Self-assembled monolayer-assisted thin metal polishing for fabricating uniform 3D microstructures

Abstract

A self-assembled monolayer (SAM) was actively used to improve the reproducibility and yield of micromachining technology. A harsh metal mechanical polishing process was replaced with a metal wet etching process by using a hexadecanethiol (HDT) SAM as an etch-protect mask. The fundamental results of the experiment show the excellent ability of the HDT SAM in protecting the gold from the gold wet etchant and the wide process margin. The proposed process, which was used to fabricate a 3D suspended inductor, greatly improves the process yield. The proposed micromachining technology with a SAM is expected to have a variety of applications for the highly reproducible and uniform fabrication of MEMS.