Monocrystalline silicon pulling furnace, and pulling method for growing monocrystalline silicon

Abstract

The invention discloses a monocrystalline silicon pulling furnace, and a pulling method for growing monocrystalline silicon. The monocrystalline silicon pulling furnace comprises a furnace chamber, atubular reactor for heating, a crucible, a monocrystalline silicon pulling mechanism and a heater for heating the crucible are arranged in the furnace chamber, a gaseous silicon source undergoes a thermal decomposition reaction in the tubular reactor to generate silicon powder, the silicon powder or molten silicon formed after melting the silicon powder enters the crucible, the monocrystalline silicon pulling mechanism is arranged above the crucible, and the monocrystalline silicon pulling mechanism is used for pulling seed crystals to achieve pulling growth of the molten silicon in the crucible into monocrystalline silicon. The furnace and the method omit the production step of a solid silicon material, so the energy consumption is reduced, the huge investment for the production and processing of the solid silicon material is saved, and the pollution introduction problem of the solid silicon material is avoided, thereby the purity of the generated monocrystalline silicon is ensured; and compared with continuous feeding of the solid silicon material, the supplementation of the molten silicon material through the thermal decomposition of the gaseous silicon source has the advantagesof simplicity in realization, and accuracy in control of the supplementing speed of the molten silicon material.

Description

technical field [0001] The invention belongs to the technical field of crystal silicon growth, and in particular relates to a single crystal silicon pulling furnace and a pulling method for growing single crystal silicon. Background technique [0002] Crystalline silicon is an important raw material for silicon-based semiconductors and solar photovoltaic cells. At present, there are two main methods of growing crystalline silicon: one method is to place solid silicon material in an ingot furnace for ingot casting, and the product produced is polycrystalline silicon, which is mainly used for the manufacture of solar photovoltaic cells after slicing; The first method is to put solid silicon material in a single crystal furnace, and after melting, use the pulling method to grow single crystal silicon rods. Single crystal silicon wafers used in semiconductors and solar photovoltaic cells can be manufactured from single crystal silicon rods. In addition to the above two methods,...

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Problems solved by technology

Chemical vapor deposition or thermal decomposition of gaseous silicon sources is generally carried out at high temperatures, while the production of crystalline silicon from solid silicon materials is generally heated from room temperature to above the melting temperature of silicon. Therefore, from an energy perspective, from high-temperature gaseous silicon sources to It is uneconomical to produce crystalline silicon from solid silicon material at room temperature and then to molten high-temperature silicon liquid

In addition, the production process of solid silicon material itself is relatively complicated and requires special equipment, such as the free space method disclosed in patents CN200580017512 and EP2019084A2. Solid silicon grown from polycrystalline ingots or single crystals

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