Silicon flower structures by maskless plasma etching

Silicon nano/microstructures are widely utilized in the semiconductor industry, and plasma etching is the most prominent method for fabricating silicon nano/microstructures. Among the variety of silicon nano/microstructures, black silicon with light-trapping properties has garnered broad interest from both the scientific and industrial communities. However, the fabrication mechanism of black silicon remains unclear, and the light absorption of black silicon only focuses on the near-infrared region thus far. Herein, we demonstrate that black silicon can be fabricated from individual flower-like silicon microstructures. Using fluorocarbon gases as etchants, silicon flower microstructures have been formed via maskless plasma etching. Black silicon forming from silicon flower microstructures exhibits strong absorption with wavelength from 0.25 μm to 20 μm. The result provides novel insight into the understanding of the plasma etching mechanism in addition to offering further significant practical applications for device manufacturing.