Hexagonal Nano-Crystalline BCN Films Grown on Si (100) Substrate Studied by X-Ray Absorption Spectroscopy

Abstract

Hexagonal nano-crystalline boron carbonitride (h-BCN) films grown on Si (100) substrate have been precisely investigated. The films were synthesized by radio frequency plasma enhanced chemical vapor deposition using tris-dimethylamino borane as a single-source molecular precursor. The deposition was performed by setting RF power at 400 - 800 W. The reaction pressure was at 2.6 Pa and the substrate temperature was recorded at 700°C - 800°C. Formation of the nano-crystalline h-BCN compound has been confirmed by X-ray diffraction analysis. The diffraction peaks at 26.3° together with a small unknown peak at 29.2° were elucidated due to the formation of an h-BCN structure. The films composed of B, C, and N atoms with different B-N, B-C, C-N chemical bonds in forming the sp2-BCN atomic configuration studied by X-ray photoelectron spectroscopy. Orientation and local structures of the h-BCN hybrid were studied by near-edge X-ray absorption fine structure (NEXAFS) measurements. The dominant presence of p* and s* resonance peaks of the sp2-hybrid orbitals in the B K-edge NEXAFS spectra revealed the formation of the sp2-BCN configuration around B atoms like-BN3 in h-BN. The orientation was suggested on the basis of the polarization dependence of B K-edge and N K-edge of the NEXAFS spectra.