Repositório do Conhecimento Institucional do Centro Universitário FEI
 

Departamento de Física

URI permanente desta comunidadehttps://repositorio.fei.edu.br/handle/FEI/785

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Resultados da Pesquisa

Agora exibindo 1 - 4 de 4
  • Artigo 37 Citação(ões) na Scopus
    Experimental setup for Single Event Effects at the São Paulo 8UD Pelletron Accelerator
    (2014) Aguiar V.A.P.; Added N.; Medina N.H.; Macchione E.L.A.; Tabacniks M.H.; Aguirre F.R.; Silveira M.A.G.; Santos R.B.B.; Seixas Jr. L.E.
    In this work we present an experimental setup mounted in one of the beam lines at the São Paulo 8UD Pelletron Accelerator in order to study Single Event Effects in electronic devices. The basic idea is to use elastic scattering collisions to achieve a low-flux with a high-uniformity ion beam to irradiate several devices. 12C, 16O, 28Si, 35Cl and 63Cu beams were used to test the experimental setup. In this system it is possible to use efficiently LET values of 17 MeV/mg/cm2 for an external beam arrangement and up to 32 MeV/mg/cm2 for in-vacuum irradiation. © 2014 Elsevier B.V. All rights reserved.
  • Artigo de evento 3 Citação(ões) na Scopus
    Comparative study of the proton beam effects between the conventional and Circular-Gate MOSFETs
    (2012) Cirne K.; Silveira M.A.G.; Santos R.B.B.; Gimenez S.P.; Barbosa M.D.L.; Tabacniks M.H.; Added N.; Medina N.H.; De Melo W.R.; Seixas Jr. L.E.; De Lima J.A.
    The study of ionizing radiation effects on semiconductor devices is of great relevance for the global technological development and is a necessity in some strategic areas in Brazil. This work presents preliminary results of radiation effects in MOSFETs that were exposed to 3.2 Grad radiation dose produced by a 2.6-MeV proton beam. The focus of this work was to electrically characterize a Rectangular-Gate MOSFET (RGT) and a Circular-Gate MOSFET (CGT), manufactured with the On Semiconductor 0.5 μm standard CMOS fabrication process and to verify a suitable geometry for space applications. During the experiment, I DS × V GS curves were measured. After irradiation, the RGT off-state current (I OFF) increased approximately two orders of magnitude reaching practically the same value of the I OFF in the CGT, which only doubled its value. © 2011 Elsevier B.V. All rights reserved.
  • Artigo de evento 13 Citação(ões) na Scopus
    Performance of electronic devices submitted to X-rays and high energy proton beams
    (2012) Silveira M.A.G.; Cirne K.H.; Santos R.B.B.; Gimenez S.P.; Medina N.H.; Added N.; Tabacniks M.H.; Barbosa M.D.L.; Seixas L.E.; Melo W.; De Lima J.A.
    In this work we have studied the radiation effects on MOSFET electronic devices. The integrated circuits were exposed to 10 keV X-ray radiation and 2.6 MeV energy proton beam. We have irradiated MOSFET devices with two different geometries: rectangular-gate transistor and circular-gate transistor. We have observed the cumulative dose provokes shifts on the threshold voltage and increases or decreases the transistor's off-state and leakage current. The position of the trapped charges in modern CMOS technology devices depends on radiation type, dose rate, total dose, applied bias and is a function of device geometry. We concluded the circular-gate transistor is more tolerant to radiation than the rectangular-gate transistor. © 2011 Elsevier B.V. All rights reserved.
  • Artigo 13 Citação(ões) na Scopus
    Elemental mapping of large samples by external ion beam analysis with sub-millimeter resolution and its applications
    (2018) Silva T.F.; Rodrigues C.L.; Added N.; Rizzutto M.A.; Tabacniks M.H.; Mangiarotti A.; Curado J.F.; Aguirre F.R.; Aguero N.F.; Allegro P.R.P.; Campos P.H.O.V.; Restrepo J.M.; Trindade G.F.; Antonio M.R.; Assis R.F.; Leite A.R.
    © 2018 Elsevier B.V.The elemental mapping of large areas using ion beam techniques is a desired capability for several scientific communities, involved on topics ranging from geoscience to cultural heritage. Usually, the constraints for large-area mapping are not met in setups employing micro- and nano-probes implemented all over the world. A novel setup for mapping large sized samples in an external beam was recently built at the University of São Paulo employing a broad MeV-proton probe with sub-millimeter dimension, coupled to a high-precision large range XYZ robotic stage (60 cm range in all axis and precision of 5 μm ensured by optical sensors). An important issue on large area mapping is how to deal with the irregularities of the sample's surface, that may introduce artifacts in the images due to the variation of the measuring conditions. In our setup, we implemented an automatic system based on machine vision to correct the position of the sample to compensate for its surface irregularities. As an additional benefit, a 3D digital reconstruction of the scanned surface can also be obtained. Using this new and unique setup, we have produced large-area elemental maps of ceramics, stones, fossils, and other sort of samples.