Zirconium alkyls were applied for the MOCVD growth of Zr -containing materials, f.e. they are convenient single-souce MOCVD precursors for the growth of of ZrC thin films [673] It was reported to be not possible to grow ZrC films using tetrabenzylzirconium (ZrBn4), or in N2 carrier gas .
Zirconium alkyls such as tetrakis-neopentylzirconium Zr(CH2tBu)4, (ZrNep4) was applied as single-souce MOCVD precursor for the growth of of ZrC thin films [673]
Synthesis: ZrCl4 + 4 LiR’ → ZrR’4 + 4 LiCl (R = CH2tBu)
Zr(CH2tBu)4 was applied for the growth of ZrC films by MOCVD. ZrC films are obtained at higher temps (>500 °C) with a Zr:C ratio of 1:2. Formation of both carbidic and graphitic carbon.was revealed by XPS.
Tetrakis(neopentyl)zirconium (ZrNep4) dissolved in in benzonitrile (PhCN) was applied for the deposition of aerosol-assisted MOCVD of thin films of zirconium carbide (ZrC) on Si(111) substrates
in the temperature range 400–600 °C. According to preliminary equilibrium calculations, a minimal level of H2 was needed to prevent codeposition of solid carbon (C), with the minimum level decreased with decreasing temperature. Films were grown at
various temperatures, pressures, and H/Zr inlet molar ratio, as well different carrier gases (H2, He, or N2), and were amorphous as determined by XRD. According to Auger electron spectroscopy, the trends in the measured composition of each film were qualitatively
consistent with those of the equilibrium calculation), while XPS analyses confirmed the formation of Zr–C and Zr–O bonds. It was not possible to grow films in N2 carrier gas or using tetrabenzylzirconium (ZrBn4). The results of density functional
theory (DFT) calculations on ZrNp4 and ZrBn4 supported the obtained result. [[i]]
[i]Y. S. Won, Y. S. Kim, V. G. Varanasi, O. Kryliouk, T. J. Anderson, Ch. T. Sirimanne, L. McElwee-White, J. Cryst. Growth, 2007, vol. 304, Iss. 2, p. 324-332, “Growth of ZrC thin films by aerosol-assisted MOCVD”