초록 ▼

The present invention relates to a method for producing highly pure, granular silicon with a narrow particle-size distribution by decomposing silanes or halosilanes in a fluidised bed and epitaxially growing silicon on silicon seed particles, which method is characterised in that the gas containing

The present invention relates to a method for producing highly pure, granular silicon with a narrow particle-size distribution by decomposing silanes or halosilanes in a fluidised bed and epitaxially growing silicon on silicon seed particles, which method is characterised in that the gas containing silicon is supplied to the reaction chamber in an upward flow and the contents of the fluidised bed are separated in a continuous or discontinuous manner, whereby a particle stream from the fluidised bed is supplied to a separator mounted outside the fluidised bed, particles of the desired size are separated and undersized particles are returned to the fluidised bed. The invention also relates to a device and the use thereof for carrying out said method.

대표청구항 ▼

The invention claimed is: 1. A method for producing highly pure, granular silicon with a narrow particle-size distribution by decomposing silanes or halosilanes in a fluidized bed and epitaxially growing silicon on silicon seed particles, the method comprising: providing a reaction chamber; providi

The invention claimed is: 1. A method for producing highly pure, granular silicon with a narrow particle-size distribution by decomposing silanes or halosilanes in a fluidized bed and epitaxially growing silicon on silicon seed particles, the method comprising: providing a reaction chamber; providing a separator; providing a separation gas supply; providing a cyclone element; supplying a gas containing silicon is supplied to the to said reaction chamber in an upward flow; separating contents of the fluidized bed in a continuous manner, whereby a particle stream from the fluidized bed is supplied through at least one side outlet into said separator, said separator being mounted outside the fluidized bed, said separator being provided with separation gas via said separation gas supply, wherein particles of a desired size are separated via said separator, said separation gas including fine material after said particles are separated via said separator; controlling a flow of said particle stream through said at least one side outlet from said reaction chamber by a gas flow entering said at least one side outlet via another outlet, said gas flow being opposite to an outlet flow direction of said particle stream; and introducing said fine material in said separation gas into said cyclone element via an ascending pipe, said fine material being separated from said separation gas via said cyclone element. 2. A method according to claim 1, wherein after separation undersized particles are returned to the fluidized bed. 3. A method according to claim 1, wherein the desired size of the particles obtained by the separation process is between 50 and 5000 μm. 4. A method according to claim 1, wherein at least 90% of the particles obtained by the separation process have a grain size differing from the desired particle size by maximum 20%. 5. A method according to claim 1, wherein the flow of said gas containing silicion is introduced into the reactor chamber through a reactor bottom with more than one aperture. 6. A method according to claim 1, wherein a pressure prevailing in a portion of said reactor chamber located behind the fluidized bed as seen in flow direction of said gas containing silicion, is between 50 and 50000 mbar. 7. A method according to claim 1, wherein the separation is carried out in a vertical upflow separator. 8. A method according to claim 1, wherein the separation is carried out in a zigzag separator. 9. A method according to claim 1, wherein said fine material is separated from the separation gas in a dust separator. 10. A method according to claim 1, wherein said fine material is delivered to said reaction chamber. 11. A method according to claim 1, wherein said gas containing silicon contains silane SiH4. 12. A method according to claim 1, wherein said gas containing silicon contains hydrogen. 13. A method according to claim 1, wherein silicon is produced, said silicon being used in the photovoltaic area. 14. A method according to claim 1, wherein silicon is produced, said silicon being used in the manufacture of electronic components. 15. A method for producing highly pure, granular silicon with a narrow particle-size distribution by decomposing silanes or halosilanes in a fluidized bed and epitaxially growing silicon on silicon seed particles, the method comprising: providing a reaction chamber, said reaction chamber having a bottom portion with at least one aperture; providing a separator including an ascending tube, said tube being connected to said reaction chamber; providing a separation gas supply; providing a connector element connected to said separation gas supply, said separator being connected to said reaction chamber via said connector element; providing a fluidized bed; supplying a flow of gas containing silicon to said reaction chamber, said flow of gas containing silicon being supplied in a longitudinal direction of said reaction chamber; separating contents of said gas containing silicon in said fluidized bed in a continuous manner such that a flow of particles from the fluidized bed is delivered to said separator via, said connector element, said separator being located at a position outside said fluidized bed, said separation gas supply supplying separation gas to said separator such that said flow of particles mixes with said separation gas, said separator separating said particles mixed in said separation gas such that said separation gas contains a desired size of particles; controlling said flow of said particles from said reaction chamber to said connector element based on a controlled feeding of a control gas supplied to said connector element; and providing a fine particle separation means for separating said desired size of particles from said separation gas; delivering said separation gas containing said desired size of particles to said fine particle separation means via said tube; separating said desired size of particles from said separation gas with said fine particle separation means after said separation containing said desired size of particles is delivered to said fine particle separation means to form separated desired sized particles. 16. A method according to claim 15, wherein said separated desired sized particles delivered to said fluidized bed. 17. A method according to claim 15, wherein said separated desired sized particles have a size between 50 and 5000 μm. 18. A method according to claim 15, wherein a pressure prevailing in a portion of said reactor chamber located behind the fluidized bed as seen in flow direction of said gas containing silicion, is between 50 and 50000 mbar. 19. A method for producing highly pure, granular silicon with a narrow particle-size distribution by decomposing silanes or halosilanes in a fluidized bed and epitaxially growing silicon on silicon seed particles, the method comprising: providing a reaction chamber, said reaction chamber having a side surface and a bottom portion with at least one aperture, said side surface having a reaction chamber opening; providing a separator including an ascending tube, said tube having a tube surface defining a tube opening, said separator being located at a spaced location from said reaction chamber; providing a separation gas supply; providing a connector element connected to said separation gas supply, said connector element being connected to said separator and said reaction chamber, wherein said reaction chamber opening is in communication with said tube opening; providing a fluidized bed; supplying a flow of gas containing silicon to said reaction chamber, said flow of gas containing silicon being supplied in a longitudinal direction of said reaction chamber; separating contents of said gas containing silicon in said fluidized bed in a continuous manner such that a flow of particles from the fluidized bed is delivered to said separator via said connector element, said separator being located at a position outside said fluidized bed, said separation gas supply supplying separation gas to said separator such that said flow of particles mixes with said separation gas, said separator separating said particles mixed in said separation gas such that said separation gas contains a desired size of particles; controlling said flow of said particles from said reaction chamber to said connector element based on a controlled feeding of a control gas supplied to said connector element; and providing a fine particle separation means for separating said desired size of particles from said separation gas; delivering said separation gas containing said desired size of particles to said fine particle separation means via said tube such that said desired size of particles are separated from said separation gas with said fine particle separation means.