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

Abstract

Four new tantalum amido precursors (η 2 -RN(CH 2 ) n NR)Ta(NMe 2 ) 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 (η 2 -t BuNC(NMe 2 )NEt)Ta(NMe 2 ) 4 ) (5) with a chelate guanidinate ligand were prepared and characterized. Their thermal behavior, especially (NMe 2 ) 3 Ta(η 2 -MeN(CH 2 ) 2 NMe) (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-(NMe 2 ) 5 (PDMAT). Introduction of the asymmetric chelate guanidine ligand in complex 5 gave improved volatility as compared with its known isomer [(η 2 -i PrNC(NMe 2 )N i Pr)Ta(NMe 2 ) 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 successfully achieved using 1. The films are based on field emission scanning electron microscopy (FESEM) and show good adhesion properties. Rutherford backscattering spectrometry (RBS) and X-ray photoelectron spectroscopy (XPS) data suggest that the film deposited using 1 at 500°C under ammonia has a composition of TaN 1.22(0.14 with negligible carbon and oxygen levels. It also shows low resistivity of 1.4 Â 10 3 μΩ cm on SiO 2 /Si and broad X-ray diffraction (XRD) peaks for the stoichiometric cubic refractory TaN, indicating the potential of 1 becoming an alternative MOCVD precursor for barrier applications.

An iron (II) guanidinate compound: Synthesis, characterization, thermal properties and its application as a CVD precursor for iron oxide film

“…In recent years, numerous transition metal guanidinate compounds have been used as precursors for the preparation of metal‐based thin film materials using CVD technology. For example, [Ta (NMe 2 ) 4 ( η 2 ‐ t BuNC (NMe 2 )NEt)] has been used for TaN film preparation; [Ti (NMe 2 ) 3 ( i PrNC (NMe 2 )N i Pr)] has been employed to manufacture N‐doped TiO 2 film; and [Co( i PrNC(N (SiMe 3 ) 2 )N i Pr) 2 ] has been used to prepare Co 3 O 4 film . By contrast, to the best of our knowledge, relevant research on the iron guanidinate compound remains unexplored.…”

Synthesis and reactivity of Li and TaMe3 complexes supported by N,N′-bis(2,6-diisopropylphenyl)-o-phenylenediamido ligands

“…Compared to this abundance of examples of Ta complexes of decorated diamido ligands, simple diamido ligands have not been as well-studied. Tantalum complexes of ligands based on 1,8-diamidonaphthalene, [39][40][41] 1,3-diamidopropane, 42, 43 1,4-diaza-1,3-butadiene, [44][45][46][47][48][49] and o-phenylenediamide (opda) are known. Of the opda complexes, most employ N,N′-disilyl groups, 41,[50][51][52][53] with one report on neopentyl groups.…”

Tunable electrical properties of TaNx thin films grown by ionized physical vapor deposition

“…6,7,9 However, in the case of nitrogen-rich TaN films, the reported a) Present address: Institut des Nanotechnologies de Lyon, CNRS, Ecole Centrale de Lyon, 36 Avenue Guy de Collongue, 69134 Ecully Cedex, France. 8,26,27 When a high aspect ratio is needed, PVD is impractical due to the nonconformal and highly directional deposition. 8 Generally, the electrical resistivity increases rapidly with increasing nitrogen content.…”