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

Metalorganic chemical vapor deposition (MOCVD) of TiN thin films at lo w temperatures and low pressures using tetrakis(diethylamino)titanium (TDEAT) and NH3 is described. Conformal TiN films, having layer resist ivities as low as 200 mu Omega.cm, densities close to those of sputter ed films, and low impurity contents can be obtained with this chemistr y. These TiN films can be applied as adhesion layers for chemical-vapo r-deposited W, or as barrier layers between Si and Al. Rapid thermal a nneal (RTA) of MOCVD-TiN and physical-vapor-deposited (PVD) Ti/MOCVD-T iN 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 substrate s, just as with completely sputter-deposited Ti/TiN bi-layers. Law con tact resistance to p(+)-Si is demonstrated with PVD-Ti/MOCVD-TiN bilay ers. It is demonstrated that thermal decomposition of TDEAT (i.e. with out 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 candida tes far barrier and adhesion layers.