[Models for implanted MOS transistors]

The effects of implantation on threshold voltage for a p-type substrate are reviewed. The I-V characteristics of an n-channel device are considered for a rectangular impurity profile and the model shown to agree with practical measurements.Francai

A finite element approach and automatic mesh generation for the resolution of Poisson's equation in reverse biased two-dimensional semiconductor devices

A finite element (FE) approach, with triangular elements, for the resolution of Poisson's equation in reverse biased semiconductors is described. An optimised successive overrelaxation method, using a space charge approximation and neglecting the exponential dependence in the potential of the carrier concentrations, yields an excellent initial guess for the resolution of the full non-linear problem by a Newton-Raphson algorithm. Various geometrical structures and interface and boundary conditions are dealt with in a natural way. An automatic mesh generation program, allowing to take full benefit of the FE method advantages, is also briefly described. An example is presented to illustrate the application of the method.Anglai

Magneto-optical and magneto-transport studies of electron- electron interactions in organic conductors using fields up to 50T

Contains fulltext : 112791.pdf (publisher's version ) (Open Access

Inversion layers in heterojunctions

Examines by means of a simple model, valid for small currents and for non-degenerate semiconductors, under which conditions of doping and applied voltage an inversion layer may exist in an abrupt heterojunction; interface states are taken into account. The influence of such a layer on the energy band diagram and on the junction capacitance is studied and compared to the influence of the interface states.Anglai

A general finite difference formulation for combined triangular and rectangular grids with application to a gate controlled rectifier in the on-state

The question whether the finite element (FE) or the finite difference (FD) method is better suited for the simulation of semiconductor devices, may loose its importance if one realizes that the most successful FE approaches can be described by FD formulas. A unique and simple formulation is presented that covers combined rectangular and triangular grids. The successive line overrelaxation method (SLOR) has been adapted to the irregular matrix structure that results from a FE like mesh. The method was found to be very interesting, because it is economic in both CPU time and memory requirements. The numerical approaches are applied to the static analysis of a gate controlled power rectifier in the on-state. The device behaviour is essentially two-dimensional and, for the considered anode currents, it is very sensitive to the gate bias and current.Anglai