Texture pretreatment method for diamond wire cut polycrystalline silicon wafer, texturing pretreated silicon wafer and application thereof

Abstract

The invention provides a texturing preprocessing method of a diamond wire cut polycrystalline silicon chip. The method comprises the following step of preprocessing the diamond wire cut polycrystalline silicon chip by phosphorus diffusion under the temperature of 850 to 900 DEG C to form an N type heavily-doped layer with square resistance of 40 to 100 ohm / Sq on the surface layer of the silicon chip so as to obtain a textured preprocessed silicon chip. The invention further provides a texturing method of the diamond wire cut polycrystalline silicon chip. The textured preprocessed silicon chip is textured generally to form a uniform and low-reflectivity textured surface so as to obtain the diamond wire cut polycrystalline silicon chip textured product. The invention also provides the textured preprocessed silicon chip and the diamond wire cut polycrystalline silicon chip textured product.

Description

technical field [0001] The invention belongs to the technical field of texturing of polycrystalline silicon wafers, and in particular relates to a diamond wire-cut polycrystalline silicon wafer texturing pretreatment method, texturing pretreated silicon wafers and applications thereof. Background technique [0002] Silicon wafers are widely used in photovoltaic solar energy, liquid crystal display and semiconductor fields, so the technology of cutting silicon blocks to make silicon wafers has also been developed. At present, the cutting of crystalline silicon wafers used in the photovoltaic industry mainly adopts the mortar multi-wire cutting technology, but this technology has problems such as low cutting process efficiency, high cost, and large discharge pollution of waste mortar after cutting. In contrast, solid abrasive diamond wire saw cutting (referred to as diamond wire cutting) technology has the characteristics of fast cutting speed, high cutting precision, low mate...

AI Technical Summary

Problems solved by technology

[0004] The surface damage layer of polycrystalline silicon wafers cut by conventional mortar is relatively uniform, about 10-11 μm, and there are no obvious line marks on the surface (such as figure 1 Shown), through the RENA process texturing process, that is, HF-HNO 3 -H 2 O acid velvet, can get the velvet surface with uniform corrosion on the whole surface (such as figure 2 shown); however, the surface damage layer of diamond wire-cut polysilicon wafers is relatively shallow, about 5-6 μm, and its damage is mainly caused by some small deep hole damage, and the surface is densely covered with smooth cutting line marks (such as image 3 shown); if the RENA texturing process of normal polysilicon wafers is used, the textured surface formed is very irregular and shallow (such as Figure 4 As shown), the reflectivity is much higher than that of normal silicon wafers, and its cell conversion efficiency is relatively low, which makes the new cutting process silicon wafers unable to be mass-produced

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