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The effect of a pulsed dc on the sintering of copper spheres to copper plates was investigated. It was shown that the current had a marked effect on neck growth between the spheres and the plates. The enhancement of sintering under the effect of the current was attributed to electromigration. Microstructural observations on fracture surfaces of necks formed under high currents showed considerable void formation. It was also observed that the current resulted in increased evaporation and the formation of bunched evaporation steps. Formation of these steps and their location relative to the neck were consistent with current density distributions. The results of this investigation provide direct evidence for the role of the current in the sintering in the pulse electric current sintering method. (c) 2007 American Institute of Physics.

We propose a generalized T-matrix definition that facilitates the conversion between the S-parameter and T-parameter for multiport networks based on the well understood and mathematically simple two-port relations. This approach generalizes all multiport networks into two cases: balanced and unbalanced. Balanced networks have the same number of entrance and exit ports and are symmetric to the two-port network. Unbalanced networks generate a nonsquare T-matrix and do not have the same number of entrance and exit ports. Through careful selection of the T-matrix, this method extends two-port symmetry to multiport networks and provides an engineering implementable relationship between the S-parameter and T-parameter for multiport networks. This symmetry extension allows a practical means to cascade and deembed such networks. Index Terms--Deembedding, multiport networks, scattering parameter, transmission parameter.

A simple model based on the representation of capacitive coupling effects between the front- and back-gate and the channels, has been developed for tri-gate and pi-gate SOI MOSFETs. The model has been validated using numerical simulation of the body factor in such devices, as well as by experimental results. The body factor is much smaller than in regular, single-gate silicon-on-insulator devices because of the enhanced coupling between gate and channel and because the lateral gates shield the device from the electrostatic field from the back gate. [ABSTRACT FROM AUTHOR]