current limits alone have not eliminated switch failure at higher RF frequencies, such as 13 MHz. Reducing the loss limit may prevent switch failure, but it also unacceptably reduces the operating window. Also, the loss limit is not well understood and is not sufficiently accurate.

[0036] The disclosed system and method uses a voltage (V)-current (I) probe (VI probe) located in the process chamber to monitor the load voltage and current during operation of the direct drive circuit. The load resistance is calculated from the measured voltage and current and compared to a predetermined resistance threshold. In some examples, a switch protection module modifies operation of the direct drive circuit if the measured load resistance is less than the predetermined resistance threshold. More specifically, if the load resistance is less than the predetermined resistance threshold, reduced RF power and / or RF current limits are applied until the load resistance changes. The load resistance increases as a transition occurs from a no-plasma state to a plasma-on state.

[0037] In another example, if the load resistance is less than a predetermined resistance threshold in a no-plasma state, increased RF power and / or RF current limits are applied for a period of time to attempt to strike a plasma. This approach is counterintuitive since the normal way to protect a switch is to reduce power. However, when a plasma is struck in response to a higher RF power and / or current limit, the load resistance typically increases as a transition occurs from a no-plasma state to a plasma-on state.

[0038] After the plasma is turned on, the power limit and / or current limit can be increased (if low load resistance reduces the limit) or decreased (if low load resistance increases the limit). In some examples, if the low load resistance condition continues for a predetermined time, the system sends an error message (or activates an alarm) and shuts off the output RF power from the direct drive circuit.

[0039] 1A and 1B, an example of a substrate processing system 10 according to the present disclosure is shown. The substrate processing system 10 includes one or more RF direct drive systems 52, which are described further below.

[0040] In some examples, a plenum 20 may be disposed between the coil 16 and the dielectric window 24 to control the temperature of the dielectric window 24 with hot and / or cold air. The dielectric window 24 is disposed along one side of the processing chamber 28. The processing chamber 28 further includes a substrate support (or pedestal) 32. The substrate support 32 may include an electrostatic chuck (ESC), a mechanical chuck, or other types of chucks. A process gas is supplied to the processing chamber 28, and a plasma 40 is generated within the processing chamber 28. The plasma 40 etches the exposed surface of the substrate 34. A separate RF direct drive system 52 (such as that described further below) may also be used to provide an RF bias to an electrode within the substrate support 32 during operation.

[0041] A gas delivery system 56 may be used to supply a process gas mixture to the processing chamber 28. The gas delivery system 56 may include a process gas and inert gas source 57, a gas metering system 58 such as valves and mass flow controllers, and a manifold 59. A gas delivery system 60 may be used to supply gas 62 to the plenum 20 via valve 61. The gas may include a cooling gas (air) used to cool the coil 16 and the dielectric window 24. A heater / cooler 64 may be used to heat / cool the substrate support 32 to a predetermined temperature. An exhaust system 65 includes valves 66 and pumps 67 for removing reactants from the processing chamber 28 by purging or evacuation.

[0042] The etching process may be controlled using a controller 54. The controller 54 monitors system parameters and controls the delivery of the gas mixture, striking, maintaining and extinguishing the plasma, removing reactants, providing cooling gases, etc.

[0043] The VI probe 92 is disposed within the process chamber and senses the load voltage and current. As can be seen in FIG. 1B, the direct drive system 52 includes a controller 93 having a switch protection module 94. In some examples, the controllers 54 and 93 can be combined. The direct drive circuit 95 includes a bridge circuit 96 and a switch 98. The switch protection module 94 calculates a load resistance based on the load voltage and the load current, and then protects the switch 98 by adjusting the operation of the direct drive system 52 based on the load resistance. More specifically, the switch protection module 94 compares the load resistance to a predetermined resistance threshold. If the measured load resistance is less than the predetermined resistance threshold, the switch protection module 94 changes the operation of the direct drive circuit 95.

[0044] In some examples, if the load resistance is less than a predetermined resistance threshold, a reduced RF power limit and / or RF current limit is applied until the load resistance increases. The load resistance increases due to a transition from a no-plasma state to a plasma-on state. In other examples, if the load resistance is less than a predetermined resistance threshold, an increased RF power limit and / or RF current limit is applied until the load resistance increases due to a plasma state. The direct drive system 52 includes a bridge circuit 96 and one or more switches modulated to generate RF power.

