On Temperature Dependency of Delay for Local,Intermediate, and Repeater Inserted Global Copper Interconnects

Cryogenic technologies not only improve the performance of interconnects but also the performance of transistors and consequently drivers and repeaters. Although in cryogenically cooled integrated circuits the local temperature of interconnects and transistors may be as low as 50 K, it may easily reach to 600 K in high-temperature chips. In this brief, we investigated the impact of temperature on the delay of local, intermediate, unit-repeater-inserted (URI), and cascaded repeater-inserted (CRI) global copper interconnects for minimum technology node with available transistor model (32-nm technology). Our results show that temperature variation of driver resistance could change the delay of local and intermediate interconnects, respectively, down to -33% and -28% at low temperatures, and up to +240% and 232% at high temperatures relative to the room temperature delay. Moreover, while the contribution of temperature dependency of interconnect is negligible for local and intermediate layers, the temperature dependency of repeater and interconnect could vary the delay of URI and CRI global layer interconnect down to -23% and -38% at low temperatures, and up to +116% and +200% at high temperatures, respectively.