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In the present study, a comparative study on the influence of different laminated stacks driven by aomic layer deposition (ALD) on the interfacial and electrcial properties of high-k/Ge gate stacks passivated by trimethylaluminum (TMA) has been performed in detail via X-ray photoelectron spectroscopy (XPS) and electrical measurements. XPS measurements indicate that HfO2/Al2O3/Ge gate stacks can effectively inhibit the formation of Ge suboxides and a low-k germanate layer. Compared to Al2O3/HfO2 and HfO2/Al2O3/HfO2 gate stacks, the HfO2/Al2O3/Ge metal oxide semiconductor (MOS) capacitors exhibited improved electrical performance, including a maximum permittivity of 18.15, disappearing hysteresis, an almost neglected flat band voltage of 0.01 V, and a minimum leakage current density of 3.82 × 10–8 A/cm2 at room temperature. Especially, the leakage current mechanisms of Ge-MOS capacitors based on different laminated stacks measured at room temperature and low temperature (77–327 K) have been comprehensively analyzed. By comparing three different laminated gate stacks, it can be inferred that HfO2/Al2O3/Ge gate stacks have a potential application prospect in Ge-based microelectronic devices.

In this paper, the effect of atomic layer deposition-derived laminated interlayer on the interface chemistry and transport characteristics of sputtering-deposited Sm2O3/InP gate stacks have been investigated systematically. Based on X-ray photoelectron spectroscopy (XPS) measurements, it can be noted that ALD-derived Al2O3 interface passivation layer significantly prevents the appearance of substrate diffusion oxides and substantially optimizes gate dielectric performance. The leakage current experimental results confirm that the Sm2O3/Al2O3/InP stacked gate dielectric structure exhibits a lower leakage current density than the other samples, reaching a value of 2.87 × 10−6 A/cm2. In addition, conductivity analysis shows that high-quality metal oxide semiconductor capacitors based on Sm2O3/Al2O3/InP gate stacks have the lowest interfacial density of states (Dit) value of 1.05 × 1013 cm−2 eV−1. The conduction mechanisms of the InP-based MOS capacitors at low temperatures are not yet known, and to further explore the electron transport in InP-based MOS capacitors with different stacked gate dielectric structures, we placed samples for leakage current measurements at low varying temperatures (77–227 K). Based on the measurement results, Sm2O3/Al2O3/InP stacked gate dielectric is a promising candidate for InP-based metal oxide semiconductor field-effect-transistor devices (MOSFET) in the future.

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In this report, the impact of atomic-layer-deposition-derived different laminated gate stacks on the interface chemistry and electrical performance of Yb2O3/GaSb metal-oxide-semiconductor (MOS) capacitors has been investigated comparatively. X-ray photoelectron spectroscopy measurements and electrical characterization have revealed the existence of less native oxides and elemental Sb at the Yb2O3/Al2O3/GaSb interface, as well as the optimized frequency dispersion and the minimum leakage current density of 2.25 × 10–7 A/cm2. Meanwhile, conductance–voltage analyses are carried out to determinate the distribution of interface-state density (D it) in the entire GaSb band gap. It has been found that an ultrathin Al2O3 layer prior to Yb2O3 deposition can effectively delay the generation of the interface state, and the lowest D it value of 8.7 × 1012 cm–2 eV–1 for the Al/Yb2O3/Al2O3/GaSb capacitor has been achieved. The possible carrier conduction mechanisms for GaSb-based MOS capacitors with different laminated structures measured at room temperatures and low temperatures have also been systematically analyzed. All the results have indicated that the Yb2O3/Al2O3/GaSb gate stack is a promising candidate for future GaSb-based metal-oxide-semiconductor field-effect transistor devices.