Atomic Vapor Depositions of Ti–Ta–O thin films for Metal–Insulator–Metal applications

Atomic Vapor Deposition technique was applied for the depositions of Ti–Ta–O oxide films for Metal–Insulator–Metal capacitors used in back-end of line for Radio Frequency applications. Composition, crystallinity, thermal stability and electrical properties were studied. Ti–Ta–O films, with the ratio of Ta/Ti ~ 1.5, deposited at 400 °C on TiN electrodes, were amorphous and possessed a dielectric constant of 50 with low voltage linearity coefficients and leakage currents densities as low as 10− 7 A/cm2 at 1 V. The films, deposited on Si wafers, were amorphous up to the annealing temperature of 700 °C and crystallized in orthorhombic Ta2O5 phase at higher temperatures.