Radio frequency (RF) ground return arrangements

A plasma processing chamber comprising:

• a top electrode;
• a bottom electrode coupled to an radio frequency (RF) source;
• a confinement ring made of a conductive material defined from a top segment, a side segment, and a bottom segment, the top, side and bottom segments being integrally defined so that an interior space is disposed between the top, side and bottom segments, the bottom segment including a plurality of slots, wherein the interior space of the confinement ring extends a confined chamber volume beyond a periphery of the top and bottom electrodes;
• an insulator ring defined to surround the bottom electrode, the bottom segment of the confinement ring disposed adjacent to the insulator ring, wherein a top surface of the insulator ring, a top surface of the bottom electrode, and an interior top surface of the bottom segment are substantially coplanar;
• a bottom electrode support structure being electrically coupled to ground, the bottom electrode support structure configured below the confinement ring and surrounding the insulator ring, the bottom electrode support structure having a vertical extension that provides a radio frequency (RF) contact to an exterior bottom surface of the bottom segment at an inner diameter of the confinement ring, wherein the plurality of slots are located at diameters of the bottom segment that are outside the inner diameter of the confinement ring;
• and
• an RF contact-enabled component defined below the bottom segment of the confinement ring and above the vertical extension of the bottom electrode support structure, the RF contact-enabled component providing RF coupling between the vertical extension of the bottom electrode and the exterior bottom surface of the bottom segment of the confinement ring, wherein said RF contact-enabled component is a spring-loaded contact sliding arrangement, wherein said spring-loaded contact sliding arrangement includes a spring member affixed to said confinement ring, wherein said spring member is biased against a side wall of said bottom electrode support structure and is configured to remain in contact with said bottom electrode support structure via a spring contact point when said bottom electrode support structure is moving vertically.

A plasma processing chamber comprising:

• a top electrode;
• a bottom electrode coupled to an radio frequency (RF) source;
• a confinement ring made of a conductive material defined from a top segment, a side segment, and a bottom segment, the top, side and bottom segments being integrally defined so that an interior space is disposed between the top, side and bottom segments, the bottom segment including a plurality of slots, wherein the interior space of the confinement ring extends a confined chamber volume beyond a periphery of the top and bottom electrodes;
• an insulator ring defined to surround the bottom electrode, the bottom segment of the confinement ring disposed adjacent to the insulator ring, wherein a top surface of the insulator ring, a top surface of the bottom electrode, and an interior top surface of the bottom segment are substantially coplanar;
• a bottom electrode support structure being electrically coupled to ground, the bottom electrode support structure configured below the confinement ring and surrounding the insulator ring, the bottom electrode support structure having a vertical extension that provides a radio frequency (RF) contact to an exterior bottom surface of the bottom segment at an inner diameter of the confinement ring, wherein the plurality of slots are located at diameters of the bottom segment that are outside the inner diameter of the confinement ring;
• and
• an RF contact-enabled component defined below the bottom segment of the confinement ring and above the vertical extension of the bottom electrode support structure, the RF contact-enabled component providing RF coupling between the vertical extension of the bottom electrode and the exterior bottom surface of the bottom segment of the confinement ring, wherein said RF contact-enabled component is a downward facing extension that is integral with said bottom segment of said confinement ring.

A plasma processing chamber comprising:

• a top electrode;
• a bottom electrode coupled to an radio frequency (RF) source;
• a confinement ring made of a conductive material defined from a top segment, a side segment, and a bottom segment, the top, side and bottom segments being integrally defined so that an interior space is disposed between the top, side and bottom segments, the bottom segment including a plurality of slots, wherein the interior space of the confinement ring extends a confined chamber volume beyond a periphery of the top and bottom electrodes;
• an insulator ring defined to surround the bottom electrode, the bottom segment of the confinement ring disposed adjacent to the insulator ring, wherein a top surface of the insulator ring, a top surface of the bottom electrode, and an interior top surface of the bottom segment are substantially coplanar;
• a bottom electrode support structure being electrically coupled to ground, the bottom electrode support structure configured below the confinement ring and surrounding the insulator ring, the bottom electrode support structure having a vertical extension with a contact top surface that provides a radio frequency (RF) contact to an exterior bottom surface of the bottom segment that is outside of an inner diameter of the confinement ring, the contact top surface of the vertical extension is not exposed to the confined chamber volume, wherein the plurality of slots are located at diameters of the bottom segment that are outside the inner diameter of the confinement ring;
• and
• an RF contact-enabled component defined below the bottom segment of the confinement ring and above the vertical extension of the bottom electrode support structure, the RF contact-enabled component providing RF coupling between the vertical extension of the bottom electrode and the exterior bottom surface of the bottom segment of the confinement ring, wherein said RF contact-enabled component is a RF gasket, wherein the RF gasket defines a direct RF return path without encapsulating a region capable of sustaining plasma outside of confined chamber volume.

A plasma processing chamber comprising:

• a top electrode;
• a bottom electrode coupled to a radio frequency (RF) source;
• a confinement ring made of a conductive material defined from a top segment, a side segment, and a bottom segment, the top, side and bottom segments being integrally defined so that an interior space is disposed between the top, side and bottom segments, the bottom segment including a plurality of slots, wherein the interior space of the confinement ring extends a confined chamber volume beyond a periphery of the top and bottom electrodes;
• an insulator ring defined to surround the bottom electrode, the bottom segment of the confinement ring disposed adjacent to the insulator ring, wherein a top surface of the insulator ring, a top surface of the bottom electrode, and an interior top surface of the bottom segment are substantially coplanar;
• a bottom electrode support structure electrically coupled to ground, the bottom electrode support structure configured below the confinement ring and surrounding the insulator ring, the bottom electrode support structure having a vertical extension having a recess filled with a conductive liquid;
• and
• a RF rod defined below the bottom segment of the confinement ring, the RF rod being defined in contact with the conductive liquid during operation of the plasma processing chamber, the RF rod providing an RF contact between the bottom segment of the confinement ring and the bottom electrode support structure, the RF contact to the bottom segment of the confinement ring being proximate to and outside of an inner diameter of the confinement ring and the plurality of slots are located at diameters of the bottom segment that are outside the inner diameter of the confinement ring, wherein a low impedance RF return path from the RF source is defined through the confinement ring, the RF rod, and the bottom electrode support structure.