Novel low k Dielectric materials for nano device interconnect technology

Abstract

Mechanically robust low k C-rich SiCN and pSiCN dielectrics with excellent built-in Cu oxidation and diffusion barrier have been developed and evaluated as potential alternative low k Interlevel dielectrics for Cu interconnects. The novel low k dense C-Rich SiCN (k=3.3) and lightly porous C-Rich SiCN (k=2.8) films have high modulus (E~> 15-30 GPa) and significantly lower Plasma Induced Damage (PID) as compared to typical pSiCOH (k~2.4-2.7) dielectrics. The excellent Cu diffusion barrier properties of these SiCN dielectrics enable the use of thinner metallic Cu barriers that resulting in larger Cu line’s volume, reduced resistance and overall improved RC in sub-50 nm pitch interconnects without TDDB and EM reliability penalty.