Method for eliminating silicon slice concentric defect

Abstract

The invention relates to a method for eliminating a silicon slice concentric defect, and belongs to the technical field of monocrystalline silicon production. Before implementation of the method, silicon slices are screened by a PL photoluminescence test system, and silicon slices which can generate the concentric defect in future are screened out; the method comprises the steps: putting the silicon slices into a quartz boat, then putting the quartz boat into a diffusion furnace, heating the silicon slices, and filling high-purity argon gas in the diffusion furnace before heating; heating the diffusion furnace to 680 DEG C, then carrying out constant temperature holding, 30 min later, taking out the silicon slices, and rapidly cooling the silicon slices with a temperature reduction device; and finally forming qualified silicon slices, wherein the temperature reduction device can be used for rapidly cooling a large number of silicon slices, the air cooling effect is relatively uniform, and a case that the silicon slices cannot be used due to nonuniform quality can be avoided; with the application of the method, original slices of silicon slices having the concentric defect can be recycled, the utilization ratio of silicon rods after slicing is improved, and the production cost of the silicon slices is reduced.

Description

technical field [0001] The invention belongs to the technical field of monocrystalline silicon production, and in particular relates to a method for eliminating concentric circle defects of silicon wafers. Background technique [0002] Monocrystalline silicon rods are the raw materials for producing monocrystalline silicon wafers. The existing monocrystalline silicon growth process is mainly carried out in single crystal furnaces. The silicon melt raw material has a certain oxygen content, and there is a phenomenon of liquid level inversion during the growth of single crystal silicon, which leads to the situation that the oxygen content in the head of the growing silicon rod is too high and the distribution is uneven. After the silicon rod is cut into silicon wafers and followed by subsequent processing, concentric circle defects will appear on the end face of the silicon wafer. This phenomenon is a manifestation of unqualified silicon wafers. If this kind of silicon wafers ...

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Problems solved by technology

[0002] Monocrystalline silicon rods are the raw materials for producing monocrystalline silicon wafers. The existing monocrystalline silicon growth process is mainly carried out in single crystal furnaces. The silicon melt raw material has a certain oxygen content, and there is a phenomenon of liquid level inversion during the growth process of single crystal silicon, which leads to the situation that the oxygen content in the head of the growing silicon rod is too high and the distribution is uneven. After the silicon rod is cut into silicon wafers and followed by subsequent processing, concentric circle defects will appear on the end face of the silicon wafer. This phenomenon is a manifestation of unqualified silicon wafers. If this kind of silicon wafers are used, the work will be unstable. , and if it is returned to the furnace for remanufacturing, the cost is high, and it cannot be well melted into the raw material, causing defects in the subsequent production of silicon rods. Therefore, a method that can eliminate the concentric circle defects is needed

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