ANALYSE DES MECANISMES DE CONDUCTION ET DE BRUIT EN 1/F DANS LES TRANSISTORS EN COUCHES MINCES DE SILICIUM POLYCRISTALLIN

NOTRE ANALYSE DES PROPRIETES ELECTRIQUES DES TRANSISTORS EN COUCHES MINCES DE SILICIUM POLYCRISTALLIN (POLY-SI TFTS) MET L'ACCENT SUR LE ROLE PRIMORDIAL, DANS LES MECANISMES DE TRANSPORT DE CHARGES ET DE BRUIT EXCEDENTAIRE EN 1/F, DES DISCONTINUITES ELECTRIQUES (BARRIERES DE POTENTIEL) INDUITES PAR LES ETATS CHARGES AUX JOINTS DE GRAINS. UNE ETUDE COMPAREE DE LA CONDUCTION ET DU BRUIT BASSE FREQUENCE MET EN EVIDENCE DEUX REGIMES L'UN CORRESPONDANT A UNE CONDUCTION THERMOIONIQUE ET L'AUTRE A UNE CONDUCTION LIMITEE PAR LA DIFFUSION AUX INTERFACES. DANS LE PREMIER REGIME, QUI SE DEMARQUE LE PLUS DE LA SITUATION DES TRANSISTORS MOS, NOUS AVONS EXPERIMENTALEMENT MONTRE QUE LE COURANT OBEIT A LA LOI EMPIRIQUE DE COMPENSATION (MEYER-NELDEL) DECRIVANT UNE ACTIVATION THERMIQUE NON IDEALE. LE FACTEUR D'IDEALITE DE L'ENERGIE D'ACTIVATION EST ATTRIBUE A LA VARIATION DU QUASI NIVEAU DE FERMI DANS LA ZONE DE DEPLETION DE PART ET D'AUTRE DES JOINTS DE GRAINS. IL PEUT ETRE UTILISE POUR QUALIFIER LA DISTRIBUTION SPATIALE DES DEFAUTS DANS LA COUCHE ACTIVE POLYCRISTALLINE. DANS CE MEME REGIME, LES VALEURS IMPORTANTES (JUSQU'A 2.10 - 1) DU PARAMETRE DE NORMALISATION DU BRUIT EN 1/F TRADUISENT L'EFFET DE LA DENSIFICATION DES LIGNES DE COURANT DANS LE CANAL HETEROGENE. UNE MODELISATION PAR LES METHODES DU CHAMP D'IMPEDANCE ET DU COURANT ADJOINT, AINSI QUE DES MESURES DE BRUIT EN FONCTION DE LA TEMPERATURE MONTRENT QUE LA VALEUR DU PARAMETRE DE BRUIT EST RELIEE A LA HAUTEUR DES BARRIERES DE POTENTIEL ET QUE LE BRUIT EN 1/F EST THERMIQUEMENT DESACTIVE. CES ENERGIES DE DESACTIVATION DU BRUIT ET D'ACTIVATION DU COURANT PEUVENT PERMETTRE DE CARACTERISER L'ECART TYPE DE LA HAUTEUR MOYENNE DES BARRIERES DE POTENTIEL. CES INTERPRETATIONS CONDUISENT A PROPOSER UNE METHODE EXPERIMENTALE PERMETTANT, EN S'AFFRANCHISSANT DE L'INCIDENCE DES BARRIERES DE POTENTIEL, D'ACCEDER A UN PARAMETRE DE BRUIT CARACTERISTIQUE DU COUPLE MATERIAU SEMI-CONDUCTEUR ET INTERFACE AVEC L'OXYDE DE GRILLE.CAEN-BU Sciences et STAPS (141182103) / SudocSudocFranceF

Impact of radiation-induced back-channel leakage and back-gate bias on drain current transients of thin-gate-oxide partially depleted silicon-on-insulator n-channel metal-oxide-semiconductor field-effect transistors

