Systems and methods for achieving plasma stability in a drive circuit

Abstract

Systems and methods for achieving plasma stability are described. One system includes a controller, a frequency source, and a drive circuit having an input coupled to the frequency source. The drive circuit includes a gate driver, a bridge circuit coupled to the gate driver, and one or more direct current (DC) source systems coupled to the bridge circuit. The system includes a parametric element coupled to the bridge circuit and a plasma load coupled to the parametric element. The controller receives one or more parameters from one or more sensors coupled between the input of the drive circuit and the plasma load. The controller then modifies one or more variables of operation of the gate driver, the bridge circuit, the one or more DC source systems, or a combination thereof, based on the one or more parameters to achieve plasma stability.

Description

[Technical Field]

[0001] The present embodiments relate to systems and methods for achieving plasma stability in a drive circuit. [Background technology]

[0002] A plasma tool is used to process a wafer to form features on the wafer. The wafer is placed in a plasma chamber. The plasma tool includes a radio frequency (RF) generator, a match, and a plasma chamber. The RF generator is coupled to the match, and the match is coupled to the plasma chamber. The RF generator generates an RF signal that is supplied to the match. The match modifies the impedance of the RF signal by matching the impedance of a load coupled to the match with the impedance of a source coupled to the match.

[0003] An RF signal having a modified impedance is output from the match to the plasma chamber, and process gas is supplied to the plasma chamber to process the substrate. However, the substrate is not processed accurately. For example, the features etched in the substrate are not uniform.

[0004] The background discussion provided herein is intended to generally present the context for the present disclosure. Work by the presently named inventors within the scope of what is described in this Background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are not admitted, expressly or impliedly, as prior art against the present disclosure. Summary of the Invention

[0005] The embodiments of the present disclosure provide a system, an apparatus, a method, and a computer program for achieving plasma stability in a drive circuit. It should be understood that the embodiments can be embodied in various ways, such as a process on a computer-readable medium, an apparatus, a system, a device, or a method. Some embodiments are described below.

[0006] In one embodiment, a system for achieving plasma stability is described. The system includes a controller, a frequency source, and a drive circuit having an input coupled to the frequency source. The drive circuit includes a gate driver, a bridge circuit coupled to the gate driver, and one or more direct current (DC) source systems coupled to the bridge circuit. The system also includes a parametric element coupled to the bridge circuit and a plasma load coupled to the parametric element. The controller receives one or more parameters from one or more sensors coupled between the input of the drive circuit and the plasma load. The controller modifies one or more variables of operation of the gate driver, the bridge circuit, the one or more DC source systems, or a combination thereof, based on the one or more parameters to achieve plasma stability.

[0007] In one embodiment, a method for achieving plasma stability is described. The method includes receiving a digital pulse signal from a frequency source and outputting, by a drive circuit having an input coupled to the frequency source, a counter-synchronized signal based on the digital pulse signal. The drive circuit includes a gate driver, a bridge circuit coupled to the gate driver, and one or more DC power supply systems coupled to the bridge circuit. The method further includes outputting, by the bridge circuit, a square wave pulse waveform based on the counter-synchronized digital pulse signal. The method also includes receiving, by a controller, one or more parameters from one or more sensors coupled between the input of the drive circuit and the plasma load. The method includes modifying, by the controller, one or more variables of operation of the gate driver, the bridge circuit, the one or more DC power supply systems, or a combination thereof, based on the one or more parameters to achieve plasma stability.

[0008] In one embodiment, a non-transitory computer-readable medium including program instructions for achieving plasma stability is described. The program instructions are executed by one or more processors of a computer system to perform a plurality of operations. The operations include receiving a digital pulse signal from a frequency source. The operations also include outputting, by a drive circuit having an input coupled to a controller, a counter-synchronized signal based on the digital pulse signal. The drive circuit includes a gate driver, a bridge circuit coupled to the gate driver, and one or more DC source systems coupled to the bridge circuit. The operations further include outputting, by the bridge circuit, a square wave pulse waveform based on the counter-synchronized digital pulse signal. The operations include receiving, by the controller, one or more parameters from one or more sensors coupled between the input of the drive circuit and a plasma load. The operations include modifying, by the controller, one or more variables of operation of the gate driver, the bridge circuit, the one or more DC source systems, or a combination thereof, based on the one or more parameters to achieve plasma stability.

[0009] Some advantages of the systems and methods described herein for achieving plasma stability include implementing sensors within the drive circuit to monitor one or more parameters associated with the drive circuit. The one or more parameters are then used to modify one or more variables, such as the duty cycle of components of the drive circuit. The one or more variables are controlled to achieve plasma stability. By using the one or more sensors, fast control of the variables is achieved, and plasma stability is achieved.

[0010] Other aspects will become apparent from the following detailed description taken in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0011] The present embodiments will be best understood by referring to the following description taken in conjunction with the accompanying drawings.

[0012] [Figure 1] FIG. 1 is a diagram of one embodiment of the system illustrating the use of the sensor system.

[0013] [Figure 2] FIG. 2 is a diagram of one embodiment of a system illustrating the use of sensors in gate drivers and in half-bridge circuits.

[0014] [Figure 3] FIG. 3 is a diagram of one embodiment of a system illustrating the use of actuators to control the gates and transistors of the system of FIG.

[0015] [Figure 4A] FIG. 4A is a diagram of one embodiment of a system illustrating the use of direct control of one or more components of the system of FIG.

[0016] [Figure 4B] FIG. 4B is a diagram of one embodiment of a system illustrating the use of a look-up table (LUT) to control one or more parameters of one or more components of the system of FIG. 3 based on sensor measurements.

[0017] [Figure 4C] FIG. 4C is a diagram of one embodiment of a system illustrating the use of an artificial intelligence (AI) model to control one or more parameters of one or more components of the system of FIG. 3 based on sensor measurements.

[0018] [Figure 5A] FIG. 5A is an embodiment of a graph illustrating that plasma instability remains in the plasma chamber if one or more components of the system of FIG. 3 are not controlled based on one or more sensor signals received from one or more of the sensors of FIG. 2 .

[0019] [Figure 5B] FIG. 5B is an embodiment of a graph illustrating that plasma stability is achieved in a plasma chamber by controlling one or more components of the system of FIG. 3 based on one or more of the sensor signals.

[0020] [Figure 5C] FIG. 5C is an embodiment of a graph illustrating that plasma instability remains if one or more components of the system of FIG. 3 are not controlled based on one or more parameters indicated in one or more of the sensor signals of FIG. 1.

[0021] [Figure 5D] FIG. 5D is an embodiment of a graph illustrating that plasma stability is achieved when one or more components of the system of FIG. 3 are controlled based on one or more parameters indicated in one or more of the sensor signals of FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0022] The following embodiments describe systems and methods for achieving plasma stability in a drive circuit. It will be apparent that the present embodiments may be practiced without some or all of these specific details. In other instances, well-known operations have not been described in detail in order to avoid unnecessarily obscuring the present embodiments.

[0023] FIG. 1 is a diagram of one embodiment of a system 100 illustrating the use of a sensor system. The system 100 includes a drive circuit 102 and a plasma chamber 104. The drive circuit 102 includes a gate driver 106, a half-bridge circuit (HBC) 108, a controller 110, a direct current (DC) source system 111A, and another DC source system 111B. By way of example, the system 100 excludes a 50-ohm radio frequency (RF) cable and an impedance matching network (IMC). For example, the IMC matches the impedance of a load coupled to the output of the IMC to the impedance of a source coupled to the input of the IMC. For further example, the IMC includes a network of circuit components, such as inductors and capacitors. The plasma chamber 104 includes a plasma load element 112 and a plasma load component 114. The plasma chamber 104 may also be referred to herein as a plasma load.

[0024] Examples of the gate driver 106 and the half-bridge circuit 108 are shown below. An example of the plasma load element 112 includes one or more transformer-coupled plasma (TCP) coils and a capacitive electrode, such as an upper electrode or an electrostatic chuck (ESC). The ESC is an example of a substrate support. The upper electrode and the ESC are both located within the plasma chamber 104, with the upper electrode facing the ESC. An example of the plasma load component 114 includes the remaining portion of the plasma chamber 104. For example, if the plasma chamber 104 is a capacitively coupled plasma (CCP) chamber, the plasma load component 114 includes a sidewall of the plasma chamber 104 and a gap formed between the upper electrode and the ESC. For another example, if the plasma chamber 104 is an inductively coupled plasma (ICP) chamber, the plasma load component 114 includes a dielectric window located below the one or more TCP coils, a sidewall of the plasma chamber 104, and a gap formed between the dielectric window and the ESC.

