Fabrication of Bonded GeOI Substrates with Thin Al2O3/SiO2 Buried Oxide Layers

In this report, GeOI substrates with thin Al₂O₃/SiO₂ buried oxide layers are fabricated for the first time. Structures of the GeOI substrates and electrical characteristics of the GeOI/BOX interfaces are investigated.work with previous products. Thin-body GeOI substrates with thin Al₂O₃/SiO₂ BOX layers are successfully fabricated for the first time. It is found that the bonding interface was robust enough for MP and CMP even after bonding at a room temperature in atmosphere. The GeOI surfaces etched with O₃ water are atomically flat. Moreover, D_it of as low as 3.9e+11 eV^-1cm^-2 at the GeOI/BOX is obtained. These results suggest that negligible negative impact on carrier mobility and sub-threshold characteristics can be realized by using the GeOI substrates with thin Al₂O₃/SiO₂ BOX layers.