Localization of Dark Current Random Telegraph Signal sources in pinned photodiode CMOS Image Sensors

This work presents an analysis of Dark Current Random Telegraph Signal (DC-RTS) in CMOS Image Sensors (CIS). The objective is to provide new insight on RTS in modern CIS by determining the localization of DC-RTS centers and the oxide interfaces involved. It is shown that DC-RTS centers are located near the transfer gate. In particular, it is demonstrated that both gate oxide and Shallow Trench Isolation (STI) contribute to this parasitic dark current variation

In-Depth Analysis on Radiation Induced Multi-Level Dark Current Random Telegraph Signal in Silicon Solid State Image Sensors

Radiation-induced phenomena constitute a big concern for image sensors dedicated to space application. Particles(such as protons or electrons) can impact the crystalline structure of the detector and create switches in the dark response. This may be a problem, especially for calibration and so on image quality. This article aims at expressing the method used for switch detection and showing some properties of these Random Telegraph Signals (RTS), concerning, among other things, their amplitudes, discrete levels, and switching times. A first analysis of these results is also given

Comparison of Dark Current Random Telegraph Signals in Silicon and InSb-Based Photodetector Pixel Arrays

In this work, the parasitic discrete fluctuation of dark current (dc) called random telegraph signal (RTS) is analyzed in image sensors based on two different semiconductor materials: InSb and silicon. The results show that this dc-RTS phenomenon exhibits similar characteristics on both technologies strongly suggesting a common physical origin. This conclusion is extended to InGaAs and HgCdTe (also referred to as MCT)-based image sensors by comparing the presented results to the existing literature

Total Ionizing Dose Radiation-Induced Dark Current Random Telegraph Signal in Pinned Photodiode CMOS Image Sensors

In this work, several studies on Total Ionizing Dose effects on Pinned Photodiode CMOS images sensors are presented. More precisely, the evolution of a parasitic signal called Random Telegraph Signal is analysed through several photodiode designs. It is shown that the population of pixels exhibiting this fluctuation depends on the design variants. This population also increases in a different way with the dose: the effects are not same considering a low or high X-rays irradiation. Moreover, a statistical analysis is realized in order to better caracterize the defects responsible for RTS. It turns out that electric field enhancement signature can appear in some specific cases

CAGIRE: a wide-field NIR imager for the COLIBRI 1.3 meter robotic telescope

The use of high energy transients such as Gamma Ray Bursts (GRBs) as probes of the distant universe relies on the close collaboration between space and ground facilities. In this context, the Sino-French mission SVOM has been designed to combine a space and a ground segment and to make the most of their synergy. On the ground, the 1.3 meter robotic telescope COLIBRI, jointly developed by France and Mexico, will quickly point the sources detected by the space hard X-ray imager ECLAIRs, in order to detect and localise their visible/NIR counterpart and alert large telescopes in minutes. COLIBRI is equipped with two visible cameras, called DDRAGO-blue and DDRAGO-red, and an infrared camera, called CAGIRE, designed for the study of high redshift GRBs candidates. Being a low-noise NIR camera mounted at the focus of an alt-azimutal robotic telescope imposes specific requirements on CAGIRE. We describe here the main characteristics of the camera: its optical, mechanical and electronics architecture, the ALFA detector, and the operation of the camera on the telescope. The instrument description is completed by three sections presenting the calibration strategy, an image simulator incorporating known detector effects, and the automatic reduction software for the ramps acquired by the detector. This paper aims at providing an overview of the instrument before its installation on the telescope.Comment: Accepted by Experimental Astronom

UNE NOUVELLE GENERATION D'ETUDE SPECTROSCOPIQUE A HAUTE RESOLUTION DES DEFAUTS ELECTRONIQUES DANS LE SILICIUM (LA LAPLACE DLTS)

