GeO2/Ge structure submitted to annealing in deuterium: Incorporation pathways and associated oxide modifications

Abstract

Deuterium (D) incorporation in GeO2/Ge structures following D2 annealing was investigated. Higher D concentrations were obtained for GeO2/Ge samples in comparison to their SiO2/Si counterparts annealed in the same conditions. Oxygen vacancies produced during the annealing step in D2 constitute defect sites for D incorporation, analogous to defects at the SiO2/Si interfacial region. Besides D incorporation, volatilization of the oxide layer is also observed as a consequence of D2 annealing, especially in the high temperature regime of the present study (>450°C). In parallel to this volatilization, the stoichiometry and chemical structure of remnant oxide are modified as well. These results evidence the broader impact of forming gas annealing in dielectric/Ge structures with respect to SiO2/Si counterparts.