Infrared vibrations of as-deposited and annealed semiconducting boron carbide thin films were investigated by midinfrared spectroscopic ellipsometry. The strong boron-hydrogen resonance at ∼2560 cm-1 in as-deposited films reveals considerable hydrogen incorporation during plasma-enhanced chemical vapor deposition. Extended annealing at 600 °C caused significant reduction in film thickness, substantial reduction of boron-hydrogen bond resonance absorption, and development of distinct blue-shifted boron-carbon and icosahedral vibration mode resonances. Our findings suggest that annealing results in substantial loss of hydrogen and in development of icosahedral structure, accompanied by strain relaxation and densification.
ASJC Scopus subject areas
- Physics and Astronomy(all)