Chemical vapor deposition of tantalum nitride films for metal gate application using TBTDET and novel single-source MOCVD precursors

摘要

In this paper, physical and electrical properties of TaN films used as metal electrodes in MOS structures are discussed. TaN films were deposited by MOCVD from commercial TBTDET and two novel mixed amido/imido/guanidinato and mixed amido/imido/hydrazido precursors. It will be shown that morphology (only films deposited from the guanidinato compound above 750℃ showed cubic TaN phase while all other films were amorphous) and O content (5 at. and 25 at. in case of guanidinato and in case of TBTDET precursor, respectively) do not necessary predetermine resistivity. Lowest resistivity (230 μΩ cm) was obtained for TBTDET. Evaluated values of metal work function are 4.4-4.6 eV (TBTDET) and 3.9 eV (guanidinato compound). Films deposited from the hydrazido compound reveal bad electrical properties (e.g., metal layers behave dielectric-like).