Chemical Nature of the Thin Films that Form on SiO2/Si(100) Surfaces Upon Manganese Deposition

Abstract

There has been much interest in recent years in the use of manganese for the self-formation of diffusion barriers to prevent the electromigration of copper interconnects into the underlying silicon substrate during microelectronic fabrication. However, the films resulting from the deposition of manganese on silicon wafers, which are covered by a thin native silicon dioxide layer, are complex and have not been fully characterized to date. Here we report on X-ray photoelectron spectroscopy (XPS) studies on the nature of films prepared by chemical means using methylcyclopentadienylmanganese tricarbonyl as the precursor. It was found that at the temperatures typically used for deposition, between approximately 550 and 750 K, a manganese silicate layer grows first upon reaction with the top SiO2 surface, and a thin manganese silicide film develops latter at the SiO2/Si(100) interface. The performance of these structures, of the silicide in particular, in microelectronic applications is still to be determined.