Ionized metal plasma deposition of titanium and titanium nitride for deep contact applications

The characteristics of ionized metal plasma PVD Ti-TiN films have been investigated for the application as a liner for small deep contacts. Compared to collimated Ti-TiN films, the bottom coverage of IMP Ti-TiN is more than two times higher at high aspect ratio contacts. With substrate bias, IMP Ti and IMP TiN show different crystallographic orientation behaviour. When applied to deep contacts, excellent contact resistance was achieved with thinner IMP Ti films, which is only one third of the thickness of collimated Ti films. Adopting the IMP TiN liner also represents a lower contact resistance than collimated TiN liners.