Study the Effect of Etching Time on the Characteristics of the Porous Silicon that Prepare from N-Type Silicon by Photoelectrochemical Etching Method

Abstract

In this paper, samples of porous silicon were studied and prepared using n-type silicon with directionality (111) using photoelectrochemical etching method with current density (20 mA/cm²) and with different etching time (5, 10, 15, and 20 min). The results of the structural properties tests of porous silicon using (XRD) showed an increase in the width of the mid-top of the curve with the increase of the etching time and thus the grain size decreases from (46.99 nm to 4.36 nm), from the (SEM) examination, the results showed that the pore depth increases with the increase in the etching time, from the (AFM) examination found that the grain size rate increases from (63.55nm to 75.68nm) and the surface roughness also increases from (2.2nm to 17.9nm) with the increase in the etching time. The porosity is within the visible light region and as the etching time increases, the curve shifts towards short wavelengths, thus increasing the optical energy gap (1.99eV to 2.02eV).