EXAFS investigation of Co sites in CoSi2 film crown by ion beam assisted deposition

Cobalt silicide is a metallic compound of great interest for interconnection in Si-based microelectronics devices. Polycrystalline CoSi/sub 2/ films are normally prepared by Physical Vapor Deposition (PVD). Thermal annealing at T /spl les/600/spl deg/C inducing the compound formation is performed during or after the deposition, but a final thermal treatment at about 800/spl deg/C is required to obtain the right stoichiometry. CoSi/sub 2/ shows thermal stability up to 950/spl deg/C, after which a strong increase in the electrical resistivity, related to formation of a very discontinuous network of the crystalline grains, is observed. This behavior is strongly inhibited in CoSi/sub 2/ films grown by Ion Beam Assisted Deposition (IBAD). In this technique an Ar/sup +/ ion beam irradiates the sample during the Co evaporation. Films stable up to 1050/spl deg/C have been produced in this way, the stability being related to experimental parameters such as the Ar/sup +/ ion current. In this work we present Extended X-ray Absorption Fine Structure (EXAFS) analysis on a set of CoSi/sub 2/ films prepared by IBAD.