A study on mechanism of nano-cutting single crystal silicon

When the ratio of the undeformed chip thickness to the tool edge radius is less than a critical value, the chip formation occurs via extrusion. With an increase of the ratio exceeding the threshold, chip formation starts to appear in the mode of brittle tensile chips. Molecular dynamics analysis shows that cracks appear at the initial cut even though the cutting is in the ductile mode. Electron diffraction patterns are achieved from the analysis of various silicon chips using a transmission electron microscope (TEM). It is noted that the silicon chips have amorphous structure and polycrystalline structure when the cutting is in ductile mode and brittle mode, respectively.