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Preparation method of ultra-high-purity silicon tetrachloride

A pure silicon tetrachloride, silicon tetrachloride technology, applied in chemical instruments and methods, halide silicon compounds, inorganic chemistry and other directions, can solve the problem of difficult to remove hydrogen impurities

Inactive Publication Date: 2017-02-08
CHINA SILICON CORP LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Table 1 shows some hydrogen-containing impurities and their boiling points in silicon tetrachloride. It can be found that the boiling points of hydrogen-containing impurities and silicon tetrachloride are very close, and it is difficult to remove hydrogen-containing impurities by conventional rectification processes

Method used

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  • Preparation method of ultra-high-purity silicon tetrachloride
  • Preparation method of ultra-high-purity silicon tetrachloride
  • Preparation method of ultra-high-purity silicon tetrachloride

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preparation example Construction

[0022] According to a typical embodiment of the present invention, a method for preparing ultra-high-purity silicon tetrachloride is provided. The method comprises the following steps: S1, continuously feeding high-purity silicon tetrachloride into the photochemical reactor under the action of nitrogen; S2, continuously feeding chlorine gas into the photochemical reactor under the condition of ultraviolet light to make the high-purity silicon tetrachloride The hydrogen-containing impurities in the silicon dioxide react with chlorine to obtain the primary product; S3, the primary product is passed into the stripping tower from the upper part of the stripping tower, and the nitrogen gas is fed from the bottom of the stripping tower to remove the primary product. The unreacted chlorine in the product is obtained as a secondary product; and S4, the secondary product is sent to a silicon tetrachloride purification tower, and after continuous light removal and weight removal, ultra-h...

Embodiment 1

[0042] Such as figure 1 As shown, the ultra-high-purity silicon tetrachloride production process of the present embodiment comprises the following steps:

[0043] S1, the purity is more than 99.9999%, that is, high-purity silicon tetrachloride raw material, which contains trace impurities such as trichlorosilane, methylchlorosilane and borophosphorus, and uses high-purity nitrogen to send the raw material silicon tetrachloride into the photochemical reaction device , the dew point of the high-purity nitrogen is not lower than -90°C.

[0044]S2, after sending the high-purity silicon tetrachloride raw material into the photochemical reaction device, under the condition of ultraviolet light, a certain amount of high-purity chlorine gas is passed into the photochemical reactor. In this method, the liquid material of high-purity silicon tetrachloride is fed first, and then the gas material of high-purity chlorine is fed. Among them, the photochemical reactor is composed of a micr...

Embodiment 2

[0060] Processing step is with embodiment 1, and concrete condition is as follows:

[0061] The purity of the raw material silicon tetrachloride is above 99.9999%, and the silicon tetrachloride after polysilicon reduction tail gas and hydrogenation condensate purification can meet the requirements. The dew point temperature of high-purity nitrogen is not lower than -90°C, and the purity of high-purity chlorine is not lower than 99.999%.

[0062] The photochemical reactor is a quartz microchannel reaction device, the diameter of the reaction channel is micron, the reaction temperature is 20°C, the reaction pressure is 0.3MPa, the volume ratio of high-purity chlorine gas and raw material silicon tetrachloride is 1:1, and the light source can use high pressure UV mercury lamp or cold light source UV lamp. The heat exchange medium is heat conduction oil, which is used to cool the photochemical reaction device and maintain the reaction temperature in the reactor.

[0063] The pro...

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Abstract

The invention discloses a preparation method of ultra-high-purity silicon tetrachloride. The preparation method comprises the following steps of S1, continuously introducing high-purity silicon tetrachloride into a photochemical reactor under the effect of nitrogen gas; S2, under the ultraviolet light illumination condition, continuously introducing chlorine gas into the photochemical reactor so that hydrogen-containing impurities in the high-purity silicon tetrachloride take photochloration reaction with the chlorine gas to obtain a primary product; S3, introducing the primary product into a stripping tower from the upper part of the stripping tower; introducing the nitrogen gas from the bottom of the stripping tower so as to remove unreacted chlorine gas in the primary product to obtain a secondary product; S4, feeding the secondary product into a silicon tetrachloride purification tower; after continuous light impurity removal and heavy impurity removal, obtaining the ultra-high-purity silicon tetrachloride. Optical fiber silicon tetrachloride prepared by the method has the advantages that the purity can reach 99.9999999 percent or higher; the relevant group infrared transmission index meets or even exceeds the Merk company high-purity silicon tetrachloride index; the quality requirements of the ultra-high-purity silicon tetrachloride are also met.

Description

technical field [0001] The invention relates to the technical field of electronic materials, in particular to a method for preparing ultra-high-purity silicon tetrachloride. Background technique [0002] In the polysilicon production process, a large amount of silicon tetrachloride will be produced as a by-product, which can be used to prepare trichlorosilane and return to the polysilicon system, and can also be used to prepare many high value-added silicon industry chain products, such as fumed silica, optical fiber Preform and ethyl silicate, etc., among which fiber-grade silicon tetrachloride is one of the important raw materials for optical fiber preform. [0003] With the launch of "fiber-to-copper" and "fiber-to-the-home" projects, triple play integration and 3G network construction projects, my country has become the world's most important optical fiber and cable market and the world's largest optical fiber and cable manufacturing country. However, the high-purity si...

Claims

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Application Information

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IPC IPC(8): C01B33/107
CPCC01B33/10778C01B33/1071C01P2006/80
Inventor 郭树虎赵雄严大洲万烨姜利霞王芳
Owner CHINA SILICON CORP LTD