Study of multi-cutting by WEDM for specific crystallographic planes of monocrystalline silicon

摘要

In this study, multi-cutting technology by wire electrical discharge machining (WEDM) for metal material processing is applied to cut semiconductor monocrystalline silicon with specific crystal orientation, which is to improve the surface quality and machining accuracy of single-crystal silicon with specific crystal orientation. First, the deterioration layer thickness of silicon wafer surface and the discharge gap under different discharge energy values are analyzed to determine the reasonable trim cutting values of multiple cutting. The effects of multiple cutting on the surface quality of silicon and crystal orientation accuracy are also studied. Results show that multi-cutting technology by WEDM can significantly improve the surface quality of silicon, with few surface cracks and low deterioration layer thickness. Processing the same quality surface under experimental conditions, multiple cutting obtained sixfold efficiency of single cutting. Furthermore, this technology can significantly reduce the orientation error band and error fluctuations as well as improve surface crystallographic orientation precision of silicon wafer when cutting silicon wafers with high thickness.