【摘要】 开展了基于GaAs界面的InAs/GaSb超晶格红外探测器材料和焦平面探测器研究。采用分子束外延（MBE）技术在InAs衬底上生长了高质量的PB₁nB₂N双势垒超晶格材料，通过GaAs界面的引入来提高了超晶格材料生长温度来改善材料晶体质量并降低暗电流；同时通过结构设计将电场加载到宽带隙的电子和空穴势垒阻挡层，实现了窄带隙吸收层与耗尽区分离，减小产生-复合暗电流。采用ICP干法刻蚀技术制备出光滑台面，通过硫化/介质膜复合钝化技术实现了低侧壁漏电，研制出长波640×512焦平面探测器组件，截止波长为10.14μm,NETD达到17.8 mK，有效像元率达到99.89%，量子效率达到37%，成像验证展现出优良的光电性能。更多还原

【Abstract】 Objective InAs/GaSb type-II superlattice infrared detectors have advantages such as adjustable wavelength,high temperature sensitivity,and good uniformity.However,there is still a certain gap between their performance and that of traditional mercury cadmium telluride devices.Mechanistically,the defects in the GaSb layer of the superlattice are considered to be the main factor restricting the minority carrier lifetime.Some studies suggest that increasing the temperature can effectively improve the quality of the superlattice material.However,the InSb interface adopted in the superlattice based on the GaSb substrate is relatively fragile and prone to failure at high temperatures.In this paper,based on the InAs/GaSb superlattice system with the GaAs interface,the research on long-wave superlattice infrared focal plane detectors is carried out by using methods such as molecular beam epitaxy technology and the double-barrier structure.Methods High-quality PB₁nB₂N double-barrier superlattice materials were grown on InAs substrates using molecular beam epitaxy （MBE） technology.The introduction of the GaAs interface enabled an increase in the growth temperature of the superlattice materials,which improved the crystalline quality of the materials and reduced dark current.Additionally,through structural design,an electric field was applied to the wide-bandgap electron and hole barrier layers,achieving separation between the narrow-bandgap absorption layer and the depletion region,thereby minimizing generation-recombination dark current.In the chip fabrication process,smooth mesas are prepared using dry etching technology,and low sidewall leakage is achieved through sulfurization/dielectric film composite passivation.Results and Discussions The 640×512 pixels long-wavelength infrared superlattice FPA detector was fabricated,which shows a cut-off wavelength of 10.14μm,a temporal noise equivalent temperature difference（NETD） of 17.8 mK,an operability of 99.89%,and quantum effiency of 37%.The camera with this detector shows high-quality imaging capability.The analysis suggests that it is related to the following factors:Based on the high-temperature resistance characteristics of the GaAs interface,the high-temperature （440℃） molecular beam epitaxy （MBE） growth technology is adopted.The crystal quality and electrical properties of the superlattice layer have been effectively improved compared with those of the epitaxial materials grown at the conventional temperature （around 400℃）.As a result,the dark current is effectively reduced while maintaining a relatively high quantum efficiency.By introducing the double-barrier structure,the material structure is improved,and the device impedance is increased.Through the optimization of the device process,the sidewall leakage current is effectively eliminated.Conclusions A high-performance long-wave superlattice focal plane detector has been developed on the n-type absorption layer/double-barrier long-wave superlattice material with GaAs interface grown by molecular beam epitaxy.The main performance parameters have reached the best levels reported both at home and abroad,verifying this technical route that is different from the material schemes of traditional superlattice infrared detectors.It shows that the n-type absorption layer material using hole minority carriers can achieve high quantum efficiency and low dark current,and it is possible to further improve the device performance by optimizing the material structure and epitaxial conditions to enhance characteristic parameters such as the carrier lifetime.更多还原