LOW-TEMPERATURE MOCVD OF ADVANCED BARRIER LAYERS FOR THE MICROELECTRONICS INDUSTRY

Metalorganic chemical vapor deposition (MOCVD) of TiN thin films at low temperatures and low pressures using tetrakis(diethylamino)titanium (TDEAT) and NH3 is described. Conformal TiN films, having layer resistivities as low as 200 mu Omega.cm, densities close to those of sputtered films, and low impurity contents can be obtained with this chemistry. These TiN films can be applied as adhesion layers for chemical-vapor-deposited W, or as barrier layers between Si and Al. Rapid thermal anneal (RTA) of MOCVD-TiN and physical-vapor-deposited (PVD) Ti/MOCVD-TiN bi-layers is described. RTA at temperatures of 600 to 800 degrees C is shown to lead to formation of a TiSi2/TiN bi-layer on Si substrates, just as with completely sputter-deposited Ti/TiN bi-layers. Law contact resistance to p(+)-Si is demonstrated with PVD-Ti/MOCVD-TiN bilayers. It is demonstrated that thermal decomposition of TDEAT (i.e. without NH, as the coreactant) leads to films having better conformality. But, the resistivity and impurity content of the material produced by thermal decomposition of TDEAT is too high for them to be good candidates far barrier and adhesion layers.