Spectroscopic ellipsometric evidence of the solid-state reactions in Ni/Si multilayered films, induced by ion-beam mixing and thermal annealing

Ion beam induced surface and interface engineering

“…The interdiffusion between Ni and Si atoms in the Ni/Si MLF [409,410] induced by IBM or thermal annealing should change its chemical and atomic ordering in the reactive zone as well as a decrease in the thickness of pure Ni. It was shown that the nucleation of new crystalline phase in the amorphous matrix of alloy could be detected by optical tools rather than by the conventional XRD methods.…”

Microstructural and magnetic properties of thermally mixed Ni/Si bilayers

“…On the other hand, after a 10 h annealing at 573 K, all the Ni has been consumed and only the stable NiSi phase detected. Using XRD and optical conductivity, Lee et al [12] have studied the solid state reactions of Ni/Si, dc-sputter-deposited, multilayer films (MLF) during thermal annealing above 473 K, the Ni layers being 3.7-4.3 nm thick and the Si layers 3.9-13.9 nm thick. For the as-deposited films, these authors confirm the results that Clevenger and Thompson [25] have obtained by means of transmission electron microscopy: a 4 nm wide amorphous NiSi phase is formed between the polycrystalline Ni and (amorphous) Si sublayers.…”

“…At the moderate implantation temperatures chosen, only weak thermal mixing resulted and the intermixed layers are usually Ni-Si solid solutions or amorphous silicide phases [12,19]. At higher temperatures the formation of several crystalline Ni silicides (Ni 3 Si, Ni 2 Si, NiSi) has been distinguished [12].…”

“…Nonetheless, the two common deposition and silicidation methods, namely ion-beam induced mixing and slow or rapid thermal annealing [6][7][8], are rather difficult to apply to achieve suitable interconnects. After several decades of intense research, detailed information on the evolution of phases and their correlation with stress and defects has been collected and even modelled as a function of the sample properties and annealing or ion-beam parameters [6][7][8][9][10][11][12][13].…”