[0045] 2, an example of a direct drive circuit 95 for supplying an RF bias (or RF plasma power) is shown. The direct drive circuit 95 includes a clock 120 that operates at one or more selected RF frequencies. A clock signal output by the clock 120 is input to a gate driver circuit 122. In some examples, the gate driver circuit 122 includes an amplifier 144 and an inverting amplifier 146, each having an input connected to the clock 120.

[0046] An output of the gate driver circuit 122 is input to a bridge circuit 138. In some examples, the bridge circuit 138 includes a first switch 140 and a second switch 142 (corresponding to the protected switch 98). In some examples, the first switch 140 and the second switch 142 include metal oxide semiconductor field effect transistors (MOSFETs). The first switch 140 and the second switch 142 each include a control terminal and first and second terminals. An output of an amplifier 144 of the gate driver circuit 122 is input to a control terminal of the first switch 140. An output of an inverting amplifier 146 of the gate driver circuit 122 is input to a control terminal of the second switch 142.

[0047] The output node 130 is connected to a second terminal of a first switch 140 and a first terminal of a second switch 142. The first terminal of the first switch 140 is connected to the DC power source 126. The second terminal of the second switch 142 is connected to a reference potential, such as ground. The output node 130 is connected to a coil or inductor by a capacitor 132.

[0048] The direct drive circuit of Figure 2 uses a single DC power supply 126 that can generate unwanted DC voltages / components on the ESC baseplate that can complicate wafer chucking / dechucking performance by affecting the ESC DC bias on the baseplate that is expected to be independently controlled.

[0049] 3, the Fourier transform of the voltage waveform at the output node 130 of the bridge circuit 138 in FIG. 2 can be expressed in equation form as follows:

number

[0050] 4, to eliminate unwanted DC voltages on the baseplate, the direct drive circuit 95 may use dual DC power supplies. DC A first DC power supply 410 operating at -V DC 2. In order to achieve the same output RF power, both the first and second DC power supplies 410, 420 operate at half the voltage of the single DC power supply in FIG. 2. In some examples, the first DC power supply 410 and the second DC power supply 420 operate at approximately the same magnitude and opposite polarity. As used herein, approximately the same refers to a difference in the magnitude of the DC voltage output by the first DC power supply 410 relative to the second DC power supply 420 being less than 10%, less than 5%, or less than 1%. The first DC power supply 410 is connected to a first terminal of the first switch 140. The second DC power supply 420 is connected to a second terminal of the second switch 142.

[0051] 5, the voltage waveform output by the direct drive circuit 95 in FIG. 4 does not have a DC component in the following Fourier transform.

number

[0052] 6, the direct drive circuit 95 includes the above-mentioned clock 120, gate driver circuit 122, bridge circuit 138, first DC power supply 410, and second DC power supply 420. The output node 130 is connected to the coil by a capacitor 132.

[0053] A current sensor 640 is connected to the output node 130. Similarly, a voltage sensor 642 is connected to the output node 130. The sensed current output by the current sensor 640 and the sensed voltage output by the voltage sensor 642 are input to a controller 644 that includes a phase offset calculation module 646 and a clock frequency adjustment module 648.

[0054] The phase offset calculation module 646 determines a phase offset between the voltage and the current. The phase offset calculation module 646 outputs the phase offset to the clock frequency adjustment module 648. If the voltage leads the current, the clock frequency adjustment module 648 decreases the frequency of the clock 120. If the current leads the voltage, the clock frequency adjustment module 648 increases the frequency of the clock 120. In some examples, hysteresis may be used. In some examples, when the voltage leads the current by a first predetermined threshold TH1, the clock frequency adjustment module 648 decreases the frequency of the clock 120. In some examples, when the voltage leads the current by a second predetermined threshold TH2, the clock frequency adjustment module 648 decreases the frequency of the clock 120.

[0055] 7, a method 700 for controlling a direct drive circuit is shown. At 710, the current and voltage waveforms are sensed at an output node or elsewhere. At 714, a phase offset is determined between the voltage and current waveforms. For example, the current and voltage zero crossings can be monitored. Differences in the timing of the zero crossings can be used to determine the phase offset. At 720, the frequency of the clock is adjusted to reduce the phase offset between the voltage and current.

