TiN-encapsulized copper interconnects for ULSI applications

TiN-encapsulized Cu interconnects were developed for ultra-large-scale integration (ULSI) by nitriding the Cu-10%Ti alloy. The 500-nm-thick Cu-Ti alloy layer was separated into an upper TiN layer and a lower Cu layer after nitriding at 800 degrees C. The interconnects had a higher oxidation resistance than Cu interconnects, and their resistivity was as low. The electromigration lifetime of the new interconnects was two orders of magnitude larger than that of pure Cu interconnects.<
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