Lu 2 O 3 ∕ Al 2 O 3 gate dielectrics for germanium metal-oxide-semiconductor devices

Effect of Ge out diffusion into Lu2O3∕Al2O3 high-k dielectric stack was investigated. Increasing Ge signal intensity with increasing annealing temperature was observed, which suggests that there may be excessive Ge incorporation into the high-k film. The electrical measurement shows an improvement of the k value with annealing temperature, as well as an increasing trend in the leakage current density suggesting degradation in electrical performance due to Ge incorporation. Our work suggests that 8.8at.% of Ge in the film is excessive and result in degradation of the electrical performance of the device due to the increased leakage current.