Study of Ni-Silicide Contacts to Si:C Source/Drain.

Abstract

Integration of recessed Si:C source/drain (S/D) for deep sub- micron nMOSFET devices results in substantial improvement of electron mobility and drive current due to introduction of tensile strain in the channel. The compatibility of Ni-silicide contacts with Si:C source/drain is investigated in this paper. The Ni-silicide morphology and phase formation were studied by means of sheet resistance measurements, X-Ray Diffraction (XRD) and Energy Dispersive Spectroscopy (EDS) analysis, Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) inspection. The carbon concentration and profile in the NiSi:C film was studied by Secondary Ion Mass Spectrometry (SIMS) analysis. The strain in the Si:C substrate and NiSi:C film was studied by high resolution XRD (HRXRD). This paper demonstrates that Ni-silicide is compatible with Si:C. The tensile strain in Si:C is maintained after Ni-silicidation. The addition of carbon to silicon is found to stabilize the silicide morphology.