6H-SiC NMOS与PMOS温度特性分析

考虑界面态电荷高斯分布模型以及Poole-Frenkel效应,对SiC MOSFET补偿电流源模型进行了修正,分析了造成6H-SiC NMOS与PMOS器件补偿电流源变化的原因.结果表明:界面态电荷的非均匀分布造成由阈值电压漂移引起的输出漏电流改变量随温度的升高逐渐减小;漏衬界面缺陷是造成体漏电流较大(达到微安量级)的主要因素,且缺陷密度越大,该值随温度增长的速度越快.     

A sub-circuit MOSFET model with a wide temperature range including cryogenic temperature

A sub-circuit SPICE model of a MOSFET for low temperature operation is presented.Two resistors are introduced for the freeze-out effect,and the explicit behavioral models are developed for them.The model can be used in a wide temperature range covering both cryogenic temperature and regular temperatures.     

Investigation on symmetry and characteristic properties of the fragmenting source in heavy-ion reactions through reconstructed primary isotope yields

In this report, a kinematical focusing technique will be briefly described, and using this technique, the primary hot isotope yields from the multiplicities of evaporated light particles, associated with isotopically identified intermediate mass fragments, are reconstructed. Symmetry energy and characteristic properties of the fragmenting source at the time of the intermediate mass fragment formation are extracted from these reconstructed primary isotope yields using a self-consistent manner. The extracted density-dependent symmetry energy is further compared with those experimentally extracted from other heavy-ion reactions in literatures. A direct connection between the freeze-out concept and transport model sim-ulations in a multifragmenting regime of heavy-ion colli-sions is also demonstrated quantitatively in the present work.     

PREDICTION OF CO2 FREEZE-OUT CONDITIONS AND CO2 HYDRATE FORMATION CONDITIONS WITH A SINGLE EQUATION OF STATE

A recent study by Eggeman and Chaffin (2005 Eggeman , T. , and Chafin , S. ( 2005 ). Beware of pitfalls of CO₂ freezing predictions , Chem. Eng. Prog. , 101 ( 3 ), 39 – 44 . [Google Scholar]), which showed large discrepancies in CO₂ freeze-out conditions as predicted by several commercial simulators, prompted a reexamination of using the TBS equation of state for phase equilibrium calculations involving solids. Salim and Trebble (1994 Salim , P. , and Trebble , M. A. ( 1994 ). Modelling of solid phases in thermodynamic calculations via translation of a cubic equation of state at the triple point , Fluid Phase Equilib. , 93 , 75 – 99 .[Crossref] , [Google Scholar]) had previously presented a methodology for extending the Trebble-Bishnoi-Salim (TBS) equation of state (Salim, 1990 Salim , P. ( 1990 ). A modified Trebble-Bishnoi equation of state, M.Sc. thesis , University of Calgary . [Google Scholar]) to calculations involving a solid phase. In this study, the CO₂ freeze-out conditions in CO₂/CH₄ and CO₂/C₂H₆ mixtures are calculated from the TBS equation of state, and it is shown that they provide a better data fit than the traditional Poynting correction method. Furthermore, since the use of an equation of state in SLE/SVE calculations does not require the explicit assumption of a pure solid phase, the model was assessed for its ability to correlate CO₂ gas hydrate equilibrium conditions. Gas hydrates were simply treated as an impure solid phase, and it was seen that the predictions of gas hydrate equilibrium were in very good agreement with the experimental data. Computationally, the use of the TBS equation of state has the advantage, over the model of Yokozeki (2005 Yokozeki , A. ( 2005 ). Methane gas hydrates viewed through unified solid-liquid-vapour equation of state , Int. J. Thermophys. , 26 ( 3 ), 743 – 765 . [Google Scholar]), that it does not require a modifying factor (c_b) in the repulsive term to handle the presence of hydrates; they are instead handled using a unique binary interaction parameter for the hydrate phase.     

应变p型Si1-xGex层中载流子冻析

本文用解析的方法研究了应变Ｐ型Ｓｉ１－ｘＧｅｘ层中载流子冻析现象，研究发现，用Ｓｉ归一化的Ｓｉ１－ｘＧｅｘ价带有效态密度、随ｘ的增加而减小，而且温度Ｔ越低，随Ｇｅ组份ｘ的增加而减少的速度越快，与Ｓｉ相比，常温下Ｇｅ组份ｘ几乎对电离 杂质浓度没有什么影响，而在低温下，随Ｇｅ组份ｘ的增加，电离杂质浓度随之增加，载流子冻析减弱，这对低温工作的Ｓｉ１－ｘＧｅｘ器件有利。     

一个适用于极低温的宽温度范围子电路MOSFET模型

本文描述了一个适用于低温下的MOSFET子电路SPICE模型。其中引入了两个电阻用于描述冻析效应,并开发了这两个电阻的解析的行为模型。该模型在从极低温到常温的较宽的温度范围内均适用。     

Experimental characterization and numerical simulation of the electrical properties of nitrogen, aluminum, and boron in 4H/6H-SiC

In order to measure the ionization time constants of dopants in 4H/6H-SiC within a wide range of temperature, nitrogen (N), aluminum (Al), and boron (B) have been characterized using thermal admittance spectroscopy (AS) and deep level transient spectroscopy (DLTS). The temperature extrapolation of the results obtained by AS shows excellent agreement with those obtained by DLTS, yielding the base for an evaluation of incomplete ionization effects in SiC devices within usual operation ranges. The measured data has been analyzed using numerical drift-diffusion simulations based on the method of finite-elements. A numerical investigation of the different freeze-out characteristics of free carriers in p⁺n, n⁺p, and Schottky diodes shows that unlike in the case of B, the ionization time constant of Al can be exclusively measured in the highly doped region of a p⁺n diode.