Apparatus and methods for controlling ion energy distribution

A pulsed direct current (DC) power delivery system, comprising:

• a main pulser configured to deliver DC pulse waveforms to a main pulser output;
• and
• a power module electrically coupled to the main pulser output of the main pulser, the power module configured to control an ion energy distribution function of ions within a formed plasma, the power module comprising:
• a voltage source or a current source, wherein the voltage source or current source is configured to be electrically coupled between the main pulser output and an electrode within a processing chamber, and wherein the voltage source or the current source comprises a DC current source or a shaped DC pulse voltage source or a DC voltage source electrically coupled in series to a resistor;
• and
• a switch electrically coupled in parallel to the voltage source or the current source.

A non-transitory computer-readable medium storing instructions that, when executed on a processor, perform operations for controlling a width of an ion energy distribution function (IEDF), the operations comprising:

• delivering a first pulse voltage waveform to an electrode of a processing chamber from a main pulser output of a main pulser, the main pulser output electrically coupled to an IEDF width control module, wherein the IEDF width control module comprises:
• a voltage source or a current source, wherein the voltage source or current source is electrically coupled between the main pulser output and ground or between the main pulser output and an electrode within a processing chamber, and wherein the voltage source or the current source comprises a DC current source or a shaped DC pulse voltage source or a DC voltage source electrically coupled in series to a resistor;
• and
• a switch electrically coupled in parallel with the voltage source or the current source, and between the main pulser output and the ground or between the main pulser output and an electrode within a processing chamber;
• measuring at least one of a current flowing from the IEDF width control module, a voltage applied by the IEDF width control module, and a voltage derivative at a node between the IEDF width control module and the electrode in the processing chamber;
• calculating an ion current of the processing chamber and a capacitance of the processing chamber based on at least one of the measured current, the measured voltage and the measured voltage derivative;
• determining a setpoint for a voltage or a current provided from the IEDF width control module or setpoint for a voltage derivative provided from the IEDF width control module;
• and
• adjusting the voltage or the current provided from the IEDF width control module, or voltage derivative provided from the IEDF width control module to control the width of the IEDF.