TRENDS AND FUTURE PROSPECTS - Total-Reflection X-Ray Fluorescence Analysis and Related Methods - page 478

Several methods of X-ray spectral analysis were applied for a characteriza-
tion of these thin layers. SEM/EDX was used to determine the main compo-
nents B, C, and N between 7% and 45% leading to a stoichiometric formula
B x C y N z . For a sum z + x + y = 10, the uncertainty of the indices was estimated to
be ± 0.5. In a triangle diagram, two main clusters of samples could be identified
as demonstrated in Figure 7.21. The first cluster was found for six samples of
TMAB and TEAB without the addition of ammonia. The respective center lies
in the carbonic region and leads to the formula B 3.7 C 4.4 N 2 . The second cluster
was built by the remaining 10 samples of TMAB and TEAB with the addition
of ammonia and for four samples of TMB without or with ammonia. The center
lies in the nitridic region with the stoichiometric formula B 3.6 C 1.5 N 4.9 . While the
fraction of boron is nearly the same for all samples, carbon and nitrogen
substitute each other in samples from the two different clusters.
Near-edge X-ray absorption fine structure spectra of B, C, and N were
recorded above 185, 280, and 395 eV, respectively, as shown in Figure 7.22.
Figure7.21. Triangle diagram for boron carbonitrides with the chemical formula B x C y N z . The
elemental composition of such layers is represented in at.%. Pure boron, pure carbon, or
pure nitrogen has a position at the three edges of the triangle; binary compounds can be found
in the center of the three sides. The different compounds analyzed by EPMA build two clusters
around B 3.7 C 4.4 N 2 and B 3.6 C 1.5 N 4.9 . Several data from literature are marked as small black dots.
Figure from Ref. [136], reproduced with permission. Copyright2012, John Wiley and Sons.