Selective bond-breaking and bond-making in oxynitride of Si and Ge: a case of chemical bond manipulation

Abstract

In this letter, we show that manipulation of the surface chemical bonds is possible by making use of the distinctly different thermodynamic pathways of the various surface species. The dissociation temperatures of GeO, GeN, SiO and SiN bonds are found to be respectively about 360°C, 490°C, 740°C and > 1000°C. These vastly different dissociation temperatures enable one to manipulate the surface chemical bonds. We demonstrate this idea by examining the reaction of Si with a Ge oxynitride film. Deposition of Si on to a thin Ge oxynitride film followed by annealing results in stepwise breaking of GeO and GeN bonds and formation of SiO and SiN bonds. This way, one can achieve formation of the desired species on a full-wafer-scale. Surface spectroscopic techniques such as UPS, XPS and AES are employed for the study.