Atomic Layer Deposition of Lanthanum Oxide Films for High-κ Gate Dielectrics

Lanthanum-containing oxide films are emerging candidates for gate-oxide films, due to expected high dielectric constants as well as promising crystal and electronic band structure. We have used tris(bistrimethylsilylamido)-lanthanum to achieve atomic layer deposition of on a (100) Si wafer. Crystalline and electrical properties of the resulting films have been characterized. Dielectric constant values in the range of 20-23, and a dielectric breakdown field of about 4.2 MV/cm were observed. The electrical properties of our structures remain consistent even after prolonged ambient exposure.