Broadband and wide-angle antireflection subwavelength structures of Si by inductively coupled plasma etching using dewetted nanopatterns of Au thin films as masks

• Published in: Thin solid films 2011-03, Vol.519 (11), p.3792-3797
• Main Authors: Leem, J.W., Yu, J.S.
• Format: Article
• Language: English
• Subjects: Antireflection property; Au nanoparticles; Cross-disciplinary physics: materials science; rheology; Dewetting process; Discharges for spectral sources (including inductively coupled plasmas); Electric discharges; Etching; Etching and cleaning; Exact sciences and technology; Gold; ICP etching; Inductively coupled plasma; Materials science; Methods of nanofabrication; Nanocomposites; Nanomaterials; Nanoscale materials and structures: fabrication and characterization; Nanoscale pattern formation; Nanostructure; Other topics in nanoscale materials and structures; Physics; Physics of gases, plasmas and electric discharges; Physics of plasmas and electric discharges; Plasma applications; Silicon; Silicon substrates; Subwavelength structures; Thin films
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2010.12.248

We report the broadband and wide-angle antireflection subwavelength structures (SWSs) on silicon (Si) substrate by inductively coupled plasma (ICP) etching using gold (Au) nanopatterns as etch masks. The reflectance depends strongly on the etched profile of Si SWSs which is influenced by both thermal dewetting and etching conditions. The size, shape, and array geometry of nano-sized patterns, which are produced via the thermal dewetting of Au thin films, are optimized under proper heat treatment. The etched depth and shape of Si nano tips are controlled additionally by ICP power, thus achieving the efficient antireflection characteristics. The optimized Si SWS with the tapered structure and sharp tips at high ICP power leads to a significantly low reflectance value of