Ab initio validation of continuum models for Si/SiO2 interfaces

A Density Functional Theory study on the scaling properties of SOI nanostructures is provided in this work. Starting from an atomistic, purely quantum-mechanical treatment of the nanostructures, we analyze the bandstructures and bandgap values to extract the main trends in their behaviours as the size of the nanodevices goes down. We compare the ab initio bandstructures with the ones obtained by means of k·p calculations, to determine the actual range of device dimensions for which the use of atomistic tools is mandatory, and whether traditional device simulation in such a range can be improved by using atomistic methods for each device type.