Understanding Smart Sensors - Nomads.usp

viiiUnderstanding Smart Sensors2.3.4 Wafer Bonding for More Complex Structures andAdding ICs 252.4 Surface Micromachining 252.4.1 Squeeze-Film Damping 292.4.2 Stiction 292.4.3 Particulate Control 302.4.4 Combinations of Surface andBulk Micromachining 302.5 Other Micromachining Techniques 312.5.1 LIGA Process 322.5.2 Dry-Etching Processes 322.5.3 Micromilling 362.5.4 Lasers in Micromachining 362.5.5 Chemical Etching and IC Technology 372.6 Other Micromachined Materials 402.6.1 Diamond as an Alternative Sensor Material 412.6.2 Metal Oxides and Piezoelectric Sensing 412.6.3 Films on Microstructures 422.6.4 Micromachining Metal Structures 432.7 Summary 44References 443 The Nature of Semiconductor Sensor Output 493.1 Introduction 493.2 Sensor Output Characteristics 493.2.1 Wheatstone Bridge 503.2.2 Piezoresistivity in Silicon 523.2.3 Semiconductor Sensor Definitions 543.2.4 Static Versus Dynamic Operation 573.3 Other Sensing Technologies 573.3.1 Capacitive Sensing 583.3.2 Piezoelectric Sensing 59