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We have developed a single-wafer vacuum encapsulation for microelectromechanical systems (MEMS), using a thick (20-mum) polysilicon encapsulation to package micromechanical resonators in a pressure <1 Pa. The encapsulation is robust enough to withstand standard back-end processing steps, such as wafer dicing, die handling, and injection molding of(More)
While the literature is rich with data for the electrical behavior of nanotransistors based on semiconductor nanowires and carbon nanotubes, few data are available for ultrascaled metal interconnects that will be demanded by these devices. Atomic layer deposition (ALD), which uses a sequence of self-limiting surface reactions to achieve high-quality(More)
Thermoelastic dissipation (TED) is analyzed for complex geometries of micromechanical resonators, demonstrating the impact of resonator design (i.e., slots machined into flexural beams) on TED-limited quality factor. Zener first described TED for simple beams in 1937. This work extends beyond simple beams into arbitrary geometries, verifying simulations(More)
The temperature dependence of the quality factor of microelectromechanical system (MEMS) resonators is analyzed and measured. For silicon MEMS resonators, there are several energy loss mechanisms that determine the quality factor. These include air-damping, thermoelastic dissipation, and anchor and surface losses. For resonators operating at a low pressure(More)
Silicon MEMS resonators have great potential for on-chip high frequency signal applications. This paper compares methods of sensing the temperature of an encapsulated silicon MEMS resonator and using this temperature measurement to stabilize the temperature, and hence the resonant frequency, of the resonator. The use of external Pt RTDs, integrated Si(More)
Si-SiO<sub>2</sub> composite resonators in wafer-scale thin-film encapsulation are demonstrated. These resonators are fabricated in hermetic wafer-scale thin-film encapsulation, which enables mass production with high yield even after harsh post processes. Also this encapsulation provides potential for integration of frequency references with CMOS(More)
We report the realization of coalescent free-standing ultra-thin (as thin as 5.5 nm) platinum layers deposited via plasma-enhanced atomic layer deposition and their characterization as an uncooled infrared detector. Such thin platinum thermistors enable a responsivity as high as 2 &#x00B7; 10<sup>7</sup> V/WA, an estimated noise equivalent temperature(More)
A method of using electrostatic tuning to compensate the phase noise due to external vibrations in a MEMS oscillator is presented in this paper. An accelerometer measures the acceleration applied to a resonator, and a compensation signal generated by the accelerometer is added to the bias voltage. We achieve 91% reduction of the acceleration sensitivity for(More)
Micromechanical resonators with resonant frequencies from 500 kHz to 10 MHz were built and examined for several energy loss mechanisms. Thermoelastic damping, clamping loss and air damping were considered. The devices were shown to be limited by thermoelastic damping, providing experimental verification of this phenomenon at the microscale. Resonators with(More)
Micromachined accelerometers have been one of the most successful MEMS devices. Once a successful MEMS device is developed, packaging is the most critical step commercializing the device. Micromachined accelerometers are currently packaged with a separate lid made of glass or silicon bonded on the accelerometer device wafer. In this study, we have developed(More)