Surface Morphology and Si 2p Binding Energy Investigation of Multilayer Porous Silicon Nanostructure

Multilayer structure of porous silicon was fabricated using electrochemical etching method. Average thickness of multilayer structure was verified. Surface morphology from Atomic Force Microscopy (AFM) shows that surface roughness was decreased when higher etching time applied to the samples. Si 2p binding energies were corresponded to the composition of void within the silicon which prompted the formation of porous silicon nanostructure. Depth profiling technique from X-Ray photoelectron spectroscopy (XPS) was used for compositional determination of porous silicon layers since samples' porosity varied according to current density applied during the electrochemical etching process. Multilayer porous silicon is a high potential candidate for Bragg grating waveguide device.