Integration of a high density Ta_2O_5 MIM capacitor following 3D damascene architecture compatible with copper interconnects

摘要

To face with the continuous integrated circuit densification, passive components size has to be reduced, particularly for RF and analog applications where lots of them are needed. A Metal-Insulator-Metal (MIM) capacitor is integrated with a high developed area architecture to increase the capacitance density and limit encumbrance. The combination of this architecture with Ta_2O_5 dielectric with a permittivity of 25 allows capacitance densities of more than 15 fF/μm~2. As metal insulator interface is critical, two stacks TiN/Ta_2O_5/ TiN and TiN/Ta_2O_5/Cu are integrated among copper interconnects, evaluated and compared.