NOUS NOUS INTERESSONS A L'ETUDE DE DEFAUTS PROFONDS DANS LE CRISTAL DE SILICIUM EN UTILISANT UNE NOUVELLE TECHNIQUE ISOTHERME DE DLTS, APPELEE LAPLACE DLTS (LDLTS). LA LDLTS, BASEE SUR LA METHODE DE REGULARISATION DE TIKHONOV, PERMET D'AMELIORER LA RESOLUTION ENERGETIQUE D'AU MOINS UN ORDRE DE GRANDEUR PAR RAPPORT A LA DLTS CLASSIQUE. TOUT D'ABORD, NOTRE ETUDE EXPERIMENTALE A PORTE SUR LE CENTRE A CREE PAR DES IRRADIATIONS DE PROTONS OU D'ELECTRONS. EN COMBINANT LA LDLTS AVEC L'APPLICATION DE CONTRAINTES UNIAXES DANS LES DIRECTIONS CRISTALLOGRAPHIQUES , ET , NOUS AVONS CONFIRME SA SYMETRIE ORTHORHOMBIQUE AU SEIN DU CRISTAL DE SILICIUM. NOUS AVONS MONTRE QUE LA VARIATION DU NIVEAU ELECTRONIQUE DU CENTRE A NE POUVAIT PAS ETRE QUANTIFIEE UNIQUEMENT PAR LES DEFORMATIONS LE LONG DE LA LIAISON DISTORDUE SI-SI. DANS SON ETAT DE CHARGE NEUTRE, LE CENTRE A SE REORIENTE SOUS PRESSION DE FACON A REDUIRE LES CONTRAINTES LE LONG DE SON AXE C 2 V ET QUE DURANT CETTE REORIENTATION L'ATOME D'OXYGENE S'ALIGNE LE LONG DE LA DIRECTION POUR LA CONFIGURATION ATOMIQUE AU POINT SELLE. DANS L'ETAT DE CHARGE NEGATIF, UNE BARRIERE DE REORIENTATION SUPERIEURE A CELLE DE L'ETAT NEUTRE A ETE OBTENUE, SUGGERANT UNE REPULSION COULOMBIENNE ENTRE L'ATOME D'OXYGENE ET LA LIAISON DISTORDUE SI-SI. NOUS AVONS POURSUIVI NOTRE ETUDE PAR LDLTS SUR LES DEFAUTS OR ET OR-HYDROGENE, INTRODUITS DANS LE SILICIUM APRES DIFFUSION D'OR ET TRAITEMENT CHIMIQUE. DANS DU SILICIUM DE TYPE N, NOUS AVONS DISSOCIE POUR LA PREMIERE FOIS LES DEFAUTS AU-/0 ET AUH -/ 0 POSSEDANT DES VITESSES D'EMISSION TROP PROCHES POUR ETRE DECELEES PAR LA DLTS CLASSIQUE. POUR DES CONCENTRATIONS EN OR ET HYDROGENE SUPERIEURES, NOUS AVONS MONTRE L'EXISTENCE D'UN DEFAUT SUPPLEMENTAIRE QUE NOUS AVONS ASSOCIE A UN COMPLEXE AUH 2-/0. EN COMBINANT LA LDLTS AVEC DES CONTRAINTES UNIAXES, NOUS AVONS MIS EN EVIDENCE LA PROPRIETE DE REORIENTATION INSTANTANEE POUR LES DEFAUTS AU ET AUH DANS DU SILICIUM DE TYPE P ET N.GRENOBLE1-BU Sciences (384212103) / SudocSudocFranceF

Efficiency of interface trap generation under hole injections in 2.1 nm thick gate-oxide P-MOSFETs

International audienceCarrier injection mechanisms have been compared in surface p-channel metal–oxide–semiconductor field-effect transistors with a 2.1 nm thick gate-oxide. Currents as a function of voltage, I(V), were correlated with a corrected charge-pumping analysis taking into account the tunneling components. Channel hot-hole injection at the gate and drain voltages, |VGS| >=|VDS|, induces damage even at low stress voltage (<1.5 V) in contrast to hot-electron injection which requires much larger field conditions close to the drain avalanche hot electron regime. Hot-hole injection is much efficient for the generation of donor-type interface traps, dNit, than the uniform (direct) tunneling of holes from the inversion layer. No trapping of positive charge has been detected by the charge-pumping analysis for these two last injections in 2.1 nm thick gate-oxide p-devices. The larger reduction of the drain current |IDS| under hot-hole injection differs from the uniform injection by the amount of dNit. This is due to the energy supply and to the extent of the degraded region towards the source which in both injection mechanisms do not exhibit a rate-limiting step during the generation of interface traps. These results indicate that the Nit generation cannot be explained by the diffusion of water related species across the gate-oxide but can by explained by the electron–hole recombination process

Use of EBIC for MTF measurement of HOT MCT focal plane planar array with very small pixel pitches

Event: SPIE Defense + Commercial Sensing, 2023, Orlando, Florida, United StatesInternational audienc

CdZnTe Crystal Quality Study by Cathodoluminescence Measurements

International audienceImproving material quality is an essential step to maintain high electro-optical performance at higher operating temperature (HOT) of cooled II-VI infrared (IR) detectors. Indeed, the electrical activity of crystal defects affects their image quality and stability. A first investigation is to correlate the point defect populations with the crystal quality of the Cd1−xZnxTe (CZT) substrate, used for the growth of the Hg1−xCdxTe (MCT) active layer. For this purpose, spectrally resolved cathodoluminescence (CL) measurements were performed for wafers with low and high crystal quality, with a respective dislocation density of 1.8 × 104 cm−2 and 6 × 103 cm−2. At 295 K, both wafers showed band-to-band transition, and CL spectra were modeled with the generalized Planck law. However, at 10 K, CL spectra showed that the visibility of phonon replicas of the donor–acceptor pair () transition at 1.57 eV is dependent on the crystalline order. In addition, the luminescence of the A-center defect () was observed at 1.43 eV only in the low-quality CZT substrate