Secondary cutting method of silicon wafers

Abstract

The invention provides a secondary cutting method of silicon wafers. The secondary cutting method comprises the steps that 1, locating grooves are cut out, wherein the cutter point locating grooves for secondary cutting are firstly cut out in silicon single crystal, and then primary cutting is carried out on the silicon single crystal; 2, silicon wafers are fixed, wherein the silicon wafers subjected to primary cutting are subjected to diffusing and thinning sorting to obtain silicon wafers to be secondarily cut, the silicon wafers to be secondarily cut are fixed in silicon wafer slitting and fixing pieces in a side-by-side and equal-distance manner or in a tight manner, and an integral workpiece is formed and fixed by glue; and 3, locating cutting is carried out, wherein the integral workpiece is fixed to a multi-wire cutting machine directly or through a resin strip, cutting lines are aligned to the locating grooves of the silicon wafers fixed in the silicon wafer slitting and fixing pieces one by one for alignment locating, and after locating is accurate, the silicon wafers are halved along the locating grooves. According to the method, the utilization rate of raw materials is increased to a large degree, and the device production cost is greatly reduced; and the method is used for production of silicon polished wafers with heavily-doped diffusion layers, and the uniwafer electric consumption can be lowered by about 50%.

Description

technical field [0001] The invention belongs to the technical field of Czochralski silicon single crystal cutting, and in particular relates to a method for performing secondary cutting on a plurality of cut silicon slices with a multi-wire cutting machine. Background technique [0002] In today's market, most VLSIs use Czochralski silicon wafers as the substrate material, and the large diameter and high surface flatness of silicon wafers are the main development directions. Multi-wire cutting technology is improving the flatness and surface geometry of silicon wafers. In terms of parameters, it has greater advantages compared with other equipment (inner circle slicer, etc.). In the past, in the multi-wire cutting process, the silicon single crystal ingot was cut into silicon wafers of a certain thickness at one time by a multi-wire cutting machine, so as to realize batch cutting of silicon wafers. However, in practical applications, a large number of silicon wafers need to...

AI Technical Summary

Problems solved by technology

In the preparation process commonly used at present (such as figure 1 Shown) the diffused silicon abrasive sheet is ground, thinned and polished on one side to remove a heavily doped region to form a silicon polished sheet with an N- / N+ structure, but this method not only wastes raw materials, but also produces Relatively low efficiency, not conducive to mass production

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