[0056] 8, a method 800 for adjusting the frequency of a clock is shown. If the voltage is leading the current as determined at 810, the frequency is decreased at 820. In some examples, the voltage must lead the current by more than a first threshold TH1 before the frequency is decreased. If the current is leading the voltage as determined at 830, the frequency is increased at 840. In some examples, the current must lead the voltage by more than a second threshold TH2 before the frequency is increased. In other examples, no hysteresis is used.

[0057] 9, a method 900 for protecting a switch of a direct drive circuit of a substrate processing system is shown. At 914, the method determines whether the direct drive circuit is on and providing RF power. If false, the method returns to 914. If 914 is true, the method proceeds to 918 to monitor the load voltage and load current. In some examples, the load voltage and load current are monitored using a VI probe. At 922, a load resistance is calculated based on the load voltage and load current. At 926, the load resistance is compared to a predetermined resistance threshold R th The load resistance is compared with a given resistance threshold R th If so, the method reduces the RF power and / or RF current in the direct drive circuit to protect the switch at 932 .

[0058] At 938, the method determines if the timer is on. If 938 is false, then the method turns on the timer at 948. At 942, the method determines whether the timer is on for a predetermined period of time t TH The timer value is compared with TH3 If so, the method proceeds to 914. TH3 If so, the method proceeds to 946 and shuts down the direct drive circuitry. In some examples, an error message is sent and / or an alarm is activated.

[0059] Now, referring to FIG. 10 , instead of reducing the RF power limit and / or the RF current limit, the RF power limit and / or the RF current limit are increased at 1010 for a predetermined period of time t TH4 In this way, the resistance measured by the VI probe generally increases as well. TH4 When not striking the plasma within the direct drive circuit, the direct drive circuit is shut down as described above.

[0060] The following is an example, but is for illustrative purposes only, other parameters can be used. For example, if the maximum power and losses are used to protect the switch, the maximum power at 2MHz may be set to 6kW, and the maximum power at 13MHz to 3kW. The maximum RF current at 2MHz is 150A. rms (+15% headroom for transients of duration 0.05 seconds to 2 seconds (or 172.5A) rms ) may be used. Maximum RF current at 13MHz is 90A. rms (+15% headroom for transients of duration 0.05 seconds to 2 seconds (or 103.5A rms )). The power dissipation limits for 2 MHz and 13 MHz are 1500 W and 1200 W, respectively. Even with these limits, switch failures occurred. As a result, the limits were reduced and the operating window was unacceptably narrowed.

[0061] As mentioned above, problems can occur when the RF direct drive circuit is operated in a non-plasma power mode. At 2 MHz, the internal resistance is equal to 16.25 mΩ for a 4-channel design, and the switches have a drain-source resistance R of 65 mΩ. DS At 13 MHz, the internal resistance is equal to 60 mΩ for a four-channel design, and the switch has a drain-source resistance R DS (On).

[0062] A typical non-plasma load at 2 MHz is 5 mΩ. A typical plasma load at 13 MHz is 70 mΩ. The RF power efficiency in non-plasma conditions is fairly low (without considering other internal stray losses). For example, at 2 MHz, the efficiency is 5 / (5+16.25)=23.53%. At 13 MHz, the efficiency is 70 / (70+60)=53.85%. A rough estimate of the maximum internal RF power dissipation of the power switches, without considering other internal stray switching losses, is: At 2 MHz, I 2 2MHz R 2MHz =110 2 × 0.01625 = 196.625 (W). At 13 MHz, I 2 13MHz R 13MHz =90 2 ×0.06=486(W).

[0063] The minimum load resistance limit for protection purposes is set higher than the nominal non-plasma load resistance. A typical non-plasma load resistance at 2 MHz is equal to approximately 5 mΩ (maximum RF current of 110 A). rms Maximum RF power = 60.5 W. Typical non-plasma load resistance at 13 MHz is equal to approximately 70 mΩ (maximum RF current 90 A rms Maximum RF power = 567W).

