Slow trap response of zirconium dioxide thin films on silicon

In this work, we explore the electrical properties of a metal-oxide-semiconductor system that incorporates a high-k zirconia dielectric with an equivalent oxide thickness of 3 nm deposited by metalorganic chemical vapor deposition. In general, the thin films examined exhibit excellent electrical properties. However, dynamic I-V measurements unveil the presence of trapping sites with response times up to 3 s. By applying a recently proposed model, this slow trap response can be consistently explained by traps located at the inner interface of a two-layer dielectric consisting of the high-k material itself and a transition layer in contact with the semiconductor. Trap energies are found to be distributed around two distinct levels. (C) 2003 American Institute of Physics.