Fracture toughness characterisation of electronic materials and interfaces

We present a technique for measuring the fracture toughness of nanoscale specimens of electronic materials and interfaces, in-situ inside electron microscopes. The technique employs a custom micro-machined mechanical testing device on which an edge-cracked tension specimen is integrated. The specimen is fabricated using a focused ion beam, which allows for testing of both single phase and interfacial materials, and virtually eliminates any restrictions on the type of materials that can be tested. We demonstrate the technique with single crystal 6H silicon carbide specimens, which are 200 500nm thick, 2 5μm wide and approximately 10μm long. The measured values of Young's modulus and fracture toughness are 590GPa and 4.82MPa-m^1/2 respectively, which compare favourably to the experimental results on bulk and thin film silicon carbide in literature.