Electromigration improvements with titanium underlay and overlay in Al(Cu) metallurgy

The reliability advantages of Ti-Al(Cu)-Ti are introduced in this work. Outstanding tolerance to electromigration damage is measured both single level interconnections and two-level interconnections with tungsten via-studs. A greater than 100* improvement in the median time to failure (t/sub 50/) is measured for Ti-Al(Cu)-Ti interconnections over simple Al(Cu). An integrated, four-level metallization has been realized.<
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