Impacts of the Oxygen Precursor on the Interfacial Properties of La(x)Al(y)O Films Grown by Atomic Layer Deposition on Ge

Amorphous La(x)Al(y)O films were grown on n-type Ge substrate by atomic layer deposition using O(3) and H(2)O as oxidant, respectively. A comparison of the XPS results indicated that a thicker interfacial layer with the component of LaGeO(x) and GeO(x) was formed at O(3)-based La(x)Al(y)O/Ge interface, causing lower band gap value as well as the conduction band offset (CBO) value relative to Ge substrate for O(3)-based La(x)Al(y)O film, with a concomitant degeneration in the interfacial properties. In contrast, for the H(2)O-based film, the leakage current of more than one order of magnitude less than that of O(3)-based La(x)Al(y)O film was obtained. All the results indicated that H(2)O is a more appropriate oxidant for improving the interfacial properties in the atomic-layer-deposited La(x)Al(y)O dielectric on Ge.