Synthetic studies of metal amide and hydrazide complexes and deposition of tantalum nitride and zirconium oxide films

A new precursor system for the deposition of tantalum nitride films has been developed. The tantalum(IV) complex Ta(NEt2) 2(NCy2)2 was synthesized and its structure was determined by X-ray crystallography. Ta(NEt2)2(NCy 2)2 has a distorted tetrahedral geometry. Tantalum nitride films were prepared from Ta(NEt2)2(NCy2) 2 and ammonia at 340°C using aerosol-assisted chemical vapor deposition. The films on glass had resistivities of 2.5 +/- 0.1 x 10 5muO·cm. Rutherford backscattering spectrometry, forward recoil spectrometry, and X-ray photoelectron spectroscopy data suggest the films have a composition of approximately TaN1.5H0.3--0.5 . The X-ray photoelectron spectroscopy data also indicates that the average tantalum oxidation state is +4 and that each hydrogen atom in the film is associated with two nitrogen atoms on average. The films were a barrier to diffusion between copper and silicon at 500°C for one hour. The results of this study suggest that the oxidation state of the metal in the precursor controls the oxidation state of the metal in the film, and thereby the film stoichiometry and properties.; Chlorotris(trimethylhydrazido)titanium, TiCl(NMeNMe2) 3, was synthesized by reacting TiCl2(NMeNMe2) 2 with one equivalent of LiNMeNMe2. Tetrakis(trimethylhydrazido)zirconium and hafnium, M(NMeNMe2)4, were prepared from MCl 4 and four equivalents of LiNMeNMe2 but Ti(NMeNMe2) 4 could not be prepared cleanly from TiCl4. Instead, it was synthesized from TiCl(NMeNMe2)3 and LiNMeNMe2. X-Ray crystallographic studies show that TiCl(NMeNMe2)3 and Ti(NMeNMe2)4 have three bidendate hydrazide ligands while Zr(NMeNMe2)4 has four bidendate ligands.; The complex Zr(NMeNMe2)4 was used as a precursor to zirconium oxide thin films in a low-pressure chemical vapor deposition system with oxygen gas as a co-reactant. Zirconium oxide films can be obtained at temperatures as low as 390°C. The films were amorphous and free of carbon and nitrogen contaminants.; The chemistry of bulky hydrazido ligands was also examined. The salts LiNEtNMe2 and LiN(i-Pr)NMe2 were prepared and used to synthesize group IV and cerium hydrazide complexes. The complexes M(NEtNMe2)4 (M = Zr, Hf), ZrCl(N(i-Pr)NMe 2)3, LiCe(N(i-Pr)NMe2)4 , and Li[Ce(NMeNMe2)4]·LiCl·OEt 2 were prepared and characterized.; Zirconium amide-iodide complexes were synthesized for possible use as chemical vapor deposition precursors to zirconium nitride films. The series of six complexes Zr(NR2)4-nIn (R = Me or Et; n = 1, 2 or 3) was prepared by reacting ZrI4 and Zr(NR 2)4 in hot toluene. X-Ray crystallographic analyses were performed for Zr(NMe2)3I, Zr(NEt2)2 I2, and Zr(NEt2)I3. In the solid state, Zr(NMe2)3I and Zr(NEt2)2I 2 are the discrete dimers [Zr(NMe2)2I(mu-NMe 2)]2 and [Zr(NEt2)2I(mu-I)] 2, and Zr(NEt2)I3 is the polymer of dimers {lcub}[Zr(NEt 2)I2(mu-I)]2{rcub}n. In solution, Zr(NEt 2)3I is proposed to be monomeric based on NMR data and a molecular weight determination. The complex Zr(NEt2)3I is the most promising precursor candidate because of its physical properties.