A universal MOSFET mobility degradation model for circuit simulation
ABSTRACT From the physical insights provided by the universal effective mobility versus effective vertical electric field curve for electrons in MOS inversion layers, a simple general expression for the gate voltage dependence of the effective electron mobility is derived for use in SPICE circuit simulation. This expression is quite accurate over a wide range of channel doping concentrations and gate oxide thicknesses, without the need for fitting parameters, such as the theta parameter of the current SPICE level 3 mobility degradation model. It is, therefore, a much more universal model than the present SPICE level 3 mobility expression. Furthermore, the relative accuracy of this new model compared to the current SPICE model is expected to increase at the higher vertical electric fields typical of submicrometer oxide semiconductor field effect transistors (MOSFETs).
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Conference Proceeding: Characterization of the electron mobility in the inverted <100> Si surface[show abstract] [hide abstract]
ABSTRACT: The effective mobility of electrons in the inverted 〈100〉 Si surface was measured over a wide range of temperatures, gate voltages, and back-bias voltages. At a first glance the mobility appears to be strongly dependent on the channel surface doping. When the data were reanalyzed under a new approach where the mobility is plotted as a function of an effective perpendicular electric field experienced by the inversion layer, a universal curve has developed from the experimental data which indicates that the inversion layer mobility is not a function of doping density in the range (N A < 1.0 × 10<sup>17</sup>cm<sup>-3</sup>) and not a function of nominal surface processing. Our model indicates that the MOSFET surface inversion layer mobility is a reproducible property associated with the Si/SiO 2 system and not a parameter sensitive to nominal process variations encountered in the present n-channel Si-Gate Technology.Electron Devices Meeting, 1979 Internationa; 02/1979
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ABSTRACT: A mobility curve for electrons in a MOSFET inversion charge layer is determined from measured drain current of transistors produced by a wide range of MOS technologies. A comparison between this mobility curve and previously published results shows that a truly universal mobility curve does not exist and only local universal mobility curves can be expected, i.e. unique mobility curves which are valid over a finite range of MOS technologies and/or over a particular set of fabrication facilities. The curve's basic characteristic of being technology-independent over a wide range of process variation points out the potential of using such a local universal mobility curve as a powerful basis for developing predictive device modeling tools. This potential is demonstrated for an analytical MOSFET model and a two-dimensional device simulator where the mobility models have the general characteristics of experiment-based local universal mobility curvesIEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems 08/1989; · 1.09 Impact Factor