1,721,001 research outputs found
4H- and 6H-SiC Rutherford backscattering-channeling spectrometry: polytype finger printing
No full textStructural, optical and chemical characterization of 300 degrees C, MeV ion implanted and 1700 degrees C annealed 6H-SiC
No full textComparison between chemical and electrical profiles in Al/sup +/ or N/sup +/ implanted and annealed 6H-SiC
No full textOCVD Measurement of Ambipolar and Minority Carrier Lifetime in 4H-SiC Devices: Relevance of the Measurement Setup
Full text linkThe open-circuit voltage decay (OCVD) method is a well-known technique for conducting electrical measurements of carrier lifetime: the main advantages lie in the simple setup and the possibility of carrying out measurements in commercial devices without the need of removing the package, as for optical methods. Despite several researchers having reported carrier lifetimes measured by the OCVD method in different devices, there has been little discussion about the potential effect of the experimental setup on the obtained results. By comparing the outputs of the experimental measurements with those of numerical simulations, this study investigates the overlooked effect of the OCVD measurement setup on the former. Due to the growing importance of SiC-based devices, the analysis is applied to a 4H-SiC p-i-n diode. Two main points are addressed: 1) the effect of circuit setup on the ambipolar lifetime is discussed and a method, originally developed for improving the estimate of low-level carrier lifetime in OCVD measurements, is used to correct the measured lifetime for this influence; 2) the origin of the local minimum eventually appearing in the lifetime versus time curves is also investigated. It is found that the minimum can also be related to the time constant of the experimental setup, giving rise to doubts about the usual interpretation of this minimum as the minority carrier lifetime. A method is thus proposed to help discriminate between the two interpretations
The role of defects on forward current in 4h-sic p-i-n diodes
No full textWe investigated the impact of defect states on the measured forward current-voltage (I -V) curves of ion-implanted planar 4H-SiC p-i-n diodes of a different anode dimension bymeans of a fine-tuned numericalmodel. Cross sections and activation energies of defects related to the carbon vacancy (EH6/7 and Z1/2) and Titanium (Ti) impurity used in our model were experimentally identified in the diodes of the same batch. We analyzed the effect of each individual defect on the I-V curves and estimated the unknown hole capture cross sections by ensuring the optimal match between simulated and measured currents. Small discrepancies between measured and simulated forward current-voltage curves of diodes of equal shape but a different perimeter-to-area ratio has been accounted for by considering, in the simulations, the presence of a fixed positive charge at the diode surface. By using this procedure, diodes of every dimension have been simulated without the use of adjustment parameters. These results are valuable in understanding the role of defects in the I-V curves of the ion-implanted SiC diode
Investigating Mesa Structure Impact on C-V Measurements
No full textCapacitance-voltage (C-V) measurements play a crucial role in evaluating semiconductor device performance by revealing vital parameters such as doping levels and charge carrier behavior. This study specifically investigates the impact of mesa structures on C-V measurements in 4H-SiC PiN vertical diodes. Our analysis uncovers distinct capacitance values per unit area among diodes with varying diameters within the same diode family. These findings underscore the limitations of conventional capacitance equations formulated for planar devices when extended to mesa-structured devices. To separate the capacitance portion dependent solely on the PN junction's area from the overall depletion capacitance, which is influenced by the device's geometry, we applied a methodology involving multiple C-V measurements across diodes with differing diameters and validated the experimental outcomes through rigorous calculations. This enables the utilization of standard capacitance equations. Neglecting the impact of device geometry has the potential to introduce significant inaccuracies in critical device parameters. The proposed methodology addresses these limitations, offering valuable insights to enhance the accuracy of extracted quantities from C-V measurements. Furthermore, it provides guidance for interpreting experimental data obtained from devices incorporating mesa structures
Leghe Metalliche Amorfe in Schemi di Metallizzazione per Dispositivi Elettronici al Silicio
No full textThe Monte Carlo binary collision approximation applied to the simulation of the ion implantation process in single crystal SiC: High dose effects
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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