Terahertz microbolometer based on metamaterial absorber and preparation method of terahertz microbolometer

Abstract

The invention discloses a terahertz microbolometer based on a metamaterial and a preparation method of the terahertz microbolometer. The terahertz microbolometer is composed of two parts including a metamaterial terahertz absorber and a thermal detector, wherein the thermal detector comprises four layers of materials, namely a microbridge supporting layer, a thermistor film, a metal electrode and a passivation layer. The metamaterial terahertz absorber comprises three layers of materials, namely a bottom-layer metal film, an intermediate medium layer and a top-layer metal film. According to the terahertz microbolometer, the metamaterial terahertz absorber and the thermal detector are integrated, heat generated by the metamaterial absorbing terahertz radiation is transmitted to the thermal detector, and then, the electrical property of the thermistor film is changed, so that the terahertz room-temperature detecting and imaging are realized. Due to the adoption of the microbridge structure and the preparation method disclosed by the invention, the problems of microbridge deformation caused by adding the metamaterial and the like are solved, and the microbolometer is high in mechanical stability and terahertz absorptivity. The defect that terahertz waves are difficultly detected by using the traditional microbolometer is overcome; and the terahertz microbolometer is prepared by using the traditional micromachining technology so as to be suitable for industrial production.

Description

technical field [0001] The invention belongs to uncooled terahertz detection technology, in particular to a terahertz microbolometer based on a metamaterial absorber and a preparation method thereof. Background technique [0002] According to different detection principles, uncooled detectors are divided into pyroelectric detectors, thermocouple detectors, and thermistor detectors. Among them, microbolometer focal plane detectors based on thermistor materials have the advantages of room temperature detection, high integration, large-scale production, and low price, and have developed rapidly in recent years (see Leonard P. Chen, "Advanced FPAs for Multiple Application", Proc. SPIE, 4721:1-15 (2002) literature). Terahertz waves generally refer to electromagnetic radiation with a frequency between 0.1 and 10 THz, and the frequency is between infrared and microwave. Because the photon energy of terahertz waves is much lower than that of X-rays, and the damage to living bodies...

AI Technical Summary

Problems solved by technology

However, the disadvantages of the NEC scheme are: the preparation conditions of high-quality terahertz absorbing films are very harsh, and its terahertz absorption rate is low (usually <10%), and it cannot respond selectively to incident electromagnetic waves.

However, if the metamaterial is integrated on the suspended microbolometer microbridge, it will face problems such as the structure size is limited by the bridge deck area of ​​the microbridge, the collapse or deformation of the microbridge due to excessive weight, and the compatibility of the preparation process. And other issues

[0005] In conclusion, metamaterial-based terahertz microbolometers also face challenges

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