Apparatus for producing polycrystalline silicon
AssigneeMitsubishi Materials Corporation
InventorsMakoto Urushihara, Kazuki Mizushima
Life of this patent
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Abstract
A polycrystalline silicon producing method with preventing meltdown and maintaining a high growing rate and a high yield by increasing temperature of raw material gas before supplying them to a reactor in a high pressure state so as to lower convection heat transfer from a silicon rod, including: supplying electric current to a silicon seed rod in a reactor to make the silicon seed rod to generate heat; and supplying a large amount of preheated raw material gas including chlorosilanes to the silicon seed rod in the reactor in the high pressure state.
Claims8
1-6. (canceled)
A polycrystalline silicon producing apparatus which produces a silicon rod by supplying raw material gas including chlorosilanes to a silicon seed rod which is heated in a reactor so as to deposit polycrystalline silicon on the silicon seed rod, comprising:
- the reactor;
- the silicon seed rod which is disposed in the reactor;
- a power supply which supplies electric current to and heat the silicon seed rod;
- a pressure controller which controls an inner pressure of the reactor in a range equal to or larger than 0.4 MPa and equal to or lower than 0.9 MPa;
- a thermometer which measures a surface temperature of the silicon rod;
- a current control device which controls the surface temperature of the silicon rod measured by the thermometer in a range equal to or higher than 1000° C. and equal to or lower than 1100° C.;
- a raw material gas-supply source which supplies the raw material gas;
- a raw material gas-controller which controls a supply amount of the raw material gas from the raw material gas-supply source;
- and
- a pre-heater which preheats the raw material gas in a range equal to or higher than 150° C. and equal to or lower than 600° C.;
- wherein the supply amount of the raw material gas is controlled by the raw material gas-controller so that a supply amount of chlorosilanes included in the raw material gas is in a range equal to or larger than 2.0×10−7 mol/sec/mm2 and equal to or smaller than 3.0×10−2 mol/sec/mm2 depending on a surface area of the growing silicon rod.
Dependencies are inferred from the claim text.