以0.18μm製程完成之新穎三軸磁力計與加速度計共通結構與整合電路設計

Abstract

本論文提出混和訊號微機電製程下，完成三軸磁力計及加速度計暨讀出電路設計。磁力計操作範圍在±70μT內，對應偵測X、Y、Z軸磁場靈敏度為1.16aF/μT, 1.74aF/μT與 1.8aF/μT。而加速度計操作範圍在±4g內，對應偵測X、Y、Z軸加速度靈敏度為85aF/g, 2.85fF/g與 10.86fF/g。而後利用讀取電路處理感測器電容變化訊號可將磁力計針對X、Y、Z軸靈敏度提升至4.7mV/μT, 7.1mV/μT與7.8mV/μT；而加速度計靈敏度提升至62mv/g, 103mv/g與94.5mv/g。利用專業微機電設計軟體，具體分析模擬微機電運動行為及電路特性，完成微機電與電路整合設計。讀出電路量測結果，電路靈敏度為2.37mV/aF，輸出雜訊為8.01μV/√Hz。

A monolithic design of three axial Lorentz-force magnetometer and accelerometer in sole combo-structure in standard 0.18μm 1P6M Complementary Metal-Oxide-Semiconductor technology (CMOS) has been proposed. Based on different metal layers routing, the modeling of magnetometer and accelerometer combo sensor whose sensing range is ±70μT and ±4g has been discussed, analyzed and simulated in this work. The capacitance sensitivity of magnetometer is 1.16aF/μT, 1.74aF/μT, and 1.8aF/μT for X, Y, and Z-axis magnetic field respectively; 85aF/g, 2.85fF/g, and 10.86fF/g for X, Y, and Z-axis acceleration respectively for accelerometer. The integrated readout circuit is composed of correlated double sampling (CDS) and chopper stabilization (CHS) which can eliminate the noise and offset effectively. The sensitivity of full system is designed to be 4.7mV/μT, 7.1mV/μT, and 7.8mV/μT for X, Y, and Z-axis magnetic field sensing; 62mv/g, 103mv/g, and 94.5mv/g for X, Y, Z-axis acceleration sensing respectively. The resolution of magnetometer is 1.56nT/√Hz, 1.03nT/√Hz, and 0.94nT/√Hz for X, Y, Z-axis magnetic field; and 7.34μV/√Hz, 7.51μV/√Hz, and 7.71μV/√Hz for X, Y, and Z-axis acceleration sensing respectively. Keywords- CMOS, three axial Lorentz force magnetometer, three axial accelerometer.