Yanqiu Lv

Three-dimensional modeling and simulation of large-format hybrid indium antimonide detector arrays

Abstract. Infrared sensors, such as indium antimonide (InSb) detectors, are generally required to be cooled to 77 K in operation. High fracture probability under thermal shock, especially in large InSb infrared focal plane arrays (IRFPAs), limits their applicability. It is necessary to establish a realistic three-dimensional (3-D) structural model of large-format InSb IRFPAs. However, few data are available on 3-D high-fidelity structural modeling and simulation of large IRFPAs due to their complicated structure and huge meshing numbers. A simple equivalent modeling method had been used in our early works, which could reduce meshing numbers, but did not consider the complicated structure, and also brought a new problem that the equivalent outer region of the model was not consistent with the actual IRFPAs. To solve the problems, an improved equivalent modeling method is proposed, where a small-format array is first split into two parts and then employed to equivalently replace the real large-format array. A 3-D high-fidelity structural model of large-format hybrid InSb IRFPAs is developed; here, a 32×32 array is adopted to replace the real 128×128 array. The results show that the simulated stress and strain distribution characteristics of InSb chip are well in agreement with the fracture photograph of actual 128×128 InSb IRFPAs in testing, verifying the validity and feasibility of the 3-D structural model of large-format IRFPAs. All these are beneficial to further explore fracture mechanisms and improve the reliability of large-format hybrid InSb IRFPAs.

Growth and Fabrication of MWIR Dual-color Focal Plane Array Based on Type-II InAs/GaSb Superlattice

We presented a fabrication of MWIR dual-color FPA based on type-II InAs/GaSb strain layer superlattice (SLs). The red and blue channel FPA devices with 128×128 pixels showed a 50% cutoff wavelength of 3.1μm and 4.73μm, the average blackbody detectivity of the detectors are 2.8 × 1010cmHz1/2/W and 1.3× 1010 cmHz1/2/W at 77K separately.