Growth and fabrication of a mid-wavelength infrared focal plane array based on type-II InAs/GaSb superlattices

• Published in: Journal of semiconductors Vol. 34; no. 11; pp. 74 - 78
• Main Author: 王国伟 向伟 徐应强 张亮 彭振宇 吕衍秋 司俊杰 王娟 邢军亮 任正伟 牛智川
• Format: Journal Article
• Language: English
• Published: 01.11.2013
• Subjects: Arrays; Detectors; Devices; Focal plane; GaSb; InAs; Indium arsenides; Infrared; Semiconductors; Superlattices; X射线衍射; 分子束外延生长; 制造; 应变层超晶格; 截止波长; 红外焦平面阵列
• ISSN: 1674-4926
• DOI: 10.1088/1674-4926/34/11/114012

We present the fabrication of a mid-wavelength infrared focal plane array （FPA） based on type-II InAs/GaSb strain layer superlattices （SLs）. The detectors contain a 400-period 8 ML InAs/8 ML GaSb SL active layer, which is grown by solid source molecular beam epitaxy on GaSb （100） N type substrates. Lattice mismatch between the superlattices and GaSb substrate achieves 148.9 ppm. The full width at half maximum of the first or- der satellite peak from X-ray diffraction was 28 arcsec. Single element detectors and FPA with a 128 x 128 pixels were fabricated using citric acid based solution wet chemical etching. Chemical and physical passivation effectively reduces the surface leakage and this process was characterized by I-V measurement. The devices showed a 50% cut-off wavelength of 4.73 μm at 77 K. The photodiode exhibited an RoA of 103 f2. cm2. The FPA was characterized with an integration time of 0.5 ms and F/2.0 optics at 77 K and the average blackbody detectivity of the detectors is 2.01 × 10^9 cm.Hz^1/2/W.