Silicon wafer preparation method

Abstract

The invention discloses a silicon wafer preparation method, which comprises the following steps of: taking a silicon material of which the crystal orientation of one end surface is + / -3 degrees of a target crystal orientation, cutting one side surface of the silicon material by adopting a filament, and cutting the silicon material into a silicon wafer; the end surface is taken as a reference surface, the side surface is taken as a cutting surface, and the cutting surface is perpendicular to the reference surface; each time of cutting comprises the following steps that a groove is formed in the cutting face, the groove serves as a reference groove, and the reference groove is parallel to the reference face; the thin wires are straightened and embedded into the reference groove, the thin wires are parallel to the reference surface, and certain pressure is applied to the reference groove through the thin wires, so that the silicon material is naturally cleaved and broken at the reference groove. According to the invention, the silicon material can be naturally cleaved and fractured to complete cutting under the dual action of thermal stress and filament pressure, and the silicon wafer can be cut under the condition that the silicon material is almost lossless, so that the yield of the silicon wafer is improved, and the silicon material cost of a single silicon wafer is reduced.

Description

technical field [0001] The invention relates to a silicon chip preparation method. Background technique [0002] During the processing of monocrystalline silicon wafers for photovoltaics, silicon wafers are obtained by cutting monocrystalline silicon rods. At present, the cutting of silicon wafers is done by multi-wire cutting, which belongs to grinding or planing cutting. During the cutting process, the cut silicon block part will be cut into silicon powder, resulting in the loss of silicon material. Silicon material loss occupies a relatively large proportion in the cost of silicon wafers. Taking the typical 40-50um diameter diamond wire cut 180um silicon wafers in current mass production as an example, for every 3 silicon wafers cut, there is about 1 silicon wafer silicon material Loss, the proportion of loss is about 25% or more. As the thickness of the silicon wafer becomes thinner, its loss ratio will further increase. In addition, in addition to the loss of silicon...

AI Technical Summary

Problems solved by technology

As the thickness of the silicon wafer becomes thinner, its loss ratio will further increase

In addition, in addition to the loss of silicon material caused by abrasion during the cutting process, there will also be a large amount of non-environmental protection factors such as cutting waste water, dust, and noise.