Tensile fracture behavior of single crystal silicon film having a notch of sub-micron-length

Here presented a work for investigating the fracture behavior of single crystal silicon film having a notch of sub-micron-length by tensile test. The specimens are 5 μm thickness, 100 μm length and 50 μm width, with different surface orientations and tensile direction. A focused ion beam (FIB) process was used to form a notch on one edge of the specimen and the notch size ranged from 0.1 to 1.0 μm. The fracture behavior of the specimens showed variety in this test. The fracture toughness, K_IC, in the plane strain state, was constant for notch length above 0.5 μm, approximately 1.0 and 2.0 MPa·√m for the <110> and <100> tensile axes, respectively. On the other hand, when the notch length is below 0.5 μm, it is scattered and the specimen untidily fractured, indicating size limitation effect of notch. And the preferred fracture orientations also showed anisotropy when notch length is above 0.5 μ, i.e., on {110} plane in the <110> direction, or on {1111} plane in the <112> direction, initiated from notch tips.