Improvement of thin film tensile testing technology using process integrated specimen and considering its out-of-plane deformation

This study has demonstrated a novel micro testing device to easily fabricate/integrate the thin film specimen, and further improve the measurements of thin film tensile test by considering the out-of-plane deformation (Fig.1). Due to “nominally-clamped” boundary condition [1] from microfabrication, additional bending moment is introduced during tensile test and cause the specimen an out-of-plane deformation. This study exploits such characteristic to determine thin film elastic modulus and modify the measured fracture strain. Merits of proposed tensile test approach: (1) the presented processes could fabricate/integrate different thin film specimens for testing; and (2) out-of-plane deformation of specimen is considered and precisely measured by interferometer (sub-nm resolution). The test-unit is implemented on Silicon-on-insulation (SOI) wafer. In applications, the mechanical and electrical properties of evaporated gold films are characterized.