Nanoscale study of the current transport through transrotational NiSi/n-Si contacts by conductive atomic force microscopy

The average electrical behaviour of transrotational NiSi layers used as contacts in diode structures on n-type Si was correlated to the local structure and conduction paths inside each domain by using conductive-atomic force microscopy. It was found that, independently of the domain orientation, the central portion of the domain (core ∼ 20 nm) possesses a Schottky barrier lower than in the rest of the structure. This was ascribed to an effect of the structural coupling between the NiSi lattice and the silicon substrate as realised at the interface in virtue of the pseudoepitaxial relationship established since the early stages of the reaction.