Scaling effect on specific contact resistivity in nano-scale metal-semiconductor contacts

Progressive downscaling has allowed semiconductor industries to continuing improve the performance of integrated circuits (ICs) [1]. The downscaling adversely affects the performance of interconnects. Specifically, the resistivity of metal interconnects and metal-semiconductor contacts increases due to downscaling. The metal-semiconductor contact resistance is becoming a performance limiting factor as it takes larger fraction of the total on-state resistance [2]. Hence, the contact resistance must be reduced to meet ITRS performance requirements of future technology nodes. As metal-semiconductor interface shrinks simultaneously as device shrinks, it becomes questionable if the resistivity still can meet the ITRS requirements when it reaches to the certain scaling limit (sub-10nm). Specific contact resistivity (ρ_C) is one of important factors affecting total contact resistance, and it is determined by important factors such as metal-semiconductor Schottky barrier height and semiconductor doping. This work investigates the effects of contact geometry, Schottky barrier height, and doping concentration on the specific contact resistivity.