Structural features of thick c-boron nitride coatings deposited via a graded B-C-N interlayer
2001 (English)In: Surface & Coatings Technology, ISSN 0257-8972, Vol. 142-144, 881-888 p.Article in journal (Refereed) Published
Thick c-BN films (up to 2.7 µm) were deposited onto Si substrates by an r.f. diode apparatus using boron carbide (B4C) targets. The c-BN films were deposited on a compositionally graded interlayer, which consisted of B, C and N. A thin B4C layer (~200 nm) had been initially deposited onto Si substrate in a pure Ar gas discharge. The following formation of the graded interlayer was conducted by the step-like or smoothly replacing Ar with N2 gas. Depending on the method implemented, the secondary ion mass spectroscopy (SIMS) depth profile showed relatively smooth or step-like changes in the elemental concentration of B, C and N. The primary analysis on the chemical bond of the graded interlayer was conducted by measuring the chemical shift of B1s, C1s and N1s spectra by X-ray photoelectron spectrometry (XPS). It is shown that the B-C bond, which was a major bonding component in the B4C layer, was gradually replaced by a mixture of B-N and C-C bond as the N2 fraction was increased. Transmission electron microscopy (TEM) images of the gradient layer showed that (0002) oriented turbostratic BN (t-BN) structure started to appear after the N2 concentration was increased by more than 2%. It was also observed that the c-BN phase nucleated non-uniformly in the gradient layer at 10% of N2 fraction. © 2001 Elsevier Science B.V. All rights reserved.
Place, publisher, year, edition, pages
2001. Vol. 142-144, 881-888 p.
c-Boron nitride films, Graded interlayer, Si substrate, Structural features
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-47331DOI: 10.1016/S0257-8972(01)01212-9OAI: oai:DiVA.org:liu-47331DiVA: diva2:268227