Characterization of thin oxide layers by use of the atomic force acoustic microscopy

We investigated the influence of thin oxide layers present on the surface of polycrystalline copper on the effective stiffness of the sample surface. The thicknesses of the oxide layers were in the range of single to few tens of nanometers. In order to detect the presence of such thin films on a sample surface, the so called atomic force acoustic microscopy (AFAM) technique was used. The investigated sample was polycrystalline <111> oriented copper. The AFAM results obtained from heat treated sample were compared to these obtained for a reference sample with a thinner native oxide layer. The study revealed the ability of the AFAM technique to detect the presence of nanometer thin films. Our preliminary results suggest that AFAM technique may have a potential application for microelectronic industry as a tool for thin film characterization.