Capacitive humidity sensor

Abstract

The invention discloses a capacitive humidity sensor. The capacitive humidity sensor comprises a detection capacitor which consists of a substrate, a dielectric layer and a metallic electrode layer, wherein the detection capacitor is of a cantilever beam structure shape, the dielectric layer is arranged on the substrate, and the metallic electrode layer is located on the dielectric layer; and a humidity-sensitive strain layer is further arranged on the metallic electrode layer. The capacitive humidity sensor disclosed by the invention is simple in structure and convenient in manufacturing and has the advantages of good linearity, little temperature drift, high response speed, low sensitive capacitive loss, low parasitic capacitance, easiness in process compatibility with a CMOS (Complementary Metal Oxide Semiconductor), and the like.

Description

technical field [0001] The invention relates to a microelectromechanical system capacitive humidity sensor based on a standard CMOS process, in particular to a capacitive humidity sensor with a cantilever beam structure. Background technique [0002] Humidity sensors have a wide range of application potential in the fields of automobile industry, aerospace, medicine, military, meteorological detection, environmental sanitation, biological science, information technology and so on. Its development has evolved from traditional humidity sensors such as psychrometers and hair hygrometers to miniature humidity sensors (including capacitive, resistive, piezoresistive, optical, etc.) that can be manufactured using standard CMOS processes. Whether it is a resistive humidity sensor or a silicon-based integrated humidity sensor, its self-heating effect often affects the measurement accuracy. For example, at room temperature, when the operating current exceeds 300uA, the self-heating e...

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Problems solved by technology

[0004] The technical problem to be solved by the present invention is to provide a capacitive sensor with simple structure, convenient processing, good linearity, temperature Capacitive humidity sensor with small drift, fast response, small loss of sensitive capacitance, small parasitic capacitance and easy compatibility with CMOS process

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