New developments on InGaAs focal plane array

Abstract

SWIR detection band benefits from natural (sun, night glow, thermal radiation) or artificial (eye safe lasers) photons sources combined to low atmospheric absorption and specific contrast compared to visible wavelengths. It gives the opportunity to address a large spectrum of applications such as defense and security (night vision, active imaging), space (earth observation), transport (automotive safety) or industry (non destructive process control).InGaAs material appears as a good candidate to satisfy SWIR detection needs. The lattice matching with InP constitutes a double advantage to this material: attractive production capacity and uncooled operation thanks to low dark current level induced by high quality material.The recent transfer of imagery activities from III-VLab to Sofradir provides a framework for the production activity with the manufacturing of high performances products: CACTUS320 SW and CACTUS640 SW.The developments, begun at III-Vlab towards VGA format with 15μm pixel pitch, lead today to the industrialization of a new product: SNAKE SW. On one side, the InGaAs detection array presents high performances in terms of dark current and quantum efficiency. On the other side, the low noise ROIC has different additional functionalities. Then this 640x512 @ 15μm module appears as well suited to answer the needs of a wide range of applications.In this paper, we will present the Sofradir InGaAs technology, some performances optimization and the last developments leading to SNAKE SW.

Flexible Thin-Film InGaAs Photodiode Focal Plane Array

“…The methods employed can readily be extended to a wide range of devices, from active pixel sensors to light-emitting diodes used in flexible displays . The method is independent of the semiconductor materials choice and can in principal achieve extremely high pixel densities due to the complete elimination of solder-bump technology typically used in bonding detectors to readout back planes. − …”

Determination of blind elements of InGaAs short-wave infrared focal plane detector with high effective pixel rate for low-orbit satellite communication based on dark signal voltage change rate and sliding window detection

“…Therefore, in the context of low-orbit satellite communication, the rate of change of the response value of the image element in each local region of the InGaAs short-wave infrared focal plane detector with respect to the luminous flux is more critical to the device's performance during interstellar alignment than the absolute response value of the image element 9,10 . To meet this evaluation requirement, we developed a sliding window blind element determination method based on the rate of change of dark signal voltage, also known as the sliding window detection algorithm, considering the detector's inherent characteristics 11 . This method capitalizes on the principle of equivalence between the effects of luminous flux and integration time on the detector signal voltage value 12 .…”

Inter-pixel crosstalk improvement based on a thin crosstalk-block layer for mesa-based InGaAs photodetectors

“…As these illumination sources can be natural such as sunlight, moonlight and nightglow, they can also be artificial such as eye-safe lasers. 1 For detecting short wavelengths up to 1.7 µm, InGaAs lattice matched to InP substrate with 0.53 In mole fraction is a quite commonly used material with its excellent electrical and optical properties. It is also possible to extend the cut-off wavelength up to 2.6 µm by increasing the In mole fraction to 0.83.…”