Cl-4(PhCN)W(NPh) as a single-source MOCVD precursor for deposition of tungsten nitride (WNx) thin films

摘要

The tungsten phenylimido Complex Cl-4(PhCN)W(NPh) (2b) was tested as a single-source precursor for growth of tungsten nitride (WNx) thin films, and results were compared to films previously deposited from the isopropylimido complexes Cl-4(RCN)W((NPr)-Pr-i) (1a, R = CH3; 1b, R = Ph). Films deposited from 2b exhibited growth rates ranging from 2 to 21 Angstrom min(-1) over a temperature range of 475-750 degreesC, and the apparent activation energy for film growth in the kinetically controlled regime was 1.41+/-0.58 eV. Amorphous beta-WNx films were deposited below 500 degreesC, with minimum film resistivity and sheet resistance of 225 muOmega-cm and 75 Omega/rectangle, respectively, observed for deposition at 475 degreesC. In contrast, films deposited from the isopropylimido complexes 1a,b exhibited higher growth rates and higher nitrogen content over a similar temperature range. These differences are attributed to the higher dissociation energy of the imido N-C bond in phenylimido complex 2b. Mass spectrometry fragmentation patterns are consistent with this behavior. (C) 2003 Elsevier B.V. All rights reserved. [References: 53]