Electromigration performance of CVD-W/Al-alloy multilayered metallization

Al alloys, including Al-Si(1%) and Al-Cu(2%), are investigated. The electromigration test results indicate that the rough surface texture of the underlying chemical vapor deposition (CVD)-W layer degrades the electromigration performance of the Al-Si film. The rough CVD-W surface texture had minimal impact on the electromigration performance of the Al-Cu films. A current-density exponent of 2.1-2.2 was found for both types of films. An activation energy for failure was determined to be 0.75 eV and 0.46 eV for the Al-Cu and Al-Si, respectively.<
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