Dielectric Properties of Thin Hf- and Zr-based Alkaline Earth Perovskite Layers

摘要

Thin layers of high dielectric constant materials are of special interest for memory, logic, and passive microelectronic applications. Memory storage capacitors based on these materials should exhibit high capacitance densities and low leakage currents. Here, we investigate a group of Hf- and Zr-based alkaline earth perovskites for this application. It is found that thin layers of polycrystalline BaHfO_3, SrHfO_3, and BaZrO_3 can provide capacitance densities about 2 times higher than that of amorphous HfO_2. Post deposition annealing above ～ 700℃ is a crucial processing step required for obtaining the cubic perovskite phase with high dielectric constant.