Can praseodymium oxide be an alternative high-K gate dielectric material for silicon integrated circuits?

We show that crystalline praseodymium oxide films can be grown on silicon [001]. Such films have outstanding dielectric properties, displaying a dielectric constant of around 30 independent of substrate doping, very low leakage current density of 5/spl times/10/sup -9/ A/cm/sup 2/ at V/sub g/=/spl plusmn/1.0 V @ T/sub EOT/=1.4 nm, good reliability, and reversible electrical breakdown. We report on the structure and stability of thin praseodymium oxide layers on Si[001] by combining scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), and Auger electron spectroscopy (AES). We present experimental evidence and theoretical explanation based on ab initio pseudopotential simulations for the formation of oxygen-rich interfacial layer between the oxide and silicon.