Method for removing boron impurities contained in polysilicon by injecting electron beams

A technology of electron injection and electron beam, which is applied in chemical instruments and methods, silicon compounds, inorganic chemistry, etc., can solve the problems of high application cost, low production efficiency, unfavorable industrial production, etc., and achieve high production efficiency, short cycle, and purification good effect
CN101891202AInactive Publication Date: 2010-11-24DALIAN UNIV OF TECH
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
DALIAN UNIV OF TECH
Publication Date
2010-11-24
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention relates to a method for removing boron impurities contained in polysilicon by injecting electron beams, in particular to a method for removing the boron impurities contained in the polysilicon by carrying out electron injection by utilizing the electron beams, belonging to the technical field of polysilicon purification by using a physical metallurgy technology. The method comprises the following steps of: firstly, heating silicon powder by utilizing a high-temperature heating furnace; then placing the silicon powder into an electron beam smelting furnace, and bombarding the silicon powder by using low-beam current electron beams; and finally removing a surface oxidation film of the silicon powder to obtain low-boron silicon powder by using an HF (hydrogen fluoride) acid solution. The invention has the outstanding advantages of showing the electrical effect of negative electricity by releasing electrons by adopting the electron beams, strengthening self electric microfields of silicon materials by combining with the self characteristics of the silicon materials, enabling the boron to be diffused to an interface by being driven by temperature and further enter a silicon dioxide layer and finally removing a silicon dioxide layer containing the boron through acid cleaning, thereby achieving the purpose of removing the boron impurities to meet the using requirements on solar grade silicon; in addition, the invention has the advantages of good purification effect and stability, little energy consumption, low cost, simple process, short period and higher production efficiency.
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Description

technical field

[0001] The invention belongs to the technical field of purifying polysilicon by physical metallurgy technology, and particularly relates to a method for removing impurity boron in polysilicon by using electron beams for electron injection. Background technique

[0002] Solar-grade polysilicon material is the most important basic raw material for manufacturing solar cells. With the rise of the global low-carbon economy, the solar photovoltaic industry has ushered in a huge space for development. At present, the preparation of polysilicon materials for solar cells has formed a large-scale production worldwide, and common preparation techniques include:

[0003] (1) Improved Siemens method: The Siemens method uses hydrochloric acid (or hydrogen, chlorine gas) and metallurgical grade industrial silicon as raw materials to perform hydrogen reduction from trichlorosilane. Now the relatively mature technology in foreign countries is the Siemens method, and it has a...

Claims

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