METHOD OF PRODUCING POLYCRYSTALLINE SILICON Russian patent published in 2013 - IPC C30B28/14 C30B29/06 C30B25/14 C30B25/16 C01B33/35 C23C16/24 C23C16/455 C23C16/52 

FIELD: chemistry.

SUBSTANCE: method involves heating multiple silicon nucleating rods placed in a reaction furnace, followed by deposition of polycrystalline silicon on the surface of the nucleating rods using a feed gas released from gas vents lying in the inner bottom part of the reaction furnace. The method includes a deposit stabilisation step, wherein the rate of release of feed gas from the gas vents is gradually increased at the first step for depositing polycrystalline silicon, wherein 5-15% of the gas vents are closed; a shaping step, wherein the first rate of release is increased, with the rate of increase higher than the rate of increase at the stabilisation step, and the rate of release is then gradually increased at a rate lower than the rate of increase; wherein the time required for the shaping step is 20-35% of the total duration of deposition of polycrystalline silicon and 30-55% of the gas vents are closed; and a growth step, wherein after the shaping step, the rate of release of feed gas is reduced by reducing the number of closed gas vents compared to the shaping step.

EFFECT: invention enables to obtain a larger amount of high-quality polycrystalline silicon, having a smooth surface morphology through efficient protection of the surface of silicon rods from deformation.

4 cl, 7 dwg, 8 ex