Understanding Smart Sensors - Nomads.usp

Micromachining 43Sensitive layerContact tosensitivelayerSiO insulation2Contacts toheatingelementIntegratedresistiveheatingelementBulkmicromachinedsiliconsubstrateFigure 2.16 Sensing layer deposited over bulk micromachined structure. (After: [37].)2.6.4 Micromachining Metal StructuresA micromachining process called electrochemical fabrication (EFAB) has beendeveloped that can build a wide range of three-dimensional structures [38].The process relies on the electroplating of metal and an in-situ mask patterningtechnique. The EFAB process is shown in Figure 2.17.ElectrolyteSelectively deposited1st materialAnodeMaskBlanket-deposited2nd material(a)Substrate(b)(c)(d) (e) (f)Figure 2.17 EFAB process. (Courtesy of USC/Information Sciences Institute.)