Valence band structure and band alignment at the ZrO2/Si interface

X-ray photoelectron spectroscopy combined with first-principles simulations are used to determine the band alignments of ZrO2 thin films on silicon. Theoretical band offsets were calculated by simulating the ZrO2/Si interface by means of plane-wave pseudopotential calculations. Experimental band offsets were determined by measuring the core-level to valence-band maximum binding energy differences. Excellent agreement was obtained between the theoretical (3.5-3.9 eV) and experimental (3.65 eV) valence band offsets. Both theoretical and experimental analyses predict the conduction band offset to be similar to0.6-1.0 eV which indicates the intrinsic limitation of ZrO2 to be considered as a viable alternative gate dielectric. (C) 2004 American Institute of Physics.