Formation of silicon nano tips using post SAM-based wet etching

This paper reports a simple method to create silicon nano tips in post self-assembled monolayer (SAM)-based anisotropic wet etching. To demonstrate the fabrication feasibility, different local etch rates at stressed surfaces at hemispherical silicon specimens in surfactant-added etchants compared to those on flat silicon surfaces have been measured, which are explained as the enhanced adsorption of surfactant molecules on surfaces at high curvature. Tips are fabricated in pure TMAH followed by TMAH + surfactant. The resultant tips after the treatment in surfactant-modified etchants with short time 6 min have a radius of curvature <;10 nm and can maintain this value so far as the surfactant molecules do not detach the tip apex.