Effective reduction of trap density at the Y2O3/Ge interface by rigorous high-temperature oxygen annealing.

The impact of thermal post deposition annealing in oxygen at different temperatures on the Ge/Y₂O₃ interface is investigated using metal oxide semiconductor capacitors, where the yttrium oxide was grown by atomic layer deposition from tris(methylcyclopentadienyl)yttrium and H2O precursors on n-type (100)-Ge substrates. By performing in-situ X-ray photoelectron spectroscopy, the growth of GeO during the first cycles of ALD was proven and interface trap densities just below 1 × 1011 eV^-1cm^-2 were achieved by oxygen annealing at high temperatures (550 °C-600 °C). The good interface quality is most likely driven by the growth of interfacial GeO₂ and thermally stabilizing yttrium germanate. [ABSTRACT FROM AUTHOR]