Apparatus and methods for preparation of high-purity silicon rods using mixed core means

Abstract

Disclosed are a method and an apparatus for preparing a polycrystalline silicon rod using a mixed core means, comprising: installing a first core means made of a resistive material together with a second core means made of silicon material in an inner space of a deposition reactor; electrically heating the first core means and pre-heating the second core by the first core means which is electrically heated; electrically heating the preheated second core means; and supplying a reaction gas into the inner space in a state where the first core means and the second core means are electrically heated for silicon deposition.

1 . A method for preparing a polycrystalline silicon rod using a mixed core means, comprising:
 installing a first core means made of a resistive material together with a second core means made of a silicon material in an inner space of a deposition reactor, wherein the resistive material is different from the silicon material;   electrically heating the first core means and pre-heating the second core means by the first core means which is electrically heated; and   electrically heating the pre-heated second core means so as to deposit the polycrystalline silicon rod from the first core means and the second core means,   
   
   
       2 . The method for preparing the polycrystalline silicon rod using a mixed core means as set forth in  claim 1 , wherein, in the step of electrically heating the pre-heated second core means, the entire second core means is electrically heated simultaneously, or the second core means divided into a plurality of second core groups are electrically heated in groups at different starting times. 
   
   
       3 . The method for preparing the polycrystalline silicon rod using a mixed core means as set forth in  claim 1 , wherein, in the step of pre-heating the second core means, the second core means is pre-heated to a temperature in the range of 350-1,000° C. with the first core means being electrically heated to a temperature in the range of 400-3,000° C. 
   
   
       4 . The method for preparing the polycrystalline silicon rod using a mixed core means as set forth in  claim 1 , wherein, in the step of pre-heating the second core means, the second core means is pre-heated in the inner space at a pressure in the range of 1-20 bar absolute under an atmosphere selected from the group consisting of hydrogen, nitrogen, argon, helium and a mixture thereof. 
   
   
       5 . The method for preparing the polycrystalline silicon rod using a mixed core means as set forth in  claim 1 , wherein a reaction gas is supplied for a silicon deposition reaction, by which a deposition output is formed outwardly on the first core means and/or the second core means with a first deposition output and/or a second deposition output being formed thereby, respectively, at a reaction pressure and a reaction temperature. 
   
   
       6 . The method for preparing the polycrystalline silicon rod using a mixed core means as set forth in  claim 5 , wherein the reaction gas contains at least one silicon-containing component selected from the group consisting of monosilane (SiH4), dichlorosilane (SiH2Cl2), trichlorosilane (SiHCl3), silicon tetrachloride (SiCl4) and a mixture thereof. 
   
   
       7 . The method for preparing the polycrystalline silicon rod using a mixed core means as set forth in  claim 6 , wherein the reaction gas further contains at least one gas component selected from the group consisting of hydrogen, nitrogen, argon, helium, hydrogen chloride, and a mixture thereof. 
   
   
       8 . The method for preparing the polycrystalline silicon rod using a mixed core means as set forth in  claim 5 , wherein the silicon deposition reaction occurs in the inner space at a reaction pressure in the range of 1-20 bar absolute and a reaction temperature in the range of 650-1,300° C. based on the surface temperature of the first deposition output and/or the second deposition output. 
   
   
       9 . The method for preparing the polycrystalline silicon rod using a mixed core means as set forth in  claim 5 , wherein a quantity of an impurity component included to the first deposition output is more than that of an impurity components included to the second deposition. 
   
   
       10 . The method for preparing the polycrystalline silicon rod using a mixed core means as set forth in  claim 1 , wherein the resistive material is a metal or an alloy comprising at least one metal element selected from the group consisting of tungsten (W), rhenium (Re), osmium (Os), tantalum (Ta), molybdenum (Mo), niobium (Nb), iridium (Ir), ruthenium (Ru), technetium (Tc), hafnium (Hf), rhodium (Rh), vanadium (V), chromium (Cr), zirconium (Zr), platinum (Pt), thorium (Th), lanthanum (La), titanium (Ti), lutetium (Lu), yttrium (Y), ferrum (Fe), nickel (Ni), aluminum (Al) and a mixture thereof. 
   
