부산대학교 도서관

In this exploratory study, selective tungsten (W) deposition is used before the copper (Cu) metallization steps with the aim to solely fill the via with W. The W deposition is tested on the bottom metal cobalt (Co) or ruthenium (Ru) and shows an excellent selectivity towards the dielectric SiO 2 and dense low-k material 3.0. The via resistance shows up to a 40% reduction for the W-Cu hybrid system compared to a Cu dual damascene (DD) filled via. The material compatibility is tested in a thermal storage study and shows no performance degradation of the bottom barrierless W vias. This feasibility study using a middle of line (MOL) metal shows that a W-Cu hybrid system can be an option for further extension of Cu interconnects while suppressing the via resistance.