CMOS-MEMS (complementary metal oxide semiconductor-micro-electromechanical system) capacitive humidity sensor

Abstract

The invention relates to a CMOS-MEMS (complementary metal oxide semiconductor-micro-electromechanical system) capacitive humidity sensor which is characterized by comprising upper interdigital electrodes and lower interdigital electrodes, wherein the lower electrodes penetrate a SiO2 oxide layer and are arranged on the same surface of a silicon substrate; the upper electrodes are arranged above the lower electrodes; humidity-sensitive mediums are filled between the upper electrodes and the lower electrodes, between the interdigital parts of the upper electrodes and between the interdigital parts of the lower electrodes; aluminum strips are arranged above the upper electrodes and positioned between the interdigital parts of the upper electrodes and the lower electrodes; humidity-sensitive mediums are filled between the aluminum strips and the upper electrodes; a cavity is formed in the silicon substrate under the upper electrodes and the lower electrodes, so that the lower electrodes and the humidity-sensitive mediums between the interdigital parts of the lower electrodes are directly in contact with the air; the interdigital parts of the upper electrodes and the interdigital parts of the lower electrodes coincide in the height direction; the humidity-sensitive mediums are polyimide. The CMOS-MEMS capacitive humidity sensor is quick in response, high in sensitivity, wide in output range, high-temperature-resistant, small in humidity error and good in temperature characteristic and long stability.

Description

Technical field [0001] The invention relates to a CMOS MEMS capacitive humidity sensor, in particular to a capacitive humidity sensor compatible with CMOS technology, and belongs to the technical field of MEMS device design and manufacturing. Background technique [0002] Humidity measurement is a major application aspect of MEMS technology, and humidity detection and control technology has been widely used. For example, military, meteorology, agriculture, industry (especially textiles, electronics, food), medical, construction, and household appliances require strict humidity monitoring. In some cases, humidity control and alarms are even required, such as air conditioning systems and greenhouses. Control system, warehouse monitoring system. The need for humidity monitoring and control has promoted the development of humidity sensors. [0003] Traditional humidity sensors are prepared using MEMS bulk silicon processing technology, which is complex and expensive, and it is diffic...

AI Technical Summary

Problems solved by technology

[0003] Traditional humidity sensors are manufactured using MEMS bulk silicon processing technology, the process is complex, the processing cost is expensive, and it is difficult to achieve standardization

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