TITLE: Crystalline Oxides on Semiconductors: a future for the nanotransistor

SPEAKER: Professor Marco Buongiorno Nardelli

TIME: Thursday April 15, 2004 at 4 PM

PLACE: George P. Williams, Jr. Lecture Hall, (Olin 101)

Exciting new classes of device applications are becoming viable because of advances in ultra thin film growth of epitaxial oxides on semiconductors. The central issue in the epitaxial oxide semiconductor systems is the role of the interface. Preparation of the semiconductor surface is essential to successful, high quality, crystalline oxide formation. Furthermore, the chemical nature of the surface then controls such fundamental properties of the system as band offsets, band bending and transport. In this talk I will illustrate how high-performance simulations combined with experiments have been able to characterize an interface phase whose structure-specific chemical bonding is fundamental in determining the properties of the semiconductor/crystalline oxide system. This interface phase results in gap states that cannot be readily identified with either of the bulk terminations. Moreover, these interface states result in a tunable Coulomb buffer whose properties can be modified to adjust the offset of the relative electrostatic potential on either side of the interface. I will illustrate this interface phase with the prototypical case of silicide/oxide heteroepitaxy on silicon and discuss the fundamental implications of this concept for science and technology.