A two-dimensional analysis for MOSFET´s fabricated on buried SiO2layer

An accurate numerical analysis for predicting characteristics of MOSFET´s Fabricated on an epitaxial Si layer on top of a buried SiO2layer formed by oxygen ion implantation is presented. Basic equations, that is, the current continuity equation for minority carriers, Poisson´s equation, and the equation for the majority-carrier concentration including carrier multiplication due to impact ionization, are iteratively calculated for obtaining a self-consistent solution. Good agreement between theoretical and experimental results was obtained over a wide range of device parameters and terminal biases. Threshold dependence upon Si/buried SiO2interface charge as well as Si film thickness is shown. As the Si film and buried SiO2thicknesses are reduced, the threshold voltage shift with channel shortening becomes smaller. Finally, theoretical analysis shows that the short-channel effect in MOSFET fabricated on an epitaxial layer with an underlining buried SiO2layer is smaller than those in bulk Si MOSFET and MOSFET/SOS.