The effect of dopants on the dielectric constant of HfO2 and ZrO2 from first principles

Based on first-principles calculations, we elucidate the influence of dopants on the dielectric properties of the high-k materials HfO2 and ZrO2. Our calculations demonstrate that by doping the tetragonal phase can become energetically more favorable than the monoclinic phase present at ambient conditions. The stabilization of the tetragonal phase increases the dielectric constant significantly. A series of dopants was investigated to understand the efficiency and the mechanism of the stabilization process. The calculations reveal that at a moderate doping level (∼12%) only some of the dopants stabilize the tetragonal phase and that Si is the most efficient stabilizer atom.