Influence of ingot rocking on the surface quality of multi-wire sawing monocrystalline silicon wafers

Abstract

This paper aims on slicing of monocrystalline silicon wafers using a newly developed diamond multi-wire reciprocating saw under ingot rocking process. A contact wire length model based on ingot rocking was established. The influence of motion parameters of ingot rocking on the surface quality of multi-wire sawn monocrystalline silicon wafers had been experimentally studied. The slicing surface morphology, surface roughness, and surface hardened layer were investigated by using scanning electron microscope, laser scanning microscopy, and microhardness tester. Results show that compared with the multi-wire cutting mode with an ingot rocking amplitude of 0°, ingot rocking (θm ≠ 0) can reduce the contact wire length of sawing by almost half at any time, and realize discontinuous and segmented sawing of large-diameter silicon wafers. By reducing the contact wire length, the cutting mode under ingot rocking can achieve better surface morphologies, and reduce roughness, thickness of the hardened layer and microhardness of the surface in silicon wafer cutting. Compared with the mode of multi-wire reciprocating sawing with an ingot rocking amplitude of 0°, an ingot rocking amplitude of 5°can reduce roughness, thickness of the hardened layer, and microhardness of the surface in silicon wafer cutting about 30.1%, 20.1%, and 11.3%. Though the ingot rocking amplitude did not significantly influence the contact wire length during the cutting process, the ingot rocking motion significantly influences the ingot feed speed, an ingot rocking amplitude of 5°instead of 3° or 7° is suggested for the best surface quality.