Electrically inactive via for electromigration reliability improvement

摘要

A semiconductor device 300 includes a metal line 304 formed in a first dielectric layer 302. A capping layer 306 is formed the metal line 304. A second dielectric layer 308 is formed over the first dielectric layer 302 and the metal line 304. A first via 310 is formed in the second dielectric layer 308 and in contact with the metal line 304. A second via 312 is formed in the second dielectric layer 308 and in contact with the metal line 304, and is positioned a distance away from the first via 310. An electrically isolated via 326 is formed in the second dielectric layer 308 and in contact with the metal line 304 and in between the first via 310 and the second via 312. A third dielectric layer 314 is formed over the second dielectric layer 308. First and second trenches 316, 318 are formed in the third dielectric layer 314 and in contact with the first via 310 and the second via 312, respectively. An isolated trench 328 is formed in the third dielectric layer and in contact with the isolated via 326. The isolated via 326 mitigates void formation and/or void migration during operation/conduction with electrons traveling from the first trench 316 to the second trench 318 via the metal line 304.