The shape of the potential and space charge density distributions within buried channel MOS structures, obtained from a one‐dimensional numerical solution of Poisson's equation, allows to understand the low‐ and high‐ frequency behaviour and the experimental C–U curves of such structures. The same numerical analysis is also found to be very helpful in the search of a suitable strong surface inversion condition for this type of MOS structures; one may then build up a quite simple theoretical model which leads to the computation of the drain current of buried channel MOS transistors. Experimental devices were made by the SILOX technique. A least squares method is used to determine the actual parameters of the structures. This allows then to compare the results of the theoretical model with the experimental data.

A method is presented for calculating numerically the reverse current of p‐n junctions, taking the multiplication phenomenon into account. Reduction of the computer time may be achieved by the introduction of an adequate approximation for generation‐dominated junctions. The last method can be used to compute the values of the ionization coefficients starting from the experimental reverse current characteristics. An example is given for Si p‐n junctions at 125 °C.

A simple semi-analytical method is proposed to compute the principal characteristics of non-uniformly doped MOS devices. By considering an inversion layer with a non-zero width it is possible t o compute the complete C-U curve. The influence of the doping profile on the characteristics of such structures is shown. The high frequency C-U curve calculated by means of the method leads to a more accurate definition of the threshold voltage. Finally, t h e described model may be applied to compute the drain current of non-uniformly doped P+P MOS transistors in good agreement with the experimental values.Le modble semi-analytique simple propose ici est destine au calcul des principales caractbristiques de structures MOS 8, dopage non-uniforme. La prise en compte d'une largeur non nulle de zone d'inversion permet d'6tablir la courbe C-U dans son entikrete.On montrera comment le profil d'impuretbs influence le comportement de tels dispositifs; d'autre part, sur base de courbes C-U haute frbquence 6tablies 8, partir du modble, on pourra prbciser la notion de forte inversion dans ces m6mes structures. Enfin, la mbthode proposbe est appliqnb avec succbs au calcul du courant de transistors MOS B dopage nonuniforme.