Epitaxial Growth of CoSi2 on Si Using a CoNx Interlayer Deposited by Reactive Metallorganic Chemical Vapor Deposition

Abstract

A CoNx film has been introduced as a new interlayer material for the epitaxial growth of CoSi2 on Si. The CoNx film was deposited by metallorganic chemical vapor deposition using a cobalt carbonyl source in NH3 ambient. From the Co/CoNx/Si structure, a uniform and ultrathin epitaxial CoSi2 layer with the thickness of 15 nm has been obtained. During the CoNx deposition, a SiN/cobalt silicide double layer has been observed at the interface. It is believed that the SiN layer limits the supply of Co to Si,resulting in allowing the growth of the CoSi2 epitaxial layer.