Determination of the material properties of multilayered thin films using the elastic wave propagation approach

Abstract

In this paper we propose the use of an elastic wave propagation approach to determine the material properties of multilayered thin films. In this approach, the material properties of each layer in the multilayered thin films are determined by solving an optimization problem of minimizing the difference between the measured and calculated displacement response acquired on the surface of the thin films. The calculated displacement response is generated from the trial material properties by using a computational model of elastic wave propagation. A novel evolutionary algorithm, capable of searching the global optima, is used to solve the optimization problem and thus to determine the actual material properties. Numerical simulations are performed in both noise-free and noisy environments. The simulated results demonstrate the effectiveness of the present approach.