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−1 cm−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.

Y2O3 and L2O3/ZrO2 stacks have been examined in terms of their electrical properties in Ge capacitors. It is discussed that scaling of L2O3/ZrO2 stacks into the sub 1 nm EOT regime can be achieved either by using thin amorphous La2O3 capped by a thin ZrO2 layer or by stabilizing the tetragonal or cubic very high-k phase of ZrO2 induced by diffused La and Ge atoms during a PDA step. Y2O3 shows very good interfacial qualities in terms of a low interface trap density and hysteresis when an annealing in O2 atmosphere is applied. Fowler-Nordheim tunneling is identified as the primary leakage current mechanism at high gate bias whereas for the low bias regime leakage current is primary conducted by direct tunneling through the Y2O3 layer.

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The resistance of ultrathin metal films (Ag, Au, Cr, Ir, Pt, and Ti) on hydrofluoric acid-treated Si(111) surfaces is investigated during room temperature evaporation at very low deposition rates (0.003–0.006 nm/s). High-resolution in situ measurements are performed using the four-point probe technique. The authors find that, in addition to the type of metal, the resistance versus metal thickness characteristics heavily depend on the doping of the Si substrate. Furthermore, for most metals on p-type Si, the resistance initially increases as a function of deposition time. The authors explain this by a conductive path at the surface due to H-terminated Si bonds which are destroyed during deposition.