In situ observation of interfacial fracture in low-dimensional nanostructures

In order to quantitatively evaluate the interface strength of low-dimensional nanoscale components, a fracture test has been performed in a TEM (transmission electron microscope) using a special holder equipped with a small loading apparatus. The loading apparatus, which involves a 3D piezoelectric tube and a special load sensor placed behind the loading tip, allows precise control of the loading point and the measurement of infinitesimal fracture load. A low-dimensional nanoscale component with interface edges has been fabricated from a multi-layered material using FIB (focused ion beam). With this testing system, an in situ observation of crack initiation from the interface edge of low-dimensional SiN/Cu lines has been successfully implemented along with a quantitative measurement of the fracture load. Using the information obtained from the fracture test, the stress field around the SiN/Cu interface edge has been analytically evaluated.