Reliability assessment and physical failure analysis of nanoscale hard-mask-etching Al interconnect

For the first time, both reliability assessment and physical failure analysis of nanoscale hard-mask-etching Al interconnect were done. The activation energy E_a of electromigration (EM) is 0.8 eV (interfacial activation energy of the most robust electromigration failure) and current density exponent is 1.71 (close to mechanism of void nucleation). For the stressmigration (SM) tests, the resistance degradation of all splits was no more than 5 % after 1000H bake. The good reliability shows feasible extension of hard-mask-etching process to nanowires.