The theory and experiment of very-long-wavelength 256×1 GaAs/AlxGa1−xAs quantum well infrared detector linear arrays

The 256×1 linear array of multiple quantum wells infrared photodetector (QWIP) is designed and fabricated for the peak response wavelength at λP = 14.6 μm. The response spectral width is bigger than 2.2 μm. The two-dimensional (2D) diffractive coupling grating has been formed on the top QWIP photosensitive pixel for coupling the infrared radiation to the infrared detective layers. The performance of the device at VB = 3 V and T = 45 K has the responsibility 4.28×10−2 (A/W), the blackbody detectivity Db* = 5.14×109 (cm·Hz1/2/W), and the peak detectivity Dλ* = 4.24× 1010 (cm·Hz1/2/W). The sensor pixels are connected with CMOS read out circuit (ROC) hybridization by indium bumps. When integral time is 100 μs, the linear array has the effective pixel of QWIP FPA Nef of 99.2%, the average responsibility \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \overline R $$\end{document} (V/W) of 3.48×106 (V/W), the average peak detectivity Dλ* of 8.29×109 (cm·Hz1/2/W), and the non-uniformity UR of 5.83%. This device is ready for the thermal image application.