Study the Effect of Etching Current Time on Porous Silicon Preparation

This study aims to investigate the effect of etching current time on the preparation of porous silicon using the photoelectrochemical etching method. N-type silicon (111) with a resistivity of 1.5-4 Ω.cm was used to prepare the porous silicon layers. The etching process was carried out using a solution of hydrofluoric acid (HF) with a concentration of 18% mixed with high-purity ethanol. The etching current densities were varied at 10, 15, 20, and 30 mA/cm² with an etching time of 15 minutes. The structural and morphological characterization of the porous silicon layers was performed using X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and Atomic Force Microscopy (AFM). The XRD results showed a broad diffraction peak as the crystal size decreased to the nanometer scale. SEM and AFM images revealed that the porous silicon layer had a sponge-like structure, with pore sizes increasing as the etching current density increased.