New Tantalum Amido Complexes with Chelate Ligands as Metalorganic (MO) Precursors for Chemical Vapor Deposition (CVD) of Tantalum Nitride Thin Films

Four new tantalum amido precursors (η2-RN(CH2)nNR)Ta(NMe2)3 (where R = Me, n = 2, 1; R = Et, n = 2, 2; R = Me, n = 3, 3; R = Et, n = 3, 4) with chelate diamide ligands and one new tantalum amido precursor (η2-tBuNC(NMe2)NEt)Ta(NMe2)4) (5) with a chelate guanidinate ligand were prepared and characterized. Their thermal behavior, especially (NMe2)3Ta(η2-MeN(CH2)2NMe) (1), were investigated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) experiments to demonstrate the enhancement of their thermal stability and preservation of the volatility as metalorganic chemical vapor deposition (MOCVD) precursors as compared to Ta(NMe2)5 (PDMAT). Introduction of the asymmetric chelate guanidine ligand in complex 5 gave improved volatility as compared with its known isomer [(η2-iPrNC(NMe2)NiPr)Ta(NMe2)4 (6). The crystal structures of 5 and 6 were measured to investigate the correlation between the volatility and intermolecular interactions. The MOCVD of tantalum nitride thin films was succe...