InAs/GaSb二类超晶格中/短波双色红外焦平面探测器

Mid-/short-wavelength dual-color infrared focal plane arrays based on type-Ⅱ InAs/GaSb superlattice

InAs/GaSb超晶格材料已经成为了第三代红外焦平面探测器的优选材料。开展了InAs/GaSb二类超晶格中/短波双色焦平面探测器器件结构设计、材料外延、芯片制备,对钝化方法进行了研究,制备出性能优良的320×256双色焦平面探测器。首先以双色叠层背靠背二极管电压选择结构作为基本结构,设计了中/短波双色芯片结构,然后采用分子束外延技术生长出结构完整、表面平整、低缺陷密度的PNP结构超晶格材料。采用硫化与SiO2复合钝化方法,最终制备的器件在77 K下中波二极管的RA值达到13.6 kΩ·cm^2,短波达到538 kΩ·cm^2。光谱响应特性表明短波响应波段为1.7~3μm,中波为3~5μm。双色峰值探测率达到中波3.7×10^11cm·Hz^1/2W^-1以上,短波2.2×10^11cm·Hz^1/2W^-1以上。响应非均匀性中波为9.9%,短波为9.7%。中波有效像元率为98.46%,短波为98.06%。

InAs/GaSb superlattice material has become the primary choice for the fabrication of the third-generation infrared detectors.Practical researches on detector design,material epitaxy,chip processing,etc were carried out.320×256 dual-color focal plane arrays with excellent performance was fabricated.Firstly,a mid-/short-wavelength dual-color chip structure was designed based on two back-to-back n-i-p junctions with voltage selection structure.Then the PNP superlattice material with complete structure,smooth surface and low defect density was grown by molecular beam epitaxy(MBE).The device was passivated with sulfide treatment and a SiO2 layer.Finally,at 77 K,the RA value of middle-wave channel reached 13.6 kΩ·cm^2 and the short-wave channel reached 538 kΩ·cm^2.The spectral response indicated the short-wave response band of 1.7-3μm and the middle-wave of 3-5μm.The middle-wave channel exhibited a detectivity value of 3.7×10^11 cm·Hz^1/2 W^-1,a photo-response non-uniformity of 9.9%and an effective pixel rate of 98.46%,while the short-wave channel exhibited a detectivity value of 2.2×10^11 cm·Hz^1/2 W^-1,a photo-response non-uniformity of 9.7% and an effective pixel rate of 98.06%.