Theoretical and spectroscopic investigations on the structure and bonding in B–C–N thin films

Abstract

In this study, we have synthesized boron, carbon, and nitrogen containing films using RF sputter deposition. We investigated the effects of deposition parameters on the chemical environment of boron, carbon, and nitrogen atoms inside the films. Techniques used for this purpose were grazing incidence reflectance-Fouriertransform infrared spectroscopy (GIR-FTIR), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS). GIR-FTIR experiments on the B-C-N films deposited indicated presence of multiple features in the 600 to 1700 cm − 1 range for the infrared (IR) spectra.Analysis of the IR spectra, XPS and the corresponding EELS data from the films has been done in a collective manner. The results from this study suggested even under nitrogen rich synthesis conditions carbon atoms in the B-C-N films prefer to be surrounded by other carbon atoms rather than boron and/or nitrogen. Furthermore, we have observed a similar behavior in the chemistry of B-C-N films deposited with increasing substrate bias conditions. In order to better understand these results, we have compared and evaluated the relative stability of various nearest-neighbor and structural configurations of carbon atoms in a single BN sheet using DFT calculations. These calculations also indicated that structures and configurations that increase the relative amount of C-C bonding with respect to B-C and/or C-N were energetically favorable than otherwise. As a conclusion, carbon tends to phase-segregate in to carbon clusters rather than displaying a homogeneous distribution for the films deposited in this study under the deposition conditions studied.

Bias in bonding behavior among boron, carbon, and nitrogen atoms in ion implanted a-BN, a-BC, and diamond like carbon films

“…Recently, many researchers have been engaged on the synthesis and characterization of solids in the B-C-N ternary system due to their interesting properties, such as extreme hardness and low coefficient of friction. [1][2][3][4] B, C, and N are close neighbors in the periodic table with the following electronegativity values; 2.04, 2.55, and 3.04, respectively. 5 However, binary compounds between them exhibit a variety of crystal structures.…”

“…The promising physical properties of BCN materials may potentially allow them to be used in the development of bandgap-engineered applications in electronics and optics, 12,13 as wear-resistant coatings, 14 intercalation material in Li-ion batteries, 15 and low-k dielectric layers in electronics industry. 16 Various techniques ranging from high temperature=high pressure processing, 17 explosive compaction, 18 pulsed laser deposition, 19 ion-beam assisted deposition, 3,5,20 to magnetron sputtering, 2,21,22 have been used for the synthesis of BCN materials in bulk or as thin films. The physical properties of BCN materials are directly related with the chemical environment, bonding, and atomic structure of the B, C, and N atoms within.…”

“…There are several studies which scrutinize the characterization methods used for understanding the atomic environment and bonding structure of BCN films. [2][3][4]20,[23][24][25] Often, x-ray photoelectron spectroscopy (XPS) has been used for probing the chemical bonding between boron, carbon and nitrogen atoms [2][3][4][24][25][26][27][28] as binding energy (BE) peak positions in a spectrum obtained during XPS for core shell electrons are affected by the relative electronegativity of coordinated atomic species. While, XPS is a relatively widespread and well-established technique for understanding local chemical interactions in solids, other techniques such a)…”

Synthesis of Hexagonal Boron Carbonitride without Nitrogen Void Defects

“…In order to confirm that the sample was really made up of B-C-N atomic hybrid rather than a mixture of BN and graphite binary phases, narrow scan B1s, C1s and N1s XPS spectra were measured. eV in the N1s spectra would observed if there is an existence of formation of BN-like and graphite-like phases as observed in the references [10] [18]. Therefore, formation of separated binary phases such as BN and/or graphite was not obvious in the present sample.…”

Chemical Vapor Deposition of Hexagonal Boron Nitride

“…The O 1s peak was also observed for the graphene film. The relative compositions of B, C, and N atoms did not strongly depend on the substrate and were determined to be B [13,[15][16][17]). Although the B and N 1s spectra are slightly asymmetric on Co, they show similar shapes.…”