Polysilicon deposition

A method and process for the production of bulk polysilicon by chemical vapor deposition (CVD) where conventional silicon "slim rods" commonly used in Siemens-type reactors are replaced with shaped silicon filaments of similar electrical properties but larger surface areas, such as silicon tubes, ribbons, and other shaped cross sections. Silicon containing gases, such as chlorosilane or silane, are decomposed and form a silicon deposit on the hot surfaces of the filaments The larger starting surface areas of these filaments ensures a higher production rate without changing the reactor size, and without increasing the number and length of the filaments. Existing reactors need only the adaptation or replacement of filament supports to use the new filaments. The filaments are grown from silicon melt by Edge-defined, Film-fed Growth (EFG) method. This also enables the doping of the filaments and simplification of power supplies for new reactors.