MECHANICAL BEHAVIOR OF NANO SCALE THIN FILMS USING MEMS SENSORS

Thin metal films are extensively used in micro and nano electronics as well as micro and nano mechanical systems. However, their mechanical properties are yet to be fully explored. In this paper, we describe a novel method, based on MEMS technology, for studying free-standing thin films of nano meter dimension in-situ in SEM and TEM. We employ the method to test aluminum films with thickness 30-200nm and with grain size 20-100nm. We find two unique properties as grain size decreased: (1) modulus of elasticity decreases, and (2) material behaves non-linear elastically. We propose that abundance of grain boundary in nano grained metals gives rise to both of these properties.