Cu-refractory metal composites such as Cu-Ta alloys are attracting research interest because of their potential high electrical and thermal conductivity and high mechanical strength at elevated temperatures [1]. In the previous study, it has been shown that the hardness of Cu-Ta is three times of the Cu substrate [2] and the Ta was found to exist as discrete particle and aligned particles. In this presentation, we report the detailed study on the microstructure of the heat treated film and hot-pressed film.

The Cu-6at%Ta films were deposited on Cu foil at 100°C by RF co-sputtering. The films examined in this study was hot-pressed under 35 MPa pressure at Ar atmosphere for 1 hour. Cross-sectional TEM samples were examined using a Hitachi 9000 high resolution transmission electron microscope (HRTEM) at the Center for Microanalysis, Materials Research Laboratory, University of Illinois at Urbana-Champaign.