Chemical vapor deposited TiCN: A new barrier metallization for submicron via and contact applications

High quality chemical vapor deposited (CVD) TiCN films were produced in a single wafer reactor using a metalorganic precursor (tetrakisdimethylamino titanium). The films have excellent step coverage (≳80%) over high aspect-ratio contacts as well as a very low particle level. These properties are obtained because the films were deposited under surface-reaction controlled conditions; the measured activation energy is 0.9 eV. The stress levels of the films are relatively low, below 5×109 dyn/cm2 compressive. The films also show good barrier properties against Al, Cu, and WF6 attack, that are attributed to their amorphous component, to the high C content of the films, and to the high step coverage. The electrical properties of the CVD TiCN films were evaluated at the via level, and the resistance contribution was shown in many cases to be comparable to that of sputtered TiN. These properties make this material a suitable barrier material for contact and via applications in sub-0.5 μm devices.