Single Mask Metal-Insulator-Metal (MIM) Capacitor with Copper Damascene Metallization for Sub-0.18microns Mixed Mode Signal and System-on-a-Chip (SOC) Applications

A one-mask metal-insulator-metal (MIM) capacitor using damascene Cu as the bottom electrode has been developed. Using a PECVD SiN as both the capacitor dielectric and the diffusion barrier for Cu we have demonstrated, for the first time, the achieving of low leakage, high linearity MIM capacitors directly on Cu. The leakage and breakdown characteristics of the MIM capacitor depend strongly on both the surface conditions of the damascened Cu and on the PECVD SiN. We found that multi-layered SiN is superior than single layer SiN, and Cu CMP plays an important role. However, the inevitable dishing on large area capacitors during Cu CMP shows little impact on the electrical characteristics.