Control of liquid bridging induced stiction of micromechanical structures

Abstract

Stiction, the unwanted adhesion of micromachined components to the underlying substrate, is a vexing problem encountered during the fabrication of microelectromechanical systems. Liquid bridging of rinse liquids after release etch processing introduces significant surface tension forces which can initiate stiction. We show that liquid bridging can be substantially eliminated by appropriate design of the microstructure periphery. Antistiction tabs located at the center of doubly clamped beams, or at the ends of cantilevered beams, are shown to improve release yield significantly in both surface and bulk micromachining processes.