Anomalous distribution of germanium implanted into a SOI dielectric layer after the annealing of radiation defects

The germanium-distribution profile is investigated in a Si/SiO$_2$/Si structure after the implantation of $^{74}$Ge into SiO$_2$ dielectric layer, bonding with the Si device layer, and high-temperature annealing. The anomalously high transport and accumulation of $^{74}$Ge atoms near the SiO$_2$/Si interface far from the bonded boundary is found. The observed $^{74}$Ge distribution is beyond the framework of the existing model of diffusion of Ge in Si and SiO$_2$ after postimplantation annealing. A modified model of diffusion of Ge atoms near the Si/SiO$_2$ interface qualitatively explaining the observed features is proposed.