Pt–Si reaction through interfacial native silicon oxide layers

Abstract

Abstract High-resolution transmission electron microscopy (HRTEM) and selectedarea electron diffraction (SAED) were used to study the formation of 20 nm thick platinum silicide films in the presence of an interfacial native silicon oxide layer. Pt films 10 nm thick were sputtered on Si[001] substrates covered by a native oxide layer 0–2.2 nm thick and annealed between 165 and 800°C. HRTEM observations on cross-sections show that, when an interfacial oxide layer is present, the reactants interdiffuse through the oxide pinholes. The pinholes influence the Pt–Si reaction over all the annealing temperature range examined. Up to 250°C their influence is observed by differences in the silicide phases formed and in the silicide–Si interface flatness. In the 350–550°C annealing temperature range. films with or without an interfacial oxide layer are continuous, polycrystalline and quite homogeneous in thickness, being equivalent for electrical uses. Silicide films grown through an interfacial oxide layer consist o...