Method and equipment for purifying polysilicon by utilizing shallow molten pool to carry out vacuum smelting

A vacuum smelting, polysilicon technology, applied in chemical instruments and methods, silicon compounds, sustainable manufacturing/processing, etc., can solve the problems of unfavorable solar cell popularization, slow phosphorus removal, large equipment investment, etc. The effect of good effect, high production efficiency and compact equipment structure

Inactive Publication Date: 2011-08-10
GAOYOU INST CO LTD DALIAN UNIV OF TECH
View PDF3 Cites 4 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the improved Siemens method and silane method require large equipment investment, high cost, serious pollution, and complicated processes, which are not conducive to the popular application of solar cells. In comparison, the metallurgical method has the characteristics of short

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 and equipment for purifying polysilicon by utilizing shallow molten pool to carry out vacuum smelting
  • Method and equipment for purifying polysilicon by utilizing shallow molten pool to carry out vacuum smelting

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] A method for purifying polysilicon by vacuum smelting and purifying polysilicon in a shallow melting pool. Under a high vacuum condition with a vacuum degree of 0.0008 Pa, high-purity polysilicon material is first melted in a melting crucible 13 by induction heating at 1430°C to form a high-purity silicon melt 14, and Keep it liquid.

[0027] Then increase the power of the induction coil 12 to make the temperature of the silicon melt reach 1500°C, and then vertically and slowly extend the high-phosphorus and high-metal silicon rod 9 suspended above the silicon melt into the silicon melt through the suspension clamping device Among them, the front end of high-phosphorus and high-metal silicon rod 9 is continuously melted to form a shallow molten pool of high-phosphorus and high-metal, and impurity phosphorus is continuously evaporated and removed in the shallow molten pool.

[0028] Finally, after the high-phosphorus and high-metal silicon rods are completely melted into...

Embodiment 2

[0030] like figure 1 The equipment for purifying polysilicon by vacuum smelting and purifying polysilicon in a shallow molten pool is shown. The vacuum equipment is composed of a furnace cover 4 and a vacuum furnace wall 18 . The inner chamber of the vacuum equipment is the vacuum chamber 3 . The bottom of the vacuum chamber 3 is fixedly installed with a supporting base 16, and the supporting base 16 is equipped with an induction coil 12, a graphite sleeve 11, and a thermal insulation carbon felt 10 from the outside to the inside. The graphite sleeve 11 is used for the early stage of induction heating and the silicon material is non-conductive To heat the silicon material, the thermal insulation carbon felt 10 is used to prevent heat loss from the side wall during the directional solidification process. The bottom of the vacuum chamber in the support base 16 is equipped with a water-cooled ingot rod 17, and the graphite block 15 is installed on the water-cooled ingot rod 17. A...

Embodiment 3

[0035] Adopt the equipment described in embodiment 2 to carry out the method for purifying polysilicon by shallow melting pool vacuum smelting, its specific steps are as follows:

[0036] The first step of material preparation: lift the lifting rod 2 through the lifting electric device 1, the lifting rod 2 drives the suspension clamping device to rise to the upper limit position, add 500g of high-purity polysilicon material with a total impurity content of 0.0002% to the melting crucible 13, and then Clamp four polysilicon round rods with a mass of 1000g each, with impurity phosphorus contents of 0.0012%, 0.0015%, 0.0010%, and 0.0013%, and total metal impurity contents of 0.013%, 0.011%, 0.017%, and 0.019%, respectively. on the suspension clamp;

[0037] The second step of pretreatment: after closing the furnace cover 4, use the mechanical pump 20, the Roots pump 21 and the diffusion pump 22 to pump the vacuum to the equipment respectively, and pump the vacuum chamber 3 to a h...

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

PropertyMeasurementUnit
Qualityaaaaaaaaaa
Login to view more

Abstract

The invention belongs to the technical field of purification of polysilicon by a physical metallurgical technology. A method for purifying polysilicon by utilizing a shallow molten pool to carry out vacuum smelting comprises the following steps of: under the high-volume condition with the vacuum degree below 0.001Pa, firstly melting a high purity polysilicon material in a smelting crucible by induction heating at a temperature of 1,430 to 1,460 DEG C to form high purity silicon solution, keeping the liquid state of the high purity silicon solution, and then heating the high purity silicon solution so that the temperature of the high purity silicon solution reaches 1,500 to 1,600 DEG C; continuously and slowly adding a rod with high phosphorus content and high metal silicon content into the silicon solution, continuously evaporating to remove a phosphorus impurity in the shallow molten pool; and after the rod with high phosphorus content and high metal silicon content is totally molten into the molten pool, keeping the silicon solution in the liquid state for a certain time in the smelting crucible at a temperature of 1,450 to 1,500 DEG C through induction heating, carrying out unidirectional solidification and cutting off the polysilicon with high content of metal impurities on the top of a silicon ingot. In the invention, a high-temperature high-vacuum large-area shallow molten pool smelting technology and an unidirectional solidification technology are integrated; the method has good purifying effect, is simple to operate, has low cost and high production efficiency and is suitable for batch production; and resources are saved.

Description

technical field [0001] The invention belongs to the technical field of purifying polysilicon by using physical metallurgy technology, and particularly relates to a method for removing phosphorus and metal impurities in polysilicon; in addition, the invention also relates to its equipment. Background technique [0002] Solar-grade polysilicon material is an important raw material for solar cells. Solar cells can convert solar energy into electrical energy. In today's shortage of conventional energy sources, solar energy has great application value. At present, the preparation of polysilicon materials for solar cells has formed a large-scale production worldwide, and the current main technical routes are as follows: [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 fore...

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
CPCY02P20/10
Inventor 战丽姝谭毅姜大川邹瑞洵顾正
Owner GAOYOU INST CO LTD 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