GaN metal–oxide–semiconductor field-effect transistors (MOSFETs) with a tetraethylorthosilicate (TEOS) SiO2 insulator were developed and evaluated using an AlGaN/GaN HFET structure as the source and drain regions. Operation up to a gate voltage of 10 V was realized at a low gate leakage current. A new method of measuring the mobility of a MOSFET was developed to prevent the effect of hysteresis, in which a relay was used to switch between current measurement and capacitance measurement at the same gate voltage. The maximum field-effect mobility is approximately 45 cm2 V-1 s-1 at an interface state density of 1.02 ×1013 cm-2 eV-1.

Evidence of space charge limited flow in the gate current of AlGaN/GaN high electron mobility transistors Appl. Phys. Lett. 100, 223504 (2012) Off-state breakdown and dispersion optimization in AlGaN/GaN heterojunction field-effect transistors utilizing carbon doped buffer Appl. Phys. Lett. 100, 223502 (2012) Charge transport and trap characterization in individual GaSb nanowires J. Appl. Phys. 111, 104515 (2012) The asymmetrical degradation behavior on drain bias stress under illumination for InGaZnO thin film transistors Appl. Phys. Lett. 100, 222901 (2012) Mechanism of random telegraph noise in junction leakage current of metal-oxide-semiconductor field-effect transistor J. Appl. Phys. 111, 104513 (2012) Additional information on J. Appl. Phys. For AlGaN/GaN heterojunction field-effect transistors, on-state-bias-stress (on-stress)-induced trapping effects were observed across the entire drain access region, not only at the gate edge. However, during the application of on-stress, the highest electric field was only localized at the drain side of the gate edge. Using the location of the highest electric field as a reference, the trapping effects at the gate edge and at the more distant access region were referred to as localized and non-localized trapping effect, respectively. Using two-dimensional-electron-gas sensing-bar (2DEG-sensing-bar) and dual-gate structures, the non-localized trapping effects were investigated and the trap density was measured to be $1.3 Â 10 12 cm À2 . The effect of passivation was also discussed. It was found that both surface leakage currents and hot electrons are responsible for the non-localized trapping effects with hot electrons having the dominant effect. Since hot electrons are generated from the 2DEG channel, it is highly likely that the involved traps are mainly in the GaN buffer layer. Using monochromatic irradiation (1.24-2.81 eV), the trap levels responsible for the non-localized trapping effects were found to be located at 0.6-1.6 eV from the valence band of GaN. Both trap-assisted impact ionization and direct channel electron injection are proposed as the possible mechanisms of the hot-electron-related non-localized trapping effect. Finally, using the 2DEG-sensing-bar structure, we directly confirmed that blocking gate injected electrons is an important mechanism of Al 2 O 3 passivation. V C 2012 American Institute of Physics.

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We report on the on-wafer device characteristics of 150 and 200 mm GaN-on-Si-based blue LED wafers grown by metalorganic chemical vapor deposition on Si(111) substrates with electroluminescence at 447 nm. Excellent uniformity was achieved with standard deviations of 3.9% for the electroluminescence intensity, 0.6–0.8% for the peak wavelength and 1.3% for the forward voltage. The high uniformity confirms the viability of the GaN-on-Si technology on large-diameter substrates for next-generation LED manufacturing. The reverse bias current leakage mechanism is also investigated to provide an insight into improving device reliability.

A GaN Schottky diode with a lateral structure for microwave power rectification was developed on a semi-insulating silicon carbide substrate. Device evaluation showed that the turn-on voltage was around 0.8 V. The on-resistance of the diode with one finger was 25.6 , the breakdown voltages for those with the field plate reached 93 V, for the wafer with a doping level of 4:0 Â 10 16 cm À3 . The forward and reverse characteristics became stabilized after surface etching. RF measurement at 2.45 GHz showed that the capacitance of the diode was about 0.29 pF at a bias of 0 V. The value is satisfactorily small for microwave rectification. If the superior material characteristics of GaN are fully utilized, GaN Schottky diodes will play key roles in microwave power transmission applications.