Device of oxygen control growth in single crystal furnace

Abstract

The invention belongs to the technical field of semiconductor separation and particularly relates to a device of oxygen control growth in processes of producing and separating single crystal silicon. The device is formed by improving a heater, a guiding cylinder and a lower insulation system in a single crystal furnace, the height of a blade of the heater is reduced, the hot source area at the bottom of a crucible is decreased, the bottom of the quartz crucible is heated little and less oxygen in the production process is generated; a sealing guide system is reconstructed, an encryption type guiding cylinder is additionally arranged on an upper cover plate, and can accelerate the cooling speed; and a lower insulation system in the furnace is reconstructed, therefore, the insulation effect of a lower insulation cylinder is reinforced, more oxygen from a crystal and melt interface can be taken away, the oxygen content is reduced and generated boroxol complex is decreased. The invention can effectively reduce generation and retention of the oxygen in the production process and control generation and transportation of the oxygen, reduces the process and the quantity of the oxygen entering a single crystal, and has the advantages of simple structure, low cost and convenient installation, use and operation.

Description

technical field [0001] The invention belongs to the technical field of semiconductor separation, in particular to an oxygen-controlled growth device for producing and separating single crystal silicon. Background technique [0002] At present, when the manufacturers of semiconductor monocrystalline silicon rods (anchor) in my country produce semiconductor silicon materials, most of them use the single crystal furnace to produce single crystal silicon rods (anchor). Most of these single crystal silicon rods (anchor) are For the manufacture of monocrystalline silicon solar cells; scientific research has found that the initial light-induced attenuation of P-type (boron-doped) monocrystalline silicon solar cells is related to the concentration of boron and oxygen in the silicon wafer. Boron and oxygen form a boron-oxygen complex, which reduces the minority carrier lifetime, B+2O→(light or current injection) BO 2 .According to relevant literature, the greater the content of boron ...

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Problems solved by technology

[0006] The oxygen generated after decomposition enters the silicon single crystal during the subsequent growth and stretching process, and finally exists in the silicon crystal in a gap state. Therefore, in order to improve the photoelectric conversion rate of single crystal silicon solar cells and reduce light attenuation rate, it is necessary to start from the production process to reduce the oxygen content in the stretching process of the single crystal silicon rod (anchor): and the existing single crystal furnace has the following defects: the blade height of the heater is too high, so that the bottom of the crucible The area of ​​the heat source is large, so the quartz crucible is heated, and the reaction between silicon and oxygen at the bottom of the quartz crucible is severe. At the same time, the longitudinal temperature gradient in the single crystal furnace is large, the heat convection is strong, and the oxygen content and oxygen concentration are relatively high. The diversion mechanism of the flow device is not ideal, so oxygen cannot be quickly taken away from the silicon liquid surface, thereby increasing the contact time and opportunity between oxygen and the single crystal, so oxygen enters the silicon single crystal during the growth and stretching of the single crystal increase

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