LaAlO{sub 3}/Si capacitors: Comparison of different molecular beam deposition conditions and their impact on electrical properties
A study of the structural and electrical properties of amorphous LaAlO{sub 3} (LAO)/Si thin films fabricated by molecular beam deposition (MBD) is presented. Two substrate preparation procedures have been explored namely a high temperature substrate preparation technique-leading to a step and terraces surface morphology-and a chemical HF-based surface cleaning. The LAO deposition conditions were improved by introducing atomic plasma-prepared oxygen instead of classical molecular O{sub 2} in the chamber. An Au/Ni stack was used as the top electrode for its electrical characteristics. The physico-chemical properties (surface topography, thickness homogeneity, LAO/Si interface quality) and electrical performance (capacitance and current versus voltage and TunA current topography) of the samples were systematically evaluated. Deposition conditions (substrate temperature of 550 Degree-Sign C, oxygen partial pressure settled at 10{sup -6} Torr, and 550 W of power applied to the O{sub 2} plasma) and post-depositions treatments were investigated to optimize the dielectric constant ({kappa}) and leakage currents density (J{sub Gate} at Double-Vertical-Line V{sub Gate} Double-Vertical-Line = Double-Vertical-Line V{sub FB}- 1 Double-Vertical-Line ). In the best reproducible conditions, we obtained a LAO/Si layer with a dielectric constant of 16, an equivalent oxide thickness of 8.7 A, and J{sub Gate} Almost-Equal-To 10{sup -2}A/cm{sup 2}. This confirms the importance of LaAlO{sub 3} as an alternative high-{kappa} for ITRS sub-22 nm technology node.