Atom Probe Tomography (APT) was applied to analyze the silicidation reaction between a titanium metal film, capped by a TiN layer, and a boron-implanted silicon substrate. The concentration depth profile observed by APT, depicts low concentrations of B in titanium silicide itself and the B accumulation at the interface between the TiSi2 and the TiN capping layer. Moreover the three dimensional atomic reconstruction from APT revealed a laterally inhomogeneous B distribution along the interface as well as B precipitation. APT enables the stoichiometric identification of TiB2 precipitates smaller than 7 nm in diameter. (C) 2011 Elsevier B.V. All rights reserved.