Fracture behaviors of a stiff film/complaint substrate structure under thermally induced loads

摘要

With the rapid development of nanoscience and microfabrication technology, Thin Films on Substrate Structure (TFSS) has been widely used in many domains, such as microelectronics, material science and biomedical science, etc. Soft substrate-stiff film structure draws great attention due to its unique mechanical properties compared with traditional TFSS and becomes a hot issue in recent years. A typical stiff film/compliant substrate structure is usually composed of a compliant substrate and one or several layers of stiff films adhered to the surface of the substrate by means of sputtering, evaporation or deposition technology. On account of the tremendous diversities of mechanical properties, such as elastic modulus, hardness, rigidity and coefficient of thermal expansion, between the soft substrate and the attached stiff film, nonlinear elasticity behaviors that lead to the structural instabilities including the so-called buckling and wrinkling phenomena emerge when the structure is under external mechanical or thermal loads, as shown in Fig. 1.