Micro-bridge infrared detector and preparation method thereof

Abstract

The invention relates to a micro-bridge infrared detector and a preparation method thereof. The micro-bridge infrared detector comprises a readout circuit substrate, and a plurality of hollow column structures positioned on the readout circuit substrate; a micro-bridge structure comprises a column through hole etching protection layer which is positioned on one side, far away from the readout circuit substrate, of the sacrificial layer and is in contact with the sacrificial layer; the projection of a hole-shaped structure formed at the position, corresponding to the hollow column structure, ofthe column through hole etching protection layer on the readout circuit substrate is overlapped with the projection of a hole-shaped structure formed at the position, corresponding to the hollow column structure, of the sacrificial layer on the readout circuit substrate; and the column through hole etching protection layer and the sacrificial layer are etched at the same time, so that a pluralityof column through holes can be formed; and the micro-bridge structure further comprises a thermosensitive layer, an isolation dielectric layer, an electrode layer and a passivation layer which are sequentially arranged on the column through hole etching protection layer. According to the technical schemes, the roughness of the inner wall of a column through hole is reduced, and the sensitivity ofthe micro-bridge infrared detector is improved.

Description

technical field [0001] The present disclosure relates to the technical field of infrared detection, in particular to a microbridge infrared detector and a preparation method thereof. Background technique [0002] Non-contact infrared detectors include, for example, non-contact temperature measurement sensors. The detection principle is that the infrared detector converts the infrared radiation signal emitted by the target object to be measured into a heat signal, and converts the heat signal into an electrical signal through the detector sensitive element, and then The electrical signal is processed and output by the circuit chip, and the infrared detector thus realizes the infrared detection function. [0003] The infrared detector generally includes a columnar structure on the circuit for supporting the micro-bridge structure, and the electrical signal finally formed by the detector sensitive element needs to be transmitted to the circuit chip through the columnar structur...

AI Technical Summary

Problems solved by technology

At present, in the preparation process of infrared detectors, the roughness of the inner wall of the hollow column structure is relatively large, which reduces the transmission speed of the infrared detection electrical signal at the hollow column structure, and the infrared detection electrical signal between different infrared detection pixels The uniformity of the transmission is poor, which affects the infrared detection performance of the infrared detector

In addition, due to the influence of the hollow column structure with relatively large inner wall roughness, the size of the upper opening of the formed column through hole is relatively large, which makes it difficult to improve the sensitivity of the infrared detector, which is not conducive to the miniaturization of the infrared detector.

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