Ge nanodot-mediated densification and crystallization of low-pressure chemical vapor deposited Si₃N₄ for advanced complementary metal-oxide-semiconductor photonics and electronics applications

A new phenomenon of highly localized, nanoscale densification and crystallization of silicon-nitride (Si₃N₄) layers has been observed. A drastic reduction in the thermal budget (temperature and processing time) for local densification and even nanocrystallization of low-pressure chemical vapor deposited amorphous Si₃N₄ layers is mediated by the presence of Ge, Si, and O interstitials in close proximity to the Si₃N₄. The enhancement of localized densification and nanocrystallization observed in Si₃N₄ layers appears to be catalyzed by proximal Ge quantum dots (QDs) 'migrating' through the Si₃N₄/Si layers and are influenced by the oxidation time and Ge QD size. Implications of the highly localized, nanoscale densification and crystallization of silicon-nitride (Si₃N₄) layers for photonic and electronic device applications are discussed.