Impact of AI addition on the formation of Ni germanosilicide layers under different temperature annealing

摘要

Solid reactions between Ni and relaxed Sio.7Geo.3 substrate were systematically investigated with different Al interlayer thicknesses.The morphology,composition,and micro-structure of the Ni germanosilicide layers were analyzed with different annealing temperatures in the appearance of Al.The germanosilicide layers were characterized by Rutherford backscattering spectrometry,cross-section transmission electron microscopy,scan transmission electron microscopy,and secondary ion mass spectroscopy.It was shown that the incorporation of Al improved the surface and interface morphology of the germanosilicide layers,enhanced the thermal stabilities,and retarded the Ni-rich germanosilicide phase to mono germanosilicide phase.With increasing annealing temperature,Al atoms distributed from the Ni/Si0.7Ge0.3 interface to the total layer of Ni2Si0.7Ge0.3,and finally accumulated at the surface of NiSi0.7Ge0.3.We found that under the assistance of Al atoms,the best quality Ni germanosilicide layer was achieved by annealing at 700 ℃ in the case of 3 nm Al.