Critical Length and Resistance Saturation Effects in Al(Cu) Interconnects

摘要: A new test structure for electromigration failure analysis of via-interconnect metallization schemes was developed. Multi-via/interconnect chain arrays were used in a parallel/serial testing arrangement. Due to improved statistical sampling, the multi-via structures enabled measurement drift velocity phenomena at via/interconnect interfaces with very limited number devices per stressing condition, and without reducing signal noise ratio. Furthermore, realistic, production-type can be characterized usually required “traditional” velocity-type metal stacks incorporating highly resistive shunt-layers. Critical length effects investigated as function line current density. At interconnect lengths close critical Blech-length, resistance saturation encountered calculations density-length product, (jl)*. model developed found correlate well acquired data. accurately measured length-dependent performance evaluation on device-level.