[0025] Examples of controllers used herein include integrated controllers, microcontrollers, desktop computers, laptop computers, smartphones, and host computers. A controller, as used herein, includes a processor and a memory device. The processor is coupled to the memory device. As an example, a processor used herein is an application specific integrated circuit (ASIC), a central processing unit (CPU), a field programmable gate array (FPGA), a programmable logic device (PLD), or a microprocessor. Examples of memory devices used herein include read-only memory (ROM) and random access memory (RAM). For example, the memory device is a flash memory or a redundant array of independent disks (RAID). An example of a DC power supply system used herein is described below.

[0026] The system 100 further includes a parametric element 116. By way of example, the parametric element 116 is a capacitor or an inductor. For example, the parametric element 116 is controlled by the stability controller 120 via a driver and motor system (not shown), such as a driver and a motor, to reduce (e.g., eliminate) the reactance of the plasma load. For further example, if the plasma load is capacitive, an inductor is used as the parametric element 116, and if the plasma load is inductive, a capacitor is used as the parametric element 116. For example, if the plasma chamber 104 is a CCP chamber, the parametric element 116 is an inductor, and if the plasma chamber 104 is an inductively coupled plasma (ICP) chamber with one or more TCP coils, the parametric element 116 is a capacitor.

[0027] The controller 110 includes a frequency source 118 and a stability controller 120. Examples of the frequency source 118 include a digital pulse source, such as a clock source, that generates a digital pulse signal having a high frequency, such as a frequency of 400 kilohertz (kHz), or 2 megahertz (MHz), or 13.65 MHz, or 60 MHz.

[0028] The gate driver 106 includes a sensor system 122. The half-bridge circuit 108 also includes a sensor system 124, the DC source system 111A includes a sensor system 126A, and the DC source system 111B includes a sensor system 126B. Examples of the sensor systems include one or more sensors. For example, the sensor is a complex voltage sensor, a complex current sensor, a complex voltage-current sensor, a power sensor, an ammeter, a voltmeter, or a resistor. For example, a sensor used herein measures a parameter such as a complex voltage, a complex current, a complex impedance, a complex voltage-current, or a complex power. For another example, a sensor used herein is an analog sensor that is a magnetic sensor.

[0029] The frequency source 118 is coupled to the gate driver 106 via an RF connection 127. An example of an RF connection is one or more wires, such as one or more conductors. For example, an RF connection is a communication medium that facilitates the transfer of an RF signal. The gate driver 106 is coupled to the half-bridge circuit 108 via an RF connection 128. The half-bridge circuit 108 is also coupled to a DC source system 111A via an RF connection 130A and to a DC source system 111B via an RF connection 130B. The half-bridge circuit 108 is coupled to a parametric element 116 via an RF connection 132, and the parametric element 116 is coupled to a plasma load element 112 via an RF connection 140.

[0030] Sensor 142 is coupled to a point on RF connection 132, and sensor 144 is coupled to a point on RF connection 140. Also, sensor 146, such as an optical sensor, is coupled to plasma load component 114. For example, sensor 146 has a field of view directed toward a gap formed in plasma chamber 104.

[0031] Each of sensor system 122, sensor system 124, sensor system 126A, sensor system 126B, sensor 142, sensor 144, and sensor 146 is coupled to stability controller 120 via a respective transmission cable. An example of a transmission cable is a cable that enables data transfer in serial, parallel, or via the Universal Serial Bus (USB) protocol. Stability controller 120 is coupled to frequency source 118, gate driver 106, half-bridge circuit 108, DC source system 111A, and DC source system 111B. Stability controller 120 is also coupled to parametric element 116 via a driver and motor system.

[0032] The stability controller 120 provides an operating frequency, such as a high frequency, to the frequency source 118. Based on the operating frequency, the frequency source 118 generates a digital pulse signal 148 having a high frequency and transmits the digital pulse signal 148 to the gate driver 106. Upon receiving the digital pulse signal 148, the gate driver 106 outputs a plurality of digital pulse signals 150 and transmits the digital pulse signals 150 to the half-bridge circuit 108 via the RF connection 128.

[0033] The stability controller 120 also controls the DC source system 111A to output a first predetermined voltage and controls the DC source system 111A to output a second predetermined voltage, which, by way of example, is equal in magnitude to the first predetermined voltage but opposite in polarity to the first predetermined voltage.

[0034] When DC source system 111A is controlled to output a first predetermined voltage and DC source system 111B is controlled to output a second predetermined voltage, half-bridge circuit 108 outputs a rectangular pulse waveform 152 upon receiving digital pulse signal 150. As used herein, a rectangular pulse waveform is also referred to herein as a square wave pulse waveform. Square pulse waveform 152 is also a digital pulse signal. Parametric element 116 receives rectangular pulse waveform 152 and reduces (e.g., eliminates) harmonics of rectangular pulse waveform 152 to reduce the reactance of the plasma load. The harmonics of rectangular pulse waveform 152 are reduced to output an RF sine wave signal 154. RF sine wave signal 154 is transmitted from parametric element 116 to plasma load element 112. When RF sine wave signal 154 and one or more process gases are supplied to a gap in plasma chamber 104, a plasma is ignited or sustained in the gap to process a substrate, such as a semiconductor wafer, positioned on a substrate support.

[0035] While the substrate is being processed, sensor system 122 measures a parameter to generate a sensor signal SS1 and sends the sensor signal SS1 to the stability controller 120. Similarly, sensor system 124 measures a parameter to generate a sensor signal SS2 and sends the sensor signal SS2 to the stability controller 120, sensor system 126A measures a parameter to generate a sensor signal SS3 and sends the sensor signal SS3 to the stability controller 120, sensor system 126B measures a parameter to generate a sensor signal SS4 and sends the sensor signal SS4 to the stability controller 120, and sensor 142 measures a parameter of the rectangular pulse waveform 152 to generate a sensor signal SS5 and sends the sensor signal SS5 to the stability controller 120. In addition, the sensor 144 measures a parameter of the RF sine wave signal 154 to generate a sensor signal SS6 and transmits the sensor signal SS6 to the stability controller 120, and the sensor 146 measures a parameter based on light emitted from the plasma in the gap to generate a sensor signal SS7 and transmits the sensor signal SS7 to the stability controller 120.

[0036] A parameter measured by a sensor described herein may be the same as or different from a parameter measured by another sensor described herein. For example, sensor systems 122 and 124 both measure complex voltages and currents. As another example, sensor system 122 measures complex voltages and currents, and sensor system 124 measures complex voltages.

[0037] The stability controller 120 receives the sensor signals SS1-SS7 and controls one or more of the frequency source 118, the gate driver 106, the half-bridge circuit 108, the DC source system 111A, the DC source system 111B, and the parametric element 116 to achieve stability of the plasma formed in the gap in the plasma chamber 104. For example, the processor of the stability controller 120 determines that a set of parameter values ​​received from the sensor signal SS1 corresponds to a first plasma stability. In this example, the processor of the stability controller 120 determines that the variables of the gate driver 106 are controlled to modify the values ​​of the parameters to another set of parameter values ​​to achieve a predetermined plasma stability. The processor of the stability controller 120 controls the gate driver 106 to modify the values ​​of the set to another set of parameter values ​​to achieve a predetermined plasma stability. As used herein, one example of plasma stability is the uniformity of the process rate across the top surface of a substrate. Another example of plasma stability is the uniformity of the plasma impedance across the top surface of a substrate. Yet another example of plasma stability is the uniformity of a parameter over a predetermined period of time. In this example, uniformity is achieved when the plasma stability is within a predetermined range.

[0038] In one embodiment, system 100 excludes one or more of the sensors. For example, system 100 excludes sensor system 122, or sensor system 124, or sensor system 126A, or sensor system 126B, or sensor 142, or sensor 144, or sensor 146. For example, system 100 includes sensor system 122 but excludes sensor systems 124, 126A, and 126B. Also, in this example, system 100 excludes sensors 142, 144, and 146.

[0039] In one embodiment, system 100 excludes DC source system 111 B. Instead of being coupled to DC source system 111 B, half-bridge circuit 108 is coupled to ground potential.

[0040] 2 is a diagram of one embodiment of a system 200 illustrating the use of sensors 202 and 204 in the gate driver 106 and sensors 206 and 208 in the half-bridge circuit 108. The system 200 includes a stability controller 120, a frequency source 118, the gate driver 106, the half-bridge circuit 108, a parametric element 116, a plasma load element 112, and a plasma load component 114.

[0041] The gate driver 106 includes a gate 210 and another gate 212, which may be a NOT gate, such as an inverter. An example of the gate 210 is a buffer or pass-through gate. The gate driver 106 includes sensors 202 and 204.

