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International audience; This paper proposes a patient-specific model-based estimation of myocardial strain signals and the evaluation of echo-based parameters, adapted to patients with left bundle branch block (LBBB). The left ventricle (LV) was divided into 16 segments in order to evaluate concurrently different regions at the ventricular contraction process. For each LV segment, some parameters, associated with the active and passive components of the cardiac muscle, the electro-mechanical driving function and the electrical depolarization time, were identified using evolutionnary algorithms. The proposed approach was evaluated on data obtained from 3 LBBB patients. From patient-specific simulations, we also analysed electrical activation delay and myofiber contractility in LV segments. A close match was observed between experimental and simulated myocardial strain curves for all the subjects. The root mean square error (RMSE) is equal to 2.87(± 1.00), 2.49(± 0.55) and 3.63(± 0.81) for the anterior ischemic, the lateral ischemic and the non-ischemic LBBB patients, respectively. The proposed patient-specific model-based approach may be a useful tool for understanding LV mechanical dyssynchrony and identifying patients suitable for cardiac resynchronization therapy (CRT). © 2020 Creative Commons; the authors hold their copyright.

Funding-Acknowledgement = CNM Barcelona (Spain) ; Franck Torregrossa from IBS-Rousset (France) Funding-Text = We greatly thank Philippe Godignon from CNM Barcelona (Spain) and Franck Torregrossa from IBS-Rousset (France) for providing us with the implanted samples investigated in this work. We also acknowledge Pierre Valvin and Philippe Arcade from GES for expert assistance with the irradiation and measurement procedures. Finally we acknowledge Marcin Zielinski and Servane Blanque from GES for performing SIMS and Raman measurements. One of us (D.J.B.) also acknowledges the CNRS and NRF for supporting grants during his stays in Montpellier; International audience; We report on a quantitative analysis of the effect of visible light laser irradiation (VLLI) on hexagonal (alpha) silicon carbide implanted with nitrogen and aluminum. In both cases of 4H and 6H polytypes we show that a short, but intense, irradiation with the 532 nm wavelength of a frequency-doubled neodymium: ytterbium aluminum garnet (Nd:YAG) laser results in a substantial reduction in the damage level produced by room temperature ion implantation. Up to now the recovery could not be made complete but, in the best conditions, it could reach similar to 80\% of the initial damage value. This is not enough to qualify VLLI as a full activation step but, rather, suggests to use it as a new processing tool in order to lower the constraints of high temperature ion implantation or, after implantation performed at room temperature, to reduce the total budget for high temperature annealing and activation steps.

International audience; 4H-and 6H-SiC small samples were implanted by keV Al + ions at room temperature and annealed in an induction heating furnace, at the center of the susceptor, for different temperatures and times in the range 1600-1800°C and 5-60 min, respectively. The implanted layers were amorphous but the SiC crystalline structures were recovered after annealing, as measured by Rutherford Back-Scattering analyses in Channeling geometry. Al + electrical activation determined by sheet resistance and Hall effect measurements increases with the annealing temperature or time, on both polytypes. When whole SiC wafers were annealed in the same induction heating furnace, sheet resistance mapping systematically presented a radial gradient from the center to the periphery of the wafer. The measured linear dependence between sheet resistance and temperature allowed us to rebuild the radial temperature gradient at the crucible-susceptor furnace during the annealing process. Introduction Silicon carbide (SiC) is envisaged as a promising semiconductor material for a wide variety of high-temperature, high-power and high-frequency electronic applications. Ion implantation, an indispensable technique to locally dope silicon carbide still presents many problems in particular for p-type zone creation. High ionization energy of dopants imposes to raise the implanted dose above the amorphization threshold for room temperature implantations. Structure recrystallization and electrical activation of dopants, i.e. their incorporation in active SiC atomic sites, require high temperature annealing, about 1700°C in special configuration, with an overpressure of silicon and carbide. In this work p-type 6H and 4H-SiC layers created by Aluminum (Al) ion implantations followed by high temperature annealings are studied in order to realize efficient p +-n junctions for bipolar power diodes. Dopant electrical activation dependence on the post-implantation annealing conditions is discussed considering the non-uniform temperature at the SiC sample surface during this process.

