In situ study of the formation of NiSi2 nanoplates and Ni nanocrystals embedded in a Si(001) wafer and in a deposited Ni-doped SiO2 thin film

DA SILVA COSTA, DANIEL; KELLERMANN, GUINTHER; CRAIEVICH, ALDO F.; GIOVANETTI, LISANDRO J.; HUCK-IRIART, CRISTIÁN; REQUEJO, FÉLIX G.

JOURNAL OF ALLOYS AND COMPOUNDS

ELSEVIER SCIENCE SA

Año: 2021

0925-8388

We have studied for the first time the relevant features of the thermally activated nanostructural transformations occurring in a material initially consisting of a flat Si(001) wafer in which a nanoporous Ni-doped silica film is deposited. Two joint transformation processes occur and both were investigated by in situ grazing-incidence small-angle X-ray scattering during isothermal annealing at 405 °C, namely the kinetics of formation of (i) oriented NiSi2 hexagonal nanoplates endotaxially buried in a Si(001) wafer, and (ii) a set of randomly oriented spherical Ni nanocrystals with a two-mode radius distribution embedded in the Si(001) wafer and in the deposited Ni-doped silica film. The analyses of the successive 2D scattering patterns measured in situ during isothermal annealing led us to establish the time invariances of the average radii of the spherical Ni nanocrystals and the time dependence of their number, together with the time dependences of the maximum diameter, thickness, number and total volume of the hexagonal NiSi2 nanoplates buried in the Si wafer.