Bias supplies, plasma processing systems, and associated methods are disclosed. One bias supply comprises a bidirectional switch configured to enable bidirectional control of current. A controller is configured to control a direction of current through the bidirectional switch over a full current cycle, the full current cycle comprising a first half current cycle and a second half current cycle, the first half current cycle comprising positive current flow, starting from zero current that increases to a positive peak value and then decreases back to zero. The second half current cycle comprises negative current flow, starting from zero current that increases to a negative peak value and then decreases back to zero current to cause an application of the periodic voltage between the output node and the return node.

A radio frequency (RF) power generation system includes a RF power source that generates a RF output signal delivered to a load. A RF power controller is configured to generate a control signal to vary the RF output signal. The controller adjusts a parameter associated with the RF output signal, and the parameter is controlled in accordance with a trigger signal. The parameter is adjusted in accordance with a cost function, and the cost function is determined by intruding a perturbation into an actuator that affects the cost function. The actuator may control an external RF output signal, and the trigger signal may vary in accordance with the external RF output signal.

Plasma applications are disclosed that operate with argon and other molecular gases at atmospheric pressure, and at low temperatures, and with high concentrations of reactive species. The plasma apparatus and the enclosure that contains the plasma apparatus and the substrate are substantially free of particles, so that the substrate does not become contaminated with particles during processing. The plasma is developed through capacitive discharge without streamers or micro-arcs. The techniques can be employed to remove organic materials from a substrate, thereby cleaning the substrate; to activate the surfaces of materials, thereby enhancing bonding between the material and a second material; to etch thin films of materials from a substrate; and to deposit thin films and coatings onto a substrate; all of which processes are carried out without contaminating the surface of the substrate with substantial numbers of particles.

An apparatus to decouple RF signals from input signal conductors of a process chamber includes at least a first switch to decouple an energy storage element from an active element within a process station. In particular embodiments, while the first switch is in an opened position, a second switch located between a current generator and energy storage element is closed, thereby permitting the current generator to charge the energy storage element. In response to the energy storage element attaining a predetermined voltage, the first switch may be closed, and the second switch may be opened, thereby permitting current to be discharged from the energy storage element to the active element. In certain embodiments, the first and second switches are not permitted to simultaneously operate in a closed position, thereby preventing RF from being coupled from the process station to the current generator.

A plasma processing apparatus is provided. The apparatus comprises a chamber, a lower electrode, an upper electrode, a gas supply, an RF power supply and a circuit. The circuit is configured to provide a potential to the lower electrode and includes a first circuit and a second circuit. The first circuit has a rectifier, a capacitor, a first current path, and a second current path. In the first current path, the rectifier is electrically connected between the lower electrode and the capacitor, and the capacitor is electrically connected between the rectifier and the ground. In the second current path, the rectifier is electrically connected between the lower electrode and the ground. The rectifier is configured to allow a current to flow toward the capacitor in the first current path and to allow a current to flow toward the lower electrode in the second current path. The second circuit is electrically connected to the capacitor and is configured to provide a voltage generated in the capacitor.

A multi-signal radio frequency (RF) source includes an RF source; and a switch including an input in communication with an output of the RF source, a first output and a second output. The switch is configured to selectively connect the input to one of the first output and the second output. An RF generator in communication with the first output of the multi-signal RF source is configured to generate plasma in a processing chamber. A remote plasma generator in communication with the second output of the multi-signal RF source is configured to supply remote plasma to the processing chamber.

Systems and methods for using a transformer to achieve uniformity in processing a substrate are described. One of the systems includes a primary winding having a first end and a second end. The first end is coupled to an output of an impedance matching circuit and the second end is coupled to a capacitor. The system further includes a secondary winding associated with the primary winding and coupled to a first end and a second end of a transformer coupled plasma (TCP) coil of a plasma chamber. The primary winding receives a modified radio frequency (RF) signal from the impedance matching circuit to generate a magnetic flux to induce a voltage in the secondary winding. An RF signal generated by the voltage is transferred from the secondary winding to the TCP coil.

Provided are apparatuses and methods for performing deposition and etch processes in an integrated tool. An apparatus may include a plasma processing chamber that is a capacitively-coupled plasma reactor, and the plasma processing chamber can include a showerhead that includes a top electrode and a pedestal that includes a bottom electrode. The apparatus may be configured with an RF hardware configuration so that an RF generator may power the top electrode in a deposition mode and power the bottom electrode in an etch mode. In some implementations, the apparatus can include one or more switches so that at least an HFRF generator is electrically connected to the showerhead in a deposition mode, and the HFRF generator and an LFRF generator is electrically connected to the pedestal and the showerhead is grounded in the etch mode.

Various embodiments are directed to a switch circuit comprising: two terminal nodes, comprising an upper node and a lower node; a plurality of switch modules, connected in series between the upper node and the lower node, wherein each of the switch modules comprises a switch, a rectifier, and a capacitor; a connecting circuit, coupled to the switch modules; and a power converter, coupled to the connecting circuit and to a power sink. The switch circuit is configured to limit a voltage or a component of a voltage in the switch circuit, and to recover power from the limiting of the voltage, wherein recovering the power comprises diverting power from the switch modules via the connecting circuit to the power converter, and the power converter outputting the power to the power sink.

A plasma processing apparatus includes a balun having a first unbalanced terminal, a second unbalanced terminal, a first balanced terminal, and a second balanced terminal, a grounded vacuum container, a first electrode electrically connected to the first balanced terminal, a second electrode electrically connected to the second balanced terminal, and a ground electrode arranged in the vacuum container and grounded.