Superior dielectric properties for template assisted grown (100) oriented Gd2O3 thin films on Si(100)

We report about the single crystalline growth and dielectric properties of Gd2O3(100) thin films on Si(100) surface. Using a two step molecular beam epitaxy growth process, we demonstrate that controlled engineering of the oxide/Si interface is a key step to achieve the atypical (100) oriented growth of Gd2O3. Unusually, high dielectric constant values (∼23–27) were extracted from capacitance voltage measurements. Such effect can be understood in terms of a two dimensional charge layer at the Gd2O3/Si interface (W. Sitaputra and R. Tsu, Appl. Phys. Lett. 101, 222903 (2012)) which can influence the dielectric properties of the oxide layer by forming an additional negative quantum capacitance.