182 research outputs found
De l'écorché au schéma anatomique. A propos de la « Mémoire artificielle » de Goiffon et Vincent (1779).
No full textGuillerme Jacques. De l'écorché au schéma anatomique. A propos de la « Mémoire artificielle » de Goiffon et Vincent (1779).. In: Revue d'histoire des sciences, tome 25, n°2, 1972. pp. 151-170
Hardening Techniques for Image Sensors
No full textDr. Vincent Goiffon, ISAE-SUPAERO, University of Toulouse, will provide an overview of the main radiation-induced degradations in solid state image sensors and present mitigation techniques to improve their radiation hardness and enable their use in harsh radiation environments. Among the wide variety of radiation effects relevant for pixel arrays and detectors, radiation-induced leakage currents in PN junctions are by far the main factor limiting the performances of these mixed signal integrated circuits when exposed to fields of high energy particles. How Total Ionizing Dose affects these leakages and how design and process optimizations can reduce the dark current in irradiated sensors will be discussed. What can enhance or reduce the sensitivity of an image sensor to more specific effects such as displacement damage and radiation induced random telegraph signal will also be addressed. The presentation will primarily focus on the CMOS Image Sensor technology, but will also explore the applicability of the presented concepts to other solid state image sensor technologies, as well as the similarities with other leakage sensitive devices such as DRAMs. This presentation will conclude by an overview of the relevant pixel radiation hardening techniques to use depending on the application requirements: from Earth observation space instruments to the exploration of the Jovian system and nuclear fusion instrumentation
In-Pixel source follower transistor RTS noise behavior under ionizing radiation in CMOS image sensors
Get PDFThis paper presents temporal noise measurement results for several total ionizing dose (TID) steps up to 2.19 Mrad of an image sensor designed with a 0.18-μm CMOS image sensor process. The noise measurements are focused on the random telegraph signal (RTS) noise due to the in-pixel source follower transistor of the sensor readout chain inducing noisy pixels. Results show no significant RTS noise degradation up to 300 krad of TID. Beyond this TID step, a limited RTS noise degradation is observed, and for the 2.19-Mrad step, an additional increase of total noise, including thermal, 1/f, and RTS noises, is noted.
Noisy pixels have been studied for high TIDs, and three cases have been observed: 1) no change on RTS behavior; 2) creation of RTS behavior; and 3) modifications of RTS behavior
Overview of ionizing radiation effects in image sensors fabricated in a deep-submicrometer CMOS imaging technology
Get PDFAn overview of ionizing radiation effects in imagers
manufactured in a 0.18-μm CMOS image sensor technology is presented. Fourteen types of image sensors are characterized and irradiated by a 60Co source up to 5 kGy. The differences between these 14 designs allow us to separately estimate the effect of ionizing radiation on microlenses, on low- and zero-threshold-voltage MOSFETs and on several pixel layouts using P+ guard-rings and edgeless transistors. After irradiation, wavelength dependent responsivity drops are observed. All the sensors exhibit a large dark current increase attributed to the shallow trench isolation that surrounds the photodiodes. Saturation voltage rises and readout chain gain variations are also reported. Finally, the radiation hardening perspectives resulting from this paper are discussed
Displacement Damage Effects in Pinned Photodiode CMOS Image Sensors
Get PDFThis paper investigates the effects of displacement damage in Pinned Photodiode (PPD) CMOS Image Sensors (CIS) using proton and neutron irradiations. The DDD ranges from 12 TeV/g to TeV/g. Particle fluence up to n.cm is investigated to observe electro-optic degradation in harsh environments. The dark current is also investigated and it would appear that it is possible to use the dark current spectroscopy in PPD CIS. The dark current random telegraph signal is also observed and characterized using the maximum transition amplitude
Generic radiation hardened photodiode layouts for deep submicron CMOS image sensor processes
Get PDFSelected radiation hardened photodiode layouts, manufactured in a deep submicron CMOS Image Sensor technology, are irradiated by 60Co gamma-rays up to 2.2 Mrad(SiO2) and studied in order to identify the most efficient structures and the guidelines (recess distance, bias voltage) to follow to make them work efficiently in such technology. To do so, both photodiode arrays and active pixel sensors are used. After 2.2 Mrad(SiO2), the studied sensors are fully functional and most of the radiation hardened photodiodes exhibit radiation induced dark current values more than one order of magnitude lower than the standard photodiode
Optoelectrical performance evolution of CMOS image sensors exposed to gamma radiation
Get PDFIn this paper we present a study of ionizing radiation effects, up to 5 kGy, in several CMOS image sensors manufactured using a commercial 0.18 μm technology dedicated to imaging
Single Event Effects in CMOS Image Sensors
Get PDFIn this work, 3T Active Pixel Sensors (APS) are exposed to heavy ions (N, Ar, Kr, Xe), and Single Event Effects (SEE) are studied. Devices were fully functional during exposure, no Single Event Latch-up (SEL) or Single Event Functional Interrupt (SEFI) happened. However Single Event Transient (SET) effects happened on frames: line disturbances, and half or full circular clusters of white pixels. The collection of charges in cluster was investigated with arrays of two pixel width (7 and 10 \textmu{}m), with bulk and epitaxial substrates. This paper shows technological and design parameters involved in the transient events. It also shows that STARDUST simulation software can predict cluster obtained for bulk substrate devices. However, the discrepancies in epitaxial layer devices are large - which shows the need for an improved model
Influence of displacement damage dose on dark current distributions of irradiated CMOS image sensors
Get PDFDark current increase distributions due to displacement damages are modeled using displacement damage dose concept. Several CMOS image sensors have been exposed to neutrons or protons and we have characterized their degradation in terms of dark current increase. We have been able to extract a set of two factors from the experimental dark current increase distributions. These factors are used to predict and build dark current increase distribution and leads to a better understanding of displacement damage effects on CMOS image sensors
Radiation Damage on Silicon Photomultipliers from Ionizing and Non-Ionizing Radiation of Low-Earth Orbit Operations
No full textSilicon Photomultipliers (SiPMs) are single photon detectors that gained increasing interest in many applications as an alternative to photomultiplier tubes. In the field of space experiments, where volume, weight and power consumption are a major constraint, their advantages like compactness,
ruggedness, and their potential to achieve high quantum efficiency from UV to NIR makes them ideal candidates for spaceborne, low photon flux detectors. During space missions however, SiPMs are usually exposed to high levels of radiation, both ionizing and non-ionizing, which can deteriorate the performance of these detectors over time. The goal of this work is to compare process and layout
variation of SiPMs in terms of their radiation damage effects to identify the features that helps reduce the deterioration of the performance and develop the next generation of more radiation-tolerant detectors. To do this, we used protons and X-rays to irradiate several Near Ultraviolet High-Density
(NUV-HD) SiPMs with small areas (single microcell, 0.2 × 0.2 mm2 and 1 × 1 mm2) produced at
Fondazione Bruno Kessler (FBK), Italy. We performed online current-voltage measurements right after each irradiation step, and a complete functional characterization before and after irradiation. We observed that the main contribution to performance degradation in space applications comes
from proton damage in the form of an increase in primary dark count rate (DCR) proportional to the
proton fluence and a reduction in activation energy. In this context, small active area devices show a lower DCR before and after irradiation, and we propose light or charge-focusing mechanisms as future developments for high-sensitivity radiation-tolerant detectors
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