Basic research on micro processing characteristics of reverse lift-off process

Abstract

In micro electromechanical systems(MEMS) technology, lift-off processes are general patterning methods for the formation of amorphous alloy thick film structures. However, thicknesses of structures fabricated in this method are not uniform and cross-sectional shapes are not flat because sputtered particles are blocked by the sidewalls of the lift-off layer. In order to solve this problem, a reverse lift-off process is proposed as a new patterning method [1]. In the reverse lift-off process, the desired structure is formed on the top of the convex pattern such as the substrate. In contrast to the lift-off process, the thickness of the structure is uniform and the cross-sectional shape is rectangular because sputtered particles are not blocked by the sidewalls. In this research, thick film structures were fabricated in reverse lift-off processes from the width of the convex pattern on the order of micrometers. And the film thickness and the cross-sectional shape of the fabricated structure are measured, and the micro processing characteristics of the reverse lift-off process, which had not yet been elucidated, were investigated. This demonstrates the usefulness of fabricating the thick film micro structures in the reverse lift-off process.