[0042] Half-bridge circuit 108 includes a transistor 214 and another transistor 216. Transistors 214 and 216 are illustrated as N-channel metal-oxide-semiconductor field-effect transistors (MOSFETs), each having a gate (G), a drain (D), and a source (S).

[0043] DC source system 111A includes DC source 218 and sensor 220. DC source system 111B also includes DC source 222 and sensor 224. As used herein, one example of a DC source is a series of cells, such as an array of batteries.

[0044] The RF connection 127 includes junction J1, which is an example of an input. If the system 200 is a matchless plasma system, a 50 ohm RF cable is not used between junction J1 and the plasma chamber 104. The output of the frequency source 118 is coupled to the input of gate 210 and the input of gate 212 via junction J1. The output of gate 210 is coupled to the gate G of transistor 214 via line 211A. Line 211A is coupled to the sensor 202 of the sensor system 122 ( FIG. 1 ). Examples of a line as used herein include a conductor, wire, via, or other communication medium for transferring an RF signal. The sensor 202 is coupled to the output 231 of the gate driver 106. The sensor 202 is coupled between the gate 210 and the output 231. The output 231 is coupled to the gate G of transistor 214. If the sensor 202 is not present, the output 231 is the output of the gate 210.

[0045] Similarly, the output of gate 212 is coupled to gate G of transistor 216 via line 211B. Line 221B is coupled to sensor 204 of sensor system 122. An enable input (E), such as a control input, of gate 210 is coupled to output O1 of half-bridge circuit 108. The enable input of gate 212 is also coupled to point 226. Point 226 is on line 219B between the source of transistor 216 and sensor 224. Each of sensors 202 and 204 is coupled to stability controller 120. Sensor 204 is coupled to output 233 of gate driver 106. Sensor 204 is coupled between gate 212 and output 233. Output 233 is coupled to gate G of transistor 216. In the absence of sensor 204, output 233 is the output of gate 212.

[0046] The drain of transistor 214 is coupled to DC source system 111A via line 219A. Line 219A is coupled to sensor 220. The source of transistor 214 is coupled to output O1 via line 221A. Line 221A is coupled to sensor 206. Sensor 206 is coupled between transistor 214 and output O1. Output O1 is coupled to the drain of transistor 216 via line 221B. Line 221B is coupled to sensor 208. Sensor 208 is coupled between transistor 216 and output O1. The source of transistor 216 is coupled to DC source system 111B via line 219B. Line 219B is coupled to sensor 224. Sensors 206, 208, 220, and 224 are coupled to stability controller 120.

[0047] The output O1 is the output of the driver circuit 102 (FIG. 1) and the half-bridge circuit 108. The output O1 is coupled to the parametric element 116 via an RF connection 132. Note that a diode D1 is coupled between the drain and source of the transistor 214 to protect the transistor 214 from overvoltage, and another diode D2 is coupled between the drain and source of the transistor 216 to protect the transistor 216 from overvoltage.

[0048] Digital pulse signal 148 is transmitted from stability controller 120 to junction J1. Power from digital pulse signal 148 is split at junction J1 into a first power, such as a first power signal, and a second power, such as a second power signal. The first power of digital pulse signal 148 is provided from junction J1 to gate 210, and the second power of digital pulse signal 148 is provided from junction J1 to gate 212. Gate 210 receives the first power at an input, passes the first power, and outputs digital pulse signal 230 at an output. Gate 212 inverts the second power of digital pulse signal 148 and outputs digital pulse signal 232 at an output. Digital pulse signals 230 and 232 are examples of digital pulse signal 150 (FIG. 1).

[0049] Digital pulse signal 232 is counter-synchronized, e.g., inverted, with respect to digital pulse signal 230. For example, when digital pulse signal 230 transitions from a first high level power to a second low level power, digital pulse signal 232 transitions from a third low level power to a fourth high level power. In this example, the first high level is greater than the second low level, and the third low level is less than the fourth high level. Also in this example, when digital pulse signal 230 transitions from the second low level power to the first high level power, digital pulse signal 232 transitions from a fourth high level power to a third low level power. Digital pulse signal 230 is transmitted from the output of gate 210 via line 211A to the gate of transistor 214, and digital pulse signal 232 is transmitted from the output of gate 212 via line 211B to the gate of transistor 216.

[0050] Stability controller 110 controls DC source system 111A to output a voltage to the drain of transistor 214 and controls DC source system 111B to output a voltage to the source of transistor 216. The anti-synchronization of digital pulse signals 230 and 232 occurs to operate transistors 214 and 216 in push-pull mode. For example, when digital pulse signal 230 has a first high level of power, transistor 214 is on, the voltage of DC source 218 is input to transistor 214, and transistor 214 outputs a voltage to output O1 based on the voltage of DC source 218. For example, current signal 234 flows from DC source 218 to the drain of transistor 214 via line 219A, and the source of transistor 214 outputs current signal 223 based on current signal 224 to output O1. In this example, current signal 234 is generated based on the voltage of DC source 218. In this example, applying the voltage of DC source 218 to turned-on transistor 214 is an example of a push mode of transistor 214. Further, in this example, when digital pulse signal 230 has a first high level of power, digital pulse signal 232 has a third low level of power. In this example, when digital pulse signal 232 has a third low level of power, transistor 216 is off, and the voltage of DC source 222 is not applied to output O1 through transistor 216.

[0051] Continuing with this example, when digital pulse signal 232 has a fourth high level of power, transistor 216 is on, the voltage of DC source 222 is input to transistor 216, and transistor 216 outputs a voltage to output O1. For example, when transistor 216 is on, current signal 225 flows from output O1 to the drain of transistor 216, and the source of transistor 216 outputs current signal 236 based on current signal 225 to DC source 222 via line 219B. In this example, current signal 236 is output based on the voltage of DC source 222. In this example, applying the voltage of DC source 222 to turned-on transistor 216 is an example of the pull mode of transistor 216. Further, in this example, when digital pulse signal 232 has a fourth high level of power, digital pulse signal 230 has a second low level of power. In this example, when digital pulse signal 230 has a second, low level of power, transistor 214 is off and the voltage of DC source 218 is not applied to output O1 through transistor 214. By operating transistors 214 and 216 in push-pull mode, rectangular pulse waveform 152 is generated at output O1 and transmitted from output O1 to parametric element 116.

[0052] A digital pulse signal 230 is supplied from the output of gate 210 via sensor 202 and output 231 of gate driver 106 to gate G of transistor 214. Similarly, a digital pulse signal 232 is supplied from the output of gate 212 via sensor 204 and output 233 of gate driver 106 to gate G of transistor 216.

[0053] Sensor 220 measures a parameter of current signal 234 and outputs a sensor signal SS3, and sensor 224 measures a parameter of current signal 236 and outputs a sensor signal SS4. Sensor signal SS3 is provided from sensor 220 to stability controller 120, and sensor signal SS4 is provided from sensor 224 to stability controller 120.

[0054] The processor of the stability controller 110 receives the sensor signals SS3 and SS4 and controls one or more of the DC source systems 111A and 111B to achieve plasma stability. For example, the processor of the stability controller 110 receives the sensor signal SS3 and determines to modify (e.g., increase or decrease) a parameter, such as the amount of voltage output from the DC source 218, to achieve a predetermined plasma stability. Upon making such a determination, the processor of the stability controller 110 controls the DC source 218 to modify the amount of voltage output from the DC source 218 via the transistor 214 to the output O1. As another example, the processor of the stability controller 110 receives the sensor signal SS4 and determines to modify (e.g., increase or decrease) the amount of voltage output from the DC source 222 to achieve a predetermined plasma stability. Upon making such a determination, the processor of the stability controller 110 controls the DC source 222 to modify the amount of voltage output from the DC source 222 via the transistor 216 to the output O1.

[0055] Furthermore, the sensor 202 outputs a sensor signal SS1A by measuring a parameter of the digital pulse signal 230 and provides the sensor signal SS1A to the processor of the stability controller 120. The processor of the stability controller 120 controls the gate 210 based on the sensor signal SS1A to achieve plasma stability. For example, the processor of the stability controller 120 determines to modify (e.g., increase or decrease) the duty cycle of the digital pulse signal 230 based on the parameter received in the sensor signal SS1A. The processor controls the gate 210 to modify the duty cycle of the digital pulse signal 230. The sensor signal SS1A is one of the sensor signals SS1 (FIG. 1).

