Abstract: A broad-band sensor for a radio frequency plasma processing system that includes a reaction chamber housing an electrode within a vacuum processing environment. The sensor includes an inductive pickup positioned in the vacuum processing environment proximate to the electrode. The inductive pickup includes a wire formed into a loop extending in an azimuthal direction about a symmetry axis of the reaction chamber. A lead carrying an electric signal from the inductive pickup extends through a vacuum wall of the reaction chamber outside the vacuum processing environment. An attenuator circuit including an electrical resistance bridge couples the lead to a signal carrier extending outside the vacuum processing environment. The broad-band sensor has radio frequency detection capability for measuring electromagnetic surface modes within the plasma chamber and coupling the measured electromagnetic surface modes to the signal carrier.

Abstract: The present disclosure relates to a switching circuitry for a variable reactance matching network as may be used by plasma generation systems which utilize plasma for semiconductor processing. The switching circuitry may be used within a hybrid matching network that has a first-stage switched matching network and a second-stage mechanically-tuned matching network. The switching circuitry may also be used for variable reactance matching in telecom applications, plasma laser cutting applications, and/or RADAR/LIDAR implementations. The switching circuitry includes individual isolated power supplies that are fed from a main power supply. The individual isolated power supplies receive inductive power from a main power supply loop powered by the main power supply. The inductive coupling provides isolated power supply loops to drive circuitry for a single switch. Multiple instances of the isolated switch circuitry are used to receive a digital signal from a connected controller.

Abstract: A method for homing a stepping motor having a plurality of full-step positions within each full rotation of a rotor of the stepper motor includes applying a first drive current to windings of the stepper motor to rotate the rotor at least one full rotation in a first direction away from an end-of-travel (EOT) position. Thereafter, the drive current is applied to the windings to rotate the rotor in a second direction toward the EOT position. Upon detection of EOT, the drive current is discontinued. Drive current is then applied to the windings to rotate the rotor of the stepper motor in micro-steps in the first direction to a closest full-step position of the stepper motor. Finally, a drive current is applied to drive the stepper motor a predetermined number of full steps away from the EOT position.

Abstract: A plasma generation system includes an impedance matching network calibrated to map desired matching network impedance values to closest available settings of impedance control components. The tuning controller defines a set of target impedance values spaced-apart throughout the tuning range and drives the matching network to generate a set of closest frame tuning values proximate to each target impedance value. The tuning controller computes interpolated tuning values between adjacent pairs of frame tuning values and stores a tuning database that maps available matching network impedance values to specific sets of settings for the impedance control components. After the calibration stage, the tuning controller automatically utilizes the tuning database to map desired matching network impedance values to available settings of the impedance control components on an ongoing basis. Representative embodiments include variable loading and tuning capacitors in series with a fixed or variable phase-shift inductor.

Abstract: An electromagnetic field sensor may include a housing including an opening extending therethrough; a dielectric element including a first section having a first interior space and a second section having a second interior space, the dielectric element being received within the opening of the housing; and a conductor disposed within and approximating the first interior space and the second interior space of the dielectric element, the conductor including a first portion defining a first frustrum shape and a second portion defining a second frustrum shape, the first interior space receiving the first portion of the conductor and the second interior space receiving the second portion of the conductor. The electromagnetic field sensor for use in a matching network of a plasma generation system or other application.

Abstract: A variable capacitor includes first and second movable capacitor plate assemblies disposed in the interior of an enclosure and include a first and second movable capacitor plates. A first fixed capacitor plate and a second fixed capacitor plate are respectively disposed proximal to the first and second movable capacitor plates. The capacitor plates may comprise variably interdigitated concentric cylindrical blades. The first movable capacitor plate and the first fixed capacitor plate may be coaxial with the second movable capacitor plate and the second fixed capacitor plate. Actuators may be provided for independently advancing and retracting the first and second movable capacitor plate assemblies with respect to the first and second fixed capacitor plate assemblies to vary the capacitance of the variable capacitor by independently adjusting an amount of interdigitization of the capacitor plates of respective capacitor plate assembly pairs.

