PHYSICS OF NANOTRANSISTORS: UNIFICATION OF TRANSMISSION MODEL WITH VIRTUAL SOURCE MODEL – MVS-TRANSMISSION MODEL

Abstract

In the eigth one from the line our new tutorial reviews, directed to serve students, university teachers and researchers, іt is shown that the transmission model can be closely related to the virtual source model. By simply replacing the diffusion mobility μ in the virtual source model by the apparent mobility app μ for a linear current, we obtain the correct results from the ballistic limit to the diffusion limit. By replacing the saturation rate sat v limited by scattering by the injection rate inj v , we obtain the correct value of the current ON I . A comparison of the experimentally measured characteristics shows that nanotransistors on a silicon substrate work very far from the ballistic limit, while nanosized III-V FETs work very close to the ballistic limit. There are two serious complaints about the model of passage. One of them is connected with the difficulty of calculating the dependence IDS ∝VDS due to the problems of calculating the dependence DS T ∝V . The other is due to the difficulties in predicting the current ON I , which in turn is due to the difficulty of calculating the critical length  at a high voltage on the drain, as a result of which it is difficult to predict the magnitude of SAT T . Because of these limitations, the transmission model and the virtual source model are combined in such a way that the parameters of the transmission model are taken from the insertion of the experimental results into the virtual source model, and the physical meaning of the parameters is taken from the transmission model. It is shown how it is possible to analyze the VAC of nanotransistors on the basis of the MVS/ passage model. The variety of types of transistors generates new peculiar problems, however, the methodology for analyzing experimental data does not change fundamentally. It was stressed that the application of the MVS/transmission model is justified if the transistor is assembled qualitatively. For such transistors, the model makes it possible to obtain physically meaningful parameters reliably.