Creation of an antireflection coating for the optical range based on a nanoporous germanium layer formed by implantation with indium ions

Abstract

The possibility of using a nanoporous Ge layer formed by implantation with 115In+ ions on a monocrystal c-Ge substrate as an antireflection optical coating (In:PGe) was studied. For this purpose, ion implantation of c-Ge wafers was performed at an energy E=30 keV, current density in the ion beam J=5 μA/cm2, and dose D=1.8· 1016 ion/cm2. It was shown that the fabricated In:PGe spongy layer, which consists of intertwining Ge nanowires, is characterized by a low reflectivity (~ 5%) in a wide optical spectral range of 250-1050 nm. Keywords: nanoporous germanium, ion implantation, antireflection optical coating.