Patrick Audebert

High-performance LWIR 256 x 256 HgCdTe focal plane array operating at 88 K

A 256 by 256 IRCMOS array with a 35 micron pitch operating at 88 K and above 10 microns has been developed at LETI/LIR. High performances have been obtained owing on one hand to a reduced dark current detector technology and on the other hand to a new readout circuit architecture which maximizes both charge handling capacity and responsivity. We have measured a NEDT of 13 mK at 88 K for a cutoff wavelength of 10.1 micrometer. A description of the array is given and the main electro-optical characteristics of the component are presented.

Long linear MWIR and LWIR HgCdTe arrays for high-resolution imaging

High resolution infrared imaging system calls for very long scanning arrays with several thousands of detectors and high performance. This paper presents the technological developments and the electro-optical performance obtained at LETI/SLIR (Infrared Laboratory) on linear HgCdTe (MCT) arrays working in the 3-5, 8-10 and 11-12.5 micrometers spectral ranges. These large arrays have an indirect hybrid architecture composed of butted HgCdTe PV detection circuits and Si readouts hybridized on a mechanically close-matched fanout substrate. Defect free dicing and butting, respecting the detector pitch, is made by accurate and nondamaging techniques.

1500-element linear MWIR and LWIR HgCdTe arrays for high-resolution imaging

High resolution infrared imaging system calls for very long scanning arrays with several thousands of detectors and high performance. This paper presents the recent technological developments and the electrooptical performances obtained at LETI I LIR (Infrared Laboratory) on 1500 detector linear HgCdTe arrays working in the 3-5 and 8-10 pm spectral ranges. These very large arrays (length 50 mm) have an indirect hybrid architecture composed of butted HgCdTe PV detection circuits and Si CMOS readouts hybridized on a mechanically close-matched fanout substrate. Defect free dicing and butting, respecting the detector pitch, is made by accurate and non damaging techniques. Keywords: Infrared, HgCdTe, linear array, butting, focal plane array

Long-MWIR HgCdTe butted linear arrays

High resolution infrared imaging system calls for very long scanning arrays with several thousands of detectors and high performance. This paper presents the recent technological developments carried out at LETI/LIR on long butted arrays and gives the results obtained on a 1500 detector linear HgCdTe array with a 30 micrometer pitch and a 5.5 micrometer cut-off wavelength. This very large array (length approximately equals 50 mm) has an indirect hybrid architecture composed of 5 butted HgCdTe PV detection circuits and 5 Si CMOS readouts hybridized on a mechanically close-matched fanout substrate. Defect free dicing and butting, respecting the detector pitch, is made by accurate and non damaging techniques. A detailed description of the array and the main electro-optical performances are presented.

640x480 MCT 3- to 5-μm snapshot focal plane array

A 640 X 480 snapshot IRCMOS array with 25 micron pitch operating in the 3 - 5 microns range was fabricated and an image demonstrated at the Infrared Laboratory (LIR). The readout circuit with 2 pC charge handling capacity was designed and processed with a 1.2 micrometer design rules standard CMOS technology. Photovoltaic (PV) detectors were achieved by ion implantation in liquid phase epitaxy MCT layers and interconnected by indium bumps on the readout circuit. A description of the component is given and the main electro-optical characteristics are presented. The pixel operability is greater than 99.8% and a NEDT of 15 mK was measured at half dynamics. Excellent imagery has been obtained with this component operating at 77 K and f/2 optics.

IRFPA advanced behavioral modeling dedicated to optronic systems evaluation

To help system designers to evaluate the performances of a 128 * 128 cooled IRFPA, a behavioral model has been realized. It simulates the characteristics of the component in term of temporal and fixed pattern noise. This model was designed to be incorporated in a complete simulation of an optronic system including IR scene generation, optics modeling, post-treatment and corrections of the simulated video signal delivered by the detector. By this way, costs and duration of system evaluation for different kinds of scenario were strongly reduced. The architecture of the model was based on electrical simulations of the circuit. Its parameters were fitted with measurements on a real IRCMOS demonstrator in order to reflect with precision its behavior. In this paper we present the architecture of the IRFPA model. Comparisons between modeling and measurements are also presented exhibiting a real good agreement in term of video signal uniformity and noise. This demonstrates the advantages of this modeling approach for optronic system evaluations.