Realization and Characterization of Aligned Silicon Nanowire Array With Thin Silver Film

Abstract

Wafer-scale fabrication of aligned and uniform silicon nanowire (SiNW) arrays is achieved with good controllability and reproducibility by depositing a thin silver film on a silicon surface prior to wet etching. Fast SiNW formation with a rate of 1.4 μm/min is achieved with optimized process condition, while lower etching rate enables finer SiNW formation in a small open area. Realized SiNWs are demonstrated to have good material and optical properties. With the help of aligned SiNWs, we demonstrate the fabrication of a black nonreflecting silicon surface with a surface reflectivity of around 2-4% uniformly over a 4-in wafer area. This material is expected to be promising as a building block for various applications due to its low-cost and mass-producible fabrication and excellent characteristics.