[0056] Similarly, the sensor 204 outputs a sensor signal SS1B by measuring a parameter of the digital pulse signal 232 and sends the sensor signal SS1B to the processor of the stability controller 120. The processor of the stability controller 120 controls the gate 212 based on the sensor signal SS1B to achieve plasma stability. For example, the processor of the stability controller 120 determines to modify (e.g., increase or decrease) the duty cycle of the digital pulse signal 232 based on the parameter received in the sensor signal SS1B. The processor controls the gate 212 to modify the duty cycle of the digital pulse signal 232. The sensor signal SS1B is another signal of the sensor signal SS1.

[0057] Furthermore, the sensor 206 measures a parameter of the current signal 223 to generate a sensor signal SS2A and sends the sensor signal SS2A to the processor of the stability controller 120. The processor of the stability controller 120 controls the transistor 214 based on the sensor signal SS2A to achieve plasma stability. For example, the processor of the sensor signal SS2A determines to modify (e.g., increase or decrease) the duty cycle of the current signal 223 based on the parameter received in the sensor signal SS2A. The processor controls the on / off of the transistor 214 to modify the duty cycle of the current signal 223. The sensor signal SS2A is one of the sensor signals SS2 (FIG. 1).

[0058] The sensor 208 also measures a parameter of the current signal 225 to generate a sensor signal SS2B and sends the sensor signal SS2B to the processor of the stability controller 120. The processor of the stability controller 120 controls the transistor 216 based on the sensor signal SS2B to achieve plasma stability. For example, the processor of the sensor signal SS2B determines to modify (e.g., increase or decrease) the duty cycle of the current signal 225 based on the parameter received in the sensor signal SS2B. The processor controls the on / off of the transistor 216 to modify the duty cycle of the current signal 225. The sensor signal SS2B is another signal of the sensor signal SS2.

[0059] In one embodiment, the N-channel MOSFET is replaced by another type of transistor, such as a bipolar junction transistor (BJT).

[0060] In one embodiment, the system 200 excludes diodes D1 and D2.

[0061] In one embodiment, instead of being coupled to a DC source 222, point 226 is coupled to ground potential.

[0062] 3 is a diagram of one embodiment of a system 300 illustrating the use of actuators to control gates 210 and 210 and transistors 214 and 216. System 300 includes frequency source 118, stability controller 120, gate driver 106, DC source system 111A, DC source system 111B, and half-bridge circuit 108.

[0063] The frequency source 118 includes a clock source 302 and a frequency adjuster 304. An example of the clock source 302 is a clock oscillator that generates a digital pulse signal, such as a clock signal, at a high frequency. An example of the frequency adjuster 304 is one or more flip-flops. The gate driver 106 also includes a gate actuator 308 and another gate actuator 310. As used herein, an example of a gate actuator is a switch, and as used herein, an example of a switch is a transistor.

[0064] Half-bridge circuit 108 includes a transistor actuator 312 and another transistor actuator 314. An example of a transistor actuator as described herein is a switch, such as a transistor. Additionally, DC source system 111A includes DC source 316 and DC source actuator 318, and DC source system 111B includes DC source 320 and DC source actuator 322. An example of a DC source as used herein includes a series of cells, such as a series of batteries. An example of a DC source actuator as described herein is a series of switches.

[0065] Each switch of the DC source actuator is coupled to a corresponding cell, e.g., a respective cell, of the DC source. For example, a first switch of the DC source actuator 318 is coupled to a first cell of the DC source 316, and a second switch of the DC source actuator 318 is coupled to a second cell of the DC source 316. As another example, a first switch of the DC source actuator 322 is coupled to a first cell of the DC source 320, and a second switch of the DC source actuator 322 is coupled to a second cell of the DC source 320.

[0066] Stability controller 120 is coupled to frequency adjuster 304, gate actuators 308 and 310, DC source actuators 318 and 322, and transistor actuator 312. Clock source 302 is also coupled to frequency adjuster 304, which is coupled to gate actuator 308 via line 324, junction J1, and line 326. Frequency adjuster 304 is further coupled to gate actuator 310 via line 324, junction J1, and line 328.

[0067] Gate actuator 308 is coupled between frequency source 118 and gate 210, and gate actuator 310 is coupled between frequency source 118 and gate 212. Gate actuator 308 is coupled to the input of gate 210 via line 330, and gate actuator 212 is coupled to the input of gate 212 via line 332. The output of gate 210 is coupled to transistor actuator 312 via line 211A, and the output of gate 212 is coupled to transistor actuator 314 via line 211B. Transistor actuator 312 is coupled between gate 210 and transistor 214, and transistor actuator 314 is coupled between gate 212 and transistor 216. Transistor actuator 312 is coupled to gate G of transistor 214 via line 334, and transistor actuator 314 is coupled to gate G of transistor 216 via line 336. DC source actuator 322 is coupled to the source S of transistor 216 via line 219B, and DC source actuator 318 is coupled to the drain D of transistor 214 via line 219A.

[0068] Based on sensor signal SS3 (FIG. 2) received from sensor 220, or sensor signal SS4 (FIG. 2) received from sensor 224, or sensor signal SS2A (FIG. 2) received from sensor 206, or sensor signal SS5 received from sensor 142 (FIG. 2), or sensor signal SS6 received from sensor 144 (FIG. 2), or sensor signal SS7 received from sensor 146 (FIG. 2), or a combination thereof, stability controller 120 controls DC source actuator 318 to modify the voltage of DC source 316 from which current signal 234 (FIG. 2) is output. For example, upon determining that the parameter received in sensor signal SS3 is greater than a predetermined threshold, or that the parameter received in sensor signal SS4 (FIG. 2) is less than a preset threshold, or a combination thereof, stability controller 120 controls DC source actuator 318 to modify (e.g., reduce) the amount of voltage output from DC source 316 to a predetermined voltage. On the other hand, if the stability controller 120 determines that the parameter received in the sensor signal SS3 is less than the predetermined threshold, or that the parameter received in the sensor signal SS4 is greater than the preset threshold, or a combination thereof, the stability controller 120 controls the DC source actuator 318 to modify (e.g., increase) the amount of voltage output from the DC source 316 to the predetermined voltage. For example, the stability controller 120 sends a predetermined number of control signals to the DC source actuator 318 to couple a predetermined number of switches of the DC source actuator 318 to the same number of cells of the DC source 316. For a further example, a first cell is coupled to a first switch, and a second cell is coupled to a second switch. In a further example, a third cell of the DC source 316 is not coupled to a third switch of the DC source actuator 318. In a further example, two control signals are sent to the first and second switches, and no control signal is sent to the third switch. When the first to third cells are coupled to the first to third switches, the voltage output from DC source 316 increases compared to when the first and second cells are coupled to the first and second switches.Furthermore, when the first and second cells are coupled to the first and second switches, the voltage output from DC source 316 is lower than when the first to third cells are coupled to the first to third switches.

[0069] Similarly, based on sensor signal SS3 (FIG. 2) received from sensor 220, or sensor signal SS4 (FIG. 2) received from sensor 224, or sensor signal SS2B (FIG. 2) received from sensor 208, or sensor signal SS5 received from sensor 142 (FIG. 2), or sensor signal SS6 received from sensor 144 (FIG. 2), or sensor signal SS7 received from sensor 146 (FIG. 2), or a combination thereof, stability controller 120 controls DC source actuator 322 to modify the voltage of DC source 320 from which current signal 236 (FIG. 2) is output. For example, upon determining that the parameter received in sensor signal SS3 is less than a predetermined threshold, or that the parameter received in sensor signal SS4 is greater than a preset threshold, or a combination thereof, stability controller 120 controls DC source actuator 322 to modify (e.g., reduce) the amount of voltage output from DC source 320 to a predetermined voltage. On the other hand, if the stability controller 120 determines that the parameter received in sensor signal SS3 is greater than the predetermined threshold or that the parameter received in sensor signal SS4 is less than the preset threshold, the stability controller 120 controls the DC source actuator 322 to modify (e.g., increase) the amount of voltage output from the DC source 320 to a predetermined voltage. For example, similar to that described above with reference to the DC source actuator 318 and the DC source 316, the stability controller 120 sends a predetermined number of control signals to the DC source actuator 322 to couple a predetermined number of switches of the DC source actuator 322 to a corresponding number of cells of the DC source 320.

[0070] Modifying the voltage of DC source 316, or DC source 320, or a combination thereof, modifies the voltage magnitude of rectangular pulse waveform 152 at output O1 (FIG. 2). For example, increasing the voltage output from DC source 316 or decreasing the voltage output from DC source 320 increases the voltage magnitude of rectangular pulse waveform 152. As another example, decreasing the voltage output from DC source 316 or increasing the voltage output from DC source 320 decreases the voltage magnitude of rectangular pulse waveform 152.

