Influence of Porosity on TDDB Lifetime of Low-k Dielectrics

When you increase the porosity of intrinsic low-k dielectrics, the Time-Dependent Dielectric Breakdown (TDDB) lifetime can suffer. Even if we minimize other factors like defects and impurities, the breakdown and TDDB performance of low-k dielectrics still tend to degrade with higher porosity. However, the failure kinetics stay relatively consistent, and the percolation model, originally developed for gate oxides, might still apply here.

Challenges in BEOL with Low-k Dielectrics

Introducing low-k dielectrics into the Backend-of-Line (BEOL) and continuously scaling down the Critical Dimension (CD) significantly reduces the reliability margin of intermetal dielectrics. Because of this, we need to conduct further in-depth research to address these reliability concerns and understand how porosity impacts the TDDB lifetime of low-k dielectrics.