Improvement of tensile strength of freestanding single crystal silicon microstructures using localized harsh laser treatment

Single crystal silicon freestanding microstructures were laser annealed for improving tensile strength. Annealing parameters were controlled to achieve smooth surfaces while using harsh laser energy conditions (4 J/cm2) without fracture occurring by having localized treatment at the gauge section. Samples were tilted for efficient exposure of sidewalls to laser. Treated samples showed smooth sidewalls having the scallops due to fabrication eliminated. Such treatment was reflected in the increase in tensile strength from 3.2 to 3.84 GPa and in the fracture location shifting from being mainly on sidewalls to being evenly distributed on all surfaces.