[0071] Stability controller 120 also receives sensor signal SS3 (FIG. 2) from sensor 220, sensor signal SS4 (FIG. 2) from sensor 224, sensor signal SS2A (FIG. 2) from sensor 206, sensor signal SS5 (FIG. 2) from sensor 142, sensor signal SS6 (FIG. 2) from sensor 144, and sensor signal SS7 (FIG. 2) from sensor 146, and controls gate actuator 308 based on a parameter of sensor signal SS3, or a parameter of sensor signal SS4, or a parameter of sensor signal SS2A, or a parameter of sensor signal SS5, or a parameter of sensor signal SS6, or a parameter of sensor signal SS7, or a combination thereof, to control the amount of time that power is supplied from DC source 222 to output O1 via transistor 214. For example, upon determining that the parameters of sensor signal SS3 indicate that power provided from DC source 316 to output O1 is for an amount of time greater than a predetermined percentage, such as 50% of a predetermined time period, stability controller 120 controls gate actuator 308 to modify (e.g., reduce) the duty cycle of digital pulse signal 230 ( FIG. 2 ). By way of example, in response to determining that the parameters of sensor signal SS3 indicate that power provided from DC source 316 to output O1 is for an amount of time greater than a predetermined percentage, stability controller 120 sends a control signal to gate actuator 308 to open a switch of gate actuator 308 and decouple frequency source 118 from gate 210. When frequency source 118 is decoupled from gate 210, the duty cycle of digital pulse signal 230 is reduced to the predetermined duty cycle. When the duty cycle of digital pulse signal 230 decreases to a predetermined duty cycle, transistor 214 turns off and the power delivered from DC source 316 to output O1 through transistor 214 decreases to achieve a predetermined percentage for a predetermined time period.

[0072] It should be noted that the duty cycle of digital pulse signal 230 defines the duty cycle of operation of gate 210. For example, the duty cycle of digital pulse signal 230 is the amount of time that digital pulse signal 230 is output from gate 210.

[0073] The stability controller 120 determines that the duty cycle of the digital pulse signal 230 has been reduced to a predetermined duty cycle based on a parameter indicated in the sensor signal SS1A (FIG. 2) received from the sensor 202. For example, the stability controller 120 receives the parameter of the sensor signal SS1A and determines the duty cycle of the parameter. The stability controller 120 compares the duty cycle to the predetermined duty cycle to determine whether the duty cycle is equal to the predetermined duty cycle. The stability controller 120 controls the gate actuator 308 to modify the duty cycle of the digital pulse signal 230 until the duty cycle of the parameter indicated by the sensor signal SS1A is equal to the predetermined duty cycle.

[0074] Similarly, stability controller 120 receives sensor signal SS3 (FIG. 2) from sensor 220, sensor signal SS4 (FIG. 2) from sensor 224, sensor signal SS2B (FIG. 2) from sensor 208, sensor signal SS5 (FIG. 2) from sensor 142, sensor signal SS6 (FIG. 2) from sensor 144, and sensor signal SS7 (FIG. 2) from sensor 146, and controls gate actuator 310 based on a parameter of sensor signal SS3, or a parameter of sensor signal SS4, or a parameter of sensor signal SS2B, or a parameter of sensor signal SS5, or a parameter of sensor signal SS6, or a parameter of sensor signal SS7, or a combination thereof, to control the amount of time that power is transferred from output O1 through transistor 216 to DC source 320. As an example, upon determining that a parameter of sensor signal SS4 indicates that power transferred from output O1 to DC source 320 is for an amount of time less than a preset percentage, such as 50% of the preset time period, stability controller 120 controls gate actuator 310 to modify (e.g., increase) the duty cycle of digital pulse signal 232 ( FIG. 2 ). For example, in response to determining that a parameter of sensor signal SS4 indicates that power transferred from output O1 to DC source 320 is for an amount of time less than a preset percentage, stability controller 120 sends a control signal to gate actuator 310 to close a switch in gate actuator 310 and couple frequency source 118 to gate 212. When frequency source 118 is coupled to gate 212, the duty cycle of digital pulse signal 232 increases to the preset duty cycle. When the duty cycle of digital pulse signal 232 increases to the preset duty cycle and gate 212 is coupled to transistor 216 through transistor actuator 314, transistor 216 turns on and the power transferred from output O1 through transistor 216 to DC source 320 increases to achieve the preset percentage for the preset time period.

[0075] It should be noted that the duty cycle of digital pulse signal 232 defines the duty cycle of operation of gate 212. For example, the duty cycle of digital pulse signal 232 is the amount of time that digital pulse signal 232 is output from gate 212.

[0076] Similar to how the stability controller 120 verifies that the duty cycle of the digital pulse signal 230 increases to a predetermined duty cycle, the stability controller 120 verifies that the duty cycle of the digital pulse signal 232 increases to a preset duty cycle based on a parameter indicated in the sensor signal SS1B (FIG. 2) received from the sensor 204. For example, the stability controller 120 receives the parameter of the sensor signal SS1B and determines the duty cycle of the parameter. The stability controller 120 compares the duty cycle with the preset duty cycle to determine whether the duty cycle is equal to the preset duty cycle. The stability controller 120 controls the gate actuator 310 to modify the duty cycle of the digital pulse signal 232 until the duty cycle of the parameter indicated by the sensor signal SS1B equals the preset duty cycle.

[0077] Also, as an alternative to controlling gate actuator 308, transistor actuator 312 is controlled by stability controller 120 based on sensor signal SS3 (FIG. 2) received from sensor 220, or sensor signal SS2A (FIG. 2) received from sensor 206, or sensor signal SS4 received from sensor 224, or sensor signal SS2A (FIG. 2) received from sensor 206, or sensor signal SS2B received from sensor 208, or sensor signal SS5, or sensor signal SS6, or sensor signal SS7, or a combination thereof. For example, stability controller 120 receives sensor signal SS3 from sensor 220 and sensor signal SS2A from sensor 206, and controls transistor actuator 312 based on a parameter of sensor signal SS3, or a parameter of sensor signal SS2A, or a combination thereof, to control the amount of time power is provided from DC source 222 to output O1 through transistor 214. By way of example, upon determining that the parameters of sensor signal SS3 indicate that power provided from DC source 316 to output O1 is for a greater amount of time than a predetermined percentage of a predetermined time period and power output from output O1 to DC source 320 is for a lesser amount of time than a preset percentage, stability controller 120 controls transistor actuator 312 to modify (e.g., reduce) the duty cycle of current signal 223 ( FIG. 2 ). In this example, in response to determining that the parameters of sensor signal SS3 indicate that power provided from DC source 316 to output O1 is for a greater amount of time than a predetermined percentage, stability controller 120 sends a control signal to transistor actuator 312 to open its switch and decouple gate 210 from transistor 214. With gate 210 decoupled from transistor 214, the duty cycle of current signal 223 is reduced to the predetermined duty cycle.When the duty cycle of current signal 223 decreases to a predetermined duty cycle and frequency source 118 is coupled to gate 210 via gate actuator 308, transistor 214 turns off and the power delivered from DC source 316 to output O1 via transistor 214 decreases to achieve a predetermined percentage for a predetermined time period and a preset percentage.

[0078] As another example, upon determining that the parameters of sensor signal SS3 indicate that power provided from DC source 316 to output O1 is for an amount of time less than a predetermined percentage of the predetermined time period and power output from output O1 to DC source 320 is for an amount of time greater than the preset percentage, stability controller 120 controls transistor actuator 312 to modify (e.g., increase) the duty cycle of current signal 223 ( FIG. 2 ). In this example, in response to determining that the parameters of sensor signal SS3 indicate that power provided from DC source 316 to output O1 is for an amount of time less than a predetermined percentage, stability controller 120 sends a control signal to transistor actuator 312 to close the switch of transistor actuator 312 and couple gate 210 to transistor 214. With gate 210 coupled to transistor 214, the duty cycle of current signal 223 increases to the predetermined duty cycle. When the duty cycle of current signal 223 increases to a predetermined duty cycle and frequency source 118 is coupled to gate 210 via gate actuator 308, transistor 214 turns on and the power delivered from DC source 316 to output O1 via transistor 214 increases to achieve a predetermined percentage for a predetermined time period and a preset percentage.

[0079] A decrease in the duty cycle of the current signal 223 decreases the duty cycle of the rectangular pulse waveform 152 at the output O1, and an increase in the duty cycle of the current signal 223 increases the duty cycle of the rectangular pulse waveform 152 at the output O1.

