Abstract: A cascade source provided with a cathode housing, a number of cascade plates insulated from each other and stacked on top of each other which together bound at least one plasma channel, and an anode plate provided with an outflow opening connecting to the plasma channel, wherein one cathode is provided per plasma channel, which cathode comprises an electrode which is adjustable relative to the cathode housing in the direction of the plasma channel, wherein the clamping provision is preferably of the collet chuck type. Also described is method for controlling the cascade source in use.

Abstract: A cascade source includes a cathode housing, a number of cascade plates insulated from each other and stacked on top of each other which together bound at least one plasma channel, and an anode plate provided with an outflow opening connecting to the plasma channel. One cathode is provided per plasma channel, which cathode includes an electrode which is adjustable relative to the cathode housing in the direction of the plasma channel. The clamp may be of the collet chuck type. At least a part of the housing of the source may be substantially transparent. A method for controlling the cascade source in use includes monitoring the electromagnetic radiation of the plasma through the substantially transparent housing part, and, dependent on the monitored radiation, controlling the plasma forming process in the source by variation of the gas supply, or variation of the potential difference between the cathode and the anode or a combination thereof.

Abstract: A method is provided for the production of solar cells from raw crystalline p-type silicon wafer material. The surface condition prior to SiNx deposition is improved by providing additional process steps following the phosphorous glass removal and prior to the SiNx anti-reflection coating deposition. In one embodiment, the wafer is submitted to a thermal anneal under oxygen atmosphere followed by a wet-chemical oxide removal. The anneal reduces the surface phosphorous concentration by diffusion, reduces lattice defects in the emitter and oxidizes the silicon surface. In another embodiment, both a surface oxide is obtained and subsequently removed with wet chemistry. This sequence allows for an integration of the phosphorous glass removal, the wet-chemical oxidation, and the SiOx removal into a single machine.