This paper presents a review of silicon micromachined accelerometers and gyroscopes. Following brief introduction to their operating principles specifications, various device structures, fabrication, technologies, designs, packaging, interface electronics issues, along with the present status in commercialization inertial sensors, are discussed. Inertial sensors have seen steady improvement performance, today, microaccelerometers can resolve accelerations micro-g range, while performance...

This paper presents the design, fabrication, and testing of an 80-/spl mu/m-thick, 1.1 mm in diameter high aspect-ratio (20:1) polysilicon ring gyroscope (PRG). The vibrating was fabricated through combined poly single-crystal silicon MEMS technology (HARPSS). all-silicon single-wafer is capable producing electrically isolated vertical electrodes as tall main body structure (50 to 100's (/spl mu/m tall)) with various size air-gaps ranging from submicron tens microns. A detailed analysis has...

This paper reports on the design and characterization of a process, temperature supply compensation technique for 7-MHz clock oscillator in 0.25-/spl mu/m, two-poly five-metal (2P5M) CMOS process. Measurements made across range -40/spl deg/C to 125/spl 94 samples collected over four fabrication runs indicate worst case combined variation /spl plusmn/2.6% (with supply). No trimming was performed any these samples. The oscillation frequencies 95% were found fall within plusmn/0.5% mean...

This paper studies the application of lateral bulk acoustic thin-film piezoelectric-on-substrate (TPoS) resonators in high-frequency reference oscillators. Low-motional-impedance TPoS are designed and fabricated 2 classes--high-order coupled-array. Devices each class used to assemble oscillators performance characteristics measured discussed. Since motional impedance these devices is small, transimpedance amplifier (TIA) oscillator loop can be reduced a single transistor 3 resistors, format...

This paper reports on the design, fabrication, and characterization of piezoelectrically-transduced micromechanical single-crystal-silicon resonators operating in their lateral bulk acoustic modes to address need for high-Q microelectronic-integrable frequency-selective components. A simple electromechanical model optimizing performance is presented. For verification, were fabricated 5-mum-thick silicon-on- insulator substrates use a 0.3-mum zinc oxide film transduction. mode was observed...

We discuss the contribution of phonon interactions in determining upper limit f.Q product micromechanical resonators. There is a perception MEMS community that maximum microresonator limited to ldquofrequency-independent constantrdquo determined by material properties resonator. In this paper, we for frequencies higher than omega <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">tau</sub> = 1/tau, where tau relaxation time, no longer constant but...

In this paper, we report on the design, fabrication, and characterization of an in-plane mode-matched tuning-fork gyroscope (M <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> -TFG). The M -TFG uses two high-quality-factor (Q) resonant flexural modes a single crystalline silicon mi- crostructure to detect angular rate about normal axis. Operating device under condition, i.e., zero-hertz frequency split between drive sense modes, enables Q...

This paper describes a system architecture and CMOS implementation that leverages the inherently high mechanical quality factor (Q) of MEMS gyroscope to improve performance. The proposed time domain scheme utilizes often-ignored residual quadrature error in achieve, maintain, perfect mode-matching (i.e., ~ 0 Hz split between high-Q drive sense mode frequencies), as well electronically control sensor bandwidth. A IC algorithm have been interfaced with 60 mum thick silicon mode-matched tuning...

This work reports on the first demonstration of frequency tuning and intrinsic polarization switching film bulk acoustic resonators (FBARs), based sputtered AlScN piezoelectric thin films with Sc/(Al + Sc) ratio approx. 30%. A box-like ferroelectric hysteresis behavior 900 nm-thick Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.7</sub> Sc xmlns:xlink="http://www.w3.org/1999/xlink">0.3</sub> N is obtained, showing a coercive electric field...

Abstract Mechano-acoustic signals emanating from the heart and lungs contain valuable information about cardiopulmonary system. Unobtrusive wearable sensors capable of monitoring these longitudinally can detect early pathological signatures titrate care accordingly. Here, we present a wearable, hermetically-sealed high-precision vibration sensor that combines characteristics an accelerometer contact microphone to acquire wideband mechano-acoustic physiological signals, enable simultaneous...

This paper presents a single-wafer high aspect-ratio micromachining technology capable of simultaneously producing tens to hundreds micrometers thick electrically isolated poly and single-crystal silicon microstructures. High polysilicon structures are created by refilling deep trenches with deposited over sacrificial oxide layer. Thick released from the substrate through front side wafer means combined directional isotropic dry etch protected on sides refilled trenches. process is...

This paper reports on the fabrication and characterization of high-quality factor (Q) single crystal silicon (SCS) in-plane capacitive beam resonators with sub-100 nm to submicron transduction gaps using HARPSS process. The resonating element is made while drive sense electrodes are trench-refilled polysilicon, yielding an all-silicon microresonator. fabricated SCS 20-40 μm thick have self-aligned gaps. Vertical as small 80 in between 20 structures been demonstrated this work. A large number...

