Higher-k LaYOx films with strong moisture-robustness

The permittivities and the resistance to moisture of LaYOx (LYO) films annealed at 600degC with different Y concentrations are investigated. The permittivities of 40%Y-LYO film and 70%Y-LYO film are higher than 25. The high permittivities come from the well crystallized hexagonal phase of LYO films. For rare earth oxides, the hexagonal phase shows higher permittivity than the cubic phase due to the smaller molar volume of the hexagonal phase. Furthermore, the high permittivity LYO films (40%Y-LYO and 70%Y-LYO) show strong resistance to the moisture due to the introduction of Y₂O₃ which owns stronger resistance to the moisture than La₂O₃