Ionizing radiation hardening of a CCD technology
TL;DR: A three-level polysilicon, buried channel charge coupled device (CCD) technology has been tested for Co/sup 60/ ionizing radiation damage up to a total dose of 90 krad(Si) as discussed by the authors.
Abstract: A three-level polysilicon, buried channel charge coupled device (CCD) technology has been tested for Co/sup 60/ ionizing radiation damage up to a total dose of 90 krad(Si). For this purpose CCD image sensors have been irradiated together with their associated test structures. These include different types of MOSFETs, natural transistors, buried channel transistors, field transistors, and diodes. The devices have been fully characterized during irradiation and afterwards, as a function of time. The standard technology has been assessed, leading to the implementation of process and design modifications. The modified technology has been further tested according to the same procedure and significant improvement in the sensors' behavior under irradiation and during annealing has been observed. The radiation hardness of the CCDs has been correlated with the results of the test structures, allowing a better understanding of the degradation phenomena and of the countermeasures needed for a radiation-hardened technology. >
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TL;DR: An overview of these radiation-induced effects, their dependencies, and the many different approaches to their mitigation is presented in this paper, where the authors present an overview of the radiation effects on metal-oxide-semiconductor devices and integrated circuits.
Abstract: Total ionizing dose radiation effects on the electrical properties of metal-oxide-semiconductor devices and integrated circuits are complex in nature and have changed much during decades of device evolution. These effects are caused by radiation-induced charge buildup in oxide and interfacial regions. This paper presents an overview of these radiation-induced effects, their dependencies, and the many different approaches to their mitigation.
274 citations
TL;DR: In this paper, the surface and bulk radiation damage effects on a two-phase charge-coupled device (CCD) operated in a multipinned phase (MPP) mode have been evaluated.
Abstract: Surface and bulk radiation damage effects on a two-phase charge-coupled device (CCD), operated in a multipinned phase (MPP) mode have been evaluated Two-phase CCD's are one of the candidates for application in the vertex detector of a future linear collider Flat-band voltage shifts, dark current, dark current spikes, and charge transfer efficiency (CTE) were studied on devices subjected to irradiation with fluences reaching 43/spl times/10/sup 12/ electrons/cm/sup 2/ and 89/spl times/10/sup 9/ neutrons/cm/sup 2/ An additional source of dark signal in electron irradiated devices was observed and explained by impact ionization by holes, released by tunneling from defect states near the Si-SiO/sub 2/ interface A model for the CTE in a two-phase CCD as a function of temperature, background charges, and clock timing is described Calculations based on the model are in good agreement with the experimentally determined values of CTE in electron and neutron irradiated CCD's
32 citations
01 Jul 2014-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this article, the effects of total dose radiation effects on COTS array charge-coupled device (CCD) and annealing measurements are shown, and their mechanisms induced by radiation are also demonstrated.
Abstract: Experiments of total dose radiation effects on COTS array charge-coupled device (CCD) and annealing measurements are shown. Degradations of saturation output voltage at different bias conditions are analyzed, and their mechanisms induced by radiation are also demonstrated. Degradations of saturation output imaging at different total doses and the recovery after annealing are also compared. The phenomena of imaging degradation induced by total dose irradiation are analyzed. The camera imaging quality of resolution test card degraded by total dose irradiation is also analyzed. Finally, integration research from the irradiation-sensitive parameter degradation to the camera imaging degradation of the array CCD is achieved.
9 citations
18 Sep 1995
TL;DR: In this article, the development and evolution of device parameters as a function of total dose are presented, and the process development and the evolution of the device parameters are presented as well.
Abstract: Modifications of the standard fabrication techniques of the 0.6 /spl mu/m CMOS technology lead to a radiation tolerant process in terms of immunity to total dose effects (up to 500 Gy) and to latchup under heavy ions (LET up to 100 MeV/(mg/cm/sup 2/)). In this paper, the process development and the evolution of device parameters as a function of total dose are presented.
4 citations
TL;DR: The evaluation of the degradation on a COTS linear Charge Coupled Device (CCD) induced by total ionizing dose (TID) radiation damage was presented and the degradation mechanisms of the CCD induced by TID damage were discussed.
Abstract: The evaluation of the degradation on a COTS linear Charge Coupled Device (CCD) induced by total ionizing dose (TID) radiation damage was presented. The radiation experiments were carried out at a 60Co γ-ray source. The parameters of DALSA’s linear CCD were measured at the CCD test systems as the EMVA1288 standard before and after the radiation. The dark current, dark signal nonuniformity (DSNU), photo response nonuniformity (PRNU), saturation output, full-well capacity (FWC), quantum efficiency (QE), and responsivity versus the TID were analyzed. The behavior of the tested CCD had shown a remarkable degradation after radiation. The degradation mechanisms of the CCD induced by TID damage were also discussed.
