Reliability of Al2O3-doped ZrO2 high-k dielectrics in three-dimensional stacked metal-insulator-metal capacitors

In this paper, we report reliability evaluation results for nanomixed amorphous ZrAlxOy and symmetrically or asymmetrically stacked ZrO2/Al2O3/ZrO2 dielectric thin films grown by atomic layer deposition method in cylindrical metal-insulator-metal capacitor structure. Clear distinctions between their I-V asymmetry and breakdown behavior were correlated with the differences in compositional modification of bottom interface, defect density, and conduction mechanism of the film stacks. The thermochemical molecular bond breakage model was found to explain the dielectric constant dependent breakdown field strength and electric field acceleration parameter of lifetime very well.