Total dose evaluation of deep submicron CMOS imaging technology through elementary device and pixel array behavior analysis

Ionizing radiation effects on CMOS image sensors (CIS) manufactured using a 0.18 µm imaging technology are presented through the behavior analysis of elementary structures, such as field oxide FET, gated diodes, photodiodes and MOSFETs. Oxide characterizations appear necessary to understand ionizing dose effects on devices and then on image sensors. The main degradations observed are photodiode dark current increases (caused by a generation current enhancement), minimum size NMOSFET off-state current rises and minimum size PMOSFET radiation induced narrow channel effects. All these effects are attributed to the shallow trench isolation degradation which appears much more sensitive to ionizing radiation than inter layer dielectrics. Unusual post annealing effects are reported in these thick oxides. Finally, the consequences on sensor design are discussed thanks to an irradiated pixel array and a comparison with previous work is discussed

Ionization versus displacement damage effects in proton irradiated CMOS sensors manufactured in deep submicron process

Proton irradiation effects have been studied on CMOS image sensors manufactured in a 0.18 μm technology dedicated to imaging. The ionizing dose and displacement damage effects were discriminated and localized thanks to 60Co irradiations and large photodiode reverse current measurements. The only degradation observed was a photodiode dark current increase. It was found that ionizing dose effects dominate this rise by inducing generation centers at the interface between shallow trench isolations and depleted silicon regions. Displacement damages are responsible for a large degradation of dark current non-uniformity. This work suggests that designing a photodiode tolerant to ionizing radiation can mitigate an important part of proton irradiation effects

Some Information Systems Research Trends over the Past Decade

In order to gain an understanding of the recent evolution and the current state of information systems (IS) development research, three sub-topic areas within IS development, were examined: IS development methodology, IS architecture, and IS design and modeling. Relevant papers were selected from the Association for Information Systems (AIS) basket of eight journals. Using these articles, an empirical method based on author keywords was used to identify categorical research trends in each of the three areas. Research trends observed in each of the categories over the past decade are discussed

Multilevel RTS in proton irradiated CMOS image sensors manufactured in a deep submicron technology

A new automated method able to detect multilevel random telegraph signals (RTS) in pixel arrays and to extract their main characteristics is presented. The proposed method is applied to several proton irradiated pixel arrays manufactured using a 0.18um CMOS process dedicated to imaging. Despite the large proton energy range and the large fluence range used, similar exponential RTS amplitude distributions are observed. A mean maximum amplitude independent of displacement damage dose is extracted from these distributions and the number of RTS defects appears to scale well with total nonionizing energy loss. These conclusions allow the prediction of RTS amplitude distributions. The effect of electric field on RTS amplitude is also studied and no significant relation between applied bias and RTS amplitude is observed

Ionizing radiation effects on CMOS imagers manufactured in deep submicron process

We present here a study on both CMOS sensors and elementary structures (photodiodes and in-pixel MOSFETs) manufactured in a deep submicron process dedicated to imaging. We designed a test chip made of one 128×128-3T-pixel array with 10 µm pitch and more than 120 isolated test structures including photodiodes and MOSFETs with various implants and different sizes. All these devices were exposed to ionizing radiation up to 100 krad and their responses were correlated to identify the CMOS sensor weaknesses. Characterizations in darkness and under illumination demonstrated that dark current increase is the major sensor degradation. Shallow trench isolation was identified to be responsible for this degradation as it increases the number of generation centers in photodiode depletion regions. Consequences on hardness assurance and hardening-by-design are discussed

Recherche à visée sociétale, un enjeu pour nous tous

National audienceNous examinons les caractéristiques des différents types de recherche - fondamentale, appliquée, recherche-développement, sociétale

Pourquoi sélectionner de nouvelles variétés de blé tendre adaptées à l’agriculture biologique ?

