Atomic layer deposition of $LaxZr1−xO2−δ$ $(x=0.25)$ high-$k$ dielectrics for advanced gate stacks

Thin $LaxZr1−xO2−δ$ $(x=0.25)$ high permittivity $(k)$ films are grown on Si(100) by atomic layer deposition at $300°C$ using $(PirCp)3La$⁠, $(MeCp)2ZrMe(OMe)$ and $O3$ species. Their properties are studied by grazing incidence x-ray diffraction, high resolution transmission electron microscopy, electron energy loss spectroscopy, x-ray photoelectron spectroscopy, and electrical measurements on the as-grown films and after vacuum annealing at $600°C$⁠. Annealed films feature resistance to hygroscopicity, a large $k$ value of around 30 and an acceptable leakage current density. A low-$k$ silica-rich interlayer is also evidenced at both pristine and annealed high-$k/Si$ interfaces.