Page 11 - Microsensors, MEMS and Smart Devices - Gardner Varadhan and Awadelkarim

x CONTENTS

12.2.1 Mask Generation 347
12.2.2 Wafer Preparation 348
12.2.3 Metallisation 349
12.2.4 Photolithography 350
12.2.5 Wafer Dicing 352
12.3 Deposition of Waveguide Layer 353
12.3.1 Introduction 353
12.3.2 TMS PECVD Process and Conditions 354
12.4 Concluding Remarks 358
References 358

13 IDT Microsensors 359
13.1 Introduction 359
13.2 Saw Device Modeling via Coupled-mode Theory 360
13.3 Wireless SAW-based Microsensors 364
13.4 Applications 367
13.4.1 Strain Sensor 367
13.4.2 Temperature Sensor 371
13.4.3 Pressure Sensor 375
13.4.4 Humidity Sensor 376
13.4.5 SAW-Based Gyroscope 380
13.5 Concluding Remarks 395
References 395

14 MEMS-IDT Microsensors 397
14.1 Introduction 397
14.2 Principles of a MEMS-IDT Accelerometer 398
14.3 Fabrication of a MEMS-IDT Accelerometer 399
14.3.1 Fabrication of the SAW Device 401
14.3.2 Integration of the SAW Device and Seismic Mass 402
14.4 Testing of a MEMS-IDT Accelerometer 402
14.4.1 Measurement Setup 403
14.4.2 Calibration Procedure 404
14.4.3 Time Domain Measurement 405
14.4.4 Experimental 406
14.4.5 Fabrication of Seismic Mass 408
14.5 Wireless Readout 412
14.6 Hybrid Accelerometers and Gyroscopes 414
14.7 Concluding Remarks 416
References 416

15 Smart Sensors and MEMS 417
15.1 Introduction 417
15.2 Smart Sensors 421
15.3 MEMS Devices 434
15.4 Concluding Remarks 442
References 443