An advanced back-end-of-line (BEOL) metallization structure is disclosed. The
structure includes a bilayer diffusion barrier or cap, where the first cap layer
is formed of a dielectric material preferably deposited by a high density plasma
chemical vapor deposition (HDP CVD) process, and the second cap layer is formed
of a dielectric material preferably deposited by a plasma-enhanced chemical vapor
deposition (PE CVD) process. A method for forming the BEOL metallization structure
is also disclosed. The invention is particularly useful in interconnect structure
comprising low-k dielectric material for the inter-layer dielectric (ILD) and copper
for the conductors.