[0064] The load resistance is monitored when the RF is turned on. If a minimum load resistance is detected during normal operation, the switch protection module will turn off the RF output power and / or reduce the output power until it is below a safe limit. For example, the multiplier K 2 and K. 13 can be used (i.e., K 2 ×60.5W 2MHz , K 13 ×567W 13MHz where K 2 and K. 13 is a configurable parameter between 0 and 1).

[0065] When a minimum load resistance is detected during ignition or process step transition, the switch protection module will stop the RF output power control if operating in power mode and will not allow the RF current to drop below its safe limit (i.e., K 2 x110A 2MHz and K. 13 x 90A 13MHz , where K 2 and K. 13 The NI 8110 reduces or keeps the DC rail to a low enough level to stay within the specified threshold (where V is a configurable parameter between 0 and 1).

[0066] If the condition persists for longer than a predetermined period of time, the switch protection module shuts off the RF power and sends an alarm. In some examples, the predetermined period of time ranges from 5 milliseconds to 1 second.

[0067] The foregoing description is merely exemplary in nature and is not intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be embodied in various forms. Thus, while the disclosure includes specific examples, other variations will become apparent upon review of the drawings, specification, and the following claims, and should not be so limited as to limit the true scope of the disclosure. It should be understood that one or more steps in a method may be performed in different orders (or simultaneously) without altering the principles of the disclosure. Furthermore, although each embodiment is described above as having specific features, any one or more of those features described with respect to any embodiment of the disclosure can be implemented and / or combined with the features of any other embodiment, even if the combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and one or more embodiments can be substituted for one another within the scope of the disclosure.

[0068] Spatial and functional relationships between elements (e.g., between modules, between circuit elements, between semiconductor layers, etc.) are described using various terms such as "connected," "engaged," "coupled," "adjacent," "next to," "on top of," "above," "below," and "disposed." Unless expressly described as "direct," when a relationship between a first and second element is described in the above disclosure, the relationship may be a direct relationship where there are no other intervening elements between the first and second elements, but may also be an indirect relationship where there are one or more intervening elements (spatially or functionally) between the first and second elements. As used herein, the phrase at least one of A, B, C should be interpreted as meaning a logical (A or B or C) with a non-exclusive logical OR, and not as meaning "at least one of A, at least one of B, and at least one of C."

[0069] In some implementations, the controller is part of the system and may be part of the examples described above. Such systems may include semiconductor processing equipment including single or multiple processing tools, single or multiple chambers, single or multiple processing platforms, and / or specific processing components (wafer pedestals, gas flow systems, etc.). These systems may be integrated with electronics to control the operation of the system before, during, and after processing of a semiconductor wafer or substrate. This electronics may be referred to as a "controller" that may control various components or subparts of the system or systems. Depending on the processing requirements and / or type of system, the controller may be programmed to control any of the processes disclosed herein, such as supply of process gases, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow settings, liquid supply settings, position and motion settings, wafer loading and unloading from the tool, and wafer loading and unloading from other transport tools and / or load locks connected or interlocked with the particular system.

[0070] In a broad sense, a controller may be defined as electronic equipment having various integrated circuits, logic, memory, and / or software, etc., that receive instructions, issue instructions, control operations, enable cleaning operations, enable endpoint measurements, etc. Integrated circuits may include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and / or one or more microprocessors or microcontrollers that execute the program instructions (e.g., software). Program instructions may be instructions communicated to the controller in the form of various personalized settings (or program files) that define operational parameters for performing a particular process on or for a semiconductor wafer or for a system. The operational parameters may, in some embodiments, be part of a recipe defined by a process engineer to accomplish one or more processing steps during the manufacture of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or molds of a wafer.

[0071] The controller, in some implementations, may be part of or connected to a computer that is integrated into, connected to, or otherwise networked to the system, or a combination thereof. For example, the controller may be in the "cloud" or in all or part of a fab host computer system that enables remote access of wafer processing. The computer may enable remote access to the system to monitor the current progress of a manufacturing operation, examine the history of past manufacturing operations, examine trends or performance criteria from multiple manufacturing operations, change parameters of a current process, set up processing steps following a current process, or start a new process. In some examples, a remote computer (e.g., a server) can provide process recipes to the system over a network that may include a local network or the Internet. The remote computer may include a user interface that enables entry or programming of parameters and / or settings, which are then communicated from the remote computer to the system. In some examples, the controller receives instructions in the form of data that specify parameters for each processing step that is performed during one or more operations. It should be understood that the parameters may be specific to the type of process that is being performed and the type of tool that the controller is configured to interface with or control. Thus, as described above, the controller may be distributed, such as by being comprised of one or more separate controllers networked together working toward a common purpose, such as the processing and control described herein. An example of a distributed controller for such purposes would be one or more integrated circuits on the chamber that communicate with one or more remotely located integrated circuits (such as at the platform level or as part of a remote computer) coupled to control a process on the chamber.

