Abstract
Porous GaAs were prepared by electrochemical etching of p-type GaAs and investigated by Spectroscopic Ellipsometry (SE). The ellipsometry is an optical technique devoted to the analysis of surfaces. The objective of this study is to determine the porosity, refractive index and the thickness. A standard Scanning Electron Microscope (SEM) technique is used to characterise the surface morphology and to confirm this study by ellipsometry.