Abstract: A hybrid nozzle for use in a plasma spray gun, especially for plasma spraying silicon to form semiconductor devices such as solar cell. The outlet of the gun includes a two-piece annular electrode against which the plasma is ignited and through which the plasma plume exits the gun together with entrained silicon. In one embodiment, the upstream part is composed of graphite to allow ignition of the plasma and the downstream part is composed of pure silicon. In another aspect, the silicon feedstock is injected into the plasma plume through ports formed through the silicon part.

Abstract: Doped silicon particles, including powder suitable for plasma spraying semiconductor devices, is formed by liquid doping applied to larger particles, which are then milled to a smaller size. Doped or undoped silicon may be milled by a roller mill including silicon rollers and advantageously having feed and collection systems formed of silicon and operated in a nitrogen ambient. A two-stage system includes sieving the rolled product for further size reduction in a jet mill.

Abstract: A hybrid nozzle for use in a plasma spray gun, especially for plasma spraying silicon to form semiconductor devices such as solar cell. The outlet of the gun includes a two-piece annular electrode against which the plasma is ignited and through which the plasma plume exits the gun together with entrained silicon. In one embodiment, the upstream part is composed of graphite to allow ignition of the plasma and the downstream part is composed of pure silicon. In another aspect, the silicon feedstock is injected into the plasma plume through ports formed through the silicon part.