Impact of the Pre Amorphization by Ge Implantation on Ni0.9Pt0.1 Silicide

The impact of the Pre Amorphization by Ge Implantation (PAI) on Ni0.9Pt0.1 silicide is studied. Reactions between a 10 nm thick Ni0.9Pt0.1 film and Si (100) substrate are analyzed as a function of the induced amorphous-Si thicknesses. In view of being compatible with the integration constraint of the 28 nm CMOS technologies, the Ge implantation dose is fixed at a low level. The relative position of the amorphous-Si/crystalline-Si interface and the silicide growth front is defined for each sample. Then, in-situ XRD analyses, X-Ray Reflectometry (XRR) and Sheet resistance (Rs) measurements are achieved to provide a deep study of silicide growth kinetics and silicide properties. First, a clear relationship is established between the silicide growth rate and the amorphous-Si thickness. Secondly, an easier NiSi nucleation and a decrease of its resistivity is observed when NiSi nucleates at the theta-Ni2Si/a-Si interface. These observations are discussed considering the impact of the amorphous-Si layer on the driving force, the nucleation barrier, the lateral growth rate, and NiSi roughness.