共查询到20条相似文献,搜索用时 15 毫秒
1.
Neugroschel A. Bersuker G. Choi R. Byoung Hun Lee 《Device and Materials Reliability, IEEE Transactions on》2008,8(1):47-61
A relative contribution of the interface and bulk dielectric defects to negative bias temperature instability (NBTI) in the metal/HfO2/SiO2 gate stacks was investigated. Interface trap generation was assessed by the direct-current current-voltage (DCIV) technique, which independently measures the interface defect density from bulk oxide charges and delineates the contribution of the interface defect generation to the overall NBTI measured by the threshold voltage shift (DeltaVTH). The metal/high-fc induced traps in the interfacial SiO2 layer were found to control the fast transient trap charging/generation processes, which affect the power-law exponents of DeltaVTH and the stress-generated interface trap density DeltaDIT stress time dependencies. Similar kinetics of the long-term DeltaVTH(t) and DeltaDIT(t) dependencies in the high-fe and SiO2 gate stacks suggests that the degradation is governed by the same mechanism of trap charging/generation in the SiO2 film. The investigation leads to a novel methodology for the time-to-failure (TTF) extrapolation, in which the measured DeltaVTH and DeltaDIT values are adjusted for the contributions from the fast transient defect charging/generation processes. It is shown that the conventional TTF analysis might greatly overestimate TTF. Post-NBTI stress recovery at zero relaxation voltage measured by the DCIV method showed that oxide charges and interface traps relax at the same rate indicating that the interface processes may dominate DeltaVTH relaxation. At positive relaxation voltages, however, the oxide charge relaxation exhibits a fast transient component. Relaxation at positive bias also shows an as yet unexplained fast component in the interface trap recovery. 相似文献
2.
《Device and Materials Reliability, IEEE Transactions on》2008,8(4):635-641
3.
4.
Positive Bias Temperature Instability Effects in nMOSFETs With $hbox{HfO}_{2}/hbox{TiN}$ Gate Stacks
《Device and Materials Reliability, IEEE Transactions on》2009,9(2):128-134
5.
《Device and Materials Reliability, IEEE Transactions on》2009,9(2):163-170
6.
《IEEE journal of selected topics in quantum electronics》2009,15(1):93-102
7.
CO2 reforming of methane ( CH4) and propane (C3H8) was performed with a silent discharge reactor (SDR). The reactor performance was evaluated in terms of energy efficiencies for the conversion of the substrates and formation of H2 and CO. The reactivity of C3H8 was 2- to 3-fold higher than that of CH4, and both of CH4 and C3H8 were reformed in the order of 1016 molecules/J at 298 K. The energy efficiencies for the conversion of these substrates increased with their initial concentrations, but decreased with an increase in reactor energy density. On the other hand, the energy efficiencies for the conversion of CO2, which were not affected by the hydrocarbon types, were lower than those for the hydrocarbon substrates. A positive temperature effect was observed in the conversion of the hydrocarbon substrates only at low reactor energy densities from 298 to 433 K. 相似文献
8.
Diaz G. Gonzalez-Moran C. Gomez-Aleixandre J. Diez A. 《Power Systems, IEEE Transactions on》2009,24(4):1720-1730
This paper focuses on representing the state space model of a microgrid in which power regulated (PQ ) and voltage/frequency regulated (Vf) generation units share a distribution system. The generation units considered in this paper are inverter interfaced. This introduces some interesting modeling problems which are treated in the paper, such as the decoupled cascaded control schemes or the non-negligible grid dynamics. A modeling approach is proposed based on four defined complex vectors. These vectors allow for complex-valued system matrices to be formed in a quite automated way. Moreover, a convenient partition of the system matrices is proposed, which in turn allows fast and easy modifications. Additionally, a multivariable methodology is proposed to simultaneously find the control system gains in an optimal sense. A 69-bus radial system, supplied by 20 generation units, is used to demonstrate how the proposal is of easy implementation to conduct small-signal stability analyses. 相似文献
9.
Yi-Hsien Chiang Jyh-Ching Juang 《Intelligent Transportation Systems, IEEE Transactions on》2008,9(2):193-208
This paper devises a freeway controller that is capable of stabilizing traffic flow when the traffic system is in the unstable (congested) phase, in which a shock wave is likely to occur in the presence of any inhomogeneity and where the system is on the verge of a jam condition. Two types of traffic controllers are developed through the use of either a speed command approach that can be implemented in an intelligent transportation system (ITS) or ramp metering that is a typical way of preventing a freeway from overloading. By means of the feedback linearization technique, the discretized macroscopic traffic flow model is reformulated, in which the desired change of volume in each section is treated as a virtual input. By exploring the casual relations among density, speed, and flow change, the corresponding speed commands can be determined. The traffic flow control problem is formulated as an Hinfin control design problem so that uncertainties that are associated with the macroscopic model can be taken into account. Simulations show that the devised controller can effectively stabilize the traffic flow in the unstable phase. Design flexibilities associated with the method are also discussed. 相似文献
10.
