Dielectric constant enhancement due to Si incorporation into HfO2

The authors investigated the dielectric constant change of Hf(1−x)SixO2 film as functions of Si concentration and annealing temperature. As a result, the dielectric constant of Hf(1−x)SixO2 was increased when doped with a small amount of Si after 800°C annealing. The authors revealed that the dielectric constant enhancement of Hf(1−x)SixO2 films is related to the phase transformation from the monoclinic to the tetragonal phase of HfO2. By using the Clausius-Mossotti relation, it is concluded that the dielectric constant enhancement through the structural phase transformation is derived from the molar volume shrinkage rather than the molar polarizability increase.