SI-based unreleased hybrid MEMS-CMOS resonators in 32nm technology

This work presents the first unreleased Silicon resonators fabricated at the transistor level of a standard CMOS process, and realized without any release steps or packaging. These unreleased bulk acoustic resonators are driven capacitively using the thin gate dielectric of the CMOS process, and actively sensed with a Field Effect Transistor (FET) incorporated into the resonant body. FET sensing using the high f[subscript T], high performance transistors in CMOS amplifies the mechanical signal before the presence of parasitics. This enables RF-MEMS resonators at orders of magnitude higher frequencies than possible with passive devices. First generation CMOS-MEMS Si resonators with Acoustic Bragg Reflectors are demonstrated at 11.1 GHz with Q~17 and a total footprint of 5μm × 3μm using IBM's 32nm SOI technology.United States. Defense Advanced Research Projects Agency. Leading Edge Access ProgramUnited States. National Security Agency. Trusted Access Program OfficeInternational Business Machines Corporatio

An unreleased mm-wave resonant body transistor

In this work, we present the first fully unreleased Micro-Electro-Mechanical (MEM) resonator. The 1st harmonic longitudinal resonance of a silicon FinFET fully clad in SiO[subscript 2] is demonstrated. The device exhibits two resonances at 39 and 41 GHz, corresponding well with simulation results. The quality factor (Q) of 129 at 39 GHz is ~4× lower than that of its released counterpart. Methods to improve Q and reduce spurious modes are introduced. This first demonstration of unreleased resonators in a hybrid MEMS-CMOS technology can provide RF and microwave CMOS circuit designers with active high-Q devices monolithically integrated in Front-End-of-Line (FEOL) processing without the need for post-processing or special packaging.Microelectronics Advanced Research Corporation (MARCO)United States. Defense Advanced Research Projects Agenc

Resonant body transistors in standard CMOS technology

This work presents Si-based electromechanical resonators fabricated at the transistor level of a standard SOI CMOS technology and realized without the need for any postprocessing or packaging. These so-called Resonant Body Transistors (RBTs) are driven capacitively and sensed by piezoresistively modulating the drain current of a Field Effect Transistor (FET). First generation devices operating at 11.1-11.5 GHz with footprints of 3μm×5μm are demonstrated. These unreleased bulk acoustic resonators are completely buried within the CMOS stack and acoustic energy at resonance is confined using Acoustic Bragg Reflectors (ABRs). The complimentary TCE of Si/SiO[subscript 2] in the resonator and the surrounding ABRs results in a temperature stability TCF of <;3 ppm/K. Comparative behavior of devices is also discussed to analyze the effect of fabrication variations and active sensing.United States. National Security Agency. Trusted Access Program OfficeUnited States. Defense Advanced Research Projects Agency. Leading Edge Access ProgramIBM Researc

Resonant Body Transistors in IBM's 32nm SOI CMOS technology

This work presents an unreleased CMOS-integrated MEMS resonators fabricated at the transistor level of IBM's 32SOI technology and realized without the need for any post-processing or packaging. These Resonant Body Transistors (RBTs) are driven capacitively and sensed piezoresistively using an n-channel Field Effect Transistor (nFET). Acoustic Bragg Reflectors (ABRs) are used to localize acoustic vibrations in these resonators completely buried in the CMOS stack and surrounded by low-k dielectric. Experimental results from the first generation hybrid CMOS-MEMS show RBTs operating at 11.1-11.5 GHz with footprints <; 5μm × 3μm. The response of active resonators is shown to contrast with passive resonators showing no discernible peak. Comparative behavior of devices with design variations is used to demonstrate the effect of ABRs on spurious mode suppression. Temperature stability and TCF compensation due to complimentary materials in the CMOS stack are experimentally verified