Thin nickel silicide layer formation on silicon on insulator material

In this work we study the phase transition of 14 and 7 nm thin Ni layers grown on standard silicon and silicon on insulator (SOI) wafers implanted with As. We investigate the thermal stability of the NiSi phase using spike thermal processes which are widely used to preserve shallow junction from dopant diffusion during electrical activation. Nickel reaction has been performed in nitrogen ambient in the temperature range from 450 to 1125 °C and has been characterised by electrical and structural analyses. In spite of the thin layers used, spike annealing processes extend the stability window up to 900 °C preserving the NiSi layer from structural degradation. Moreover, the use of SOI substrates has a favourable impact on the silicide structure that prevents agglomeration and hole formation.