Agradecimentos: The authors would like to acknowledge the technical contribution due to Jose Augusto Lopes da Rocha (X-ray data) at the IFSC-USP and Rodrigo Antonio Barbieri (FE-SEM/EDS micrographs) at the LCMIC-UCS. They also are particularly indebted to the developers of the SRIM software. The...

Agradecimentos: The authors would like to acknowledge the technical contribution due to Jose Augusto Lopes da Rocha (X-ray data) at the IFSC-USP and Rodrigo Antonio Barbieri (FE-SEM/EDS micrographs) at the LCMIC-UCS. They also are particularly indebted to the developers of the SRIM software. The study was financially supported by the Brazilian National Council of Scientific and Technological Development (CNPq) and the Research Support Foundation of the State of Sao Paulo (FAPESP) are gratefully acknowledged. F.G.E. is a FAPESP fellow (Grant No. 2019/00757-0). C.A.F., A.R.Z., and F.A. are CNPq fellows. This work was also partially supported by the CNPq (projects 2019/24095-7 and 2019/18460-4)

Abstract: In this paper, topographically asymmetric TiOx/TiSix metastable ultrathin (nano)films on SiO2/Si(100) are produced by controlling interface reactions through ion beam synthesis. The film growth process involves a dual ion beam system, combining Ar+ sputtering a Ti target and in situ...

Abstract: In this paper, topographically asymmetric TiOx/TiSix metastable ultrathin (nano)films on SiO2/Si(100) are produced by controlling interface reactions through ion beam synthesis. The film growth process involves a dual ion beam system, combining Ar+ sputtering a Ti target and in situ postirradiation (Ar+ + H-2(+) ion etching) at normal incidence to modify the surface morphology. The film's production and characterization are challenging due to the formation of a complex mixed interface+layers (heterophases) containing nanocrystalline and amorphous compounds of Ti and Si. The results for different ion etching times (0-600 s) are systematically presented and analyzed. With the experimental+theoretical information, it is possible to deduce that the heterophase interface is originated by oxide intermixing in combination with the formation of titanium silicides taking place at the early stages of growth. The reactivity of oxygen and hydrogen species is the dominating factor influencing the metastable film growth mediated by solid-state phase reactions. Given its crucial role at the (Ti/Si):O interface, the chemical route and control of intrinsic defects (non-stoichiometry) are defined by domain ordering mechanisms followed by surface restructuring. In view of their main characteristics, taken altogether, the current functional metastable films represent a promising alternative for high-performance photonic and optoelectronic applications

CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ

2019/18460-4; 2019/24095-7

FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP

2019/00757-0

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