   
       11 . The method for preparing the polycrystalline silicon rod using a mixed core means as set forth in  claim 1 , wherein the resistive material is a ceramic metal material containing at least one component selected from the group consisting of molybdenum silicide (Mo—Si), lanthanum chromium oxide (La—Cr—O), zirconia and a mixture thereof. 
   
   
       12 . The method for preparing the polycrystalline silicon rod using a mixed core means as set forth in  claim 1 , wherein the resistive material is a carbon-based material comprising at least one component selected from the group consisting of amorphous carbon, graphite, silicon carbide (SiC) and a mixture thereof. 
   
   
       13 . The method for preparing the polycrystalline silicon rod using a mixed core means as set forth in  claim 1 , wherein the silicon material is selected from the group consisting of intrinsic polycrystalline silicon, intrinsic single crystalline silicon, doped silicon and a mixture thereof. 
   
   
       14 . An apparatus used as a deposition reactor for preparing a polycrystalline silicon rod by carrying out a silicon deposition reaction, comprising:
 a first core means and a second core means installed in an inner space of the deposition reactor;   a first electrode means electrically connected to the first core means; and   a second electrode means electrically connected to the second core means, which is electrically independent to the first electrode means,   wherein the material of the first core means is different from that of the second core means, the first core means are made of a resistive material and the second core means are made of a silicon material.   
   
   
       15 . The apparatus as set forth in  claim 14 , further comprising a base unit and a shell to form the inner space of the deposition reactor, the first electrode means and/or the second electrode means are/is installed on the base unit. 
   
   
       16 . The apparatus as set forth in  claim 14 , wherein the first electrode means is divided into one or a plurality of first electrode groups and the second electrode means is divided into one or a plurality of second electrode groups, with electric powers being independently supplied to the respective electrode groups. 
   
   
       17 . The apparatus as set forth in  claim 14 , wherein the first electrode means is constructed such that an electric power required for heating the first core means is independently supplied from a first electric power supply source through a first electric power transmitting means, and the second electrode means is constructed such that an electric power required for heating the second core means is independently supplied from a second electric power supply source through a second electric power transmitting means. 
   
   
       18 . The apparatus as set forth in  claim 17 , wherein the first electric power supply source and the second electric power supply source are constituted separately as independent electric power converting systems or constituted as one integrated electric power converting system. 
   
   
       19 . The apparatus as set forth in  claim 17 , wherein the first core means included to one or a plurality of deposition reactors are electrically interconnected with each other by the first electric power supply source. 
   
   
       20 . The apparatus as set forth in  claim 17 , wherein the second core means included to one or a plurality of deposition reactors are electrically connected to each other by the second electric power supply source. 
   
   
       21 . The apparatus as set forth in  claim 14 , wherein the first core means or the second core means have a shape selected from the group consisting of a rod, a wire, a filament, a bar, a strip and a ribbon having a cross-sectional shape of a circle, an oval or a polygon, and of a conduit, a tube, a cylinder, and a duct having a cross-sectional shape of a concentric circle, a concentric oval or a concentric polygon. 
   
   
       22 . The apparatus as set forth in  claim 14 , wherein the resistive material of the first core means is a metal or an alloy comprising at least one metal element selected from the group consisting of tungsten (W), rhenium (Re), osmium (Os), tantalum (Ta), molybdenum (Mo), niobium (Nb), iridium (Ir), ruthenium (Ru), technetium (Tc), hafnium (Hf), rhodium (Rh), vanadium (V), chromium (Cr), zirconium (Zr), platinum (Pt), thorium (Th), lanthanum (La), titanium (Ti), lutetium (Lu), yttrium (Y) ferrum (Fe), nickel (Ni), aluminum (Al) and a mixture thereof. 
   
