Systems and methods for multi-level pulsing of a parameter and multi-level pulsing of a frequency of a radio frequency (RF) signal are described. The parameter is pulsed from a low level to a high level while the frequency is pulsed from a low level to a high level. The parameter and the frequency are simultaneously pulsed to increase a rate of processing a wafer, to increase mask selectivity, and to reduce angular spread of ions within a plasma chamber.

Carrier rings with radially-varied plasma impedance are provided herein. In some embodiments, a carrier ring may include an outer ring that holds a removable inner ring. The outer ring may be formed of a dielectric material such as ceramic. The inner ring may be formed of a metal such as aluminum to provide a desired impedance. In some other embodiments, a carrier ring is formed from a single piece with radially-varying impedances.

Systems and methods for increasing peak ion energy with a low angular spread of ions are described. In one of the systems, multiple radio frequency (RF) generators that are coupled to an upper electrode associated with a plasma chamber are operated in two different states, such as two different frequency levels, for pulsing of the RF generators. The pulsing of the RF generators facilitates a transfer of ion energy during one of the states to another one of the states for increasing ion energy during the other state to further increase a rate of processing a substrate.

A method and apparatus for controlling RF plasma attributes is disclosed. Some embodiments of the disclosure provide RF sensors within processing chambers operable at high temperatures. Some embodiments provide methods of measuring RF plasma attributes using RF sensors within a processing chamber to provide feedback control for an RF generator.

In some implementations, there is provided an apparatus comprising a resonant amplifier circuit including a first inductor having a first inductive input and a first inductive output; a second inductor having a second inductive input and a second inductive output; a first switch coupled to the first inductive output; and a second switch coupled to the second inductive output, wherein the first switch and the second switched are driven out of phase, wherein the first inductor is configured to be resonant with a first capacitance associated with the first switch, and wherein the second inductor is configured to be resonant with a second capacitance associated with the second switch. Related systems and articles of manufacture are also provided.

A matchless plasma source is described. The matchless plasma source includes a controller that is coupled to a direct current (DC) voltage source of an agile DC rail to control a shape of an amplified square waveform that is generated at an output of a half-bridge transistor circuit. The matchless plasma source further includes the half-bridge transistor circuit used to generate the amplified square waveform to power an electrode, such as an antenna, of a plasma chamber. The matchless plasma source also includes a reactive circuit between the half-bridge transistor circuit and the electrode. The reactive circuit has a high-quality factor to negate a reactance of the electrode. There is no radio frequency (RF) match and an RF cable that couples the matchless plasma source to the electrode.

A method for applying RF power in a plasma process chamber is provided, including: generating a first RF signal; generating a second RF signal; generating a third RF signal; wherein the first, second, and third RF signals are generated at different frequencies; combining the first, second and third RF signals to generate a combined RF signal, wherein a wave shape of the combined RF signal is configured to approximate a sloped square wave shape; applying the combined RF signal to a chuck in the plasma process chamber.

A method for controlling a critical dimension of a mask layer is described. The method includes receiving a first primary parameter level, a second primary parameter level, a first secondary parameter level, a second secondary parameter level, and a third secondary parameter level. The method also includes generating a primary signal having the first primary parameter level, and transitioning the primary signal from the first primary parameter level to the second primary parameter level. The method further includes generating a secondary radio frequency (RF) signal having the first secondary parameter level, and transitioning the secondary RF signal from the first secondary parameter level to the second secondary parameter level. The method includes transitioning the secondary RF signal from the second secondary parameter level to the third secondary parameter level.

Methods and apparatus for processing a substrate are provided herein. For example, an RF power delivery compensation circuit comprises a first input configured to receive an RF forward power from an RF power source connected to a processing chamber and a second input configured to receive an RF delivered power from a matching network connected between the RF power source and the processing chamber. The RF power delivery compensation circuit calculates an RF forward power compensation factor based on the RF forward power and the RF delivered power for adjusting the RF forward power delivered to the processing chamber during operation.

A power supply system controls the source impedance of a generator utilizing two amplifiers having asymmetrical power profiles in reference to a nominal load impedance that are diametrically opposite in reference to the nominal load impedance. Variations in power profiles may be achieved by using different topologies for each of the amplifiers or implementing a phase delay network. The output power from the first and second amplifiers may be combined using a combiner circuit or device and the output power from the combiner is transmitted to a plasma load. The output power of each amplifier may be independently controlled to alter one or more characteristics of the output power signal provided by the individual amplifiers. By changing the ratio of the output power of the first amplifier to the output power of the second amplified, the source impedance of the generators may be varied.