Structural and dielectric properties of amorphous ZrO2 and HfO2

Abstract

Zirconia (ZrO2) and hafnia (HfO2) are leading candidates for replacing SiO2 as the gate insulator in CMOS technology. Amorphous versions of these materials (a-ZrO2 and a-HfO2)) can be grown as metastable phases on top of a silicon buffer; while they tend to recrystallize during subsequent annealing steps, they would otherwise be of considerable interest because of the promise they hold for improved uniformity and electrical passivity. In this work, we report our theoretical studies of a-ZrO2 and a-HfO2 by first-principles density-functional methods. We construct realistic amorphous models using the ``activation-relaxation'' technique (ART) of Barkema and Mousseau. The structural, vibrational, and dielectric properties of the resulting models are analyzed in detail. The overall average dielectric constant is computed and found to be comparable to that of the monoclinic phase.

5 pages, 6 figures. Submitted to Physical Review B

Cited by in corpus (5)

• Structure and Dielectric Properties of Amorphous High-kappa Oxides: HfO2, ZrO2 and their alloys
• Exploration of co-sputtered Ta${}_2$O${}_5$-ZrO${}_2$ thin films for gravitational-wave detectors
• Understanding the Clean Interface between Covalent Si and Ionic Al2O3
• Searching for activated transitions in complex magnetic systems
• Numerical study of synaptic behavior in amorphous HfO2-based ferroelectric-like FETs generated by voltage-driven ion migration