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> This paper presents a robust fabrication technique for manufacturing ultrasensitive micromechanical capacitive accelerometers in thick silicon-on-insulator substrates. The inertial mass of the sensor is significantly increased by keeping full thickness handle layer attached to top proof mass. High-aspect-ratio sense gaps are fabricated depositing polysilicon on sidewalls low aspect-ratio trenches...

This work, the second of two parts, reports on implementation and characterization high-quality factor (Q) side-supported single crystal silicon (SCS) disk resonators. The resonators are fabricated SOI substrates using a HARPSS-based fabrication process 3 to 18 /spl mu/m thick. They consist resonant structure trench-refilled polysilicon drive sense electrodes. have self-aligned, ultra-narrow capacitive gaps in order 100 nm. Quality factors up 46 000 mTorr vacuum 26000 at atmospheric pressure...

The paper describes the design and implementation of an electronically temperature compensated reference oscillator based on capacitive silicon micromechanical resonators. a 5.5-MHz bulk acoustic resonator has been optimized to offer high quality factor (> 100 000) while maintaining tunability in excess 3000 ppm for fine-tuning compensation. Oscillations are sustained with CMOS amplifier. When interfaced compensating bias circuit, exhibits frequency drift 39 over 100degC as compared...

In this paper, the design, implementation and characterization of a continuous time transimpedance-based ASIC for actuation sensing high-Q MEMS tuning fork gyroscope (TFG) is presented. A T-network transimpedance amplifier (TIA) used as front-end low-noise, sub-atto-Farad capacitive detection. The TIA provides on-chip gains up to 25 MOmega, has measured resolution 0.02 aF/radicHz at 15 kHz, wide dynamic range 104 dB in bandwidth 10 Hz consumes 400 muW power. CMOS interface uses sustain...

This paper demonstrates the dependence of temperature coefficient frequency (TCF) silicon micromechanical resonators on charge carrier concentration. TCF compensation is demonstrated by degenerate doping bulk acoustic (SiBARs) using both boron and aluminum dopants. The native -33×ppm/ <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">°</sup> C for resistivity >; 10 xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> Ω · shown to reduce -1.5×;ppm/...

This paper presents an overview of multi degrees-of-freedom (DOF) inertial MEMS in applications ranging from gaming to dead reckoning. Approaches the implementation high-performance measurement units (IMU) are examined, focusing on challenges related tri-axial gyroscope implementation. Benefits and tradeoffs homogeneous multi-axis sensors reviewed contrasted with advances single-chip integrated IMUs.

Abstract This paper reports on a new type of high-frequency mode-matched gyroscope with significantly reduced dependencies environmental stimuli such as temperature, vibration, and shock. A novel stress-isolation system is used to effectively decouple an axis-symmetric bulk-acoustic wave (BAW) vibratory gyro from its substrate, minimizing the effect that external sources error have offset scale factor device. Substrate-decoupled (SD) BAW gyros resonance frequency 4.3 MHz Q values near 60 000...

<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Objective:</i> Systolic time intervals, such as the pre-ejection period (PEP), are important parameters for assessing cardiac contractility that can be measured non-invasively using seismocardiography (SCG). Recent studies have shown specific points on accelerometer- and gyroscope-based SCG signals used PEP estimation. However, complex morphology inter-subject variation of signal make this...

This work, the first of two parts, presents design and modeling VHF single-crystal silicon (SCS) capacitive disk resonators operating in their elliptical bulk resonant mode. The are modeled as circular thin-plates with free edge. A comprehensive derivation mode shapes frequencies in-plane vibrations structures is described using two-dimensional (2-D) elastic theory. An equivalent mechanical model extracted from elliptic bulk-mode shape to predict dynamic behavior resonators. Based on model,...

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> In this paper, design, implementation and characterization of a 3-V switched-capacitor (SC) &lt;formula formulatype="inline"&gt;&lt;tex&gt;$\Delta\Sigma$&lt;/tex&gt; &lt;/formula&gt; CMOS interface circuit for the closed-loop operation lateral capacitive micro-gravity silicon-on-insulator (SOI) accelerometer is presented. The based on front-end programmable reference-capacitorless SC charge...

This paper presents the perfect matched-mode operation of a type I non-degenerate z-axis tuning-fork gyroscope (i.e., 0 Hz frequency split between high-Q drive and sense modes). The tuning fork (M <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> -TFG) is fabricated on 50-µ m thick SOI substrate displays an overall rate sensitivity 24.2 mV/º/s. Allan Variance analysis mode-matched device demonstrates angle random walk (ARW) 0.045 º/√ hr...