Atomic layer deposition of Al2O3, ZrO2, Ta2O5, and Nb2O5 based nanolayered dielectrics

Abstract Ta2O5, Ta–Nb–O, Zr–Al–Nb–O, and Zr–Al–O mixture films or solid solutions were grown on Si(1 0 0) substrates at 300 °C by atomic layer deposition. The equivalent oxide thickness of Ta2O5 based capacitors was between 1 and 3 nm. In Zr–Al–O films, the high permittivity of ZrO2 was combined with high resistivity of Al2O3 layers. The permittivity, surface roughness and interface charge density increased with the Zr content and the equivalent oxide thickness was between 2.0 and 2.5 nm. In the Zr–Al–Nb–O films the equivalent oxide thickness remained at 1.8–2.0 nm.