Inductively coupled plasma apparatus with novel faraday shield

A plasma source, comprising:

• a plasma chamber, the plasma chamber surrounding a plasma space to contain a plasma therein;
• and an antenna assembly, disposed within the plasma chamber or adjacent to the plasma chamber, the antenna assembly comprising:
• an antenna, having a loop structure;
• a dielectric window, adjacent to the antenna;
• anda Faraday shield assembly disposed between the antenna and the dielectric window, the Faraday shield assembly being disposed at least partially around the antenna, wherein the Faraday shield assembly comprises, a plurality of circumferentially opposed shield pairs, each shield pair being electrically isolated from adjacent shield pairs along the length of the antenna, each shield pair including a first metallic section and a second metallic section disposed opposite one another about the loop structure and electrically connected to one another only within the shield pair and not to any other metallic section, wherein the Faraday shield assembly is configured to limit voltage buildup along the antenna and to maintain magnetic coupling to the plasma through gaps defined between adjacent shield pairs.

A processing apparatus, comprising:

• a plasma chamber surrounding a plasma space to contain a plasma therein;
• and
• an antenna assembly, disposed within the plasma chamber or adjacent to the plasma chamber, the antenna assembly comprising:
• an antenna having a loop structure;
• a dielectric window positioned between the antenna and the plasma chamber, adjacent to the antenna;
• and
• a Faraday shield assembly disposed between the antenna and the dielectric window, the Faraday shield assembly being disposed at least partially around the antenna, wherein the Faraday shield assembly comprises a plurality of metallic sections arranged into circumferentially opposed shield pairs, each pair including two metallic sections electrically connected only to each other and electrically isolated from other shield pairs;
• and
• an RF power source configured to apply a balanced RF signal to the antenna so that each shield pair defines a localized equipotential region that reduces capacitive coupling to the plasma while preserving magnetic coupling through inter-pair gaps.