The current-voltage characteristics of the Ni/InAlN/GaN Schottky diodes were measured at various temperatures in the range of 300–820 K. The experimental data were analyzed considering different current-transport mechanisms, such as thermionic emission, generation-recombination, tunneling and leakage currents. From the fitting of experimental data it follows that the tunneling current dominates in whole temperature range. The thermionic emission becomes comparable to the tunneling current only at highest temperatures used. The barrier height of the Ni/InAlN/GaN Schottky diodes, evaluated from the thermionic emission current, shows a slightly negative temperature coefficient and its value at 300 K is 1.47 eV. Lower barrier heights were reported before, which follow from an incorrect evaluation of measured data without separation of individual current components. The dislocation density of about 2×109 cm−2 is obtained assuming dislocation governed tunneling current mechanism.

The current-voltage characteristics of the Ni/InAlN/GaN Schottky diodes were measured at various temperatures in the range of 300–700 K. The experimental data were analyzed considering different current-transport mechanisms. From the analysis it follows that the tunneling current, which might be due to a multistep tunneling along dislocations, is the dominant component at all temperatures in the samples investigated. The barrier height of the Ni/InAlN/GaN Schottky diodes, evaluated from the thermionic emission current, shows a slightly negative temperature coefficient and its value at 300 K is ≥1.46 eV. This is significantly higher barrier height than reported before (<1 eV). This discrepancy follows from an incorrect evaluation using the intercept and slope of a measured characteristic without separation of the individual current components.

This paper proposes a novel method of average channel temperature and channel temperature profile determination is discussed in theoretical part and subsequently applied to InAlN/AlN/ GaN HEMT using quasi-static I-V characterization supported by thermal 3D FEM simulations. Experimentally was determined HEMT source resistance and threshold voltage from low-power output and transfer I-V characteristics at different thermal chuck temperatures. The HEMT channel average temperature nearly 88 °C for dissipated power 2 W was calculated taking advantage of the drain current change analysis applied in recurrent differential form. Additionally, the HEMT channel temperature profile was simulated utilizing the calculated channel dissipated power density.

In this work, we report on the thermal oxidation of AlInN/AlN/GaN heterostructures. A “nearly native” Al2O3 oxide was formed during this oxidation procedure, which can be used as a gate oxide and thus enables the fabrication of metal insulator semiconductor hetero field effect transistors. A constant barrier height of ΦB ≈ 2.34 eV was obtained for all oxidized samples, independent of the oxidation time and temperature, indicating a stable AlInN-oxide interface. The interface state density was approximated to be as low as Nint = 2.5 × 1012 cm-2. Oxide thicknesses were estimated to be in the range of 0.6 nm and 3.2 nm, resulting in a suppression of reverse leakage currents oflarge area metal insulator semiconductor diodes by up to three orders of magnitude. Two-dimensional electron gas density and, in particular, carrier mobility are strongly affected by the thermal oxidation in the O2 atmosphere. A narrow processing window for successful thermal oxidation was identified, covering temperatures between 700 °C and 800 °C and durations of few minutes. The resulting oxide thickness scales well with the square root of oxidation time, indicating diffusion of oxygen atoms into the barrier.

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