Atomic layer deposition grown metal-insulator-metal capacitors with RuO2 electrodes and Al-doped rutile TiO2 dielectric layer

Metal-insulator-metal structures for dynamic random access memory capacitor applications were prepared by atomic layer deposition. Rutile TiO2 dielectric layers were grown on top of RuO2 electrodes. TiO2 layers were doped in different ways by aluminum and these structures were compared to undoped ones. C-V and J-V measurements show that Al doping reduces the capacitance density of the stacks while reducing leakage current. Varying the initial Al doping profile did not change the electrical properties of the stacks. Leakage current analysis revealed that the current in the doped samples is controlled by Schottky emission.