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

Inactive Publication Date: 2010-11-24
DALIAN UNIV OF TECH
View PDF3 Cites 10 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The main disadvantage of this method is that after a period of smelting, a dense silicon dioxide film is formed on the silicon surface under an oxygen atmosphere, and only a smal

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for removing boron impurities contained in polysilicon by injecting electron beams
  • Method for removing boron impurities contained in polysilicon by injecting electron beams

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0015] In the manufacturing process of semiconductor devices, the silicon dioxide film has the function of absorbing boron, that is, in Si / SiO 2 The enrichment of boron exists on the side of the interface oxide layer. The diffusion rate of impurity boron in silicon is much faster than that in silicon dioxide, and in Si / SiO 2 The interface layer exists in a cationic state, and the SiO of the interface layer 2 One-way diffusion behavior occurred, macroscopically, there was a segregation effect, and the segregation coefficient (the content of boron in silicon / the content of boron in silicon dioxide) was 0.3. Studies have shown that the silicon dioxide layer with PLD (Peroxy linkage defects) has the effect of adsorbing boron. Because of its negative charge, according to the principle that the same-sex charges repel and the opposite-sex charges attract each other, boron atoms are segregated in the silicon dioxide layer during high-temperature heat treatment. In the process, elect...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

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.

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

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): C01B33/037
Inventor 谭毅姜大川邹瑞洵董伟
Owner DALIAN UNIV OF TECH
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap