Evaluating the Effects of Laser Dicing on the Residual Stress and Mechanical Properties of Silicon and Silicon Carbide Wafers

Laser dicing has emerged as a critical technique for singulating semiconductor wafers, particularly for materials such as silicon (Si) and silicon carbide (SiC). While laser dicing offers several advantages over mechanical methods, it introduces a recast layer—a region of resolidified material along the die sidewalls—whose microstructure and residual stresses can significantly impact die strength and reliability. This study investigates the recast layer's morphology, residual stress distribution, and mechanical integrity in laser-diced Si and SiC dies.
Using scanning electron microscopy (SEM), the microstructural differences in the recast layer were characterized. To assess residual stress distributions, cross-sectional X-ray nanodiffraction (CSnanoXRD) was employed, providing high-resolution stress maps of the recast layer with nanometer-scale precision. Additionally, laboratory-based X-ray diffraction (XRD) was evaluated as an alternative method for residual stress analysis. The findings from CSnanoXRD and laboratory XRD were compared to determine the feasibility of accessible residual stress measurement techniques.