PURPOSE: To prevent impurities from being mixed in silicon particles over a long period of time by specifying the total content of impurity elements in a fluidized reactor construction material in depth up to the prescribed surface of the fluidized bed reactor construction material to a prescribed value.
CONSTITUTION: In a fluidized bed reactor for producing polycrystalline silicon particles, a reactor where impurity elements (group Ia, group IIa, transition metal elements, boron, phosphorus and arsenic) are contained by ≤10ppm altogether in the material of a reactor construction member with which silicon particles come into contact, in depth of at least 20μm from the surface of the reactor construction member is used, causing the contamination due to the diffusion of the impurity elements to be prevented. Heat resistant materials of good workability, such as SiC, SiC/Si, alumina, mullite, graphite and silicon nitride are used as the reactor construction member. In the production process of the materials and that of the formed parts, the impurity elements are prevented from being mixed. And the surface of the reactor construction member thus produced may be coated with a silicon film of ≥10μm thickness.
ISHII MASAAKI
TAKATSUNA KAZUTOSHI
SARUWATARI YASUHIRO
ISHIKAWA NOBUHIRO
HIROTA DAISUKE
TOA GOSEI CHEM IND
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