Improvement of interfacial properties with interfacial layer in La₂O₃/Ge structure

The electrical characteristics and interfacial properties of La₂O₃/Ge structures under various post-deposition annealing (PDA) conditions are studied. We found that the interfacial Ge oxide layer reduced the D_it, while redundant growth of the oxide led to increment of CET. In order to satisfy small CET and low D_it, appropriate interfacial layer (IL) thickness is assumed to be 1.0-1.5 nm. On the other hand, Ge sub-oxide in the IL caused to increase hysteresis. Instead, by introducing the Ge chemical oxide, an interfacial La-germanate layer formed with PDA at 500 °C in N₂, which could reduced both the hysteresis and D_it.