Inductively coupled plasma reactor with top electrode for enhancing plasma ignition

A plasma reactor for carrying out plasma processing of a semiconductor substrate, comprising:

• a vacuum chamber including means for introducing a gas into the interior thereof;
• an induction coil surrounding a portion of said vacuum chamber, said coil being connected across an RF power source, and an integrated auxiliary electrode electrically connected at a portion of said induction coil with a potential sufficient to facilitate igniting a plasma;
• and
• wherein said RF powered auxiliary electrode has a surface area facing said interior of said vacuum chamber so as to capacitively couple RF power to the gas in said interior of said vacuum chamber said surface area of said auxiliary electrode being limited in area covering said chamber to limit capacitive coupling therefrom to said gas to an amount sufficient for plasma ignition at a selected pressure in said chamber.

A plasma reactor for carrying out plasma processing of a semiconductor substrate, comprising:

• a vacuum chamber including means for introducing a gas into the interior thereof;
• an RF power source;
• an induction coil facing a region of said vacuum chamber, said coil being connected across said RF power source, and an integrated auxiliary electrode electrically connected to a portion of said induction coil;
• and
• wherein said RF power source provides sufficient power to the electrode to ignite the plasma, and provides power to said induction coil;
• wherein said auxiliary electrode has a surface area suitable to limit capacitive coupling of RF power to said gas in said vacuum chamber so that, during steady-state maintenance of the plasma, most of the RF power coupled to the plasma from said RF power source is coupled inductively rather than capacitively.