mems capacitive relative humidity sensor and preparation method thereof

Abstract

The invention relates to a MEMS capacitive relative humidity sensor and a preparation method thereof, which belong to semiconductor chip technology. Since the MEMS capacitive relative humidity sensor supports the upper plate of the capacitor through an insulating support body, the upper plate of the capacitor and the humidity sensitive layer are reduced. The distance between the upper pole plate of the capacitor and the humidity sensitive layer is formed with an air gap, and on the upper pole plate of the capacitor, a number of through holes are opened to communicate the air gap with the outside, so that the upper surface of the humidity sensitive layer is completely In contact with air, the diffusion distance of water vapor molecules is short. Therefore, the humidity sensitive layer dehumidifies evenly and quickly, which can effectively reduce the hysteresis error generated during natural dehumidification. The MEMS capacitive relative humidity produced by this preparation method The humidity sensitive layer of the sensor dehumidifies evenly and quickly, which can effectively reduce the hysteresis error generated during natural dehumidification.

Description

technical field [0001] The invention relates to a MEMS capacitive relative humidity sensor and a preparation method thereof, belonging to semiconductor chip technology. Background technique [0002] Humidity sensors are widely used in many fields such as national defense aviation, meteorological detection, industrial control, and agricultural production. In recent years, miniaturized humidity sensors have gradually become the mainstream of the market. Existing miniature humidity sensors mainly include capacitive, resistive, piezoresistive and other types. Capacitive humidity sensors have been widely used in commercial fields due to their advantages of low power consumption and low cost. The development of MEMS technology provides a platform for the design and manufacture of some high-performance humidity sensors. These high-performance humidity sensors include types such as fast response, low temperature drift, and high sensitivity, which can meet the corresponding needs. ...

AI Technical Summary

Problems solved by technology

[0007] A heating humidity sensor involved in the patent CN 103698367A, the heating circuit is distributed around the humidity sensitive unit, sacrificing part of the chip area

Images