Borderless vias with CVD barrier layer

摘要

Borderless vias are filled by initially depositing a thin, conformal layer of titanium nitride by chemical vapor deposition to cover an undercut, etched side surface of a lower metal feature. A metal, such as tungsten, is subsequently deposited to fill the borderless via. Embodiments include thermal decomposition of an organic-titanium compound, such as tetrakis-dimethylamino titanium, and treating the deposited titanium nitride in an H2/N2 plasma to lower its resistivity.