Abstract: A plasma confinement ring for a plasma chamber comprises a ring-shaped element and a cylindrical element. The ring-shaped element of the plasma confinement ring surrounds a substrate support assembly in the plasma chamber and is arranged along a plane in which a substrate is arranged on the substrate support assembly. The ring-shaped element includes a plurality of orifices. The cylindrical element of the plasma confinement ring extends from an outer edge of the ring-shaped element in a direction perpendicular to the plane in which the substrate is arranged on the substrate support assembly in the plasma chamber. The plasma confinement ring is monolithic.

Abstract: A crucible includes an outer element and an inner element. The outer element includes a first portion that is horizontal at a bottom end of the crucible and a second portion that ascends radially outwardly from the bottom end of the crucible to a top end of the crucible at a first acute angle to a vertical axis. The inner element includes a conus with a cylinder at a base of the conus. The conus descends radially outwardly from the top end of the crucible to the bottom end of the crucible at a second acute angle to the vertical axis. The inner element includes a base portion of the cylinder attached to the first portion of the outer element using a sealant to form a hollow mold between an inner portion of the outer element and an outer portion of the inner element.

Abstract: A furnace includes a pedestal, a crucible, first and second heaters, and a controller. The crucible is arranged on a pedestal that is movable downwardly and is rotatable. The first and second heaters are spaced vertically along an outer wall of the crucible and are arranged around the crucible to heat pieces of solid material deposited in the crucible. A third heater is arranged above the crucible if the crucible includes a solid cylindrical mold or in a hollow cylindrical space of the crucible if the crucible includes a hollow cylindrical mold. The controller is configured to control the first and second heaters to heat the pieces of the solid material to form a melted liquid. The controller is configured to control the rotational and downward movements of the pedestal relative to the first and second heaters during solidification of the melted liquid to form an ingot.

Abstract: A system comprises a silicon seed arranged on a pedestal, where the silicon seed is ring shaped and is configured to receive melted silicon at a feed rate to form an ingot, and where the pedestal is configured to rotate at a rotational speed. A controller is configured to, while the silicon seed receives the melted silicon and while the ingot is forming: receive feedback regarding a diameter of the ingot and regarding an angle of a meniscus of the ingot, and control the rotational speed of the pedestal and the feed rate of the melted silicon based on the feedback to control the diameter of the ingot and the angle of the meniscus of the ingot.