ELECTRON-SPIN-RESONANCE IN MICROCRYSTALLINE CUBIC BORON-NITRIDE AMORPHOUS HYDROGENATED BORON-NITRIDE MIXED-PHASE THIN-FILMS

Electron spin resonance and transmission electron microscopy results a re reported that confirm the presence of a microcrystalline as well as an amorphous phase in thin boron nitride films grown by plasma assist ed chemical vapor deposition. Line broadening effects in hydrogenated and deuterated samples indicate that a broad central line can be assoc iated with dangling bonds in the amorphous phase, whereas a four-line spectrum and a ten-line spectrum can be associated with paramagnetic b oron defect centers located in the microcrystalline phase. The danglin g bond concentration is ten times the concentration of the one-boron d efects. The hyperfine coupling constant for the one-boron center in th e cubic microcrystalline regions is only 20% of the previously reporte d value for a similar center in hexagonal boron nitride. The relative concentrations of the dangling bonds, the one-boron centers and the th ree-boron centers depend on the exact plasma conditions used to form t he thin films.