Recent Submissions

  • Silicon microring resonators

    Bogaerts, Wim; De Heyn, Peter; Van Vaerenbergh, Thomas; De Vos, Katrien; Kumar Selvaraja, Shankar; Claes, Tom; Dumon, Pieter; Bienstman, Peter; Van Thourhout, Dries; Baets, Roel; imec (2011-09-13)
    An overview is presented of the current state‐of‐the‐art in silicon nanophotonic ring resonators. Basic theory of ring resonators is discussed, and applied to the peculiarities of submicron silicon photonic wire waveguides: the small dimensions and tight bend radii, sensitivity to perturbations and the boundary conditions of the fabrication processes. Theory is compared to quantitative measurements. Finally, several of the more promising applications of silicon ring resonators are discussed: filters and optical delay lines, label‐free biosensors, and active rings for efficient modulators and even light sources.
  • A Cautionary Note When Looking for a Truly Reconfigurable Resistive RAM PUF

    Chuang, Kai-Hsin; Degraeve, Robin; Fantini, Andrea; Groeseneken, Guido; Linten, Dimitri; Verbauwhede, Ingrid; imec (IACR, 2018-02-14)
    The reconfigurable physically unclonable function (PUF) is an advanced security hardware primitive, suitable for applications requiring key renewal or similar refresh functions. The Oxygen vacancies-based resistive RAM (RRAM), has been claimed to be a physically reconfigurable PUF due to its intrinsic switching variability. This paper first analyzes and compares various previously published RRAM-based PUFs with a physics-based RRAM model. We next discuss their possible reconfigurability assuming an ideal configuration-to-configuration behavior. The RRAM-to-RRAM variability, which mainly originates from a variable number of unremovable vacancies inside the RRAM filament, however, has been observed to have significant impact on the reconfigurability. We show by quantitative analysis on the clear uniqueness degradation from the ideal situation in all the discussed implementations. Thus we conclude that true reconfigurability with RRAM PUFs might be unachievable due to this physical phenomena.
  • Impact of calibrated band-tails on the subthreshold swing of pocketed TFETs

    Bizindavyi, Jasper; Verhulst, Anne S.; Sorée, Bart; Groeseneken, Guido; imec (IEEE, 2018-06-27)
    The tunnel field-effect transistor (TFET) is one of the prime steep-slope device candidates to be employed in future ultra-low power logic applications [1], [2], and can achieve sub-60 mV/dec subthreshold swings (SS) using quantum mechanical (QM) band-to-band tunneling (BTBT). One of the main challenges for TFETs is obtaining a sufficiently high drive-current ION [1]. The ION can be enhanced by introducing a highly-counter-doped pocket at the tunnel junction [3], [4]. However, it is well known that high doping concentrations introduce band-tails states in the bandgap [5]. First assessments on band-tails in TFETs, linked to diode measurements, have been made [6]–[8]. However, it is unknown whether the band-tails-induced tunneling contributions limit the performance of optimized pocketed TFETs. In this work, we investigate the impact of band-tails on the SS of p-n-i-n In0.53Ga0.47As and InAs TFETs for different pocket thicknesses and doping concentrations in the source and pocket, while using band-tails density-of-states (DOS) obtained from successful diode calibrations [8].