Laminated, sacrificial-poly MEMS technology in standard CMOS

We present a micro-machining technology which enables MEMS fabrication on s tandard CMOS with very dense electrical/mechanical integration. Micro-mecha nical structures are fabricated alongside circuits on standard 0.5-mu m 3-m etal CMOS dice using four maskless dry-etch steps. The resulting laminated beams are made of CMOS metal and dielectric lavers. Multi-conductor mechani cal structures can carry multiple signals for actuation and sensing. Narrow vertical and lateral gaps enable efficient XYZ electrostatic actuation and fine capacitive position sensing. Experiments show that mechanical structu res can be integrated 1.5 mu m away from signal-processing circuits, result ing in very low parasitics, good system performance, and small die size. (C ) 2000 Elsevier Science S.A. All rights reserved.