Abstract: A cleaning method including an alkaline cleaning step followed by an acid cleaning step is used, for example, to treat a newly constructed ultrapure water distribution piping system (using PVDF piping system). The inherent inorganic and organic contaminants in the piping material as well as contaminants deposited (if any) during the construction phase can be removed efficiently. Therefore, the commissioning time of a newly constructed ultrapure water distribution system to meet the specified quality of contaminants can be shortened from several weeks to approximately one week.

Abstract: A device for thermally treating semiconductor wafers having at least one silicon layer to be oxidized and a metal layer, preferably a tungsten layer, which is not to be oxidized. The inventive device comprises the following: at least one radiation source; a treatment chamber receiving the substrate, with at least one wall part located adjacent to the radiation sources and which is substantially transparent for the radiation of said radiation source; and at least one cover plate between the substrate and the wall part of the treatment chamber located adjacent to the radiation sources, the dimensions of said cover plate being selected such that it fully covers the transparent wall part of the treatment chamber in relation to the substrate in order to prevent material, comprising a metal, metal oxide or metal hydroxide such as tungsten, tungsten oxide or tungsten hydroxide, from said substrate from becoming deposited on or evaporating onto the transparent wall part of the treatment chamber.