New Method of Porous Ge Layer Fabrication: Structure and Optical Properties

Abstract

Porous germanium films were produced by selective removal of the GeO2 matrix from the GeO2 heterolayer in deionized water or HF. On the basis of Raman and infrared spectroscopy data it was supposed that a stable skeletal framework from agglomerated Ge nanoparticles (amorphous or crystalline) was formed after the selective etching of GeO2 heterolayers. The kinetics of air oxidation of amorphous porous Ge layers was investigated by scanning ellipsometry. Spectral ellipsometry allowed estimating the porosity of amorphous and crystalline porous Ge layers, which was ~70 and ~80%, respectively.