Impact of a Germanium and Carbon Preamorphization Implant on the Electrical Characteristics of NiSi/Si Contacts With a Presilicide Sulfur Implant

This letter reports the demonstration of preamorphization implant (PAI) using germanium (Ge) and carbon (C) and its combination with presilicide sulfur (S) implant for Schottky barrier height (SBH) tuning of nickel silicide (NiSi)-silicon contacts. Ge and C PAI increases the threshold temperature for agglomeration of a NiSi film, thus enhancing its thermal stability. A presilicide S implant and its segregation at metal/semiconductor interface effectively lowers the effective electron SBH Φ
_B
ⁿ
to 0.18 eV. In addition, the distribution of reverse current in the NiSi/n-type Si contact is improved with the introduction of Ge and C PAI.