A Dual-Axis Bulk Micromachined Resonant Accelerometer With Low Cross-Axis Sensitivity Fabricated With Masked–Maskless Etching

Abstract

This paper presents the design, simulation, fabrication, and experiment of a dual-axis bulk micromachined resonant accelerometer. The resonant accelerometer consists of a proof mass, four crab-leg supporting beams, and four resonant beams. Resonant beams are located at the surface of a silicon chip in order to pattern resistors and metal lines. The gravity center of the proof mass basically lies within the neutral plane of crab-leg supporting beams to minimize the rotation of the proof mass under in-plane acceleration. The non-coplanar resonant beams and crab-leg supporting beams are formed simultaneously by masked–maskless wet etching in iodine-supersaturated KOH solution. The experimental results show that the cross-axis sensitivity of ${x}$ -axis resonant beams under ${y}$ -axis acceleration is 1.92% and that of ${y}$ -axis resonant beams under ${x}$ -axis acceleration is 1.55%.