[0080] Additionally, as an alternative to controlling gate actuator 310, transistor actuator 314 is controlled by stability controller 120 based on sensor signal SS3 received from sensor 220, or sensor signal SS2A received from sensor 206, or sensor signal SS4 received from sensor 224 (FIG. 2), or sensor signal SS2B from sensor 208 (FIG. 2), or sensor signal SS5, or sensor signal SS6, or sensor signal SS7, or a combination thereof. As an example, upon determining that a parameter of sensor signal SS4 or a parameter of sensor signal SS2B indicates that power transferred from output O1 to DC source 320 is for an amount of time less than a preset percentage of a preset time period, stability controller 120 controls transistor actuator 314 to modify (e.g., increase) the duty cycle of current signal 225 (FIG. 2). For example, in response to determining that a parameter of sensor signal SS3 indicates that power provided from DC source 316 to output O1 is for an amount of time greater than a predetermined percentage of a predetermined time period and determining that a parameter of sensor signal SS2B indicates that power transferred from output O1 to DC source 320 is for an amount of time less than a preset percentage, stability controller 120 sends a control signal to transistor actuator 314 to close a switch of transistor actuator 314 and couple gate 212 to transistor 216. When gate 212 is coupled to transistor 216, the duty cycle of current signal 225 increases to the preset duty cycle. When the duty cycle of current signal 225 increases to the preset duty cycle and frequency source 118 is coupled to gate 212 via gate actuator 310, transistor 216 turns on and the power transferred from output O1 to DC source 320 through transistor 216 increases to achieve the preset percentage of the preset time period and the predetermined percentage of the predetermined time period.

[0081] As another example, in response to determining that a parameter of sensor signal SS3 indicates that power provided from DC source 316 to output O1 is for an amount of time less than a predetermined percentage of a predetermined time period and determining that a parameter of sensor signal SS2B indicates that power transferred from output O1 to DC source 320 is for an amount of time greater than a preset percentage, stability controller 120 sends a control signal to transistor actuator 314 to open the switch of transistor actuator 314 and decouple gate 212 from transistor 216. When gate 212 is decoupled from transistor 216, the duty cycle of current signal 225 decreases to the preset duty cycle. When the duty cycle of current signal 225 decreases to the preset duty cycle and frequency source 118 is coupled to gate 212 via gate actuator 310, transistor 216 turns on and the power transferred from output O1 to DC source 320 through transistor 216 decreases to achieve the preset percentage of the preset time period and the predetermined percentage of the predetermined time period.

[0082] As the duty cycle of the current signal 225 increases, the duty cycle of the rectangular pulse waveform 152 at the output O1 decreases, and as the duty cycle of the current signal 225 decreases, the duty cycle of the rectangular pulse waveform 152 at the output O1 increases.

[0083] The stability controller 120 also controls the frequency adjuster 304 based on one or more parameters received from one or more of the sensors 220, 206, 208, 224, 142 (FIG. 2), 144 (FIG. 2), and 146 (FIG. 2). For example, upon receiving a parameter from the sensor 142, the stability controller 120 determines the frequency of the parameter and determines whether the frequency is within a predetermined threshold from a predetermined frequency. If the stability controller 120 determines that the frequency is not within the predetermined threshold, it sends a control signal to the frequency adjuster 304 to adjust the frequency of the digital pulse signal 148 until the predetermined threshold is achieved. On the other hand, if the stability controller 120 determines that the frequency is within the predetermined threshold, it does not send a control signal.

[0084] Note that the duty cycle of current signal 223 defines the duty cycle of operation of transistor 214. For example, the duty cycle of current signal 223 is the amount of time that current signal 223 is output from transistor 214. Note further that the duty cycle of current signal 225 defines the duty cycle of operation of transistor 216. For example, the duty cycle of current signal 225 is the amount of time that current signal 225 is input to transistor 216.

[0085] In one embodiment, system 300 includes either gate actuators 308 and 310 or transistor actuators 312 and 314 .

[0086] In one embodiment, ground potential is used instead of DC power supply system 111B, for example, the source S of transistor 216 is coupled to ground potential.

[0087] In one embodiment, the voltage of DC source 316 is modified based on one or more parameters indicated by one or more of sensor signals SS1-SS7 (FIG. 1).

[0088] In one embodiment, the voltage of DC source 320 is modified based on one or more parameters indicated by one or more of sensor signals SS1-SS7.

[0089] In one embodiment, the gate actuator 308 is controlled based on one or more parameters indicated by one or more of the sensor signals SS1-SS7 (FIG. 1).

[0090] In one embodiment, the gate actuator 310 is controlled based on one or more parameters indicated by one or more of the sensor signals SS1-SS7 (FIG. 1).

[0091] In one embodiment, transistor actuator 312 is controlled based on one or more parameters indicated by one or more of sensor signals SS1-SS7 (FIG. 1).

[0092] In one embodiment, transistor actuator 314 is controlled based on one or more parameters indicated by one or more of sensor signals SS1-SS7 (FIG. 1).

[0093] FIG. 4A is a diagram of one embodiment of a system 400 illustrating the use of direct control 402 of one or more components of the system 300 (FIG. 3). Examples of the one or more components of the system 300 include one or more of the frequency adjuster 304 (FIG. 3), the gate actuator 308 (FIG. 3), the gate actuator 310 (FIG. 3), the transistor actuator 312 (FIG. 3), the transistor actuator 314 (FIG. 3), the DC source actuator 318 (FIG. 3), the DC source actuator 322 (FIG. 3), and the parametric element 416 (FIG. 2). In direct control 402, the stability controller 120 receives one or more parameters from one or more sensor measurements 404, such as one or more parameters indicated by one or more of the sensor signals SS1-SS7 (FIG. 1), determines one or more variables from the one or more parameters, and controls one or more variables of one or more of the components of the system 300 based on the one or more parameters. For example, the stability controller 120 receives a voltage from the sensor signal SS5 and determines the duty cycle of the voltage. The stability controller 120 determines whether the duty cycle matches the predetermined duty cycle. If the stability controller 120 determines that the duty cycle does not match the predetermined duty cycle, the stability controller 120 controls one or more of the actuators 308, 312, 310, and 314 ( FIG. 3 ) to modify the duty cycle of the rectangular pulse waveform 152 until the predetermined duty cycle is achieved. However, in response to determining that the duty cycle does not match the predetermined duty cycle, the stability controller 120 does not control one or more of the actuators 308, 312, 310, and 314. Examples of variables used herein include frequency, power, duty cycle, voltage, and phase. Note that controlling one or more variables of one or more components of the system 300 achieves control 406 of one or more parameters of one or more components of the system 300.

[0094] 4B is a diagram of an embodiment of a system 410 illustrating the use of a look-up table (LUT) 412 for control 406 of one or more parameters of one or more components of the system 300 based on sensor measurements 404. As an example, the LUT 412 is a database. The LUT 412 is stored in a memory device of the stability controller 120. The LUT 412 includes relationships, e.g., one-to-one correspondences or unique relationships, between parameters, variables, and factors for each of the one or more components of the system 300. For example, the LUT 412 includes a first row including a first relationship between a first amount of power at the output O1 (FIG. 3) and a first etch rate achieved at the first amount of power. The LUT 412 includes a second row including a second relationship between a second amount of power at the output O1, a second etch rate achieved at the second amount of power, the duty cycle of the digital pulse signal 230 (FIG. 2), and the duty cycle of the digital pulse signal 232 (FIG. 2). The duty cycle of the digital pulse signal 230 is adjusted to achieve the second amount of power and the second etch rate. Examples of factors include process rates, such as etch rates, deposition rates, sputtering rates, and other rates at which substrates are processed. The factors determine the magnitude of the stability of the plasma in the plasma chamber 104 (FIG. 1).

[0095] The stability controller 120 receives the sensor measurement 404 and accesses the lookup table 412 to determine whether the sensor measurement 404 corresponds to a predetermined process rate, such as a second etch rate, and determines to control one or more components of the system 300 to achieve the predetermined process rate. For example, the stability controller 120 receives the sensor signal SS2A (FIG. 2) from the sensor 206 (FIG. 2) and identifies a primary power amount indicated by the sensor signal SS2A. In this example, the stability controller 120 receives the sensor signal SS2B (FIG. 2) from the sensor 208 (FIG. 2) and identifies a secondary power amount indicated by the sensor signal SS2B. The stability controller 120 accesses the LUT 412 to determine that a combination, such as the sum of the primary and secondary power amounts during a cycle of the clock signal, is not the second power amount corresponding to the second etch rate. Stability controller 120 controls gate actuator 308 (FIG. 3) to achieve the duty cycle of digital pulse signal 230 and controls gate actuator 310 (FIG. 3) to achieve the duty cycle of digital pulse signal 232. When the duty cycles of digital pulse signals 230 and 232 are achieved, a second amount of power is generated at output O1 to achieve a second etch rate.

