Abstract: Low temperature, multi-layered microshells for encapsulation of devices such as MEMS and microelectronics. The microshells may include a perforated pre-sealing layer, below which a sacrificial layer is accessed, and a sealing layer to close the perforation in the pre-sealing layer after the sacrificial material is removed. The pre-sealing layer includes a large surface area getter layer to remove contaminants from the space ultimately enclosed by the microshell to improve the pressure control and cleanliness of the microshell.

Abstract: Microshells for encapsulation of devices such as MEMS and microelectronics. In an embodiment, the microshells include a planar perforated pre-sealing layer, below which a non-planar sacrificial layer is accessed, and a sealing layer to close the perforation in the pre-sealing layer after the sacrificial material is removed. The sealing layer may include a nonhermetic layer to physically occlude the perforation and a hermetic layer over the nonhermetic occluding layer to seal the perforation as a function of the dimension of the perforation to form cavities having different vacuum levels on the same substrate.

Abstract: MEMS resonators containing a first material and a second material to tailor the resonator's temperature coefficient of frequency (TCF). The first material has a different Young's modulus temperature coefficient than the second material. In one embodiment, the first material has a negative Young's modulus temperature coefficient and the second material has a positive Young's modulus temperature coefficient. In one such embodiment, the first material is a semiconductor and the second material is a dielectric. In a further embodiment, the quantity and location of the second material in the resonator is tailored to meet the resonator TCF specifications for a particular application. In an embodiment, the second material is isolated to a region of the resonator proximate to a point of maximum stress within the resonator. In a particular embodiment, the resonator includes a first material with a trench containing the second material.

Abstract: Multi-layered, planar microshells having low stress for encapsulation of devices such as MEMS and microelectronics. The microshells may include a perforated pre-sealing layer, below which a sacrificial layer is accessed, and a sealing layer to close the perforation in the pre-sealing layer after the sacrificial material is removed. The sealing layer may further include a nonhermetic layer to physically occlude the perforation and a hermetic layer over the nonhermetic occluding layer to seal the perforation. The various layers may be formed employing processes having opposing stresses to tune the residual stress of the multi-layered microshell. In an embodiment, the hermetic layer is a metal which is deposited with a process tuned to impart a tensile stress to lower the residual stress in the microshell below the magnitude of cumulative stress present in sealing layer and pre-sealing layer.

Abstract: A MEMS structure having a compensated resonating member is described. In an embodiment, a MEMS structure comprises a resonating member coupled to a substrate by an anchor. A dynamic mass-load is coupled with the resonating member. The dynamic mass-load is provided for compensating a change in frequency of the resonating member by altering the moment of inertia of the resonating member by way of a positional change relative to the anchor.

Abstract: An IC-compatible MEMS structure and a method to form such a structure are described. In an embodiment, an integrated circuit having a MEMS device is formed. The structure comprises a plurality of semiconductor devices formed on a substrate. A plurality of interconnects is above and coupled with the plurality of semiconductor devices, incorporating the plurality of semiconductor devices into the integrated circuit. A MEMS resonator is formed above, and coupled with, the plurality of interconnects. In one embodiment, the MEMS resonator is comprised of a member and a pair of electrodes. The pair of electrodes is electrically coupled with the plurality of interconnects.

Abstract: A MEMS structure having a temperature-compensated resonating member is described. The MEMS structure comprises a stress inverter member coupled with a substrate. A resonating member is housed in the stress inverter member and is suspended above the substrate. The MEMS stress inverter member is used to alter the thermal coefficient of frequency of the resonating member by inducing a stress on the resonating member in response to a change in temperature.

Abstract: A circuit for generating an output oscillation signal with low jitter includes an oscillator to generate an oscillation signal at an initial frequency based upon a control input to vary an amplitude of the oscillation signal. A first frequency multiplier multiplies the oscillation signal to result in a first signal with first frequency and first undesired frequency components. A filter minimizes the first undesired frequency components of the first signal. A second frequency multiplier multiplies the first signal to result in the output oscillation signal with second frequency and second undesired frequency components. A second feedback circuit compares a predetermined range and at least one of the first signal and the output oscillation signal to result in a reference value. A first feedback circuit varies the control input based upon a comparison between the reference value and the amplitude of the oscillation signal to minimize the second undesired frequency components.

Abstract: A hybrid frequency synthesizer includes an analog phase lock loop (PLL), a digital PLL, and a control circuit to control an output oscillator. The control circuit assigns control of the output oscillator between the analog PLL and/or the digital PLL depending on a state of lock of the analog PLL and/or the digital PLL. During a frequency acquisition mode, the digital PLL provides a coarse control of the output oscillator. During a phase capture mode, the analog PLL provides a fine control and the digital PLL provides a coarse control of the output oscillator. During the phase capture mode, the analog PLL control signal and the digital PLL control signal may be given a percentage of control over the output oscillator depending on the state of lock of the analog PLL and/or the digital PLL. During a phase lock mode, the analog PLL controls the output oscillator.

Abstract: A circuit for varying an amplitude of an oscillation signal comprises an oscillator, signal processing circuitry, a first feedback circuit, and a second feedback circuit. The oscillator generates the oscillation signal and has a control input to vary the amplitude of the oscillation signal. The signal processing circuitry processes the oscillation signal. The first feedback circuit is configured to control the control input of the oscillator by comparing a reference value and an input amplitude of an input of the signal processing circuitry. The second feedback circuit generates the reference value by comparing an output amplitude of an output of the signal processing circuitry and a predetermined value.