Influence of TiO2 incorporation in HfO2 and Al2O3 based capacitor dielectrics

Atomic layer deposition was applied to fabricate metal oxide films on planar substrates and also in deep trenches with appreciable step coverage. Atomic layer deposition of Ru electrodes was realized on planar substrates. Electrical and structural behaviour of HfO2–TiO2 and Al2O3–TiO2 nanolaminates and mixtures as well as Al2O3 films were evaluated. The lowest leakage current densities with the lowest equivalent oxide thickness were achieved in mixed Al2O3–TiO2 films annealed at 700 °C, compared to all other films in as-deposited state as well as annealed at 900 °C. The highest permittivities in this study were measured on HfO2–TiO2 nanolaminates.