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Hironari CHIKAOKA Yoichi TAKAKUWA Kenji SHIOJIMA Masaaki KUZUHARA
We have evaluated the tunneling contact resistivity based on numerical calculation of tunneling current density across an AlGaN barrier layer in non-polar AlGaN/GaN heterostructures. In order to reduce the tunneling contact resistivity, we have introduced an n+-AlXGa1 - XN layer between an n +-GaN cap layer and an i-AlGaN barrier layer. The tunneling contact resistivity has been optimized by varying Al composition and donor concentration in n+-AlXGa1-XN. Simulation results show that the tunneling contact resistivity can be improved by as large as 4 orders of magnitude, compared to the standard AlGaN/GaN heterostructure.
At frequencies in the GHz range, an electrical connector must be considered as part of an electromagnetic transmission line. This paper reviews the effect of signal frequency on constriction resistance, interfacial capacitance and contact inductance at an electrical interface in a high speed connector. The deleterious effects of contact degradation at pin-receptacle junctions on transmitted signal integrity, are addressed. For frequencies in the GHz range, an electrical interface becomes capacitively coupled if contact resistance increases sufficiently. Contact deterioration may also lead to the generation of parasitic third-order harmonics that contribute to loss of signal integrity.
Andrea GHETTI Jeff BUDE Paul SILVERMAN Amal HAMAD Hem VAIDYA
In this paper we report on the modeling and simulation of tunneling current in MOS devices including quantum mechanical effects. The simulation model features an original scheme for the self-consistent solution of Poisson and Schrodinger equations and it is used for the extraction of the oxide thickness, by fitting CV curves, and the calculation of the tunneling current. Simulations and experiments are compared for different device types and oxide thicknesses (1.5-6.5 nm) showing good agreement and pointing out the importance of quantum mechanical modeling and the presence of many tunneling mechanisms in ultra-thin oxide MOS devices.
The author's recent research topics of organic monolayer films have been reviewed. The importance of the study of organic monolayers is discussed from the viewpoints of future electronics and dielectric physics, keeping in mind the difference between monolayers and bulk materials.
Keiichi HARAGUCHI Hitoshi KUME Masahiro USHIYAMA Makoto OHKURA
A new simple method for extracting the capacitance coupling coefficients of sub-0.5-µm flash memory cells is proposed. Different from the previously proposed methods, this method is not affected by a dopant profile of source region because a band-to-band tunneling current from the interface between the drain and the substrate is probed. Use of a reference device eliminates the necessity to make assumptions concerning the electron transport mechanism. Comparison with the other methods shows that the proposed method is simple and accurate.
Yutaka OHMORI Chikayoshi MORISHIMA Akihiko FUJII Katsumi YOSHINO
Electrical and optical properties of organic multilayer structure have been investigated. Two types of current-voltage characteristics have been found for thin multilayer structure of organic films. Optical property and its application for electroluminescent diode have been presented. The diode characteristics have been discussed in terms of energy band scheme.