title: Tungsten allylimido complexes Cl4(RCN)W(NC3H5) as single-source CVD precursors for WNxCy thin films. Correlation of precursor fragmentation to film properties.
abstract: A mixture of the tungsten allylimido complexes Cl(4)(RCN)W(NC(3)H(5)) (3a, R = CH(3) and 3b, R = Ph) was tested as a single-source precursor for growth of tungsten nitride (WN(x)) or carbonitride (WN(x)C(y)) thin films. Films deposited from 3a,b below 550 degrees C contained amorphous beta-WN(x)C(y), while those deposited at higher temperatures were polycrystalline. Film growth rates from 3a,b ranged from 5 to 10 A/min over a temperature range of 450-650 degrees C, and the apparent activation energy for film growth was 0.15 eV. A plot of the E(a) values for deposition from Cl(4)(RCN)W(NR') [R' = Ph, (i)Pr, allyl] against the N-C imido bond strengths for the analogous amines R'NH(2) is linear, implicating cleavage of the N-C bond as the rate-determining step in film growth. The correlation of mass spectral fragmentation patterns for Cl(4)(RCN)W(NR') with film properties such as nitrogen content supports the significance of facile N-C bond cleavage in film growth.
authors.affiliation: Department of Chemical Engineering, University of Florida, Gainesville, Florida 32611, USA.
authors.forename: Omar J
authors.initials: OJ
authors.lastname: Bchir
authors.forename: Kelly M
authors.initials: KM
authors.lastname: Green
authors.forename: Hiral M
authors.initials: HM
authors.lastname: Ajmera
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Zapp
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Anderson
authors.forename: Benjamin C
authors.initials: BC
authors.lastname: Brooks
authors.forename: Laurel L
authors.initials: LL
authors.lastname: Reitfort
authors.forename: David H
authors.initials: DH
authors.lastname: Powell
authors.forename: Khalil A
authors.initials: KA
authors.lastname: Abboud
authors.forename: Lisa
authors.initials: L
authors.lastname: McElwee-White