[0096] 4C is a diagram of an embodiment of a system 420 illustrating the use of an artificial intelligence (AI) model 422 for control 406 of one or more parameters of one or more components of the system 300 based on sensor measurements 404. As an example, the AI ​​model 422 is implemented by a processor of the stability controller 120, or a processor, ASIC, PLD, integrated circuit, or controller separate from the processor of the stability controller 120. By way of example, a separate processor or ASIC implementing the AI ​​model 422, or a PLD implementing the AI ​​model 422, or an integrated circuit implementing the AI ​​model 422, or a controller implementing the AI ​​model 422 is coupled to the processor of the stability controller 120.

[0097] The stability controller 120 receives the first set of one or more parameters indicated by the sensor measurements 404, identifies from a memory device of the stability controller 120 a first set of one or more variables based on which one or more components of the system 300 are controlled, and identifies a first set of one or more processing rates corresponding to the first set of one or more parameters and the first set of one or more variables from the memory device of the stability controller 120. The stability controller 120 controls one or more of the components of the system 300 to operate one or more of the components with the first set of one or more variables to achieve the first set of one or more parameters and further achieve the first set of one or more processing rates. Additionally, the stability controller 120 receives the second set of one or more parameters indicated by the sensor measurements 404, identifies from the memory device of the stability controller 120 a second set of one or more variables based on which one or more components of the system 300 are controlled, and identifies a second set of one or more processing rates corresponding to the second set of one or more parameters and the second set of one or more variables from the memory device of the stability controller 120. The stability controller 120 controls one or more of the components of the system 300 to operate one or more of the components with the second set of one or more variables to achieve the second set of one or more parameters and further achieve the second set of one or more processing rates.

[0098] The AI ​​model 422 is trained based on a first set of one or more parameters, a first set of one or more variables, a first set of one or more processing speeds, a second set of one or more parameters, a second set of one or more variables, and a second set of one or more processing speeds. During training, the AI ​​model 422 is given instructions that the second set of one or more processing speeds is preferable compared to the first set of one or more processing speeds. For example, the AI ​​model 422 is trained to learn that one or more of the components of the system 300 are controlled by the stability controller 120 to change their operation from the first set of one or more variables to the second set of one or more variables and modify the first set of one or more processing speeds to the second set of one or more processing speeds. When the substrate on which the AI ​​model 422 was trained is replaced with another substrate, the AI ​​model 422 receives a first set of one or more parameters from one or more of the sensors 202, 204, 220, 206, 208, 220, 224, 142, 144, and 146 and instructs the stability controller 120 to change the first set of one or more parameters to a second set of one or more parameters to achieve the second set of one or more processing speeds. The AI ​​model 422 further instructs the stability controller 120 to cause one or more of the components of the system 300 to operate with the second set of one or more variables to achieve the second set of one or more processing speeds. Upon receiving instructions from the AI ​​model 422, the stability controller 120 controls one or more of the components of the system 300 to operate with the second set of one or more variables to achieve the second set of one or more processing speeds.

[0099] FIG. 5A is an embodiment of a graph 500 illustrating that plasma instability remains in plasma chamber 104 (FIG. 1) unless one or more components of system 300 (FIG. 3) are controlled based on one or more of sensor signals SS1-SS7 (FIG. 1) received from one or more of sensors 202, 204, 220, 206, 208, 224 (FIG. 2), 142, 144, and 146 (FIG. 1). Graph 500 plots the stability of the plasma formed in plasma chamber 104 on the y-axis and time t along the x-axis. The x-axis of graph 500 plots time from time t0 to time t16. Plasma stability is indicated by one or more parameters indicated by one or more of sensor signals SS1-SS7, or one or more factors determined from the one or more parameters, or a combination thereof. For example, plasma instability remains if a parameter indicated by one of sensor signals SS1-SS7 is outside a predetermined threshold 502, such as a predetermined time period, range, or the like. An example of the predetermined time period is the time interval from time t0 to time t16. The predetermined threshold 502 is an example of a predetermined stability range. As another example, if one of the factors determined based on one or more of the parameters indicated by one or more of the sensor signals SS1-SS7 is outside the predetermined threshold 502 for the predetermined time period, plasma instability remains.

[0100] 5B is an embodiment of a graph 510 illustrating achieving plasma stability in plasma chamber 104 by controlling one or more components of system 300 (FIG. 3) based on one or more of sensor signals SS1-SS7 (FIG. 1). Graph 510 plots the stability of the plasma formed in plasma chamber 104 on the y-axis and time t on the x-axis. As an example, when stability controller 120 (FIG. 1) controls one or more components of system 300 based on one or more of sensor signals SS1-SS7, the value of one of the parameters received from one of sensors 202, 204, 220, 206, 208, 224 (FIG. 2), 142, 144, and 146 (FIG. 1), or the value of one of the factors determined from one of the parameters, or a combination thereof, is within a predetermined threshold 502. Therefore, plasma stability is achieved. As another example, when stability controller 120 controls one or more components of system 300 based on one or more of sensor signals SS1-SS7, the value of one of the factors determined from one or more parameters received from one or more of sensors 202, 204, 220, 206, 208, 224 (FIG. 2), 142, 144, and 146 (FIG. 1) is within a predetermined threshold 502. Therefore, plasma stability is achieved.

[0101] 5C is an embodiment of a graph 520 illustrating that plasma instability persists if one or more components of system 300 are not controlled based on one or more parameters indicated in one or more of sensor signals SS1-SS7 (FIG. 1). Graph 520 plots a parameter, such as power at the output of parametric element 116 (FIG. 1), on the y-axis and time t on the x-axis. For example, the parameter shown in graph 520 is indicated in sensor signal SS6 (FIG. 1) received from sensor 144 (FIG. 1) coupled to the output of parametric element 116. As shown in graph 520, an envelope 522 of the power at the output of parametric element 116 increases with time t, thus indicating plasma instability.

[0102] 5D is an embodiment of a graph 530 illustrating that plasma stability is achieved when one or more components of system 300 are controlled based on one or more parameters indicated in one or more of sensor signals SS1-SS7 (FIG. 1). Graph 530 plots a parameter, such as power at the output of parametric element 116 (FIG. 1), on the y-axis and time t on the x-axis. As shown in graph 530, an envelope 532 of the parameter at the output of parametric element 116 is constant for most of the time interval between time t0 and time t20 to achieve plasma stability.

[0103] It should be noted that any functions described herein as being performed by the stability controller 120 are performed by a processor in the stability controller 120 .

[0104] Broadly speaking, in various embodiments, a controller is defined as electronic equipment having various integrated circuits, logic, memory, and / or software that receive instructions, issue instructions, control operations, enable cleaning operations, and enable endpoint measurements. The integrated circuits include chips as firmware that store program instructions, digital signal processors (DSPs), chips defined as ASICs, PLDs, and / or one or more microprocessors or microcontrollers that execute program instructions (e.g., software). The program instructions are communicated to the controller in the form of various individual settings (or program files) and define parameters, factors, variables, etc., for implementing a particular process on or for a semiconductor wafer or for a system. In some embodiments, the program instructions are part of a recipe defined by a process engineer to accomplish one or more processing steps during the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or dies of a wafer.

[0105] In various embodiments, examples of systems to which the methods may be applied include, but are not limited to, plasma etch chambers or modules, deposition chambers or modules, spin rinse chambers or modules, metal plating chambers or modules, cleaning chambers or modules, bevel edge etch chambers or modules, physical vapor deposition (PVD) chambers or modules, chemical vapor deposition (CVD) chambers or modules, atomic layer deposition (ALD) chambers or modules, atomic layer etch (ALE) chambers or modules, ion implantation chambers or modules, track chambers or modules, and other semiconductor processing systems associated with or used in the manufacturing and / or production of semiconductor wafers.

[0106] Furthermore, it should be noted that in some embodiments, the operations described above apply to several types of plasma chambers, such as plasma chambers including inductively coupled plasma (ICP) reactors, transformer-coupled plasma chambers, conductor tools, dielectric tools, and plasma chambers including electron cyclotron resonance (ECR) reactors. For example, one or more RF generators are coupled to an inductor in an ICP reactor. Examples of inductor shapes include a solenoid, a dome-shaped coil, a planar coil, and the like.

[0107] Some embodiments also relate to hardware units or apparatus for performing these operations, said apparatus being specially configured for a special purpose computer. When defined as a special purpose computer, the computer is operable for a special purpose, but performs other processes, programs, or routines that are not part of the special purpose.

