Film-type pyroelectric infrared sensor and preparation method thereof

Abstract

The invention relates to the field of the infrared sensor, and provides a film-type pyroelectric infrared sensor and a preparation method thereof. The sensor comprises an upper electrode filme, a lower electrode film and a pyroelectric film, which are superimposed onto each other, wherein the sensor is of a 2 structure, and n is of a natural number; the 2n structure comprises a silicon substrate which is arranged on the bottom part of the lower electrode film, the upper surface of the upper electrode film is provided with a passivation layer and an infrared absorption layer, a heat insulation layer is arranged between the lower electrode and the silicon substrate, and the heat insulation layer is provided with a supporting layer. By adopting the film-type multi-factor structure, compared with the single-factor pyroelectric infrared sensor, the adaptability of the sensor to the environmental interference such as cold-hot air stream, temperature variation and the like can be improved. The sensor has low heat conductivity, high reliability and fast response speed. The film-type pyroelectric infrared sensor can be produced through a standard micro-processing technology. The processing technology is mature, the cost is lower, and the process is simpler.

Description

technical field [0001] The invention relates to the field of infrared sensors, in particular to a thin-film pyroelectric infrared sensor. [0002] The invention also relates to a preparation method of a thin-film pyroelectric infrared sensor. Background technique [0003] Pyroelectric infrared sensor is a commonly used infrared detection device, which is widely used in control devices such as non-contact switches and anti-theft alarms. It has broad application prospects in automatic control, electrical energy saving, security and other fields. In the field of security, in order to suppress the interference of cold and hot airflow or ambient temperature on the sensor, improve the environmental adaptability of the sensor, and reduce false alarms, the design of double or even four sensitive elements is usually adopted. The so-called dual sensitive element design means that the sensor contains two dual unit infrared detectors, which have positive and negative sensitivities resp...

AI Technical Summary

Problems solved by technology

At present, dual or quaternary pyroelectric infrared sensors on the market are mostly made of ceramic body materials. Ceramic body materials usually need to be mechanically cut, ground and thinned to tens of microns thick, and then metal electrodes are made on the upper and lower surfaces. The process is cumbersome and costly. higher

In addition, the thickness of the ceramic body material is tens of microns, the heat capacity of the device is large, and the improvement of the response rate is limited.

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