Silicon Laboratories Inc.

Silicon Clocks, Inc.

Semiconductor Manufacturing International (shanghai) Corporation

David H Bernstein

Emmanuel Philippe Quevy

Mehrnaz Motiee

Roger T Howe

Methods of forming MEMS resonators containing a first structural material and a second structural material to tailor the resonator's temperature coefficient of frequency (TCF). The first structural material has a different Young's modulus temperature coefficient than the second structural material. In one embodiment, the first structural material may be formed on substrate and patterned, and the second structural material may be formed over the first structural material and planarized to expose the first structural material. A resonator may be patterned that contains both the first and second structural materials.

Method for temperature compensation in MEMS resonators with isolated regions of distinct material

A microelectromechanical system (MEMS) device includes a resonator anchored to a substrate. The resonator includes a first strain gradient statically deflecting a released portion of the resonator in an out-of-plane direction with respect to the substrate. The resonator includes a first electrode anchored to the substrate. The first electrode includes a second strain gradient of a released portion of the first electrode. The first electrode is configured to electrostatically drive the resonator in a first mode that varies a relative amount of displacement between the resonator and the first electrode. The resonator may include a resonator anchor anchored to the substrate. The first electrode may include an electrode anchor anchored to the substrate in close proximity to the resonator anchor. The electrode anchor may be positioned relative to the resonator anchor to substantially decouple dynamic displacements of the resonator relative to the electrode from changes to the substrate.

Out-of-plane resonator

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.

A method of forming a microelectromechanical systems (MEMS) device includes forming an electrode on a substrate. The method includes forming a structural layer on the substrate. The structural layer is disposed about a perimeter of the electrode and has a residual film stress gradient. The method includes releasing the structural layer to form a resonator coupled to the substrate. The residual film stress gradient deflects a first portion of the resonator out of a plane defined by a surface of the electrode.

Out-of plane MEMS resonator with static out-of-plane deflection

A microelectromechanical systems (MEMS) device includes a tuning electrode, a drive electrode, and a resonator. The resonator is anchored to a substrate and is configured to resonate in response to a signal on the drive electrode. The MEMS device includes a tuning plate coupled to the resonator and positioned above the tuning electrode. The tuning plate is configured to adjust a resonant frequency of the resonator in response to a voltage difference between the resonator and the tuning electrode. In at least one embodiment of the MEMS device, the tuning plate and the tuning electrode are configured to adjust the resonant frequency of the resonator substantially independent of the signal on the drive electrode.

Out-of-plane MEMS resonator with static out-of-plane deflection

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

MEMS structure having a stress inverter temperature-compensated resonator member

A MEMS structure having a stress-inducer temperature-compensated resonator member is described. The MEMS structure includes a frame disposed above a substrate. The frame has an inner surface and an outer surface and is composed of a first material having a first coefficient of thermal expansion (CTE) and a second material having a second CTE, different from the first CTE. A resonator member is coupled to the inner surface of the frame.

MEMS structure having a stress-inducer temperature-compensated resonator member

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. In a specific embodiment, the shape, dimensions, location and arrangement of a second material comprising silicon dioxide is tailored so that the resonator comprising a first material of SiGe will have a TCF of a much lower magnitude than that of either a homogeneous SiGe or homogeneous silicon dioxide resonator.

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.

MEMS structure having a compensated resonating member

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.

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Oakland, CA, United States of America

David H Bernstein