Interlayer-Assisted Stability of Germanosilicide for Heavily-Doped n+-Si0.83Ge0.17 Grown by Reduced Pressure Chemical Vapor Deposition

Ni-based germanosilicide process of heavily doped n+-Si0.83Ge0.17 has been investigated to understand the influence of temperature and doping concentration on the evolution of sheet resistance and micro-structures. After annealing Ni film on various Si0.83Ge0.17 epi layers for silicide reaction, the evolution of sheet resistance and surface roughness was analyzed using x-ray diffraction, four pint probe, atomic force microscope, and transmission electron microscope. Especially, bi-layer metal structures were employed to resolve inappropriate degradation associated with heavy doping of phosphorous in Si0.83Ge0.17, from which crucial improvements in structural and electrical properties could be confirmed. Pt interlayer played an important role for uniform germanosilicide at the interface of metal and semiconductor, and resulted in low sheet resistance and relevant thermal stability