International audience; Al and N implantations were carried out in 6H-SiC n-type epitaxial layers at room temperature. RBS/C analysis confirms the presence of an amorphous layer up to the surface in the as-implanted samples. The samples rf-annealed at 1700°C during 30 mn with a preliminary 40°C per second heating slope are recrystallised in RBS/C analysis terms. SIMS measurements show no dopant loosing after the annealing and dopant profile distributions are in agreement with CNM Monte-Carlo simulation. A good surface stoichiometry is revealed by XPS after annealing but AFM surface measurements reveal a relatively high rms roughness (14 nm) on annealed samples. High electrical activation of dopants was found, 19 kΩ/& sheet resistance, which corresponds to 50 % electrical dopant activation for Al implanted layer, and 6.7 kΩ/& sheet resistance and 100% electrical activation for N-implanted layer.

International audience; 4H- and 6H-SiC small samples were implanted by keV Al+ ions at room temperature and annealed in an induction heating furnace, at the center of the susceptor, for different temperatures and times in the range 1600-1800°C and 5-60 min, respectively. The implanted layers were amorphous but the SiC crystalline structures were recovered after annealing, as measured by Rutherford Back-Scattering analyses in Channeling geometry.Al+ electrical activation determined by sheet resistance and Hall effect measurements increases with the annealing temperature or time, on both polytypes. When whole SiC wafers were annealed in the same induction heating furnace, sheet resistance mapping systematically presented a radial gradient from the center to the periphery of the wafer. The measured linear dependence between sheet resistance and temperature allowed us to rebuild the radial temperature gradient at the crucible-susceptor furnace during the annealing process.

International audience; Physico-chemical and electrical investigations were carried out in 4H-SiC p-type layers created by Aluminum ion implantation at room temperature and high temperature post-implantation annealing. Crystal recovery and dopant preservation after annealing are proved by RBS/C and respectively SIMS measurements. Dopant activation is evaluated by sheet resistance measurements. These results were applied for high voltage bipolar diodes with JTE protection realization.

International audience; Five-fold Al implantations at both room temperature and 300°C ranging from 25 keV to 300 keV and a total fluence of 1.75x10 15 cm-2 , have been performed in 6H-SiC epilayers to create p +-n junctions. The samples have been annealed at 1700°C during 30 mn in an inductively heated furnace especially configured. Surface effects, recrystallization, dopant distribution and electrical activation are investigated by XPS, RBS, SIMS and sheet resistance measurements. For both RT and 300°C-implanted samples, good recrystallization and surface stoichiometry are found as well as no dopant loosing and an interesting electrical activation (46% and 99%, respectively). Introduction p +-n junctions in SiC power devices must be realized by ion implantation due to very low diffusion coefficients of dopants in silicon carbide. SiC high density and its structural crystallinity involve a delicate post-implantation annealing. The implantation temperature, annealing environment, time and temperature of annealing and the heating rate are the essential parameters to reorder the crystal damage induced by ion implantation and to activate the dopants by migrating in SiC atomic sites. Initially, after ion implantation, almost all Al dopants are distributed in interstitial sites, where they are not electrically active. We utilized a JIPELEC TM rf induction furnace. This technique of annealing has significant advantages such as the very high rising slope in temperature and the very localized zone of heating (the susceptor). But this one implies high temperature variations, vertically in the enclosure and laterally on the surface of the SiC wafers. These temperature gradients may cause an etching of, or a layer deposition on the SiC surface. Moreover, Si is known to volatilize towards 1400°C at one atmosphere pressure, and in lack of a Si supersaturating vapor the carbonization of the surface is inevitable. This paper presents the results of an optimized thermal rf annealing, which avoids these problems.

We report a combined investigation of Raman, low temperature photoluminescence (LTPL) and high temperature transport measurements performed on nitrogen implanted p-type epitaxial layers of 6H-SiC.