Electronic structure of noncrystalline transition metal silicate and aluminate alloys

A localized molecular orbital description (LMO) for the electronic states o f transition metal (TM) noncrystalline silicate and aluminate alloys establ ishes that the lowest conduction band states are derived from d states of T M atoms. The relative energies of these states are in agreement with the LM O approach, and have been measured by x-ray absorption spectroscopy for ZrO 2-SiO2 alloys, and deduced from an interpretation of capacitance-voltage an d current-voltage data for capacitors with Al2O3-Ta2O5 allot dielectrics. T he LMO model yields a scaling relationship for band offset energies providi ng a guideline for selection of gate dielectrics for advanced Si devices. ( C) 2001 American Institute of Physics.