In this study, we analyze the impact of back-channel radiation-induced leakage and back-gate bias on switch-off drain current transients of thin-gate-oxide partially depleted (PD) silicon-on-insulator (SOI) n-channel metal-oxide-semiconductor field-effect transistors (MOSFETs). The presence of radiation-induced positive trapped charges in the buried oxide after 60 MeV proton irradiation is found to reduce the "switch-off" transient times for gate voltages above and below the front-gate threshold voltage for body-to-gate electron valence band tunnelling. An increase in steady-state drain current and an increase in the amplitude of weak inversion drain current transients are observed. A similar effect is observed when applying a positive bias to the back-gate, which is found to generate an "irradiation-like" subthreshold leakage. The observed switch-off drain current transient behavior is explained by taking into account an edge parasitic back-channel transient component, which is added to the conventional front-gate drain current transient.Peer reviewe

RFCV test structure design for a selected frequency range

The problems with the CV characterization on very leaky (thin) nitrided oxide are mainly due to the measurement precision and MOS gate dielectric model accuracy. By doing S-parameter measurement at RF frequency and using simple but reasonably accurate model. we can obtain proper CV curves for very thin nitrided gate dielectrics. Regarding the measurement frequency we propose a systematic method to find a frequency range in which we can select measurement frequencies for all biases to obtain a full CV curve. Moreover, we formulated the first order relationship between the measurement frequency range and the test structure design for CV characterization. With the established formulae, we redesigned the test structures and verified that the formulae can be used as a guideline for the test structure design for RFCV measurements

Impact of device and interconnect process variability on clock distribution

info:eu-repo/semantics/publishe

Analysis of the activation energy of the subthreshold current in laser- and solid-phase-crystallized polycrystalline silicon thin-film transistors

International audienceAnalysis of the thermal and gate-voltage dependences of the current in the subthreshold region is performed on both low-temperature laser-crystallized and solid-phase-crystallized polycrystallinesilicon (polysilicon) thin-film transistors(TFTs).Temperature measurements are made at first in order to extract the variations of the activation energyEA of the drain current with the gate voltage. The plot of the subthreshold current versus the measuredactivation energy leads to an apparent activation energyEA/n, where the n factor is extracted from the slope of this plot. The n factor is close to 1 for laser-crystallized polysilicon TFTs while it is rather close to 2 for solid-phase-crystallized ones. These two values can be attributed to a different defect distribution in the two differently crystallized TFTs polysilicon active layers

High-Frequency Noise Performance of 60-nm Gate-Length FinFETs

In this paper, the first-ever published investigation on radio-frequency (RF) noise performance of FinFETs is reported. The impact of the geometrical dimensions of FinFETs on RF noise parameters such as the channel length, the fin width, as well as the fin number is analyzed. A minimum noise figure of 1.35 dB is obtained with an associated available gain of 13.5 dB at 10 GHz for V-dd = 0.5 V. This result is quite encouraging to bring solutions for future low-power RF systems

Operationalisation of a Positioning Model in Ferry Services: an Eastern Mediterranean Case

A model is developed to identify the comparative positioning of Turkish ferry operators vis-a-vis their European Union competitors in the Eastern Mediterranean market. Given the nature of the ferry business, the model is based on principles of service marketing. The paper concentrates on the operationalisation of the positioning model by using multidimensional scaling (MDS): a multivariate analysis technique. Data include various characteristics of the ferry operators representing the supply side of the market, grouped under different marketing mix elements of service marketing. Results are further analysed in order to identify the relative positioning of ferry operators in the Italy-Greece-Turkey corridor, for the year 1994. The paper concludes that Turkish operators are clearly identifiable in most instances, positioned separately from their Greek counterparts.International Journal of Maritime Economics (1999) 1, 73–86; doi:10.1057/ijme.1999.13

Dependence of finFET RF performance on fin width

This work analyzes the radio frequency (RF) performance of 60-nm gate length finFETs, for which the DC behavior exhibits reduced SCE. The RF analysis is carried out as a function of the gate length as well as the fin width (W/sub fin/). Cut off frequencies (f/sub t/, f /sub max/) on the order of 100 GHz are reported for the first time. It is shown that W/sub fin/ has a large impact on those frequencies, due mainly to its effect on the access resistances. Nevertheless, it is also demonstrated that using optimized layout geometry, f/sub max/ values close to 170 GHz are to be expected.Anglai