320×256 Extended Wavelength In<sub>x</sub>Ga<sub>1-x</sub>As/InP Focal Plane Arrays: Dislocation Defect, Dark Signal and Noise
Yingjie Ma, L. Xue, Xiumei Shao, Shuangyan Deng, Jifeng Cheng, Yi Gu, Yage Liu, Yu Chen, Xianliang Zhu, Tao Li, Yonggang Zhang, Haimei Gong, Jiaxiong Fang
Abstract
In <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.75</sub> Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.25</sub> As and In <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.83</sub> Ga <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.17</sub> As 320×256 short-wave infrared focal plane arrays (SWIR FPAs) with pixel pitches of 24 and 30 μm, extended cutoff wavelengths of 2.2 and 2.5 μm, low dark current densities of 5.2 and 21 nA/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , and high peak detectivities of 6×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sup> and 6×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">12</sup> cmHz <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1/2</sup> W <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> are attained at 180 K, respectively. Lower 1/f noises and smaller knee frequencies are observed for the 2.2 μm FPA, indicates the dislocation defect-related trap states act as the major contributor for the 1/f noise. The non-uniformities of the dark signal and the dark noise are roughly the same for both FPAs at a short integration time of 1 ms (29% and 25% at 180 K, respectively) whereas are much smaller for the 2.2 μm FPA at longer integration times. Moreover, the dark current shot noise dominant integration time ranges are determined to be >20 and >2 ms for the 2.2 and 2.5 μm FPAs, respectively. Enhanced heat signature recording capability is also observed for wider SWIR spectral range while more effective suppression routes of dislocation defect must be incorporated for further improved sensitivity.