Chenggang Xu

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This paper presents an automated methodology for calibrating the doping profile and accurately predicting substrate parasitics with boundary element solvers. The technique requires fabrication of only a few test structures and results in an accurate three-layered approximation of a heavily doped epitaxial silicon substrate. Using this approximation, the(More)
In this paper, a new formulation for the extraction of substrate parasitics is derived that can account for the nonuniform current distribution on contacts without contact subdivision. This method is orders of magnitude faster than the original Green's function method. The speedup is achieved by a significantly reduced matrix size combined with the(More)
This paper presents an analysis of the numerical stability for the formulation of the Green's function method of Niknejad et al. (1998) for modeling and analysis of substrate coupling in integrated circuits. It is shown that the formulation has numerical overflow problems. A new stable formulation is presented.
Sulfonated polyanilines have become promising building blocks in the construction of biosensors, and therefore we use here differently substituted polymer forms to investigate the role of their structural composition and properties in achieving a direct electron transfer with the redox enzyme pyrroloquinoline quinone-dependent glucose dehydrogenase(More)
We report on the fabrication of a complex electrode architecture for efficient direct bioelectrocatalysis. In the developed procedure, the redox enzyme pyrroloquinoline quinone-dependent glucose dehydrogenase entrapped in a sulfonated polyaniline [poly(2-methoxyaniline-5-sulfonic acid)-co-aniline] was immobilized on macroporous indium tin oxide (macroITO)(More)
This paper presents a new Green function-based approach for substrate parasitic extraction in substrates with inhomogeneous layers. This new formulation allows analysis of noise coupling with sinkers, trenches and wells, - a limitation in prior Green function-based extractors. Numerical examples for sinkers and trenches are provided and compared with the(More)
This paper presents an error control method for application of the discrete cosine transform (DCT) to extraction of substrate parasitics in integrated circuits. In addition to the truncation error with approximating an infinite series with a finite number of terms, there are also errors in approximating the truncated series by the DCT. It is shown that this(More)
The multilayer formation of two different sulfonated polyanilines with cytochrome c is presented and mechanistic aspects of the contributions of the polyelectrolytes' properties to the characteristics of the assemblies are discussed. These two modified polymers, PASA1 and PASA2 are chemically synthesized and differ in the grade of sulfonation, substitution,(More)
A new formulation of Z-parameter based macro models for substrate noise coupling is presented. With this new formulation, the variation of the self Z-parameter at small contact separations can be simulated. Instead of calculating the Z-parameters directly by two-contact models, the Z-parameters are calculated as a least-square solution to an overdetermined(More)