Improvement of the electrical and interfacial propertie of TiN/ZrO ₂ by a modulated atomic layer deposition process with controlled O ₃ dosing

In this work, we have studied the atomic layer deposition (ALD) of ZrO ₂ under various O ₃ dosing conditions and systematically investigated the interfacial properties of ZrO ₂ /TiN during ALD fabrication using the CpZr(N(CH ₃ ) ₂ ) ₃ and O ₃ reactant combination. In a typical ZrO ₂ ALD process, the oxidation condition fundamentally determines the interface oxidation and bulk film properties. High oxidation power is required to enhance the crystallinity of the ZrO ₂ film with low defect densities but inevitably causes the growth of the interfacial oxide, which reduces the dielectric constant of the resulting film. In the current study, we propose a modulated ALD process with controlled O ₃ dosing to realize the high performance of a metal-insulator-metal (MIM) capacitor device. The initial ALD cycles proceeded with low O ₃ dosing to suppress the oxidation of the TiN substrate, and the subsequent bulk film was grown with high O ₃ dosing to improve the crystallinity of the ZrO ₂ . As a result, we achieved a high dielectric constant ZrO ₂ material with a reduced defect density and a minimum interface capacitance equivalent thickness (CET) of the TiN/ZrO ₂ /TiN MIM capacitor under modulated oxidation conditions. This work provides a useful method to control the interface and bulk properties of dielectric layers at the atomic level.