High Aspect Ratio Silicon Structures Produced via Metal-Assisted Chemical Etching and Assembly Technology for Cantilever Fabrication

This paper presents a metal-assisted chemical etching (MACE) method for high aspect silicon structures. Ultrahigh aspect trenches and pillars of 400 and 80, respectively, have been achieved using MACE. A survey of the MACE method investigated the etching time, pattern sizes, and concentration of etching solution. In addition, a comparison of the etching methods related to the etching depth, surface roughness, and aspect ratio structure, etc., between the deep reactive ion etching and MACE methods has been reported. A simple method for cantilever fabrication has been proposed and demonstrated. Cantilever-based pillars fabricated by MACE were successfully produced via an assembly technology. The pillars were assembled onto a glass substrate and fixed with a conductive glue. The fabricated cantilever showed a resonance frequency of 235 kHz and a quality factor of 800.