La yl preparing high dielectric constant gate dielectric material based on germanium substrate

The present invention discloses a method for preparing a high dielectric constant gate dielectric yl La material based on germanium substrates, mainly to solve the traditional low dielectric constant, thermal stability and compactness of the film is poor. The bottom-gate dielectric material comprises an interface layer (1), the barrier layer (2), La based high dielectric constant film (3) and the protective layer (4), wherein the interface layer (1) of 0.5-1nm of GeO2; barrier layer (2) with a thickness of 0.5-2nm of Al2O3; La based high dielectric constant film (3) with a thickness of 1-10nm of La2O3 or LaAlO3 or HfLaOx; protective layer (4) with a thickness of 1-2nm of Al2O3. Overall material prepared using atomic layer deposition method, for low and high temperature annealing treatment After preparation. The present invention has a high dielectric constant, the film density and good step coverage, good thermal stability, low surface roughness advantages, may be used for the gate dielectric film manufacturing a metal oxide semiconductor field effect transistor.