Abstract: A variable capacitor includes an enclosure having first and second conductive collars separated by an intermediate electrically insulating element. A movable capacitor plate assembly is electrically coupled to the first conductive collar, and a fixed capacitor plate assembly is electrically coupled to the second conductive collar. An actuator extends into the enclosure for advancing and retracting the movable capacitor plate assembly relative to the fixed capacitor plate assembly. A hermetically sealed volume within the enclosure maintains a vacuum or a liquid serving as a dielectric between a capacitor plate of the movable capacitor plate assembly and a capacitor plate of the fixed capacitor plate assembly. At least one capacitor plate comprises a coiled cylindrical plate having a having a greater height at a center portion of the capacitor plate coil and a lower height at an outer portion of the capacitor plate coil.

Abstract: A method of detecting non-uniformity in a plasma in a radio frequency plasma processing system, the method including generating a plasma within a reaction chamber of the radio frequency plasma processing system and detecting electrical signals from the plasma in a frequency range from a frequency of radio frequency power sustaining the plasma to a multiple of about ten times a frequency with a plurality of sensors disposed azimuthally about a chamber symmetry axis of the radio frequency plasma processing system. The method also including comparing the waveforms of the electrical signals picked up from the plasma by the plurality of sensors and determining when a plasma non-uniformity occurs based on the comparing the electrical property of the plasma detected by each of the plurality of sensors.

Abstract: A coil having a coil body and a plurality of concentric cross-section windings of wire disposed around the coil body, the wire having a spacing between adjacent turns of about 0.25 to 1.0 of the radius of the wire. Also, a coil for a plasma processing device, the coil having a coil body and a plurality of concentric cylindrical cross-section windings of wire disposed around the coil body, the wire having a spacing between adjacent turns of about 0.25 to 1.0 of the radius of the wire and a diameter to length ratio of between about 2:1 and about 3:1.

Abstract: A method for homing a stepping motor having a plurality of full-step positions within each full rotation of a rotor of the stepper motor includes applying a first drive current to windings of the stepper motor to rotate the rotor at least one full rotation in a first direction away from an end-of-travel (EOT) position. Thereafter, the drive current is applied to the windings to rotate the rotor in a second direction toward the EOT position. Upon detection of EOT, the drive current is discontinued. Drive current is then applied to the windings to rotate the rotor of the stepper motor in micro-steps in the first direction to a closest full-step position of the stepper motor. Finally, a drive current is applied to drive the stepper motor a predetermined number of full steps away from the EOT position.

Abstract: A broad-band sensor for a radio frequency plasma processing system that includes a reaction chamber housing an electrode within a vacuum processing environment. The sensor includes an inductive pickup positioned in the vacuum processing environment proximate to the electrode. The inductive pickup includes a wire formed into a loop extending in an azimuthal direction about a symmetry axis of the reaction chamber. A lead carrying an electric signal from the inductive pickup extends through a vacuum wall of the reaction chamber outside the vacuum processing environment. An attenuator circuit including an electrical resistance bridge couples the lead to a signal carrier extending outside the vacuum processing environment. The broad-band sensor has radio frequency detection capability for measuring electromagnetic surface modes within the plasma chamber and coupling the measured electromagnetic surface modes to the signal carrier.

Abstract: A method and system for plasma arc suppression includes a RF generator supplying power to a plasma chamber coupled to an impedance matching network reacting to impedance changes to match an impedance of the plasma chamber with an impedance of the radio frequency generator. An arc suppression device coupled to the RF generator and the plasma chamber detects plasma arcing causing a sharp impedance change increasing reflection of the power by the plasma chamber and switches a power dissipator reducing the power delivered to the plasma chamber extinguishing or mitigating the plasma arcing. The power dissipator is switched more quickly than the impedance matching network reacts to the sharp impedance change. For example, the impedance matching network may react to the impedance change on an order of hundredths of milliseconds or more, while the arc suppression device switches the power dissipator on an order of microseconds or less.

Abstract: A method of providing data on radio frequency pulses in a radio frequency plasma processing system, the method including measuring an electrical parameter within a matching network of the radio frequency plasma processing system; determining an attribute of the measurement of the electrical parameter; defining a first statistic for the attribute of the measurement of the electrical parameter; defining a second statistic based on the first statistic for at least one of a phase and a process; delivering the first statistic and second statistic to a user; and storing the first statistic and the second statistic within the matching network.

