One-mask procedure for the fabrication of movable high-aspect-ratio 3D microstructures

Abstract

This paper describes a unique surface microfabrication procedure for cost-effective manufacture of free-standing, high-aspect-ratio micromechanical structures for sensor and actuator applications. This enables microstructures to be manufactured from a two-layer system with only one standard optical mask. The entire microstructures are grown electrochemically within a patterned thick (up to m) resist template on an electroplating base layer. The movable parts are subsequently obtained by removing the underneath base layer using a current-controlled electrochemical etching approach. The novel one-mask procedure involves only a few processing steps, promising low-cost, high-yield production. The realization of a lateral sensitive acceleration sensor is taken here as an example to illustrate this fabrication procedure.