Structural and dielectric properties of amorphous ZrO2 and HfO2
نویسنده
چکیده
Zirconia ZrO2 and hafnia HfO2 are leading candidates for replacing SiO2 as the gate insulator in complementary metal-oxide semiconductor 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 aHfO2 by first-principles density-functional methods. We construct realistic amorphous models using the “activation-relaxation” technique 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.
منابع مشابه
Structural and dielectric properties of crystalline and amorphous ZrO2
We first review earlier work in which we computed the first-principles structural, vibrational, and lattice dielectric properties of the cubic, tetragonal, and monoclinic phases of ZrO2 and HfO2. We then discuss two approaches to the construction of realistic models of amorphous ZrO2: a bmelt-and-quenchQ ab-initio molecular dynamics approach, and an bactivation–relaxation techniqueQ. The struct...
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