Production of NiSi phase by grain boundary diffusion induced solid state reaction between Ni2Si and Si(100) substrate

• Published in: Applied surface science Vol. 320; pp. 627 - 633
• Main Authors: Shenouda, S.S., Langer, G.A., Katona, G.L., Daróczi, L., Csik, A., Beke, D.L.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 30.11.2014; Elsevier
• Subjects: Annealing; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Deposition; Evolution; Exact sciences and technology; Grain boundaries; Grain boundary diffusion; Nanostructures; Nickel silicide; Physics; Solid state reaction; Thin films; Transformations; Thin films; Grain boundary diffusion; Nanostructures; Solid state reaction; Silicon; Phase boundaries
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2014.09.071

Sketch of grain boundary diffusion of Si (blue) into Ni2Si film (yellow) forming NiSi (red). •New processing method for creation of homogeneous thin NiSi contacts from nanocrystalline-Ni2Si/Si(100) substrate.•The NiSi forms by grain-boundary diffusion and reaction in a certain low temperature-time and thickness-time window.•The nucleated NiSi growths perpendicular to the grain boundaries and its velocity can also be determined. We report a process to obtain thin (5–20nm thick) NiSi layers on Si(100) substrate from magnetron deposited Ni2Si thin films at low temperatures (180–200̊C). The time evolution of transformation was followed by means of Secondary Neutral Mass Spectrometry, transmission electron microscopy and resistance measurements. It is shown that there exist certain temperature-time and thickness-time windows inside of which the formation of NiSi takes place. The NiSi phase, formed along the grain boundaries of Ni2Si and grew by the motion of these interfaces, gradually consumes the Ni2Si phase. From the depth profiles of the first stage of the process, using the linear dependence of the average composition inside the film on the annealing time, the velocity of the grain boundary diffusion induced interface motion was also estimated. The normalized value of the resistance, proportional to the amount of the new phase, showed similar time evolution and yielded similar value for the interface velocity.