Deep Reactive Etching Process Research Articles

Silicon Micromachined Lens Antenna for THz Integrated Heterodyne Arrays

In this paper, we present the design, fabrication, and measurements of a lens THz antenna that can be fabricated using conventional photolithography and deep reactive etching processes. The antenna is composed of an extended hemispherical silicon lens and a leaky wave waveguide feed. Both elements are fabricated using silicon micromachining techniques, enabling the fabrication of future large antenna arrays with a parallel process. To show the concept, a first antenna prototype has been fabricated using this fabrication process. Measurements obtained at 550 GHz are presented.

Controllable fabrication of periodic arrays of high-aspect-ratio micro-nano hierarchical structures and their superhydrophobicity

This paper demonstrates a flexible and controllable fabrication of vertically aligned and high-aspect-ratio (HAR) micro-nano hierarchical structures using conventional micro-technologies. We first masked the nanopatterns on a photoresist mold by shifting the same photomask, which could be performed using conventional contact microlithography. Thereby replicating nanopatterns onto an aluminium mold and successfully fabricating silicon nanopillar arrays about 300 nm in diameter and 5 µm in height via the deep reactive etching (DRIE) process. We also fabricated micro-nano hierarchical structures with variable aspect ratios using the proposed nanopattern technology and DRIE process without using any special nanopatterning equipment or techniques. The proposed method not only simplified the fabrication process but also produced HAR (higher than 15) structures. We also investigate the replica molding steps from the fabricated silicon stamp to a UV-curable polymer replica using a PDMS mold and conventional nano-imprinting, where each nanopillar diameter was 320 nm with 95% fidelity. As a result, the hierarchical structure arrays show stable superhydrophobic surface properties with a contact angle of approximately 160°. Owing to the cost efficiency of mass production and the fidelity of the strategy, the methodology could provide a general approach for fabricating complex three-dimensional periodic hierarchical structures onto a single chip and can be applied to various fields of multifunctional applications.