Impact of Interconnect Variability on Circuit Performance in Advanced Technology Nodes

Divya Madapusi Srinivas Prasad, Chenyun Pan, Azad Naeemi
Georgia Institute of Technology


Interconnects are one of the main bottlenecks to circuit performance, with increasing importance in advanced technology nodes. With increased sensitivity of circuit delay to interconnect parasitics, we study the impact of process variation on interconnects. Based on GDSII-level layouts and Monte-Carlo simulations we accurately study sources of systematic variability and quantify their repercussions on circuit performance in the ITRS 11 nm technology node. Additionally, we compare three lithography schemes and study their impact on interconnect capacitance and interconnect resistance. Consequently, we study the influence of interconnect RC on circuit performance. The study shows that, in multi-gate transistor technology, wire capacitance is less important in circuit delay, thus increasing tolerance of the circuit performance to the overlay variation in the litho-etch-litho-etch (LELE) lithography. We compare the LELE patterning with the self-aligned-double-patterning (SADP) and the self-aligned-quadruple-patterning (SAQP) patterning, and show that it is more beneficial to circuit performance, and more resistant to variability.