AVS 45th International Symposium
    Plasma Science and Technology Division Thursday Sessions
       Session PS-ThP

Paper PS-ThP9
Molecular Dynamics Simulation of Cu and Ar Ion Sputtering of Cu Surfaces@footnote 1@

Thursday, November 5, 1998, 5:30 pm, Room Hall A

Session: Plasma Science and Technology Division Poster Session
Presenter: J.D. Kress, Los Alamos National Laboratory
Authors: J.D. Kress, Los Alamos National Laboratory
D.E. Hanson, Los Alamos National Laboratory
A.F. Voter, Los Alamos National Laboratory
C.-L. Liu, Motorola
D.G. Coronell, Motorola
Correspondent: Click to Email
In ionized physical vapor deposition (PVD) used in Cu interconnect technology, the interaction of energetic ions with the growing Cu substrate is not well characterized by a constant sticking probability independent of ion impact angle or energy. Such detailed information, not known experimentally, is necessary input for realistic feature scale modeling of step coverage in the metallization of vias and trenches in integrated circuits. Here we describe the results of molecular dynamics (MD) simulations of sputtering of Cu (111) and (100) surfaces by Cu and Ar ions suitable for incorporation into feature scale simulations. For the interatomic potentials, the many-body embedded atom method for Cu-Cu and a Ziegler-Biersack-Littmark pair potential for Ar-Cu were used. For each impact angle and energy (10 to 100 eV for Cu ion and 50 to 175 eV for Ar ion), a series of 150 impact events were run with an initial surface temperature of 300 K. At the end of each series, the average sputter yield (number of Cu atoms sputtered per impact), sticking probability, reflection angle and energy, and sputtered angle and energy were calculated as a function of impact energy and angle. For Cu and Ar ion impact energies below 50 eV or angles of incidence of 70 degrees or greater, the sputter yield is essentially zero. For Cu ion impact angles of 20 degrees or less, the sticking probability is essentially unity for all impact energies studied. @FootnoteText@ @footnote 1@Supported in part by US Department of Energy Cooperative Research and Development Agreements (CRADAs).