MTS model theory in small volume electronic materials

Efforts have been made to study and model the temperature-dependence of flow stress. Mechanical Threshold Stress (MTS) model is one of the most admired physical mechanistic models. The model was developed on the basis of dislocation-mediated, thermally-activated, obstacle-controlled local process of dislocation overcoming obstacle. The present paper deals with the development and application of MTS model theory in small volume electronic materials. Small volume term corresponds to a volume characterized by a high surface to volume ratio including foil and thin film either with or without confinement. First, foundations of the MTS model theory are revisited. Then, specific issues in small volume materials are elaborated. Discussion is limited within the kinetic regime of thermal activation. It is shown that geometrical and micro-structural constraints are mixed up in small volume material, modifying the local mechanism of interest. As mechanical behaviour is averaged only over a small section volume, reduced geometry and increased surface to volume ratio have become more significant and articulated. More efforts must be made to reinterpret the model already established in bulk materials to accurately describe the behaviour in small volume material and extract plausible parameters related to the responsible mechanism.