Resonant pressure sensor based on piezoresistive detection and its preparation method

Abstract

The invention relates to a resonant pressure sensor based on piezoresistive detection and a preparation method thereof. The resonant pressure sensor comprises a pressure sensitive film, a resonator located on the pressure sensitive film and six anchor points, wherein the resonator comprises a double-end fixed support beam and two driving electrodes arranged on the two sides of the double-end fixedsupport beam, wherein the double-end fixed support beam comprises two end parts and two single beams connected to the two end parts; etching is carried out on root regions of the two single beams symmetrically; body pressure resistance is formed at the root parts of the two single beams; the same three-electrode structures are arranged at the two end parts, one three-electrode structure is suspended, and the other three-electrode structure takes an electrode in the middle position as a grounding end and the electrodes at the two sides as detection electrodes; the six anchor points are arranged under the two three-electrode structures respectively; and the double-end fixed support beam is fixedly supported on the pressure sensitive film. According to the resonant pressure sensor and the preparation method, a piezoresistive detection and resonator tuning fork vibration mode is adopted, so that the output signal strength is improved, and the anti-interference capability and the stabilityare enhanced.

Description

technical field [0001] The invention relates to the technical field of MEMS microsensors, in particular to a resonant pressure sensor based on piezoresistive detection. Background technique [0002] The resonant pressure sensor is a pressure measurement device that uses the resonator as a sensitive structure, changes the characteristic frequency of the resonator by changing the pressure, and indirectly measures the pressure by monitoring the change of the characteristic frequency of the resonator. Since the output frequency signal of the sensor is suitable for long-distance transmission without reducing its accuracy, it can easily communicate with the host computer without AD conversion to form a high-precision control system. Resonant pressure sensors have good linearity, resolution, stability and high precision, and are widely used in important fields such as meteorology and aerospace. [0003] The core components of a resonant pressure sensor are a pressure-sensitive mem...

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Problems solved by technology

Silicon-aluminum wire can be directly pressed on silicon, but the material of silicon-aluminum wire is easy to break, and the gold wire must be pressure-welded on the gold substrate

The electrodes of MEMS devices with multi-layer structure are generally made by silicon hole technology. When sputtering the gold substrate, it is easy to sputter the metal onto the side wall of the silicon hole, resulting in a short circuit between the electrodes.

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