Nickel-Based Germanosilicide of Heavily-Doped SiGe Films for Low Resistance and High-Temperature Stability

Abstract

We have studied thermo-electrical properties for Ni-based germanosilicide to understand the influence of temperature on the evolution of sheet resistance and micro-structures of contacts on heavily-doped SiGe grown by reduced pressure chemical vapor deposition. After the deposition of Ni, Ni/Ti, Ni/Pt films on Si0.83Ge0.17 epi layer and subsequently annealing for silicide reaction, we analyzed sheet resistance, surface roughness and reaction interfaces using four point probe method, scanning probe micrograph and transmission electron microscope. Bi-layer metal structures of Ni/Ti and Ni/Pt were investigated to study feasible use for suppressing inappropriate reaction at interface. It is found that bi-layer structure with thin Pt interlayer presented promising properties for germanosilicide of n+-Si0.83Ge0.17 with low sheet resistance, smooth surface morphology and high temperature stability up to 800 oC.