ENHANCED ELECTROMIGRATION PERFORMANCE OF COPPER LINES IN METALLIZATION SYSTEMS OF SEMICONDUCTOR DEVICES BY SURFACE ALLOYING

摘要

In sophisticated semiconductor devices, the electromigration performance of copper metal lines at the top interface thereof may be enhanced by forming a copper alloy that is locally restricted to the interface. To this end, an appropriate alloy-forming species, such as aluminum, may be provided on the basis of a non-masked deposition process and may be subsequently removed by a non-masked etch process, wherein the characteristic of the resulting alloy may be adjusted during an intermediate heat treatment.