Characterization of Oxide-Coated Polysilicon Disk Resonator Gyroscope Within a Wafer-Scale Encapsulation Process

Abstract

In this paper, we present the fabrication and test results of an oxide-coated polysilicon disk resonator gyroscope in a wafer-scale encapsulation process. We demonstrate the effects of an oxide coating on the device structure and the key performance parameters of resonant-based sensors, such as the temperature coefficient of frequency and quality factor ( Q). Results from the as-fabricated device show that a thin oxide coating reduces the surface roughness of a fully encapsulated device by 10×, compared with a polysilicon device without the oxide coating. This increases the uniformity across the wafer, providing higher process yield. The open-loop rate measurement mode reveals an angle random walk of 0.18°/ √ hr and a bias instability of 1.43°/hr. [2015-0124]Index Terms-Microelectromechanical systems (MEMS) gyroscope, wineglass mode, surface roughness, oxide coating, polysilicon.

Dynamic Modeling of the Multiring Disk Resonator Gyroscope

“…The design model of a typical DRG is shown in Figure 1a [5,6,7,8,9,10,13,14,27,28,29]. The DRG consists of multiple concentric rings which are interconnected through 8 spokes on one layer that are anchored at the center.…”