Systems and methods for determining a phase difference between rf signals provided to electrodes

A method for increasing a rate of processing a substrate to cause an etch profile of the substrate, comprising:

• determining a first time at which a first amount of flux of secondary electrons from a substrate support to an upper electrode is maximum, wherein the first time occurs within a first clock cycle during which the substrate support receives a first radio frequency (RF) signal and the upper electrode receives a second RF signal;
• determining a second time at which a second amount of flux of secondary electrons from the upper electrode to the substrate support is maximum, wherein the second time occurs within the first clock cycle;
• determining a phase difference to be a difference between the second time and the first time;
• and
• causing the phase difference between a phase of a third RF signal and a phase of a fourth RF signal, wherein the third RF signal is provided to the upper electrode and the fourth RF signal is provided to the substrate support, wherein said causing the phase difference is performed to increase the rate of processing of the substrate.

A controller comprising:

• a processor configured to:
• receive a parameter signal from a first sensor when a first radio frequency (RF) signal is provided to a substrate support and a second RF signal is provided to an upper electrode;
• determine, based on the parameter signal, a first time at which a value of a parameter is maximum, wherein the first time occurs during a cycle of a clock signal;
• receive a variable signal from a second sensor;
• determine, based on the variable signal, a second time at which a first amount of flux of secondary electrons from the upper electrode to the substrate support is maximum, wherein the second time occurs during the cycle and occurs after the first time;
• determine a phase difference to be a difference between the first time and the second time;
• and
• cause the phase difference between a phase of a third RF signal and a phase of a fourth RF signal, wherein the third RF signal is provided to the upper electrode and the fourth RF signal is provided to the substrate support, wherein the phase difference is caused to increase the rate of processing of the substrate;
• and
• a memory device coupled to the processor.