Dependence of leakage mechanisms on dielectric barrier in Cu-SiOC damascene interconnects

Abstract

The leakage mechanisms Cu-SiOC damascene structures with SiC and SiN as two different cu diffusion barriers were studied. A comb capacitor test structure was used to measure the leakage currents in different dies for different temperatures. It was observed that SiOC showed different conduction mechanisms when integrated with SiC barriers than with SiN barriers. It was found that Schottky emission over Ta/SiOC barrier was the dominant leakage mechanism in structure with SiC barriers.