[0072] Without being limited thereto, exemplary systems may include a plasma etch chamber or module, a deposition chamber or module, a spin rinse chamber or module, a metal plating chamber or module, a clean chamber or module, a bevel edge etch chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an atomic layer deposition (ALD) chamber or module, an atomic layer etch (ALE) chamber or module, an ion implantation chamber or module, a track chamber or module, and any other semiconductor processing system that may be associated with or used in the fabrication and / or manufacturing of semiconductor wafers.

[0073] As described above, depending on the processing step or steps being performed by the tool, the controller may communicate with one or more of other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, nearby tools, tools located throughout the factory, a main computer, other controllers, or tools used in material transport to transport containers of wafers into and out of tool locations and / or load ports within a semiconductor manufacturing factory.

Claims

1. 1. A direct drive circuit for providing RF power to a component of a substrate processing system, comprising: a direct drive circuit including a switch and configured to provide RF power to the component; monitoring load current and load voltage within the processing chamber; Calculating a load resistance based on the load current and the load voltage; comparing the load resistance to a first predetermined load resistance; adjusting at least one of an RF power limit and an RF current limit of the direct drive circuit based on the comparison; A switch protection module configured as a direct drive circuit.

2. 2. The direct drive circuit of claim 1, further comprising a voltage / current (VI) probe disposed in the processing chamber and configured to generate the load current and the load voltage.

3. 2. The direct drive circuit of claim 1, wherein the first predetermined load resistance is selected based on a resistance in at least one non-plasma condition.

4. 4. The direct drive circuit of claim 3, wherein the at least one non-plasma state corresponds to a plasma not igniting.

5. 4. The direct drive circuit of claim 3, wherein the at least one no-plasma condition corresponds to a plasma being extinguished after process gas flow to the processing chamber is stopped.

6. 2. The direct drive circuit of claim 1 , wherein in response to the load resistance being less than or equal to a first predetermined load resistance, the switch protection module reduces at least one of the RF power limit and the RF current limit of the direct drive circuit.

7. 7. The direct drive circuit of claim 6, wherein the switch protection module is configured to shut down the direct drive circuit in response to the load resistance being less than or equal to the first predetermined load resistance for greater than a predetermined period of time.

8. 2. The direct drive circuit of claim 1, wherein in response to the load resistance being less than or equal to the first predetermined load resistance, the switch protection module increases at least one of the RF power limit and the RF current limit of the direct drive circuit.

9. 9. The direct drive circuit of claim 8, wherein the switch protection module is configured to shut down the direct drive circuit in response to the load resistance being less than or equal to the first predetermined load resistance for greater than a predetermined period of time.

10. 2. The direct drive circuit of claim 1, the switch protection module selects at least one of a first RF power limit and a first RF current limit for the direct drive circuit in response to the load resistance being less than or equal to a first predetermined load resistance, and selects at least one of a second RF power limit and a second RF current limit for the direct drive circuit in response to the load resistance being greater than the first predetermined load resistance; at least one of the first RF power limit and the first RF current limit of the direct drive circuitry is less than at least one of the second RF power limit and the second RF current limit of the direct drive circuitry; and the switch protection module is configured to shut down the direct drive circuit in response to the load resistance being less than or equal to the first predetermined load resistance for a period of time greater than a predetermined period. Direct drive circuit.

11. 2. The direct drive circuit of claim 1, the switch protection module selects at least one of a first RF power limit and a first RF current limit for the direct drive circuit in response to the load resistance being less than or equal to a first predetermined load resistance, and selects at least one of a second RF power limit and a second RF current limit for the direct drive circuit in response to the load resistance being greater than the first predetermined load resistance; at least one of the first RF power limit and the first RF current limit of the direct drive circuitry is greater than at least one of the second RF power limit and the second RF current limit of the direct drive circuitry; and the switch protection module is configured to shut down the direct drive circuit in response to the load resistance being less than or equal to the first predetermined load resistance for a period of time greater than a predetermined period. Direct drive circuit.

