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 /spl mu/m thickness, 100 /spl mu/m length and 50 /spl mu/m 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 /spl mu/m. The fracture behavior of the specimens showed variety in this test. The fracture toughness, K/sub IC/, in the plane strain state, was constant for notch length above 0.5 /spl mu/m, approximately 1.0 and 2.0 MPa/spl middot//spl radic/m for the <110> and <100> tensile axes, respectively. On the other hand, when the notch length is below 0.5 /spl mu/m, 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 /spl mu/, i.e., on {110} plane in the <110> direction, or on {1111} plane in the <112> direction, initiated from notch tips.