Multi-Frequency Hollow Cathode and Systems Implementing the Same

A hollow cathode system for plasma generation in substrate plasma processing, comprising:

• an electrically conductive member shaped to circumscribe an interior cavity, wherein the electrically conductive member is formed to have a process gas inlet in fluid communication with the interior cavity, and wherein the electrically conductive member is formed to have an opening that exposes the interior cavity to a substrate processing region;
• a first radiofrequency (RF) power source in electrical communication with the electrically conductive member so as to enable transmission of a first RF power to the electrically conductive member;
• and
• a second RF power source in electrical communication with the electrically conductive member so as to enable transmission of a second RF power to the electrically conductive member,
• wherein the first and second RF power sources are independently controllable such that the first and second RF powers are independently controllable with regard to frequency and amplitude.