Metal-assisted chemical etching of silicon and achieving pore sizes as small as 30 nm by altering gold thickness

Abstract

Metal-assisted chemical etching is applied to fabricate deep, high aspect ratio nanopores in silicon. The authors’ simple and cost-effective fabrication process has proven capable of generating nanopores with diameters as small as 30 nm, over the whole wafer surface (50.8 mm in diameter). The process uses a thin layer of DC-sputtered gold and H2O2/H2O/HF treatment to generate Au nanoislands. The formation of these nanoislands is confirmed by scanning electron microscopy. In this paper, the authors study the effect of Au-layer thickness on the diameter and morphology of the fabricated nanopores. The resulting structures have wide applications in optical sensing and filtering.