Papers by Keyword: Trap

Abstract: A simple and practical method of characterizing traps at SiC/SiO₂ interfaces close to the bottom of the conduction band by using the split C−V and Hall measurements is proposed. This technique was applied to the characterization of traps at a wet-oxidized SiC/SiO₂ interface on C-face and those at an oxynitrided SiC/SiO₂ interface on Si-face. It was shown that the density of traps near the conduction band of the oxynitrided SiC/SiO₂ interface was more than 10 times larger than that of the wet-oxidized SiC/SiO₂ interface.

Abstract: The electrical properties of metal-oxide-semiconductor (MOS) devices fabricated using dry oxidation on phosphorus-implanted n-type 4H-SiC (0001) epilayers have been investigated. MOS structures were compared in terms of interface traps and reliability with reference sample which was produced by dry oxidation under the same conditions. The notably lower interface traps density measured in MOS capacitor with phosphorus concentration exceeding 10¹⁸ cm^-3 at the SiO₂/SiC interface was attributed to interface traps passivation by incorporated phosphorus ions.

Abstract: The thermoluminescence glow curves were simulated in terms of the fractal rate kinetics. It was analyzed how effective spectral dimensions of systems of traps and recombination centers influenced geometrical parameters of peaks. It was shown that high values of the form-factors could be interpreted in fractional kinetics terms taking into account an inhomogeneous spatial distribution of defects in material.

Abstract: Polyimide-based (PI) nanocomposites possess excellent electrical and thermal performance, widely used in inverter motor. In the paper using different particle sizes made polyimide/titania (PI/TiO2) nanocomposite films in situ polymerization, including 20nm A series and 50nm B series. The results shows that A series have a larger specific surface, combination of the film and matrix is closer without affecting the imidization of PI, and there is a clear interface layer and the structure is more stable. According to the time of corona-resistant A Series films is significantly longer than B Series films, especially the A series films with 15% of which corona-resistant time is 15h, five times than the pure PI. By both SAXS and XRD particle size in the matrix can be calculated, proving small particles can be better combination of the matrix of PI, increasing the number of traps, more effectively cutting off charge corrosion and making corona resistance greater performance.

Abstract: The sunlight-excited red long afterglow phosphor ZnGa₂O₄:Cr³⁺ was prepared by the high-temperature solid state reaction. The emission lines around 690nm all originated from ²E→⁴A₂ of Cr³⁺ ions. The long-lasting phosphorescence (LLP) spectra indicated optimal long-lasting luminescence could obtain from ultraviolet (UV) light excitation. The thermoluminescence (TL) curve implied different depth of trap was caused by the dopant ions. The initial persistent luminescence was caused by the recombination between the captured electrons and Cr³⁺ ions, and this recombination process was accomplished through the conduction band. The linear dependence of the long afterglow intensity versus time in the decay curve maybe implied a new recombination mechanism.

Abstract: High-capacity OLT equipments are widely used in modern communication network. Among the communication equipments, realization of alarm function has an important research significance and wide application prospect. The article simply introduces the demand of alarm of OLT devices and simple network management protocol SNMP and explains the method of realizing alarm information by using SNMP trap. It also introduces the construction of trap message and explains the process and action of network management system after receiving trap information in detail, as a result, realizes the alarm design of high-capacity OLT equipment.

Abstract: The deep levels ON₁ and ON_2a/b introduced by oxidation into 4H-SiC are characterized via standard DLTS and via filling pulse dependent DLTS measurements. Separation of the closely spaced ON_2a/b defect is achieved by using a higher resolution correlation function (Gaver-Stehfest 4) and apparent energy level, apparent electron capture cross section and filling pulse measurement derived capture cross sections are given.

Abstract: We study the impact of positive bias temperature stress and hot carrier stress on lateral 4H-SiC nMOSFETs. These degradation mechanisms are prominent in silicon based devices where both create oxide as well as interface traps. For SiC MOSFETs only limited information regarding these mechanisms is available. We transfer the charge pumping technique, known from Si MOSFETs, reliably to SiC MOSFETs to learn about the nature of the stress induced defects.

Abstract: Constant-capacitance deep-level transient spectroscopy was carried out to characterize in detail interface states close to the conduction band edge in SiO₂/SiC structures. The measured results are summarized as follows: (1) The capture of electrons by the interface states proceeds logarithmically with time. (2) The emission of electrons accelerates slightly with increasing density of captured electrons. The oxide trap model explains the logarithmic change in capture with time but not the phenomenon of accelerated emissions. This prompted us to formulate a new model that replicates the logarithmic capture process with time. In this model, we postulated the electron density at the interface decreases exponentially as the trapped electron density increases owing to the interaction between the trapped electrons and the free electrons. In this case, the capture process is almost the same as with the oxide trap model except for the definition of parameters. Further, we do not need to take into account the delay of the emission process caused by tunneling. The phenomenon of accelerated emissions may be explained by interactions among captured electrons in this model.

Abstract: The electrical properties of nanocomposite SiO₂(Si) films containing Si nanoclusters have been investigated. The films were formed by oxide assisted growth that included ion plasma sputtering (IPS) of Si target and following high temperature annealing. It was determined that electrical conductivity of the films correspond to the mechanism of hopping conductivity with variable hopping length through the traps near the Fermi level (Mott mechanism) due to the large number of silicon dangling bonds in the dielectric matrix. The peculiarities of charge capture in nanocomposite SiO₂(Si) films for their application as the medium for charge storage in memory cells have been investigated by C-V method. The good charge storage possibility of SiO₂(Si) films formed by IPS deposition with followed temperature annealing has been observed. The negative differential capacitance has been revealed in conditions of semiconductor surface accumulation. The physical model for explanation of the negative differential capacitance of MIS structures with nanocomposite SiO₂(Si) films as the dielectric has been proposed. The model is based on the parallel conjunction of the oxide capacitance and nanocrystals capacitance.