3 citations
Cites background from "Ionizing radiation hardening of a C..."
...have presented the dark current density and threshold shift of hardening CCDs versus the accumulated dose and annealing time [4]....
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References
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TL;DR: In this article, the statistics of the recombination of holes and electrons in semiconductors were analyzed on the basis of a model in which the recombinations occurred through the mechanism of trapping.
Abstract: The statistics of the recombination of holes and electrons in semiconductors is analyzed on the basis of a model in which the recombination occurs through the mechanism of trapping. A trap is assumed to have an energy level in the energy gap so that its charge may have either of two values differing by one electronic charge. The dependence of lifetime of injected carriers upon initial conductivity and upon injected carrier density is discussed.
5,442 citations
TL;DR: In this article, a new and accurate approach to charge-pumping measurements for the determination of the Si-SiO 2 interface state density directly on MOS transistors is presented.
Abstract: A new and accurate approach to charge-pumping measurements for the determination of the Si-SiO 2 interface state density directly on MOS transistors is presented. By a careful analysis of the different processes of emission of electrons towards the conduction band and of holes towards the valence band, depending on the charge state of the interface, all the previously ill-understood phenomena can be explained and the deviations from the simple charge-pumping theory can be accounted for. The presence of a geometric component in some transistor configurations is illustrated and the influence of trapping time constants is discussed. Furthermore, based on this insight, a new technique is developed for the determination of the energy distribution of interface states in small-area transistors, without requiring the knowledge of the surface potential dependence on gate voltage.
1,249 citations
TL;DR: In this paper, an extensive set of experimental results on the behavior of electron surface mobility in thermally oxidized silicon structures are presented, which allow the calculation of electron mobility under a wide variety of substrate, process, and electrical conditions.
Abstract: Accurate modeling of MOS devices requires quantitative knowledge of carrier mobilities in surface inversion and accumulation layers. Optimization of device structures and accurate circuit simulation, particulary as technologies push toward fundamental limits, necessitate an understanding of how impurity doping levels, oxide charge densities, process techniques, and applied electric fields affect carrier surface mobilities. It is the purpose of this paper to present an extensive set experimental results on the behavior of electron surface mobility in thermally oxidized silicon structures. Empirical equations are developed which allow the calculation of electron mobility under a wide variety of substrate, process, and electrical conditions. The experimental results are interpreted in terms of the dominant physical mechanisms responsible for mobility degradation at the Si/SiO 2 interface. From the observed effects of process parameters on mobility roll-off under high vertical fields, conclusions are drawn about optimum process conditions for maximizing mobility. The implications of this work for performance limits of several types of MOS devices are described.
610 citations
TL;DR: In this paper, an empirical model of radiation-induced interface states at the SiO2/Si interface in SiO 2 MOS capacitors is developed, which explicitly addresses the time-dependent two stage nature of the buildup process, and gives the mathematical dependencies of the experimentally observed buildup on time, field, temperature, and dose.
Abstract: An empirical model of radiation-induced interface states at the SiO2/Si interface in SiO2 MOS capacitors is developed. The formulation explicitly addresses the time-dependent two stage nature of the buildup process, and it gives the mathematical dependencies of the experimentally observed buildup on time, field, temperature, and dose. The model is applied to both wet and dry grown oxides. The implications of the empirical model for microscopic mechanisms involved in the buildup are discussed. In particular, it is argued that the experimental observations can best be understood in terms of a positive ion (probably H+) release in the SiO2 bulk and the subsequent transport of the liberated ions to the SiO2/Si interface (for positive gate bias). The induced interface states result from an interaction of the ions at the interface.
524 citations
TL;DR: In this paper, the anneal of radiation-induced trapped holes in MOS transistors is found to be thermally activated and a quantitative, physical model based on thermal emission and tunneling is developed.
Abstract: The anneal of radiation-induced trapped holes in MOS transistors is found to be thermally activated. A quantitative, physical model based on thermal emission and tunneling is developed. It accurately predicts the anneal of radiation-induced trapped holes in constant or time-varying thermal environments. Data are presented which quantitatively verify the accuracy of the model for temperatures between 25 and 160 degrees C. This model provides the basis for developing accurate quantitative screens for the rebound failure mechanism. >
199 citations