PLASMA TREATMENT OF THERMAL CVD TAN FILMS FROM TANTALUM HALIDE PRECURSORS

摘要

Plasma treated chemical vapor deposition (PTTCVD) method for depositing high quality conformal tantalum nitride (TaNx) films from inorganic tantalum halide (TaX5) precursors and nitrogen containing gas is described. Inorganic tantalum halide precursors are tantalum pentafluoride (TaF5), tantalum pentachloride (TaCl5) and tantalum pentabromide (TaBr5). In thermal CVD process, TaX5 vapor is delivered into heated chamber (11). Vapor is combined with process gas containing nitrogen to deposit TaNx film on substrate that is heated to 300 DEG C-500 DEG C. Hydrogen gas is introduced in radiofrequency generated plasma to plasma treat TaNx film. Plasma treatment is performed periodically until desired TaNx film thickness is achieved. PTTCVD films have improved microstructure and reduced resistivity with no change in step coverage. Deposited TaNx film is useful for integrated circuits containing copper films, especially in small high aspect ratio features. High conformality of these films is superior to films deposited by PVD.