Material and electrical characterization of nickel silicide-carbon as contact metal to silicon-carbon source and drain stressors

Abstract

In this paper, the material and electrical characteristics of Nickel-Silicon-Carbon (NiSi:C) films were investigated for the first time to ascertain the compatibility of NiSi:C contacts to silicon-carbon (Si:C) source/drain stressors. The incorporation of 1 atomic percent of carbon was found to increase both the Ni2Si-to-NiSi and NiSi-to-NiSi2 transformation temperatures. Our results show that the incorporation of carbon stabilizes the interfacial and surface morphology of NiSi :C films. We speculate that the incorporated carbon segregates into the NiSi :C grain boundaries and suppresses film agglomeration and NiSi-to-NiSi2 phase transformation. X-ray diffraction analysis further revealed that the formed NiSi:C films possessed a preferred orientation. Current-voltage measurements for NiSi and NiSi:C n+/p junctions exhibit similar cumulative distribution for junction leakage indicating that carbon incorporation does not have a detrimental impact on the n+/p junction integrity. Our results suggest that NiSi:C is a suitable self-aligned contact metal silicide to n-channel MOSFETs with SiC S/D stressors in a similar manner to the way in which NiSiGe is used for p-channel MOSFETs with SiGe S/D stressors. © 2007 Materials Research Society.