Band offsets of high K gate oxides on high mobility semiconductors

High mobility semiconductors such as Ge and III-V compounds will be used in future field effect transistors, with the appropriate gate dielectric. The dielectrics must have band offsets over 1 eV to inhibit leakage. The band offsets of various gate dielectrics including HfO2, Al2O3, Gd2O3, Si3N4 and SiO2 on III-V semiconductors such as GaAs, InAs, Gash and GaN have been calculated using the method of charge neutrality levels. Generally, the conduction band offsets are found to be over I eV, so they should inhibit leakage for these dielectrics. There is reasonable agreement to experiment where it exists, although the GaAs:SrTiO3 case is even worse in experiment. (c) 2006 Elsevier B.V. All rights reserved.