Leakage mechanism in Cu damascene structure with methylsilane-doped low-K CVD oxide as intermetal dielectric

This letter investigates the leakage mechanism in the Cu damascene structur e with methylsilane-doped low-k CVD organosilicate glass (OSG) as the inter metal dielectric (IMD), The leakage between Cu lines was found to be domina ted by the Frenkel-Poole (F-P) emission in OSG for the structure using a 50 -nm SiC etching stop layer (ESL), In the structure using a 50-nm SiN ESL, t he leakage component through SiN also made a considerable contribution to t he total leakage in addition to the bulk leakage from trapped electrons in OSG, An appropriate ESL of sufficient thickness is essential to reduce the leakage through the ESL if an ESL is used in the Cu damascene integration s cheme.