MOCVD of niobium nitrides and oxy-nitrides using an all-nitrogen-coordinated precursor: thin-film deposition and mechanistic studies

In this study, niobium nitride and oxy-nitride thin films were grown by metalorganic chemical vapor deposition (MOCVD) from the guanidinate based niobium compound [Nb(NtBu)(NMe2){C(NiPr)2(NMe2)}2] that served either as a single source precursor (SSP) for NbN or as a niobium and nitrogen source for the growth of niobium oxy-nitride thin films in oxygen atmospheres. The decomposition of this SSP precursor was studied using NMR and mass spectrometry. From the mechanistic studies, it was evident that diisopropylcarbodiimide deinsertion takes place at elevated temperatures. Pure niobium nitride films were obtained without any additional source of nitrogen during the MOCVD process, whereas in the presence of oxygen mixed phases of NbNx, NbOxNy and Nb2O5 were formed. The most relevant results are presented and discussed.