The accelerometers disclosed herein provide excellent sensitivity, long-term stability, and low SWaP-C through a combination of photonic integrated circuit technology with standard micro-electromechanical systems (MEMS) technology. Examples of these accelerometers use optical transduction to improve the scale factor of traditional MEMS resonant accelerometers by accurately measuring the resonant frequencies of very small (e.g., about 1 m) tethers attached to a large (e.g., about 1 mm) proof mass. Some examples use ring resonators to measure the tether frequencies and some other examples use linear resonators to measure the tether frequencies. Potential commercial applications span a wide range from seismic measurement systems to automotive stability controls to inertial guidance to any other application where chip-scale accelerometers are currently deployed.

A semiconductor device includes a silicon substrate layer with a decoupling region. The decoupling region of the silicon substrate layer comprises an array of lamellas laterally spaced apart from each other by cavities. Each lamella of the array of lamellas comprises at least 20% silicon dioxide.

The accelerometers disclosed herein provide excellent sensitivity, long-term stability, and low SWaP-C through a combination of photonic integrated circuit technology with standard micro-electromechanical systems (MEMS) technology. Examples of these accelerometers use optical transduction to improve the scale factor of traditional MEMS resonant accelerometers by accurately measuring the resonant frequencies of very small (e.g., about 1 m) tethers attached to a large (e.g., about 1 mm) proof mass. Some examples use ring resonators to measure the tether frequencies and some other examples use linear resonators to measure the tether frequencies. Potential commercial applications span a wide range from seismic measurement systems to automotive stability controls to inertial guidance to any other application where chip-scale accelerometers are currently deployed.

A micromechanical resonator having one or more anchoring stems which are hollow to increase resonator Q factor. By way of example a micromechanical disk resonator embodiment is shown utilizing a resonant micromechanical disk anchored by a stem between at least one electrode used for input and output. To increase resonator Q, a hollow stem is utilized in which an outer thickness of stem material surrounds a hollow area interior of the stem, or that is fabricated with a plurality of vias and/or fabricated substructures containing hollow spaces in the stem material. Measurements have confirmed that Q values can be increased using the hollow core stems by a factor of 2.9 times in certain implementations and operating modes.

A multiple coil spring MEMS resonator includes a center anchor and a resonator body including two or more coil springs extending in a spiral pattern from the center anchor to an outer closed ring. Each pair of coil springs originates from opposing points on the center anchor and extends in the spiral pattern to opposing points on the outer ring. The number of coil springs, the length and the width of the coil springs and the weight of the outer ring are selected to realize a desired resonant frequency.