Electrical properties of AI₂O₃/La₂O ₃/AI₂O₃ films using various tunnel oxide thicknesses for non-volatile memory device applications

The electrical properties (including memory windows and leakage current densities) of Al₂O₃/La₂O₃/Al ₂O₃ (ALA) films equipped with 5 nm, 7.5 nm, and 10 nm tunnel oxide layer were investigated. The dielectric constants of all of the tunnel oxide films using Al₂O₂ were the same and the equivalent oxide thickness was dependent on film thickness. The optimized conditions were exhibited in the ALA films with a 5 nm tunnel oxide. The memory window of the ALA films using the 5 nm tunnel oxide was about 1.31 V in the program condition (11 V for 10 ms) and in the erase condition (-13 V for 100 ms). Measurement of the leakage current density showed that all of the films are sufficient for use with flash memory device.