Surface modification of single-crystal silicon by hybrid laser treatment

In this paper, recent work on picosecond and nanosecond hybrid laser treatment of mechanically sawed single-crystal silicon wafer is presented. Surface morphology, surface roughness and phase development has been analyzed by 3D laser scanning confocal microscope (LSCM), X-ray diffraction (XRD), and scanning electron microscope (SEM). Results show that as-received surface defects including SiO2 layer and saw-mark defects have been significantly reduced, while average surface roughness has been decreased. No obvious damages such as micro-cracks and micropores have been observed at the laser-treated surface. Moreover, residual stress and electrical resistivity of laser-treated surface has been measured, respectively. The insights obtained in this work provide a facile method to improve surface quality of mechanically machined silicon wafer.