   
       23 . The apparatus as set forth in  claim 14 , wherein the resistive material of the first core means is a ceramic metal material containing at least one component selected from the group consisting of molybdenum silicide (Mo—Si), lanthanum chromium oxide (La—Cr—O), zirconia and a mixture thereof. 
   
   
       24 . The apparatus as set forth in  claim 14 , wherein the resistive material of the first core means is a carbon-based material comprising at least one component selected from the group consisting of amorphous carbon, graphite, silicon carbide (SiC) and a mixture thereof. 
   
   
       25 . The apparatus as set forth in  claim 14 , wherein the silicon material of the second core means is selected from the group consisting of intrinsic polycrystalline silicon, intrinsic single crystalline silicon, doped silicon and a mixture thereof. 
   
   
       26 . The apparatus as set forth in  claim 14 , wherein one or a plurality of separation layer(s) is/are formed on a surface of a first core element constituting the first core means. 
   
   
       27 . The apparatus as set forth in  claim 26 , wherein the number of the separation layer(s) is in the range of 1 to 5. 
   
   
       28 . The apparatus as set forth in  claim 26 , wherein a component of the separation layer is selected from the group consisting of intrinsic silicon nitride, silicon oxide, silicon carbide, silicon oxynitride and a mixture thereof. 
   
   
       29 . The apparatus as set forth in  claim 26 , wherein a component of the separation layer is selected from a nitride, an oxide, a silicide, a carbide, an oxynitride or an oxysilicide comprising at least one metal element selected from the group consisting of tungsten (W), rhenium (Re), osmium (Os), tantalum (Ta), molybdenum (Mo), niobium (Nb), iridium (Ir), ruthenium (Ru), technetium (Tc), hafnium (Hf), rhodium (Rh), vanadium (V), chromium (Cr), zirconium (Zr), platinum (Pt), thorium (Th), lanthanum (La), titanium (Ti), lutetium (Lu), yttrium (Y), and a mixture thereof. 
   
   
       30 . The apparatus as set forth in  claim 26 , wherein the overall thickness of the separation layer(s) formed on the first core element is in the range of 10 μm to 20 mm. 
   
   
       31 . The apparatus as set forth in  claim 26 , wherein a silicon layer is formed on the separation layer and the thickness of the silicon layer is in the range of 1 μm-10 mm. 
   
   
       32 . The apparatus as set forth in  claim 14 , wherein the first core means is heat-treated at a temperature in the range of 400-3,000° C. 
   
   
       33 . The apparatus as set forth in  claim 32 , wherein the first core means is heat-treated by being electrically heated in the deposition reactor or an apparatus other than the deposition reactor. 
   
   
       34 . The apparatus as set forth in  claim 26 , wherein the first core means is constructed by surrounding the surface of the first core element with a plurality of units made of a component of the separation layer. 
   
   
       35 . The apparatus as set forth in  claim 26 , wherein the first core means is constructed by coating a component of the separation layer on the surface of the first element. 
   
   
       36 . The apparatus as set forth in  claim 26 , wherein part of the separation layer(s) or the entire separation layer(s) are formed in an apparatus other than the deposition reactor. 
   
   
       37 . The method for preparing the polycrystalline silicon using a mixed core means as set forth in  claim 1 , further comprising, supplying a reaction gas into the inner space of the deposition reactor in a state where the first core means and the second core means are electrically heated. 
   
   
       38 . The method for preparing the polycrystalline silicon using a mixed core means as set forth in  claim 1 , wherein the first core means or the second core means is prepared by forming a single core element or by connecting a plurality of core element parts. 
   
   
       39 . The apparatus as set forth in  claim 14 , further comprises a gas supply means for supplying a reaction gas into the inner space of the deposition reactor and a gas outlet means for discharging an off gas from the inner space of the deposition reactor. 
   
   
       40 . The apparatus as set forth in  claim 14 , wherein the first core means or the second core means is prepared by forming a single core element or by connecting a plurality of core element parts.