Preparation method and system for electronic-grade polycrystalline silicon

Abstract

The invention discloses a preparation method and system for electronic-grade polycrystalline silicon. The method includes the steps of mixing hydrogen with silane gas to obtain raw material mixed gas, wherein the mol percentage of the silane gas in the raw material mixed gas is 3% to 5%; preheating the raw material mixed gas; sending the preheated raw material mixed gas into a chemical vapor deposition furnace to react so that electronic-grade polycrystalline silicon can be obtained; cooling tail gas; conducting filtering and dust removing on the cooled tail gas; introducing the tail gas subjected to dust removing and filtering into a cold hydrogenation system to be used again. Due to the adoption of the preparation method and system for electronic-grade polycrystalline silicon, electronic-grade polycrystalline silicon can be prepared, and the preparation method and the preparation system have the advantages of being low in energy consumption, simplex in tail gas component, easy to process and reuse, simple in device, convenient to operate and high in purity.

Description

technical field [0001] The invention relates to the field of polysilicon preparation, in particular to a method and system for preparing electronic-grade polysilicon. Background technique [0002] Today, with the rapid development of the photovoltaic industry, the production technology of solar-grade polysilicon has reached a certain level, and there is not so much room for further reducing energy consumption and production costs. Under the new situation of continuous improvement of people's consumption level and constant pursuit of new energy products, the market for a series of new materials used in many high-tech products will be very broad. [0003] Electronic grade polysilicon material is an indispensable raw material for many high-tech electronic information industries. Electronic-grade polysilicon is not only used in solar photovoltaic cells, but also can be used in a large number of products such as integrated circuits and other semiconductor devices, and has an irr...

AI Technical Summary

Problems solved by technology

[0004] The existing production method mostly adopts the improved Siemens method. During the production process, the decomposition temperature of the trichlorosilane raw material is between 1050°C and 1150°C, and its energy consumption is relatively high; at the same time, the tail gas of the improved Siemens method contains trichlorosilane, Dichlorodihydrosilane, hydrogen chloride, hydrogen and other very complex components require the establishment of a huge and complicated tail gas separation and treatment system, and it is difficult to achieve the effect of tail gas utilization, and a large construction cost needs to be invested in the early stage; in addition, the existing In the improved Siemens method, the conversion rate of trichlorosilane in the bell jar is only 18% to 25%, and the conversion rate is low; the polysilicon produced by the improved Siemens method is solar grade, and the purity cannot meet the requirements of electronic grade polysilicon

Images