  Porosification of silicon (Si) by metal induced etching (MIE) process have
been studies here to understand the etching mechanism. The etching mechanism
has been discussed on the basis of electron transfer from Si to metal ion
(Ag$^+$) and metal to H$_2$O$_2$. Role of silver nanoparticles (AgNPs) in the
etching process has been investigated by studying the effect of AgNPs coverage
on surface porosity. A quantitative analysis of SEM images, done using Image J,
shows a direct correlation between AgNPs coverage and surface porosity after
the porosification. Density of Si nanowires (NWs) also varies as a function of
AgNPs fractional coverage which reasserts the fact that AgNPs governs the
porosification process during MIE.
