Group-II Hafnate, Zirconate, and Tantalate High-k Dielectrics for MIM Applications: The Defect Issue

Abstract

We discuss the role of defects in metal oxides (mostly in strontium hafnate, barium hafnate and barium zirconate). The discussion is based on macroscopic and microscopic (C-AFM) electrical meas-urements, ab initio calculations for formation energies and elec-tronic structure of defects, numerical simulations of trap-assisted leakage, and on additional data provided by SIMS and X-ray tech-niques. We argue that moisture may be a hazardous contaminant.