320×256元InAs/GaSb Ⅱ类超晶格长波红外焦平面探测器

320 × 256 long wavelength infrared focal plane arrays based on type-Ⅱ In As / Ga Sb superlattice

报道了320×256元In As/Ga SbⅡ类超晶格长波红外焦平面阵列探测器的研制和性能测试.采用分子束外延技术在Ga Sb衬底上生长超晶格材料,器件采用PBIN结构,红外吸收区结构为14 ML(In As)/7 ML(Ga Sb),焦平面阵列光敏元尺寸为27μm×27μm,中心距为30μm,通过刻蚀形成台面、侧边钝化和金属接触电极生长,以及与读出电路互连等工艺,得到了320×256面阵长波焦平面探测器.在77 K温度下测试,焦平面器件的100%截止波长为10.5μm,峰值探测率为8.41×109cm Hz1/2W-1,盲元率为2.6%,不均匀性为6.2%,采用该超晶格焦平面器件得到了较为清晰的演示性室温目标红外热成像.

The growth and fabrication of a 320 × 256 type-Ⅱ InAs/GaSb superlattice long wavelength infrared focal plane array detector were reported.The superlattice material was grown on GaSb substrate using molecular beam epitaxy （MBE） technology with a PBIN structure.The structure of infrared absorption layer is 14 ML （InAs）/7 ML（GaSb）,the focal plane array had a pixel size of 27 μm × 27 μm and a pitch of 30 μm.The device fabrication process consisted of mesa dry etching,side-wall passivation,metallization and flip-chip hybridization with readout integrated circuit （RO-IC）.At 77 K,the detector had a 100% cut-off wavelength of 10.5 μm,and a peak detectivity of 8.41 × 10^9 cmHz^1/2 W^-1.Concept proof of infrared imaging was also demonstrated with the focal plane array at liquid nitrogen temperature.