Ion solid surface interactions in ionized copper physical vapor deposition

A thorough understanding of ion-solid surface interactions is important for the predictive modeling of ionized metal plasma (IMP) Cu physical vapor deposition (PVD) at feature scales. Besides sticking coefficients and sputter yields, characterizations such as angular distributions of sputtered and reflected particles, and thermal-accommodation coefficients are also needed as inputs for a feature scale process simulator. Molecular dynamic (MD) simulations have been used to provide pertinent information and physical insights. MD results for Ar+/Cu and Cu+/Cu systems as a function of hyperthermal ion energies and incidence angles are reported. The issue of integrating different sticking coefficients for different surface roughness is addressed, based on ion travel distance analysis. We have found that the angular distribution of sputtered particles is not cosine, but can be described by a simple Gaussian-like formula. Ion reflection characteristics are also analyzed. (C) 2002 Elsevier Science B.V. All tights reserved.