METHOD OF PRODUCING POLYCRYSTALLINE SILICON AND REACTOR FOR PRODUCING POLYCRYSTALLINE SILICON Russian patent published in 2016 - IPC C01B33/35 C01B33/02 C30B28/14 C30B25/14 C30B29/06 C23C16/24 

FIELD: chemistry.

SUBSTANCE: invention relates to production of polycrystalline silicon by depositing on silicon electrode wire using Siemens method. Method includes first stage with relatively low gas supply, last stage with relatively high gas supply and intermediate step where amount of supplied gas is increased from value of supply at first stage to supply at last step at supply of initial gas containing gaseous chlorosilanes and hydrogen gas, in reactor through inlet hole with nozzle, all three stages are carried out at reaction temperature of 900 °C to 1250 °C and under pressure of 0.3-0.9 MPa, velocity in inlet hole with nozzle head piece is 150 m/s or more at maximum feeding of initial gas at last step, and gas supply and temperature of silicon rod is controlled in accordance with following conditions of A-C depending on polycrystalline silicon rod diameter D, which varies during deposition reaction after its beginning: condition A (amount of supplied gaseous chlorosilanes): gaseous chlorosilanes are fed in amount of one third or less of maximum gaseous chlorosilanes feed until specified value D₁ from 15 to 40 mm is achieved, supplied amount is increased gradually or in steps until maximum supply of gaseous in chlorosilane between when achieved value D₁, and when will be achieved specified value D₂ from 15 to 40 mm, which is more than D₁, maximum gaseous chlorosilane feed kept after achievement of D₂ value; condition B (amount of supplied gaseous hydrogen): gaseous hydrogen is supplied to concentration of gaseous chlorosilanes in initial gas is from 30 mol% to less than 40 mol% until value D₁ is achieved, ratio of amount of fed hydrogen gas to amount of gaseous in chlorosilane increases gradually or in steps after value D₁ is achieved, gaseous hydrogen is supplied to concentration of gaseous chlorosilanes in source gas makes from 15 mol% to less than 30 mol% after value D₂ is achieved and condition C (silicon rod temperature): temperature is decreased as silicon rod diameter after value D₂ is achieved.

EFFECT: thus, rod of high-purity polycrystalline silicon without minor defects of "popcorn" type may be produced without reducing efficiency even in reaction system with high pressure, high load and high rate of reaction.

5 cl, 2 dwg, 1 tbl, 6 ex