Influence of lattice parameters on the dielectric constant of tetragonal ZrO 2 and La-doped ZrO 2 crystals in thin films deposited by atomic layer deposition on Ge(001)

Abstract

In ZrO 2 crystals, the highest dielectric constant (k) is ascribed to the tetragonal phase. By the use of density functional theory and synchrotron radiation x-ray diffraction, we show how the a and c lattice parameters of the tetragonal phase influence the resulting k. Highest k values are obtained at increasing both a and c, while k is reduced for compressive strained cells. The determination of a and c on La-doped ZrO 2 and ZrO 2 thin films deposited by atomic layer deposition on Ge (001) allowed us to elucidate the influence of La doping and Ge diffusion on the k value. © 2011 American Institute of Physics.