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Chemical bonding states and local structures of the oriented hexagonal BCN films synthesized by microwave plasma CVD

✍ Scribed by Md. Abdul Mannan; Hideyuki Noguchi; Tetsuya Kida; Masamitsu Nagano; Norie Hirao; Yuji Baba


Publisher
Elsevier Science
Year
2008
Tongue
English
Weight
632 KB
Volume
11
Category
Article
ISSN
1369-8001

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✦ Synopsis


In order to synthesize oriented hexagonal boron carbonitride (h-BCN) films, boranetriethylamine complex (C 6 H 18 BN) was used as a single-source precursor. The films were deposited on Si (1 0 0) substrate by microwave plasma-enhanced chemical-vapor deposition using CH 4 +H 2 as the carrier gas. The deposition was performed at different microwave powers of 200-500 W at working pressure of 5.0 Torr. The microhardness, estimated by nano-indentation test, of the films was found to be around 4 GPa. Fourier transform infrared spectroscopy (FT-IR) confirmed the formation of hexagonal BCN phase in a short-range order. The chemical composition and the local structures of films were studied by X-ray photoelectron spectroscopy (XPS) and the near-edge X-ray absorption fine structure (NEXAFS) spectroscopic measurements. XPS revealed that B, C and N atoms in the deposited films are in various chemical environments such as B-N, B-C, C-N and B-C-N atomic hybrid configuration. The NEXAFS measurement suggested that the B atoms are bonded not only to the N atoms but also to the C atoms to form various local structures of sp 2 B-C-N hybrid configurations. The polarization dependence of NEXAFS suggested that the local structures of the sp 2 BCN layers have different atomic orientations to the substrate.