Orientation-dependent fracture strain in single-crystal silicon beams under uniaxial tensile conditions

The proposed method for testing the uniaxial tensile characteristics of thin film materials is integrated onto a silicon chip. The developed process for fabricating the test chips starts with SOI wafers whose top silicon layer is prepared for the test materials. The results of testing single-crystal silicon films having orientations of ⟨100⟩, ⟨110⟩, and ⟨111⟩ were compared with those from bending tests of bulk silicon. The measured Young´s moduli and fracture strains clearly showed orientation dependence, and the measured values were reasonable compared with those of the bulk materials. The fracture strains varied from 0.4 to 2.2% depending on the orientation and were the lowest in the ⟨111⟩ direction