Raid A. Ismail ,, Nadir F. Habubi and Ahmed N. Abd
الملخص الانجليزي
In this paper, the nanocrystalline porous silicon (PS) films are prepared by
electrochemical etching of p -type silicon wafer with current density (7 mA/cm 2 ) and
etching times on the formation nano -sized pore array with a dimension of around
different etching time. The films were characterized by the measurement of XRD, FTIR
spectroscopy and atomic force microscopy properties (AFM). 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 the surface chemical composition of PS. The etching
possesses inhomogeneous microstructures that contain a -Si clusters (Si 3 –Si–H) dispersed
in amorphous silica matrix . 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 increase.