Fluid bed process for producing polysilicon

摘要: Silicon of high purity is made by decomposing silane in a fluidized bed reactor. To obtain good process economics, two modes operation are used. In first mode, the reactor operated under productivity conditions which also result co-production silicon dust or fines. The on particles can cause problems handling. For example, bagging particles, removing from bag, become airborne larger particle surfaces and form an objectionable cloud dust. invention provides method for uniting to particles. second thin (0.1-5.0 micron) layer deposited laden This mode most preferably carried out (a) treating dust-laden with deposition gas comprising 1 5 mole % admixed inert carrier such as hydrogen, (b) reactor, (c) at temperature 620°-650° C. product polysilicon composed free flowing, approximately spherical having size distribution 150-1500 microns, average 650- 750 microns has bulk density 2.3 grams per cubic centimeter, about 1360 kg/m3 surface content less than 0.08 wt. %.