Xw. Zhou et Hng. Wadley, The low energy ion assisted control of interfacial structure: Ion incidentenergy effects, J APPL PHYS, 87(12), 2000, pp. 8487-8496
The properties of multilayered materials are often dependent upon their int
erfacial structure. For low temperature deposition processes where the stru
cture is kinetically controlled, the interfacial roughness and the extent o
f interlayer mixing are primarily controlled by the adatom energy used in t
he deposition. Inert gas ion assistance during the growth process also enab
les manipulation of the interfacial roughness and intermixing. To explore i
nert gas ion assistance, a molecular dynamics approach has been used to inv
estigate the role of ion energy and ion species upon the flattening of vari
ous surfaces formed during the growth of the Ni/Cu/Ni multilayers. The resu
lts indicated that ion energies in the 1-4 eV range could flatten the "roug
h" copper islands on either copper or nickel crystals. To flatten the rough
nickel islands on copper or nickel crystals, higher ion energies in the 9-
15 eV range would have to be used. Significant mixing between nickel island
atoms and the underlying copper crystal atoms started to occur as the ion
energy was increased to around 6-9 eV. However, little mixing was observed
between the copper island atoms and the underlying nickel crystal atoms in
the same ion energy range. At a given ion energy, the heavier (xenon) ions
were found to produce more surface flattening and mixing than the lighter (
argon) ions. (C) 2000 American Institute of Physics. [S0021-8979(00)03512-X
].