Layout dependency induced deviation from Poisson area scaling in BEOL dielectric reliability

In this paper, the TDDB lifetime of sub-100 nm single damascene structures is investigated to check the validity of the classical Poisson area scaling for BEOL dielectric reliability. A parameter RLN (ratio of line length over number of turnings) is defined to quantify the layout critical area contribution to the BEOL dielectric breakdown lifetimes. Structures with different RLN's, metal materials and layouts are compared. It is found that for similar layouts with different RLN's, the TDDB lifetime will deviate from the Poisson area-scaling trend.