Frank Feustel

Finite element analysis for BEOL stress engineering to improve yield and reliability of sub-30 nm structures

Deformation of trenches due to residual stresses in TiN may result in Cu voids forming especially at shrinking feature sizes of trenches and vias and introducing low-k dielectrics between Cu interconnects. The influence of residual stress therefore has been investigated in a parametric study using Finite Element analyses (FEA) to discover the correlation between the TiN stresses and failure occurrence at various geometric representations. FEA has been shown to allow effective BEoL (Back end of line) stress engineering leading to improved yield and reliability of next generation interconnect systems in minimum development time.