Atomic layer etching of a substrate using a wafer scale wave of precisely controlled electrons is presented. A volume of gaseous plasma including diluent and reactive species and electrons of a uniform steady state composition is generated in a positive column of a DC plasma proximate the substrate. A corrosion layer is formed on the substrate by adsorption of the reactive species to atoms at the surface of the substrate. The substrate is positively biased to draw electrons from the volume to the surface of the substrate and impart an energy to the electrons so to stimulate electron transitions in the corrosion layer species, resulting in ejection of the corrosion layer species via electron stimulation desorption. The substrate is negatively biased to repel the electrons from the surface of the substrate back to the volume, followed by a zero bias to restore the steady state composition of the volume.

A plasma processing apparatus or a plasma processing method that processes a wafer to be processed, which is placed on a surface of a sample stage arranged in a processing chamber inside a vacuum container, using a plasma formed in the processing chamber, the apparatus or method including processing the wafer by adjusting a first high-frequency power to be supplied to a first electrode arranged inside the sample stage and a second high-frequency power to be supplied, via a resonant circuit, to a second electrode which is arranged in an inner side of a ring-shaped member made of a dielectric arranged on an outer peripheral side of a surface of the sample stage on which the wafer is placed, during the processing.

A generator produces output such as delivered power, voltage, current, forward power etc. that follows a prescribed pattern of output versus time where the pattern repeats with a repetition period by controlling sections of the pattern based on measurements taken one or more repetition periods in the past. A variable impedance match network may control the impedance presented to a radio frequency generator while the generator produces the output that follows the prescribed pattern of output versus time where the pattern repeats with a repetition period by controlling variable impedance elements in the match during sections of the pattern based on measurements taken one or more repetition periods in the past.

A power supply system for a plasma process includes two separate power supplies of essentially identical performance characteristics, including a first power supply and a second power supply, and a data transfer connection operably coupling the two power supplies for data communication between the two power supplies. The first power supply is configured to: receive, in a standby mode, data via the data transfer connection from the second power supply supplying power to a plasma process in a normal operating mode, and supply, in an active backup mode, power to the plasma process in place of the second power supply, as a function of the received data. The first power supply can supply in the active backup mode to the plasma process the power having one or more characteristics that are substantially the same as those of the power provided by the second power supply in the normal operating mode.

A control circuit for at least two drivers is provided. Each of the two drivers is configured to switch on and off electrically driven switching elements that are electrically connected to each other. The control circuit includes a first parallel-to-serial-converter including a first parallel input port and a first serial output-port connectable to a first driver, a second parallel-to-serial-converter including a second parallel input port and a second serial output-port connectable to a second driver, and a processor unit configured to send a first data package stream to the first parallel input port, and send a second data package stream to the second parallel input port. Both the first data package stream and the second data package stream are configured to be converted to serial-data-streams at the first serial output-port and the second serial output-port, respectively. The serial data-streams are configured to control the at least two drivers.

An arc suppression device includes an AC to DC converter, a switch, a resistor and a controller. The switch is coupled between the AC to DC converter and a plasma chamber. The resistor is coupled in parallel with the switch. The AC to DC converter is configured to convert an AC voltage into a DC voltage for providing to the plasma chamber. The controller is configured to detect a unit-time rate of change (ROC) of a plasma current received by the plasma chamber. When the controller determines that the unit-time ROC of the plasma current is larger than a first unit-time ROC threshold, the controller controls the switch to electrically isolate the AC to DC converter and the plasma chamber to reduce the plasma current to a first current value through the resistor.

This disclosure describes systems, methods, and apparatus for waveform control, comprising: a power supply having an input terminal, and at least one output terminal for coupling to a load; a controller; a variable inductor coupled to at least one of the output terminals, the variable inductor comprising a first magnetic core having a plurality of arms, including at least a first inductor arm and a first control arm, wherein an inductance winding having one or more turns is wound around the first inductor arm, and wherein a first control winding comprising one or more turns is wound around the first control arm; and a DC current source coupled to the first control arm and the controller, the controller configured to adjust a DC bias applied by the DC current source to the first control arm to control an output waveform at the at least one output terminal.

An ion source comprising: an electrode; a counter electrode; means for generating an electrical potential between the electrode and counter-electrode; one or more magnets arranged, in use, to confine a plasma generated around the electrode upon application of the said electrical potential; and an aperture in the counter-electrode through which ions from the said plasma can escape; characterized in that: the means for generating an electrical potential between the electrode and counter electrode comprises a DC signal generator that is: electrically connected to the electrode and the counter-electrode; adapted, in use, to apply a baseline DC potential to the electrode and the counter-electrode with the DC potential at the electrode being positive relative to the DC potential at the counter electrode; and adapted, in use, to apply a sequence of DC pulses superimposed onto the baseline DC potential.

A power supply system 90 includes high frequency power supplies 92 and 93 that supply a high frequency power for plasma generation; a DC power supply 91 that supplies a DC voltage to be applied to an electrode; and control unit 94 that controls the high frequency power supplies 92 and 93 and the DC power supply 91 including a first DC power supply unit 101 that supplies a first negative DC voltage V1, a second DC power supply unit 102 that supplies a second negative DC voltage V2 having a higher absolute value than the first negative DC voltage V1, and a selecting circuit 103 that selectively connects the first DC power supply unit 101 and the second DC power supply unit 102 to the electrode; and a discharging circuit 104 connected with a node 109 between the first DC power supply unit 101 and the selecting circuit 103.

Systems and methods for tunable workpiece biasing in a plasma reactor are provided herein. In some embodiments, a system includes: a plasma chamber that performs plasma processing on a workpiece, a first pulsed voltage source, coupled directly to a workpiece, a second pulsed voltage source, coupled capacitively to the workpiece, and a biasing controller comprising one or more processors, and memory, wherein the memory comprises a set of computer instructions that when executed by the one or more processors, independently controls the first pulsed voltage source and the second pulsed voltage source based on one or more parameters of the first pulsed voltage source and the second pulsed voltage source in order to tailor ion energy distribution of the flux of ions directed to the workpiece.