Search results for "Effects"
showing 10 items of 2634 documents
Microbeam SEE Analysis of MIM Capacitors for GaN Amplifiers
2018
Broad-beam and microbeam single-event effect tests were performed on metal–insulator–metal capacitors with three different thicknesses of silicon nitride (Si3N4) dielectric insulator: 250, 500, and 750 nm. The broad-beam tests indicated that the devices with the thicker, 500- and 750-nm dielectric did not have a greater breakdown voltage. The surrounding structures of the capacitor were suspected to be a possible cause. Microbeam techniques made it possible to localize the failure location for the 500- and 750-nm devices. The failure occurs in the air bridge structure connected to the top capacitor plate, which can therefore be considered as an edge effect, while for the 250-nm devices, the…
Radiation Characterization of Optical Frequency Domain Reflectometry Fiber-Based Distributed Sensors
2016
International audience; We studied the responses of fiber-basedtemperature and strain sensors related to Optical FrequencyDomain Reflectometry (OFDR) and exposed to high γ-ray dosesup to 10 MGy. Three different commercial fiber classes areused to investigate the evolution of OFDR parameters withdose, thermal treatment and fiber core/cladding composition.We find that the fiber coating is affected by both thermal andradiation treatments and this modification results in anevolution of the internal stress distribution inside the fiber that influences its temperature and strain Rayleigh coefficients. These two environmental parameters introduce a relative error up to 5% on temperature and strain…
Impact of Electrical Stress and Neutron Irradiation on Reliability of Silicon Carbide Power MOSFET
2020
International audience; The combined effects of electrical stress and neutron irradiation of the last generation of commercial discrete silicon carbide power MOSFETs are studied. The single-event burnout (SEB) sensitivity during neutron irradiation is analyzed for unstressed and electrically stressed devices. For surviving devices, a comprehensive study of the breakdown voltage degradation is performed by coupling the electrical stress and irradiation effects. In addition, mutual influences between electrical stress and radiative constraints are investigated through TCAD modeling.
Heavy-Ion-Induced Degradation in SiC Schottky Diodes : Incident Angle and Energy Deposition Dependence
2017
International audience; Heavy-ion-induced degradation in the reverse leakage current of SiC Schottky power diodes exhibits a strong dependence on the ion angle of incidence. This effect is studied experimentally for several different bias voltages applied during heavy-ion exposure. In addition, TCAD simulations are used to give insight on the physical mechanisms involved.
Current Transport Mechanism for Heavy-Ion Degraded SiC MOSFETs
2019
IEEE Transactions on Nuclear Science, 66 (7)
Radiation effects on silica-based preforms and optical fibers-II: Coupling ab initio simulations and experiments
2008
International audience; Abstract—Experimental characterization through electron paramagnetic resonance (EPR) and confocal luminescence microscopy (CML) of a Ge-doped glass (preform and fiber) reveals the generation of several point defects by 10 keV X-ray radiation-induced attenuation: GeE', Ge(1), Ge(2), and Ge-ODC. The generation mechanisms of Ge-ODC and charged defects like GeE' centers are studied through ab initio simulation. Our calculations used a 108 atom supercell with a glass composition comparable to the Ge-doped core or to the pure-silica cladding of the canonical sample. The large size of our cell allows us to study the influence of the local environment surrounding the X-ODC d…
Impact of Terrestrial Neutrons on the Reliability of SiC VD-MOSFET Technologies
2021
Accelerated terrestrial neutron irradiations were performed on different commercial SiC power MOSFETs with planar, trench and double-trench architectures. The results were used to calculate the failure cross-sections and the failure in time (FIT) rates at sea level. Enhanced gate and drain leakage were observed in some devices which did not exhibit a destructive failure during the exposure. In particular, a different mechanism was observed for planar and trench gate MOSFETs, the first showing a partial gate rupture with a leakage path mostly between drain and gate, similar to what was previously observed with heavy-ions, while the second exhibiting a complete gate rupture. The observed fail…
Single-Event Burnout Mechanisms in SiC Power MOSFETs
2018
Heavy ion-induced single-event burnout (SEB) is investigated in high-voltage silicon carbide power MOSFETs. Experimental data for 1200-V SiC power MOSFETs show a significant decrease in SEB onset voltage for particle linear energy transfers greater than 10 MeV/cm 2 /mg, above which the SEB threshold voltage is nearly constant at half of the rated maximum operating voltage for these devices. TCAD simulations show a parasitic bipolar junction transistor turn-on mechanism, which drives the avalanching of carriers and leads to runaway drain current, resulting in SEB. peerReviewed
Enhanced Charge Collection in SiC Power MOSFETs Demonstrated by Pulse-Laser Two-Photon Absorption SEE Experiments
2019
A two-photon absorption technique is used to understand the mechanisms of single-event effects (SEEs) in silicon carbide power metal–oxide–field-effect transistors (MOSFETs) and power junction barrier Schottky diodes. The MOSFETs and diodes have similar structures enabling the identification of effects associated specifically with the parasitic bipolar structure that is present in the MOSFETs, but not the diodes. The collected charge in the diodes varies only with laser depth, whereas it varies with depth and lateral position in the MOSFETs. Optical simulations demonstrate that the variations in collected charge observed are from the semiconductor device structure and not from metal/passiva…
Combined High Dose and Temperature Radiation Effects on Multimode Silica-Based Optical Fibers
2013
International audience; We investigate the response of Ge-doped, P-doped, pure-silica, or Fluorine-doped fibers to extreme environments combining doses up to MGy(SiO $_{{{2}}}$) level of 10 keV X-rays and temperatures between 25 C and 300 C . First, we evaluate their potential to serve either as parts of radiation tolerant optical or optoelectronic systems or at the opposite, for the most sensitive ones, as punctual or distributed dosimeters. Second, we improve our knowledge on combined ionizing radiations and temperature (R&T) effects on radiation-induced attenuation (RIA) by measuring the RIA spectra in the ultraviolet and visible domains varying the R&T conditions. Our results reveal the…