Методы получения трихлорсилана для производства поликристаллического кремния

Novel technical solutions and ideas for increasing the yield of solar and semiconductor grade polycrystalline silicon processes have been analyzed. The predominant polycrystalline silicon technology is currently still the Siemens process including the conversion of technical grade silicon (synthesized by carbon-thermal reduction of quartzites) to trichlorosilane followed by rectification and hydrogen reduction. The cost of product silicon can be cut down by reducing the trichlorosilane synthesis costs through process and equipment improvement. Advantages, drawbacks and production cost reduction methods have been considered with respect to four common trichlorosilane synthesis processes: hydrogen chloride exposure of technical grade silicon (direct chlorination, DC), homogeneous hydration of tetrachlorosilane (conversion), tetrachlorosilane and hydrogen exposure of silicon (hydro chlorination silicon, HC), and catalyzed tetrachlorosilane and dichlorosilane reaction (redistribution of anti-disproportioning reaction). These processes remain in use and are permanently improved. Catalytic processes play an important role on silicon surface, and understanding their mechanisms can help find novel applications and obtain new results. It has been noted that indispensable components of various equipment and process designs are recycling steps and combined processes including active distillation. They provide for the most complete utilization of raw trichlorosilane, increase the process yield and cut down silicon costВ работе проведен анализ новых технических решений и идей, направленных на повышение производительности процессов получения поликристаллического кремния «солнечного» и полупроводникового качества. Доминирующей технологией поликристаллического кремния остается Сименс-процесс, включающий перевод технического кремния (получаемого карботермическим восстановлением кварцитов) в трихлорсилан с последующими ректификационной очисткой и водородным восстановлением. Для снижения стоимости получаемого кремния необходимо уменьшать затраты на производство трихлорсилана путем совершенствования технологии и аппаратурного оформления. Рассмотрены преимущества, недостатки и пути снижения производственных затрат четырех известных методов получения трихлорсилана: взаимодействием хлористого водорода с техническим кремнием «direct chlorination» (DC), гомогенным гидрированием тетрахлорсилана (конверсией), реакцией тетрахлорсилана и водорода с кремнием «hydro chlorination silicon» (HC), а также взаимодействием тетрахлорсилана и дихлорслана в присутствии катализатора (реакцией перераспределения или анти-диспропорционирования). Эти методы остаются актуальными и постоянно совершенствуются. Большую роль играют каталитические процессы на поверхности кремния, понимание механизма которых позволит найти новые приложения и получить новые результаты. Отмечено, что необходимыми элементами аппаратурно-технологических схем являются рециклы и совмещенные процессы, в том числе реактивная дистилляция. Это позволяет наиболее полно использовать исходный трихлорсилан, получать полезные продукты и снижать стоимость изготавливаемого кремния

Methods of trichlorosilane synthesis for polycrystalline silicon production. Part 1: Direct synthesis

Novel technical solutions and ideas for increasing the yield of solar and semiconductor grade polycrystalline silicon processes have been analyzed. The predominant polycrystalline silicon technology is currently still the Siemens process including the conversion of technical grade silicon (synthesized by carbon-thermal reduction of quartzites) to trichlorosilane followed by rectification and hydrogen reduction. The cost of product silicon can be cut down by reducing the trichlorosilane synthesis costs through process and equipment improvement. Advantages, drawbacks and production cost reduction methods have been considered with respect to four common trichlorosilane synthesis processes: hydrogen chloride exposure of technical grade silicon (direct chlorination, DC), homogeneous hydration of tetrachlorosilane (conversion), tetrachlorosilane and hydrogen exposure of silicon (hydro chlorination silicon, HC), and catalyzed tetrachlorosilane and dichlorosilane reaction (redistribution of anti-disproportioning reaction). These processes remain in use and are permanently improved. Catalytic processes play an important role on silicon surface, and understanding their mechanisms can help find novel applications and obtain new results. It has been noted that indispensable components of various equipment and process designs are recycling steps and combined processes including active distillation. They provide for the most complete utilization of raw trichlorosilane, increase the process yield and cut down silicon cost

Methods of trichlorosilane synthesis for polycrystalline silicon production. Part 2: Hydrochlorination and redistribution

Novel technical solutions and ideas for increasing the yield of solar and semiconductor grade polycrystalline silicon processes have been analyzed. The predominant polycrystalline silicon technology is currently still the Siemens process including the conversion of technical grade silicon (synthesized by carbon-thermal reduction of quartzites) to trichlorosilane followed by rectification and hydrogen reduction. The cost of product silicon can be cut down by reducing the trichlorosilane synthesis costs through process and equipment improvement. Advantages, drawbacks and production cost reduction methods have been considered with respect to four common trichlorosilane synthesis processes: hydrogen chloride exposure of technical grade silicon (direct chlorination, DC), homogeneous hydration of tetrachlorosilane (conversion), tetrachlorosilane and hydrogen exposure of silicon (hydro chlorination silicon, HC), and catalyzed tetrachlorosilane and dichlorosilane reaction (redistribution of anti-disproportioning reaction). These processes remain in use and are permanently improved. Catalytic processes play an important role on silicon surface, and understanding their mechanisms can help find novel applications and obtain new results. It has been noted that indispensable components of various equipment and process designs are recycling steps and combined processes including active distillation. They provide for the most complete utilization of raw trichlorosilane, increase the process yield and cut down silicon cost