Ab-initio screening of transition metal dichalcogenides as a barrier for copper interconnect

Abstract

Metal interconnect is a passage where current flows in semiconductor, and copper is widely used. Copper has a double-stack structure including barrier material and liner material to prevent diffusion into surrounding dielectrics. However, as the size of the semiconductor continues to decrease, its double-stack structure causes problems such as conducting volume loss and vertical resistance penalty. In this study, computational screening was conducted to find a new barrier material with reliability and electrical performance among transition metal dichalcogenides (TMDs) to overcome these problems. As a result, it was confirmed that TiS2 is the most suitable as a next -generation barrier for copper interconnects.