Abstract

COYOPOL, A. et al. Morphological and optical properties of porous silicon annealed in atomic hydrogen. Superf. vacío [online]. 2012, vol.25, n.4, pp.226-230. ISSN 1665-3521.

In this work, optical and morphological changes on hydrogen-annealed porous silicon layers (PSL) are reported. The PSL were annealed in a hot filament chemical vapor deposition (HFCVD) system at a temperature of 1000 °C. Annealing time, 10, 20, 60, 90, 180 and 360 sec was taken as parameter to changes the properties of PSL. After treatment, the samples were characterized by scanning electron microscopy (SEM), Fourier Transform infrared (FTIR) spectroscopy, reflectance and photoluminescence (PL) measurements. It was found that silicon matrix, in the PSL, was etched off by their interaction with atomic radicals causing changes in its morphology, porosity and thickness. The reflectance of the film, which is dependent on the porosity, also decreased to values near to 0% in the range of 400 to 850 nm even for short annealing times. The emission properties of the films, in the visible range, shifted to blue region for longer processing time.

Keywords : Porous Silicon; PL; FTIR; Atomic Hydrogen.

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