Polycrystalline silicon ingot doping method and ingot casting equipment for implementing method

Abstract

The invention discloses a solar polycrystalline silicon ingot doping method and doping equipment thereof. The doping method comprises the following steps of: 1, putting not less than 50 percent of primary silicon and reclaimed impurities into a crucible, and putting the crucible into an ingot furnace; 2, heating the ingot furnace, extracting a part of molten polycrystalline silicon from the molten silicon when all the silicon is melted, solidifying the molten polycrystalline silicon into a polycrystalline silicon block, quickly cooling the polycrystalline silicon block to room temperature, and performing conductive type and resistance test on the polycrystalline silicon block; 3, calculating the weight of doped boron master alloy according to the conductive type and the resistance measuring data of the polycrystalline silicon block; and 4, adding the calculated boron master alloy into the molten polycrystalline silicon in the ingot furnace, and casting ingots. The doping equipment comprises the quartz crucible, the ingot furnace, a nitrogen-charging cooling secondary chamber, a molten silicon quartz extraction bar and a boron master alloy feeding ladle. By using the method for measuring and assessing the silicon, the whole quality performance accuracy is high, so the calculated weight of the doped boron master alloy is accurate and the reject rate is low. The equipment has simple structure and is convenient to use.

Description

technical field [0001] The invention belongs to a solar polysilicon ingot casting technology, and relates to a doping method of a solar polysilicon ingot and equipment for realizing the method. Background technique [0002] At present, the conductivity type of silicon wafers for preparing polycrystalline silicon solar cells is required to be P-type, and the resistivity is required to be in the range of 1-3Ω·cm. Therefore, it is necessary to dope boron master alloy ingredients to the ingot polycrystalline silicon material. The current method is that before loading, the loading staff conducts a sample test on the loaded silicon material to measure the resistivity and conductivity type, and according to the sampled resistivity and conductivity type data, determine the weight of the boron master alloy that needs to be doped. For high-quality raw silicon materials, the overall situation of the silicon materials can be reflected by sampling and measuring part of the silicon materi...

AI Technical Summary

Problems solved by technology

Due to the existence of the above miscellaneous materials, it is difficult to evaluate the overall quality and performance of the silicon material through random testing, so the calculation of the doping weight of the boron m

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