Methods of trichlorosilane synthesis for polycrystalline silicon production

Abstract

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

The modern phase of the polysilicon market

“…This of course does not depreciate the necessity of improving the existing Siemens processes. Some authors believe that now it is the time to correct the overall approach to the advanced Siemens production of technical grade silicon [2,[19][20][21]:…”

Plasma-Chemical Disposal of Silicon and Germanium Tetrachlorides Waste by Hydrogen Reduction

“…Another source of STC waste is the Siemens process of producing polysilicon by reducing TCS, where STC is formed as a by-product [1]. In addition, in the process of TCS synthesis, 50-60 mole% of STC are formed by the silicon hydrochlorination reaction as a byproduct [16]. In this regard, the utilization of STC by reducing it to TCS or semiconductor silicon will make it possible to organize the production of silicon both using hydride technology and using the Siemens process in a closed and environmentally friendly manner.…”

Программный Комплекс Моделирования Реактора Гидрохлорирования Кремния

“…В настоящее время ТХС является важным сырьем для производства поликристаллического кремния, моносилана и дихлорсилана (которые также используются в синтезе поликремния), основного ряда кремнийорганических мономеров. Кроме того, существуют и другие области его применения, например, микроэлектроника, где он используется для эпитаксиального осаждения пленок монокристаллического кремния [2].…”

“…A software package for simulating a silicon hydrochlorination reactor I.V. Glushkov 1,2 , Ph.D. (Engineering), Doctoral Student, Director, modteh@mail.ru T.B. Chistyakova 3 , Dr.Sc.…”