Three-layer microbridge structure and microbolometer

Abstract

The invention relates to infrared detection and provides a three-layer microbridge structure comprising a substrate and a bridge surface layer; first bridge leg layers and second bridge leg layers are arranged between the substrate and the bridge surface layer; the first bridge leg layers are connected with the bridge surface layer and the substrate by two first bridge leg posts; the second bridge leg layers are connected with the bridge surface layer and the substrate by two second bridge leg posts; reflection layers are arranged at the surfaces, facing the bridge surface layer, of the first bridge leg layers and the surfaces, facing the first bridge leg layers, of the second bridge leg layers; and the second bridge leg layers approach the first bridge leg layers and face the gaps of the first bridge leg layers directly. In addition, the invention provides a micro-bolometer. The first bridge leg layers and second bridge leg layers form the three-layer microbridge structure and infrared waves passing through the bridge surface layer can be reflected to the bridge surface layer totally for absorption again. Therefore, the infrared absorption rate of the bridge surface layer can be enhanced; the bridge legs of the microbridge structure are long to reduce thermal conduction, so that the performance of the micro-bolometer can be improved substantially.

Description

technical field [0001] The invention relates to infrared detection, in particular to a three-layer micro-bridge structure and a microbolometer. Background technique [0002] The microbolometer is usually a resistive photosensitive element. When the infrared radiation is incident on the photosensitive element, the temperature of the photosensitive material rises, causing the resistance of the photosensitive material to change, so that the external processing circuit can detect the weak current change caused by the corresponding resistance change. , so as to achieve the purpose of infrared detection. In contrast, infrared imaging systems implemented with uncooled detector technology have smaller size, lower power consumption, and longer duration. It mainly increases the temperature change of thermal insulation and suspension bridge sensitive sensing materials through infrared radiation, and due to the temperature coefficient of resistance of the sensitive material itself, tha...

AI Technical Summary

Problems solved by technology

[0003] The object of the present invention is to provide a three-layer micro-bridge structure, which is intended to solve the problems of the existing microbolometers with relatively small infrared absorption area and short bridge legs

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