Traditionally porous silicon based photonic structures have been prepared by electrochemically etching of silicon. In this work, porous multilayers of nanocolumnar SiOx and SiO2 thin films acting as near infrared (NIR) 1D-photonic nanostructures are prepared by magnetron sputtering deposition at oblique angles (MS-OA). Simultaneous control of porosity and stoichiometry of the stacked films is achieved by adjusting the deposition angle and oxygen partial pressure according to a parametric formula. This new methodologoy is proved for the synthesis of SiOx thin films with x close to 0.4, 0.8, 1.2, 1.6 and nanostructures varying from compact (at 0° deposition angle) to highly porous and nanocolumnar (at 70º and 85° deposition angles). The strict control of composition, structure and nanostructure provided by this technique permits a fine tuning of the absorption edge and refraction index at 1500 nm of the porous films and their manufacturing in the form of SiOx-SiO 2 porous multilayers acting as near infrared (NIR)
ACCEPTED MANUSCRIPTRecently, SiO x nanowires have been proposed as refractive index sensing devices, [10] while in the form of stacked layers and porous films this material is utilized for the fabrication of Li battery electrodes. [11,12] Compact SiO x thin films have been fabricated by various methods, including evaporation [13][14][15] thermal chemical vapor deposition (CVD), [16,17] or magnetron sputtering (MS).[18-20] Radio frequency reactive MS was profusely utilized by Habraken et al. for the deposition of SiOx thin films.[21-26] Besides