[0108] One or more embodiments may also be fabricated as computer-readable code on a non-transitory computer-readable medium. The non-transitory computer-readable medium is a data storage hardware unit, such as a memory device, that stores data, which is then read by a computer system. Examples of non-transitory computer-readable media include hard drives, network-attached storage (NAS), ROM, RAM, compact disc-ROMs (CD-ROMs), recordable CDs (CD-Rs), rewritable CDs (CD-RWs), magnetic tapes, and other optical and non-optical data storage hardware units. In some embodiments, the non-transitory computer-readable medium comprises a computer-readable tangible medium distributed over network-coupled computer systems such that the computer-readable code is stored and executed in a distributed manner.

[0109] Although the method operations above have been described in a particular order, it should be understood that in various embodiments, other housekeeping operations may be performed between operations, the method operations may be adjusted to occur at slightly different times, may be distributed in a system that allows the method operations to occur at various intervals, or may be performed in an order other than that set forth above.

[0110] It is further noted that in embodiments, one or more features from any of the above-described embodiments may be combined with one or more features of any other of the above-described embodiments without departing from the scope of the various embodiments described in this disclosure.

[0111] Although the foregoing embodiments have been described in some detail for purposes of clarity of understanding, it will be apparent that certain changes and modifications may be practiced within the scope of the appended claims. The present embodiments are therefore to be considered illustrative and not restrictive, and the embodiments are not to be limited to the details given herein.

Claims

1. 1. A plasma system for achieving plasma stability, comprising: A controller; a frequency source; a driver circuit having an input coupled to the frequency source, the driver circuit comprising: A gate driver; a bridge circuit coupled to the gate driver; one or more direct current (DC) source systems coupled to the bridge circuit; and a parametric element coupled to the bridge circuit; a plasma load coupled to the parametric element; The controller is configured to receive one or more parameters from one or more sensors coupled between the input of the drive circuit and the plasma load, and the controller is configured to modify one or more variables of operation of the gate driver, or the bridge circuit, or the one or more DC source systems, or a combination thereof, based on the one or more parameters to achieve the plasma stability.

2. 10. The plasma system of claim 1, wherein the gate driver is coupled to the one or more sensors, the one or more configured to sense the one or more parameters, and the controller is coupled to the one or more sensors to receive the one or more parameters from the one or more sensors.

3. 3. The plasma system of claim 2, wherein the gate driver has a first output and a second output, the gate driver configured to provide a plurality of de-synchronized signals at the first output and the second output, and the gate driver includes one or more actuators configured to control duty cycles of the plurality of de-synchronized signals based on the one or more parameters, the one or more variables including the duty cycle.

4. 3. The plasma system of claim 2, wherein the gate driver has a first output and a second output, and the gate driver is configured to provide a plurality of counter-synchronized signals at the first output and the second output.

5. 5. The plasma system of claim 4, the gate driver includes a first gate and a second gate; The plasma system includes: a first sensor coupled between the first gate and the first output; a second sensor coupled between the second gate and the second output; To receive the one or more parameters, the controller: receiving a first one of the one or more parameters from the first sensor; and configured to receive a second one of the one or more parameters from the second sensor; The plasma system includes: a first actuator coupled between the frequency source and the first gate; a second actuator coupled between the frequency source and the second gate; The controller controlling the first actuator based on the first of the one or more parameters; or The plasma system is configured to control the second actuator based on the second of the one or more parameters.

6. 10. The plasma system of claim 1, wherein the bridge circuit is coupled to the one or more sensors configured to sense the one or more parameters, and the controller is coupled to the one or more sensors to receive the one or more parameters from the one or more sensors.

7. 7. The plasma system of claim 6, wherein the bridge circuit is configured to supply a square wave pulse waveform, and the bridge circuit includes one or more actuators configured to control a duty cycle of the square wave pulse waveform based on the one or more parameters, the one or more variables including the duty cycle.

8. 8. The plasma system of claim 7, wherein the bridge circuit is configured to provide a square wave pulse waveform.

9. 9. The plasma system of claim 8, the bridge circuit is a half-bridge circuit having an output, the half-bridge circuit including a first transistor and a second transistor, the first transistor coupled to the second transistor; The plasma system includes: a first sensor coupled between the first transistor and the output; a second sensor coupled between the second transistor and the output; To receive the one or more parameters, the controller: receiving a first one of the one or more parameters from the first sensor; and configured to receive a second one of the one or more parameters from the second sensor; The plasma system includes: a first actuator coupled between the gate driver and the first transistor; a second actuator coupled between the gate driver and the second transistor; The controller controlling the first actuator based on the first of the one or more parameters; or The plasma system is configured to control the second actuator based on the second of the one or more parameters.

10. 10. The plasma system of claim 1, wherein the one or more DC source systems include the one or more sensors configured to sense the one or more parameters, and the controller is coupled to the one or more sensors to receive the one or more parameters from the one or more sensors.

11. 11. The plasma system of claim 10, wherein the one or more DC source systems are configured to output one or more DC signals, the one or more DC source systems including one or more actuators configured to modify one or more voltages of the one or more DC signals based on the one or more parameters, the one or more variables including the one or more voltages.

12. 10. The plasma system of claim 1, wherein there is no 50 ohm radio frequency (RF) cable between the input of the driver circuit and the plasma load.

13. 10. The plasma system of claim 1, The controller determining a magnitude of the plasma stability based on the one or more parameters; configured to compare the magnitude of the plasma stability with a predetermined stability range; The controller is configured to modify the one or more variables until the magnitude of the plasma stability is within the predetermined stability range.

14. The plasma system of claim 1 , wherein the one or more parameters include a complex voltage, or a complex current, or a complex voltage and complex current.

15. 1. A method for achieving plasma stability, comprising: receiving a digital pulse signal from a frequency source; outputting a counter-synchronized signal based on the digital pulse signal by a drive circuit having an input coupled to the frequency source, the drive circuit including a gate driver, a bridge circuit coupled to the gate driver, and one or more direct current (DC) source systems coupled to the bridge circuit; outputting a rectangular pulse waveform based on the inversely synchronized digital pulse signal by the bridge circuit; receiving, by a controller, one or more parameters from one or more sensors coupled between the input of the drive circuit and a plasma load; and modifying, by the controller, one or more variables of operation of the gate driver, or the bridge circuit, or the one or more DC source systems, or a combination thereof, based on the one or more parameters to achieve the plasma stability.

16. 16. The method of claim 15, the gate driver includes one or more sensors configured to sense the one or more parameters, the controller is coupled to the one or more sensors to receive the one or more parameters from the one or more sensors, the gate driver having a first output and a second output; The method comprises: providing, by the gate driver, a plurality of inversely synchronized signals at the first output and the second output; and controlling duty cycles of the plurality of desynchronized signals based on the one or more parameters, the one or more variables including the duty cycles.

17. 16. The method of claim 15, the bridge circuit includes one or more sensors configured to sense the one or more parameters, the controller coupled to the one or more sensors to receive the one or more parameters from the one or more sensors; The method comprises: The method further comprising controlling a duty cycle of the square wave pulse waveform based on the one or more parameters, the one or more variables including the duty cycle.

18. 1. A non-transitory computer-readable medium containing program instructions for achieving plasma stability, wherein execution of the program instructions by one or more processors of a computer system causes the one or more processors to: receiving a digital pulse signal from a frequency source; outputting a counter-synchronized signal based on the digital pulse signal by a drive circuit having an input coupled to the controller, the drive circuit including a gate driver, a bridge circuit coupled to the gate driver, and one or more direct current (DC) power systems coupled to the bridge circuit; outputting a rectangular pulse waveform based on the inversely synchronized digital pulse signal by the bridge circuit; receiving, by a controller, one or more parameters from one or more sensors coupled between the input of the drive circuit and a plasma load; and modifying, by the controller, one or more variables of operation of the gate driver, or the bridge circuit, or the one or more DC source systems, or a combination thereof, based on the one or more parameters to achieve the plasma stability.

19. 20. The non-transitory computer-readable medium of claim 18, the gate driver includes one or more sensors configured to sense the one or more parameters, the controller is coupled to the one or more sensors to receive the one or more parameters from the one or more sensors, the gate driver having a first output and a second output; The plurality of operations include: providing, by the gate driver, a plurality of inversely synchronized signals at the first output and the second output; and controlling duty cycles of the plurality of desynchronized signals based on the one or more parameters, the one or more variables including the duty cycles.

20. 20. The non-transitory computer-readable medium of claim 18, the bridge circuit includes one or more sensors configured to sense the one or more parameters, the controller coupled to the one or more sensors to receive the one or more parameters from the one or more sensors; The plurality of operations include: and controlling a duty cycle of the square wave pulse waveform based on the one or more parameters, wherein the one or more variables include the duty cycle.

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