In this paper, the nanocrystalline porous silicon (PS) films is prepared by
electrochemical etching of p-type silicon wafer with different currents density (15 and
30 mA/cm2
) and etching times on the formation nano-sized pore array with a
dimension of around few hundreds nanometric. The films were characterized by the
measurement of XRD, FTIR spectroscopy and atomic force microscopy properties.
We have estimated crystallites size from X-Ray diffraction about nanoscale for porous
silicon and Atomic Force microscopy confirms the nanometric size
Chemical fictionalization during the electrochemical etching show on surface
chemical composition of PS. The etching possesses inhomogeneous microstructures
that contain a-Si clusters (Si3–Si–H) dispersed in amorphous silica matrix and (O-SiO,
C-SiO). From the FTIR analyses showed that the Si dangling bonds of the as-prepared
PS layer have large amount of Hydrogen to form weak Si–H bonds.
The atomic force microscopy investigation shows the rough silicon surface, with
increasing etching process (current density and etching time) porous structure
nucleates which leads to an increase in the depth and width (diameter) of surface pits.
Consequently, the surface roughness also increases.
Keywords: Nanocrystalline porous silicon; Anodization; XRD; FTIR; AFM
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