Impact of nitridation on open volumes in HfSiOx studied using monoenergetic positron beams

The effects of nitridation on open volumes in thin HfSiOx films fabricated by metal-organic chemical vapor deposition were studied using monoenergetic positron beams. It was found that positrons were annihilated from the trapped state by open volumes that exist intrinsically in amorphous HfSiOx structures. In an as-deposited film, the positrons were annihilated from two different types of open volume. After plasma nitridation, the probability of positrons trapped by larger open volumes decreased, which is attributed to nitride trapped by such regions. The mean size of the open volumes increased after annealing, suggesting expansion of the open volumes due to the incorporation of nitride into the HfSiOx matrix.