Industrial polysilicon reactor types: (a) Siemens SiHCl3 (TCS) hydrogen reduction or SiH4 (MS) pyrolysis reactor. Hereinafter denoted as Siemens TCS or Siemens MS, respectively. Polysilicon is deposited on seed rods: (a) SiHCl3 + H2 → Si +3HCll; (b) SiH4 → Si + H2; (b) MS decomposition or TCS hydrogen reduction fluidized bed reactor. Hereinafter denoted as FBR-MS or FBR-TCS, respectively. Polysilicon is produced in a granulated form: (a) SiH4 → Si + H2; (b) SiHCl3 + H2 → Si +3HCl.