Abstract: Disclosed is a method and apparatus for utilizing a variable gain algorithm for adjusting a capacitor in an automatic radio frequency (RF) impedance matching network. The apparatus may operate in a closed-loop feedback control system, with one or more error signals driving the capacitors within the system. To achieve a critically damped control system response, multiple operating regions for the matching network and its constituent elements may be identified and a set of gains (e.g., different per region) may be applied to the error signals in the control system when operating in those regions. An operating region may be defined by characteristics of the input signals measured by the apparatus, calculated by the apparatus, or the state of the apparatus itself. These features may be arranged in a look up table (or determined by calculation) for the apparatus to use to determine the variable gains in the system.

Abstract: The present disclosure relates to plasma generation systems which utilize plasma for semiconductor processing. The plasma generation system disclosed herein employs a hybrid matching network. The plasma generation system includes a RF generator and a matching network. The matching network includes a first-stage to perform low-Q impedance transformations during high-speed variations in impedance. The matching network includes a second-stage to perform impedance matching for high-Q impedance transformations. The matching network further includes a sensor coupled to the first-stage and the second-stage to calculate the signals that are used to engage the first and second-stages. The matching network includes a first-stage network that is agile enough to tune each state in a modulated RF waveform and a second-stage network to tune a single state in a RF modulated waveform. The plasma generation system also includes a plasma chamber coupled to the matching network.

Abstract: A variable capacitor includes first and second movable capacitor plate assemblies disposed in the interior of an enclosure and include a first and second movable capacitor plates. A first fixed capacitor plate and a second fixed capacitor plate are respectively disposed proximal to the first and second movable capacitor plates. The capacitor plates may comprise variably interdigitated concentric cylindrical blades, The first movable capacitor plate and the first fixed capacitor plate may be coaxial with the second movable capacitor plate and the second fixed capacitor plate. Actuators may be provided for independently advancing and retracting the first and second movable capacitor plate assemblies with respect to the first and second fixed capacitor plate assemblies to vary the capacitance of the variable capacitor by independently adjusting an amount of interdigitization of the capacitor plates of respective capacitor plate assembly pairs.

Abstract: A high frequency, high voltage compound helical inductor coil includes a primary coil configured as a helix, a secondary coil configured as a helix and being surrounded by and parallel with the primary coil. A dielectric insulator, configured as a helix, is disposed between and separates the primary coil and the secondary coil. A center conductor may extend axially through the primary and secondary coils and may be attached at a first end to the primary coil and at a second end to the secondary coil.

Abstract: A radio frequency plasma processing system including a reaction chamber, an electrode having an electrode symmetry axis, the electrode disposed in the reaction chamber, and a plurality of plates, each having an electrically conducting layer, disposed in the reaction chamber azimuthally with respect to the electrode symmetry axis around a perimeter of the electrode at a gap from the electrode surface, each of the plurality of plates connected to an electrical ground through a variable reactance circuit.

Abstract: A broad-band sensor for a radio frequency plasma processing system that includes a reaction chamber housing an electrode within a vacuum processing environment. The sensor includes an inductive pickup positioned in the vacuum processing environment proximate to the electrode. The inductive pickup includes a wire formed into a loop extending in an azimuthal direction about a symmetry axis of the reaction chamber. A lead carrying an electric signal from the inductive pickup extends through a vacuum wall of the reaction chamber outside the vacuum processing environment. An attenuator circuit including an electrical resistance bridge couples the lead to a signal carrier extending outside the vacuum processing environment. The broad-band sensor has radio frequency detection capability for measuring electromagnetic surface modes within the plasma chamber and coupling the measured electromagnetic surface modes to the signal carrier.

Abstract: The present disclosure relates to a switching circuitry for a variable reactance matching network as may be used by plasma generation systems which utilize plasma for semiconductor processing. The switching circuitry may be used within a hybrid matching network that has a first-stage switched matching network and a second-stage mechanically-tuned matching network. The switching circuitry may also be used for variable reactance matching in telecom applications, plasma laser cutting applications, and/or RADAR/LIDAR implementations. The switching circuitry includes individual isolated power supplies that are fed from a main power supply. The individual isolated power supplies receive inductive power from a main power supply loop powered by the main power supply. The inductive coupling provides isolated power supply loops to drive circuitry for a single switch. Multiple instances of the isolated switch circuitry are used to receive a digital signal from a connected controller.