84 research outputs found
Electrical and structural properties of ultrathin SiON films prepared by plasma nitridation
No full textThe authors combined electrical and structural characterizations with analytical and spectroscopic measurements in order to fully analyze oxynitride nanofilms on Si that were produced in a minibatch type plasma nitridation reactor. The authors demonstrate that for the investigated samples the result of nitridation is different in the 2-nm-thick SiO2 films compared to the 5-nm-thick films. In the first case, nitridation results in an increase of the oxide film thickness compared to the non-nitrided film, with a consequent decrease in leakage current and an increase in the electrically measured equivalent oxide thickness (EOT). In contrast, nitridation of the 5-nm-thick SiO2 films leads to a reduction of both the leakage current and EOT. Finally, the authors demonstrate that the applied nitridation process results in the desired nitrogen profile with high nitrogen concentration near the top surface or the middle of the SiON film and low nitrogen concentration near the SiON/Si interface, which leads to a relatively low density of interface states at the SiON/Si interface ( ∼ 1011 states/cm2) for nonannealed films
Simple method for determining Si p-n junction depth using anodization
No full textA simple method for the determination of a Si p+/n junction depth is presented. The method is designed to delineate the specific junction due to its importance in the field of Si solar cells where cost effective and fast characterization techniques are necessary. It consists of the electrochemical transformation of the p+ Si to porous Si. The determination of the porous Si depth with the use of cross-sectional Scanning Electron Microscope (SEM) images provides a direct, fast and easy to implement measurement of the junction depth. In addition, through a simple 4-point probe electrical measurement of the sheet resistance, the average dopant concentration is determined, which allows the creation of an abrupt junction approximation of the p+/n junction. The method is shown to produce accurate results in two types of doping techniques, namely implantation and spin-on-doping and a range of junction depths between 200 nm and 1500 nm, as compared to the well-established secondary ion mass spectrometry (SIMS) technique
La Pathologie de la Guerre et la Pédagogie de la Paix chez Thucydide
No full textIn ancient Greece, war was considered a standard situation that was occasionally interrupted by peace. On one hand the following may be considered as aspects of the phenomenon of war: a) the manifestations of violence between rival groups and b) the armed conflicts between organized states, while forms of this phenomenon, according to Thucydides would be: a) dissension and b) fighting. On the other hand, we could reflect on the phenomenon of peace as: a) the status of harmony, order, equilibrium and of calm between different socio-political forces, b) the status of tranquility and serenity in all sorts of human activities and c) the prosperity and the happiness of individuals, social groups and states. According to the historian, war seems to be a malady of human nature for which he tries to find the origin and the symptoms. Hence, history is not viewed as a simple lesson of morality but rather as a practical and scientific one, a diachronically study of human psychology. Therefore, the amelioration of human mentality, thought and behavior depends mainly on the development and education of human beings.Dans la Grèce antique, la guerre était considérée comme une situation normale, interrompue de temps à autre par un temps `mort: la paix. On peut considérer comme aspects du phénomène de la guerre: a) les manifestations de violence entre groupes rivaux, b) les luttes entre États organisés. D’après Thucydide les formes de ce phénomène sont: a) la dissension et b) la guerre. A l’opposé, on peut considérer comme aspects de la paix: a) l’état d’harmonie, d’ordre, d’équilibre et de calme des différentes puissances socio-politiques de toute espèce, b) l’état de tranquillité et de sérénité dans le Spectrum des rapports humains et c) le bien-être et le bonheur autant des individus, des groupes sociaux ou des États. Pour l’historien, la guerre semble être une maladie dont il essaie de dépister l’origine et les symptômes dans le comportement et la nature de l’homme. L’histoire selon Thucydide ne constitue pas seulement une simple leçon de morale, mais plutôt un enseignement pratique et scientifique, une étude diachronique de la psychologie humaine. L’amélioration de la mentalité, de la pensée et du comportement de l’homme passent donc par la formation et le développement de la raison et de l’esprit
Leakage current and charging/discharging processes in barrier-type anodic alumina thin films for use in metal-insulator-metal capacitors
No full textBarrier-type anodic alumina thin films are interesting for use in high capacitance density metal-insulator-metal capacitors due to their excellent dielectric properties at small thickness. This thickness is easily controlled by the anodization voltage. In previous papers we studied the main parameters of interest of the Al/barrier-type anodic alumina/Al structure for use in RF applications and showed the great potential of barrier-type anodic alumina in this respect. In this paper, we investigated in detail charging/discharging processes and leakage current of the above dielectric material. Two different sets of metal-insulator-metal capacitors were studied, namely, with the top Al electrode being either e-gun deposited or sputtered. The dielectric constant of the barrier-type anodic alumina was found at 9.3. Low leakage current was observed in all samples studied. Furthermore, depending on the film thickness, field emission following the Fowler-Nordheim mechanism was observed above an applied electric field. Charging of the anodic dielectric was observed, occurring in the bulk of the anodic layer. The stored charge was of the order of few μC/cm2 and the calculated trap density ∼2 × 1018 states/cm3, the most probable origin of charge traps being, in our opinion, positive electrolyte ions trapped in the dielectric during anodization. We do not think that oxygen vacancies play an important role, since their existence would have a more important impact on the leakage current characteristics, such as resistive memory effects or significant changes during annealing, which were not observed. Finally, discharging characteristic times as high as 5 × 109 s were measured. © 2018 Author(s)
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