Strategic Materials for MEMS Functionality in Standard ICs

Micro-ElectroMechanical Systems (MEMS) offer compact, high-performance hardware solutions for sensors and actuators, communication, timing, ultrasonic imaging and stimulation, and energy harvesting. If MEMS can be embedded within ICs, whether in standard CMOS or in emerging 3D heterogeneously integrated (3DHI) platforms, trusted foundries can dramatically increase their microelectronics capabilities with little to no modification to their process flow or packaging. Moreover, embedded MEMS devices could provide chip-scale security through uniquely designed signatures. This talk focuses on the design of acoustically waveguided modes achieved within standard CMOS technology. Methods for mode selection and optimization, confinement, and focusing are discussed. We show both analytically and experimentally the ability to realize high-Q resonance modes in multiple IC platforms ranging from ~100MHz to ~30GHz. Dispersion engineering of the CMOS-stack acoustic metamaterial, under strict design rule check (DRC) constraints, to reduce spurious modes and minimize radiative losses is discussed. We also consider a complete model of these electromechanical devices for ease of system-level integration using industry-standard circuit design tools and process design kits (PDKs) provided by the foundry. Looking forward to emerging materials in CMOS, we also address opportunities and challenges to ferroelectric transducers, typically implemented for Ferroelectric Random Access Memory (FRAM).