We investigate the electrical properties of doped single wall (SW) and double wall (DW) carbon nanotube (CNT) for integrated circuits interconnect applications. P-type Iodine charge transferred doping has been studied for modifying electrical properties and models of CNT interconnects. We perform circuit-level simulations on a 5-stage ring oscillator implemented with 45nm CMOS technology node devices for power and performance analysis with doped SWCNT and DWCNT interconnects.