Anisotropy in fracture of single crystal silicon film characterized under uniaxial tensile condition

In this work, we studied the effect of crystallographic orientation on fracture toughness and fracture paths of single crystal silicon film by a uniaxial tensile test. A focused ion beam (FIB) process was used to introduce a notch in the middle of silicon (1 1 0) and (0 0 1) film specimens that have different tensile orientations. The fracture toughness value varied from 1 to 2 MPa m1/2, depending on the tensile orientation. The scanning electron microscope (SEM) observations suggested that the inclination angle of the low index planes, {1 1 1} and {1 1 0}, relative to the specimen surface affects the fracture path significantly. The {1 1 1} and {1 1 0} planes were the preferred cleavage planes.