基于金属表面等离子体滤光微结构的新型近红外多光谱探测器及其光电耦合机理

Near-infrared focal plane array (FPA) detectors show great potential for applications in military and space sensing fields. In order to meet the demands of small size, low cost and high reliability for the infrared detector system, it is necessary to fabricate multispectral and integrated near-infrared FPA detectors, and so integrated filter is a good choice. The international researchers now focus on the Extraordinary Optical Transmission of metal-surface-plasmonic filter to realize on-chip multispectral detectors, with enhanced transmission in specified wavelength bands. Based on the excellent photoelectric properties of InGaAs detector and our great accumulation in high-performance InGaAs FPA detectors, a new device structure with on-chip metal-surface-plasmonic filter is proposed in this project. The project will obtain a filter structure with high transmission efficiency and narrow band wavelength, after modeling and analyzing the optical properties of some different kinds of metal-surface-plasmonic filter with Finite Difference Time Domain(FDTD) Technology . Equivalent physical models will be established to investigate the photoelectric coupling mechanism between the metal-surface-plasmonic filter and the detector. The method of reducing the color cross-talk will be studied to optimize the device structure. Then, key technologies of the new-type near-infrared multispectral detector with monolithically integrated metal-surface-plasmonic filter will be investigated, for the good coupling of the process technologies of the filter and the detector. Finally, the project will obtain the monolithic integration technology of metal-surface-plasmonic filters and InGaAs detectors, and fabricate the prototype device for the first time in our country. The research in this project will aid in the development of advanced near-infrared multispectral detectors with low cost and small size.

为了适应红外探测系统小型化、低功耗、高可靠性的需求，近红外焦平面探测器向多谱段、集成化方向发展，集成式分光是优选方案。利用金属表面等离子体微结构的异常光学透射来实现片上集成的多光谱探测器是目前国内外的研究热点。本项目基于铟镓砷（InGaAs）探测器在近红外波段优异的光电性能和课题组在高性能InGaAs焦平面探测器方面的积累，提出了一种金属表面等离子体滤光微结构单片集成的近红外多光谱InGaAs探测器新结构。采用时域有限差分技术进行模拟仿真，获得高透过率、窄带宽的滤光微结构设计；建立物理模型，揭示滤光微结构和InGaAs探测器集成的光电耦合机理，研究谱段间“串扰”的来源和抑制方法，获得优化的器件结构参数；研究滤光微结构和InGaAs探测器一致耦合的工艺兼容新方法。本项目可望获得滤光微结构和InGaAs探测器的片上集成新方法，得到近红外多光谱原型探测器，对实现红外探测器的精细遥感具有重要的意义

红外焦平面探测器的一个重要发展方向是向多谱段、集成化、低功耗方向发展，以适应先进光电探测系统小型化、高可靠性的需求。本项目基于InGaAs近红外探测材料优异的光电性能以及器件工艺的稳定性、兼容性，通过采用电子束光刻等微纳加工工艺，开展集成金属表面等离子体滤光微结构的多光谱InGaAs探测器研究，实现多波段窄带谱型精细控制和多波段光学串音抑制。本项目主要研究内容包括滤光微结构光电响应模型建立、结构参数设计、微纳加工工艺优化、微结构与探测器的光电耦合机理、微结构在探测器上的单片集成等，为新型近红外多光谱探测器制备提供理论和技术基础。建立等离子体滤光微结构物理模型，分析微结构内电磁场分布，对等离子体滤光微结构的结构参数与性能参数的关系进行了数值建模和仿真分析，实现了滤光微结构精细波长调控。对电子束曝光、光刻标记生长、金属刻蚀等微结构生长工艺进行了优化，实现了滤光微结构的良好形貌控制。开发了滤光微结构在探测器表面的单片集成工艺，并对集成工艺流程、精细套刻技术进行优化，获得了微结构与探测器一致耦合的工艺兼容新方法。通过本项目的开展，解决了近红外波段滤光微结构的波长调控机理、高透过滤光微结构设计、多光谱 InGaAs 探测器件结构模型和光电响应模型、滤光微结构在探测器上的单片集成等关键机理和技术问题。这些关键科学问题的解决为实现小型化、高透过率、窄带光谱响应的多光谱探测器提供了技术途径，可有效提高目标探测识别，在航天遥感、高光谱成像、成分分析等方面具有重大的应用价值。