Characterization of a-B5C:H prepared by PECVD of orthocarborane: Results of preliminary FTIR and nuclear reaction analysis studies

The electronic properties of a-Si:H vary with hydrogen passivation of dangling bond defects. It appears this effect is also operative in semiconducting amorphous hydrogenated boron carbide (a-B5C:H). Therefore, the ability to quantify the amount of hydrogen will be key to development of the materials science of a-B 5 C:H. The results of an initial investigation probing the ability to quickly correlate hydrogen concentration in a-B 5 C:H films with infrared spectroscopy are reported. a-B 5 C:H thin films were growth on Si (111) substrates by plasma-enhanced chemical vapor deposition (PECVD) using sublimed orthocarborane and argon as the precursor gas. Nuclear reaction analysis (NRA) was performed to quantify the atomic concentration of H in the a-B 5 C:H films. While the observed vibronic structure does not show stretches due to terminal C-H or bridging B-H-B, analysis of the terminal B-H stretch at ∼2570 cm -1 gives a proportionality constant of A = 2 x 10 22 cm -2 . We conclude that the methods previously developed for correlating H concentration to infrared data in a-Si:H are similarly viable for a-B 5 C:H films.