12. 2. The direct drive circuit of claim 1, wherein the switch protection module is configured to shut down the direct drive circuit in response to the load resistance being less than or equal to the first predetermined load resistance for a period of time greater than a predetermined period.

13. 2. The direct drive circuit of claim 1, a clock generator for generating a clock signal at a first frequency; a gate driver for receiving the clock signal; a bridge circuit, The bridge circuit includes a first switch having a control terminal connected to the gate driver, a first terminal, and a second terminal; a second switch having a control terminal connected to the gate driver, a first terminal connected to the second terminal of the first switch and an output node, and a second terminal; a direct drive circuit.

14. 14. The direct drive circuit of claim 13, a current sensor that senses a current at the output node to generate a current signal; a voltage sensor that senses a voltage at the output node and generates a voltage signal; A controller, the controller includes a phase offset calculation module for calculating a phase offset between the voltage signal and the current signal; a clock adjusting module for adjusting the first frequency based on the phase offset; a direct drive circuit.

15. 15. The direct drive circuit of claim 14, wherein the component comprises a coil located outside the processing chamber.

16. 1. A method for providing RF power to a component of a substrate processing system, comprising: providing RF power to the component using a direct drive circuit including a switch; monitoring a load current and a load voltage in the processing chamber; calculating a load resistance based on the load current and the load voltage; performing a comparison of the load resistance to a first predetermined load resistance; adjusting at least one of an RF power limit and an RF current limit of the direct drive circuit based on the comparison; A method comprising:

17. 17. The method of claim 16, further comprising: disposing a voltage / current (VI) probe in the processing chamber; and generating the load current and the load voltage using the VI probe.

18. 17. The method of claim 16, wherein the first predetermined load resistance is selected based on a resistance in at least one non-plasma condition.

19. 20. The method of claim 18, wherein the at least one non-plasma state corresponds to a plasma not igniting.

20. 20. The method of claim 18, wherein the at least one non-plasma state corresponds to plasma being extinguished after process gas flow to the processing chamber is stopped.

21. 17. The method of claim 16, further comprising: reducing at least one of the RF power limit and the RF current limit of the direct drive circuit in response to the load resistance being less than or equal to a first predetermined load resistance.

22. 22. The method of claim 21, further comprising: in response to the load resistance being less than or equal to the first predetermined load resistance for a period of time greater than a predetermined period, shutting down the direct drive circuit.

23. 17. The method of claim 16, further comprising: increasing at least one of the RF power limit and the RF current limit of the direct drive circuit in response to the load resistance being less than or equal to a first predetermined load resistance.

24. 24. The method of claim 23, further comprising shutting down the direct drive circuit if the load resistance is less than the first predetermined load resistance for greater than a predetermined period of time.

25. 17. The method of claim 16 further comprising: selecting at least one of a first RF power limit and a first RF current limit of the direct drive circuit in response to the load resistance being less than or equal to a first predetermined load resistance, and selecting at least one of a second RF power limit and a second RF current limit of the direct drive circuit in response to the load resistance being greater than the first predetermined load resistance; at least one of the first RF power limit and the first RF current limit of the direct drive circuitry is less than at least one of the second RF power limit and the second RF current limit of the direct drive circuitry; shutting down the direct drive circuit in response to the load resistance being less than the first predetermined load resistance for a period of time greater than a predetermined period. method.

26. 17. The method of claim 16 further comprising: selecting at least one of a first RF power limit and a first RF current limit of the direct drive circuit in response to the load resistance being less than or equal to a first predetermined load resistance, and selecting at least one of a second RF power limit and a second RF current limit of the direct drive circuit in response to the load resistance being greater than the first predetermined load resistance; at least one of the first RF power limit and the first RF current limit of the direct drive circuitry is greater than at least one of the second RF power limit and the second RF current limit of the direct drive circuitry; shutting down the direct drive circuit in response to the load resistance being less than or equal to the first predetermined load resistance for a period greater than a predetermined period. method.

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