Reliability test results for W FIB interconnect structures

The reliability of W-based FIB modifications is assessed through the stress testing of FIB test structures. Three structure types were created that examined the integrity of vias, lines, and FIB-deposited insulator material. Structures were stressed at 125/spl deg/C with no current for 3900 hours and 170/spl deg/C with current for 2700 hours. Structures were also temperature cycled for 2000 cycles. Electrical resistance remained stable throughout all stress conditions and there was no evidence of degradation to the FIB-deposited W or SiO/sub 2/ films or to the Al lines. The only failure observed was with the insulator material due to misalignment of the structure.