Study of thermally oxidized yttrium films on silicon

Electrical and structural characteristics of thin thermally oxidized yttrium layers on Si and on Si covered with 40 A of SiO2 have been investigated. The factor of ∼ four advantage in the dielectric constant of Y2O3 over SiO2, coupled with extremely low leakage current density of better than 10−10 A/cm2 in a field of 1.9 MV/cm, sufficiently high breakdown strength, and well‐behaved capacitance‐voltage characteristics makes Y2O3 a viable candidate for Si very large scale integration applications, at least in passive devices. High‐resolution transmission electron microscopy reveals the structure of the composite dielectric and provides good agreement between calculated and experimental capacitance.