Spontaneous nanoclustering of ZrO2 in atomic layer deposited LayZr1-yOx thin films.

During atomic layer deposition of homogeneous LayZr1-yOx thin films spontaneous segregation of ZrO2 nanocrystals that are embedded in an amorphous La2O3 matrix takes place. This occurs if the Zr content in the LayZr1-yOx film rises above 30%, i.e., if the pulse ratio between the lanthanum precursor and the zirconium precursor is larger than four. X-ray diffraction analysis shows that the ZrO2 nanocrystals are in the tetragonal phase, which is the most stable configuration of this material with the highest dielectric permittivity. These nanocrystal-embedded thin films exhibit higher dielectric constants as the Zr content increases. [ABSTRACT FROM AUTHOR]