Abstract: A non-axisymmetric electromagnet coil used in plasma processing in which at least one electromagnet coil is not symmetric with the central axis of the plasma processing chamber with which it is used but is symmetric with an axis offset from the central axis. When placed radially outside of an RF coil, it may reduce the azimuthal asymmetry in the plasma produced by the RF coil. Axisymmetric magnet arrays may include additional axisymmetric electromagnet coils. One axisymmetric coil is advantageously placed radially inside of the non-axisymmetric coil to carry opposed currents. The multiple electromagnet coils may be embedded in a molded encapsulant having a central bore about a central axis providing the axisymmetry of the coils.

Abstract: A plurality of RF power signals have the same RF frequency as a reference RF signal and are coupled to respective RF connection points on an electrode of a plasma chamber. At least three of the RF connection points are not collinear. At least two of the RF power signals have time-varying phase offsets relative to the reference RF signal that are distinct functions of time. Such time-varying phase offsets can produce a spatial distribution of plasma in the plasma chamber having better time-averaged uniformity than the uniformity of the spatial distribution at any instant in time.

Abstract: An isolator ring is provided for a substrate support used in a substrate processing chamber. The substrate support comprises an annular ledge having a circumferential edge, and an inner perimeter sidewall. The isolator ring comprises an L-shaped dielectric ring comprising a laser textured surface; a horizontal leg capable of resting on the annular ledge of the support, and having a length that extends radially outward and stops short of the circumferential edge of the annular ledge; and a vertical leg abutting the inner perimeter sidewall of the support. A ring assembly includes the isolator ring and a deposition ring.

Abstract: A non-axisymmetric electromagnet coil used in plasma processing in which at least one electromagnet coil is not symmetric with the central axis of the plasma processing chamber with which it is used but is symmetric with an axis offset from the central axis. When placed radially outside of an RF coil, it may reduce the azimuthal asymmetry in the plasma produced by the RF coil. Axisymmetric magnet arrays may include additional axisymmetric electromagnet coils. One axisymmetric coil is advantageously placed radially inside of the non-axisymmetric coil to carry opposed currents. The multiple electromagnet coils may be embedded in a molded encapsulant having a central bore about a central axis providing the axisymmetry of the coils.

Abstract: A ring assembly is provided for a substrate support used in a substrate processing chamber, the substrate support comprising an annular ledge and an inner perimeter sidewall. In one version, the ring assembly comprises (i) an L-shaped isolator ring comprising a horizontal leg resting on the annular ledge of the support, and a vertical leg abutting the inner perimeter sidewall of the support, and (ii) a deposition ring comprising an annular band having an overlap ledge that overlaps the horizontal leg of the isolator ring. In another version, the deposition ring comprises a dielectric annular band that surrounds and overlaps the annular ledge of the support, and a bracket and fastener.