Cutting method of crystalline silicon ingot

Abstract

The invention relates to a method for cutting a crystalline silicon ingot, which comprises the following steps: cutting the crystalline silicon ingot into silicon strips whose cross-sectional size is the required silicon sheet size along the direction perpendicular to the crystal grain growth; cutting the silicon strips to obtain silicon wafer in the direction of grain growth. The above cutting method directly obtains a crystalline silicon wafer parallel to the growth orientation of the crystal grain through one square extraction and one slicing process. This method omits the truncation process, simplifies the production cycle, and improves the production efficiency. Growth-oriented polycrystalline silicon wafers with larger grains reduce grain boundaries and improve the quality of silicon wafers.

Description

technical field [0001] The invention relates to the technical field of polycrystalline silicon slicing, in particular to a method for cutting crystalline silicon ingots. Background technique [0002] Polysilicon is currently one of the most important substrate materials in the solar cell industry. According to different growth methods, the temperature gradient of the solid-liquid interface is controlled during the solidification process to form a unidirectional heat flow, and the controllable directional solidification will form a physical and mechanical property Anisotropic polycrystalline columnar crystals, most of the current polycrystalline silicon ingots are produced by this directional solidification method, and the orientation of the polycrystalline grains obtained by casting the ingot is perpendicular to the bottom surface of the crucible. Then the whole polysilicon ingot is cut, the process is as follows figure 1 As shown: First, the whole silicon ingot is vertical...

AI Technical Summary

Problems solved by technology

Then the whole polysilicon ingot is cut, the process is as follows figure 1 As shown: First, the whole silicon ingot is vertically squared into 5×5 or 6×6 small square ingots, and then the head and tail material of the small square ingots are cut off, and then the cut small square ingots are sliced ​​to obtain The grain orientation of the polycrystalline silicon wafer is perpendicular to the growth direction of the columnar grains of the silicon ingot. There are many grain boundaries in the silicon wafer, and the three-step process of square extraction, truncation, and slicing is required, and the production cycle is longer.

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