Yi-Hao Pai Chung-Hsiang Chang Gong-Ru Lin 《IEEE journal of selected topics in quantum electronics》2009,15(5):1387-1392
Near-infrared (NIR) photo- and electroluminescence (PL and EL) of Si nanocrystals buried in Si-rich SiOx, film, and their correlation with the structural phase transformation and the varied oxygen composition of SiOx, are investigated. By detuning the N2O flowing ratio (YN 2 O = [N2O/(N2O + SiH4)] times 100%) from 93% to 80% during plasma-enhanced chemical vapor deposition growth, the oxygen composition ratio of the Si-rich SiOx, can be adjusted from 1.64 to 0.88. The grazing incident X-ray diffraction and X-ray photoelectron spectroscopy spectra indicate that the SiOx, transforms its structural phase from Si + SiO2 isomer to Si + SiO + SiO2 isomer. With O/Si ratio >1.24, the SiOx, matrix becomes SiO2 isomer, whereas the SiOx, structure approaches SiO phase at O/Si ratio that is nearly 1.0. The formation of SiO matrix in SiOx, grown at YN 2 O below 85% reduces the precipitated Si nanocrystal density from 2.8 times 1018 to 7 times 1016 cm-3, and monotonically attenuates the NIR PL by one order of magnitude. Such a structural phase transformation from SiO2 to SiO in SiOx with lower O/Si ratio causes the degradation in EL power conversion efficiency and external quantum efficiency (EQE). Maximum EL power of 0.5 muW and EQE of 0.06% are obtained from MOSLED made on SiOx, with optimized O/Si ratio of 1.24. 相似文献
11.
Castillo E. Conejo A.J. Pruneda R.E. Solares C. Menendez J.M. 《Power Systems, IEEE Transactions on》2008,23(2):296-305
This paper provides a technique to determine the minimum required measurement set to ensure observability in state estimation even if any meters fail. The technique relies on solving a nonlinear integer programming problem. The proposed procedure is illustrated through a simple example and three case studies based on the IEEE Test Systems. Conclusions are finally drawn. 相似文献
12.
《Device and Materials Reliability, IEEE Transactions on》2009,9(4):529-536
13.
《Device and Materials Reliability, IEEE Transactions on》2008,8(3):576-581
14.
《Industry Applications, IEEE Transactions on》2008,44(5):1403-1409
15.
《Device and Materials Reliability, IEEE Transactions on》2009,9(2):180-189
16.
Sheng-Kun Zhang Wubao Wang Alfano R.R. Dabiran A.M. Osinsky A. Wowchak A.M. Hertog B. Chow P.P. 《IEEE journal of selected topics in quantum electronics》2008,14(4):1010-1013
Three periods of Al0.1Ga0.9N/Al0.15Ga0.85 N multiple quantum wells (MQWs) were used as the active region of a p-i-n diode fabricated on 6H-SiC substrate. Electroluminescence (EL) of these MQWs has been investigated in both injection and avalanche modes. Band-to-band luminescence of the Al0.1Ga0.9N wells was found to peak at 364 nm in the injection mode and in the range of 364-372 nm in the avalanche mode. The most striking phenomenon is that band-to-band EL of the Al0.15Ga0.85N barriers has also been observed in the injection mode, while it is not seen in the avalanche mode. This is explained by considering different sources of carriers and different carrier transportation mechanisms in the two modes. The luminescence intensity I EL has a power-law dependence on the current I by I EL prop I 2 in the injection mode and by I EL prop I 4 in the avalanche mode. 相似文献
17.
《IEEE journal of selected topics in quantum electronics》2009,15(1):12-19
18.
Yonghang Shen Alam S.-u. Kang Kang Chen Dejiao Lin Shuangshuang Cai Bo Wu Peipei Jiang Malinowski A. Richardson D.J. 《IEEE journal of selected topics in quantum electronics》2009,15(2):385-392
We report a periodically poled magnesium-oxide-doped lithium niobate (PPMgLN) based optical parametric oscillator (OPO) pumped by a diode-seeded, linearly polarized, high-power, pulsed, ytterbium fiber master oscillator power amplifier (MOPA). Using adaptive pulse shaping of the seed laser (using an external modulator), we demonstrate a reduction in the impact of dynamic gain saturation and optical Kerr/Raman nonlinearities within the fiber MOPA, obtaining shaped signal and idler pulses at the OPO output and reduced spectral bandwidths. A maximum average output power of 26.5 W was obtained from the MOPA at 1062 nm. An output power as high as 11 W from the OPO at an overall slope efficiency of 67% was achieved, with 2.7 W of output power obtained at a wavelength of 3.5 mum. Our experiments were pump-power-limited and considerable scope remains for further power scaling of such OPOs using this approach. 相似文献
19.
《Industry Applications, IEEE Transactions on》2008,44(5):1431-1435
20.
《Device and Materials Reliability, IEEE Transactions on》2008,8(4):689-693