The authors apply the conductance method at 25 and $150°\mathrm{C}$ to $\mathrm{Ga}\mathrm{As}–{\mathrm{Al}}_2{\mathrm{O}}_3$ metal-oxide-semiconductor devices in order to derive the interface state distribution $\left(D_{\mathrm{it}}\right)$ as a function of energy in the bandgap. The $D_{\mathrm{it}}$ is governed by two large interface state peaks at midgap energies, in agreement with the unified defect model. S-passivation and forming gas annealing reduce the $D_{\mathrm{it}}$ in large parts of the bandgap, mainly close to the valence band, reducing noticeably the room temperature frequency dispersion. However the midgap interface state peaks are not affected by these treatments, such that Fermi level pinning at midgap energies remains.

The formation and detailed characterisations of a 200 mm germanium-on-insulator substrate made from germanium bulk material as donor wafer using the Smart Cut^TM technology is reported. Detailed characterisations of final GeOI structures are presented: final roughness, defectivity evaluation, thickness measurement, and electrical characterisation.

We will shortly review the basic physics of charge-carrier trapping and emission from trapping states within the bandgap of a semiconductor in order to show that high-temperature capacitance-voltage (C-V) measurements are necessary for GaAs metal-oxide-semiconductor characterization. The midgap trapping states in GaAs have characteristic emission times on the order of 1000 s, which makes them extremely complicated to measure at room temperature. Higher substrate temperatures speed up these emission times, which makes measurements of the midgap traps possible with standard C-V measurements. C-V characterizations of GaAs/Al2O3, GaAs/Gd2O3, GaAs/HfO2, and In0.15Ga0.85As/Al2O3 interfaces show the existence of four interface state peaks, independent of the gate oxide deposited: a hole trap peak close to the valence band, a hole trap peak close to midgap energies, an electron trap peak close to midgap energies, and an electron trap peak close to the conduction band. (c) 2008 The Electrochemical Society. [DOI: 10.1149/1.2988045] All rights reserved.status: publishe