Ge-based metal-oxide semiconductor structures exhibiting thin ALD-grown high-k dielectric HfO₂ films were fabricated and characterized chemically, structurally, and electrically. X-ray photoelectron (XP) spectroscopy confirms the good stoichiometry of the ALD-grown HfO₂ films. Furthermore, through the analysis of the XP spectra, the conduction and valence band offsets of HfO₂|p-Ge were calculated to be equal to 1.8±0.2 eV and 2.8±0.2 eV, respectively. C(V) and G(V) analysis reveals structures with a well-defined MOS behavior with D_it values in the range of 10¹¹ eV^-1cm^-2 and a dielectric constant of HfO₂ films of 20. The dominant carrier transport conduction mechanisms were studied through J(V) analysis, performed at both substrate and gate electron injection. Specifically, in the low voltage region (V<0.2 V), the prevailing conduction mechanism is Ohmic, with an activation energy of 0.28 eV for both substrate and gate electron injection. In the voltage range 0.4-1.5 V, the dominant conduction mechanism is Frenkel-Poole, through which the trap energy level into HfO₂ films (φ_t) is calculated to be φ_t=0.36 eV. Schottky conduction mechanism is the prevailing one, for high applied bias voltages (V>3.0 V) and high temperatures (>450 K). Applying Schottky's emission model the energy barrier heights of HfO₂|p-Ge and Al|HfO₂ interfaces were evaluated equal to 1.7±0.2 eV and 1.3±0.2 eV, respectively. Combining the XPS and J(V) analysis results, the energy band diagram of Al|HfO₂|p-Ge structures is constructed. The calculated values of conduction and valence band offsets via XPS and J(V) measurements are in very good agreement. Keywords: ALD HfO₂, p-Ge, XPS, conductivity mechanisms, energy band diagram.

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Дата начала обработки статистических данных - 27 января 2016 г.