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

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.