Investigation on multilayered chemical vapor deposited Ti/TiN films as the diffusion barriers in Cu and Al metallization

Abstract

A novel multilayered chemical vapor deposition ͑CVD͒ Ti/TiN structure was found to be a more effective diffusion barrier in Cu metallization than TiN alone. The Ti and TiN films were deposited by plasma enhanced CVD and low pressure CVD, respectively. In order to reduce the concentration of chlorine in the films, NH 3 plasma posttreatment was applied to multilayered CVD-Ti/TiN films. The resistivity of the film was reduced from 240 to 120 ⍀ cm using NH 3 plasma posttreatment. Cu was electroplated on the multilayered CVD-Ti/TiN films. X-ray diffraction patterns showed a small ͑002͒ peak and strong ͑111͒ peak from the Cu film. The leakage current was kept low during the device application test indicating the Ti/TiN film possessed an enhanced barrier property over the TiN film alone.

Glycine as an Efficient Corrosion Inhibitor for TiN Oxidation Environments

“…With the decrease in the feature size, titanium nitride (TiN) has become the preferred barrier metal for new interconnect metal cobalt (Co) due to its excellent thermal stability, high melting point, direct deposition on Si, and effective prevention of metal ion diffusion even at an ultrathin thickness. [1][2][3][4][5] After the deposition of TiN and Co by the dual damascene process, bulk Co on the TiN layer needs to be removed by chemical mechanical polishing (CMP), stopping at the TiN barrier. This requires that the removal rate (RR) of TiN be very low, which plays a role in polishing self-stopping.…”