Formation of All-Silicon Metasurfaces for Sensor Devices

This study addresses the critical challenge of fabricating silicon metasurfaces with precise geometric parameters, which are essential for their sensor functionality. A key research gap lies in the insufficiently explored effect of the CCl2F2 percentage in the plasma-etching gas mixture on the combined control over height, roughness, sidewall angle, and lateral dimensions. This work aims to establish quantitative correlations between the inductively coupled plasma (ICP) source power, gas composition, and morphological characteristics to develop optimized fabrication processes. The research yielded arrays of structures, enabling the derivation of dependencies. Specifically, at an ICP power of 400 W and 14% CCl2F2, a toroidal metasurface element was achieved with a height of 274 nm, a sidewall angle of 83°, and a critical dimension bias of 1.5%, demonstrating a viable regime for high-precision manufacturing.