International audienceLongtemps marginale en France, l’agriculture biologique est un secteur émergent à fort potentiel : les objectifs fixés par la loi Grenelle I ambitionnaient de faire passer les surfaces cultivées en agriculture biologique de 2% de la SAU française à 6% en 2012 puis de franchir un nouveau palier avec une couverture de 20% de la SAU en 2020. Même si en réalité c’est seulement 3% de la SAU qui est actuellement cultivée en agriculture biologique, les recherches consacrées à ce domaine, dont le cahier des charges interdit le recours aux produits de la chimie de synthèse, permettent d’anticiper le probable fort renchérissement du coût de l’énergie fossile (pic pétrolier).Ce travail pionnier de réduction des engrais et des pesticides sera alors utile à l’ensemble de l’agriculture. Tous les systèmes de culture ont bénéficié des progrès de la sélection végétale excepté l’agriculture biologique, parent pauvre de l’amélioration génétique. En effet la sélection s’est faite depuis 50 ans pour des itinéraires techniques artificialisés pour lesquels la fertilisation azotée minérale est abondante et où les herbicides sont utilisés pour lutter contre les adventices des cultures. Elle a conduit à l’obtention de variétés à paille courte donc peu concurrentielles vis-à-vis des mauvaises herbes et qui peinent en conditions de disponibilités réduites en azote, conditions rencontrées en agriculture biologique. La sélection variétale sur des critères adaptés à ces milieux aux contraintes fortes se justifie. Nous présenterons pourquoi elle peut être porteuse d’enseignements et discuterons de sa possible évolution au regard des premiers résultats obtenus

From selection to cultivation with the support of all stakeholders: first registration in France of two bread wheat varieties after VCU in organic farming system

As bread wheat is the most important cash crops for French organic farmers, the question of the kind of varieties farmers should be using is therefore very important. Most of varieties available were bred for intensive “conventional” farming systems (with high inputs of mineral fertilizers and pesticides), also screening current varieties for organic conditions becomes a necessity to identifiy suitable varieties for organic farming conditions in a short term experiment. After 20 years of selection and screening combined in two different crop management systems, low inputs and organic, two lines, Hendrix and Skerzzo, have been registered in the official catalogue with the special mention « organic farming ». For the second year of seed production, 150 hectares were sown in autumn 2013 to be sell to organic farmers in 2014. This successful process was possible with the support of all the agricultural organic sector associated in the initiative

Universal cumulants of the current in diffusive systems on a ring

We calculate exactly the first cumulants of the integrated current and of the activity (which is the total number of changes of configurations) of the symmetric simple exclusion process (SSEP) on a ring with periodic boundary conditions. Our results indicate that for large system sizes the large deviation functions of the current and of the activity take a universal scaling form, with the same scaling function for both quantities. This scaling function can be understood either by an analysis of Bethe ansatz equations or in terms of a theory based on fluctuating hydrodynamics or on the macroscopic fluctuation theory of Bertini, De Sole, Gabrielli, Jona-Lasinio and Landim

Associer des itinéraires techniques de niveau d'intrants variés à des variétés rustiques de blé tendre : évaluation économique, environnementale et énergétique

International audienceL’impact de l’utilisation des engrais azotés et des pesticides (Aubertot et al., 2005) sur l’environnement ainsi que l’instabilité des prix de vente des céréales ont suscité un certain nombre de réflexions sur de nouvelles manières de produire du blé tendre d’hiver, en prenant notamment appui sur le progrès variétal. Ainsi, à partir de 1999, l’INRA, l’ITCF (puis ARVALIS-Institut du végétal), les sélectionneurs du GIE Club des Cinq et les chambres d’agriculture d’Indre-et-Loire et du Morbihan ont engagé une collaboration afin d’évaluer l’intérêt des variétés rustiques conduites avec des itinéraires techniques à niveaux d’intrants réduits. Ces variétés ont été choisies parmi celles présentant des caractères de multirésistance aux maladies et à la verse, tout en s’assurant d’un niveau de rendement comparable aux autres cultivars du catalogue. Le réseau expérimental multilocal mis en place de 2000 à 2002 a révélé des performances économiques satisfaisantes de ces itinéraires techniques au regard des recommandations locales, et ce pour le prix de vente moyen de cette période, à savoir 100 € par tonne (Loyce et al., 2001 ; Félix et al., 2002 ; Rolland et al., 2003 ; Loyce et al., accepté)