The effects of proton irradiation dose on the dc characteristics of AlGaN/GaN high electron mobility transistors (HEMTs) with source field plates were studied. The HEMTs were irradiated with various protons doses ranging from 5 × 1012 to 5 × 1015 cm−2 at a fixed energy of 5 MeV. HEMTs irradiated with proton dose below 5 × 1013 cm−2 showed less than 2% degradation of either saturation drain current (IDSS) or transconductance (gm). Significant changes of these parameters were observed for the devices irradiated with doses above 5 × 1013 cm−2. HEMTs irradiated with the highest proton dose of 5 × 1015 cm−2 showed a reduction of IDSS and gm of 86% and 64.7%, and a positive Vth shift of 0.84 V, respectively. Despite the significant IDSS and gm reductions, the off-state drain breakdown voltage (VBR) was improved more than five times at this particular irradiation condition. The significant improvement of off-state drain breakdown voltage was attributed to the formation of a virtual gate at drain side of gate edge, which was the result of the generation of defect centers at AlGaN/GaN interface.

2015): Low and moderate dose gamma-irradiation and annealing impact on electronic and electrical properties of AlGaN/GaN high electron mobility transistors, Radiation Effects and Defects in Solids: Incorporating Plasma Science and Plasma Technology,To understand the effects of 60 Co gamma-irradiation, systematic studies were carried out on n-channel AlGaN/GaN high electron mobility transistors. Electrical testing, combined with electron beam-induced current measurements, was able to provide critical information on defects induced in the material as a result of gamma-irradiation. It was shown that at low gamma-irradiation doses, the minority carrier diffusion length in AlGaN/GaN exhibits an increase up to ∼ 300 Gy. The observed effect is due to longer minority carrier (hole) life time in the material's valence band as a result of an internal electron irradiation by Compton electrons. However, for larger doses of gamma irradiation (above 400 Gy), deteriorations in transport properties and device characteristics were observed. This is consistent with the higher density of deep traps in the material's forbidden gap induced by a larger dose of gamma-irradiation. Moderate annealing of device structures at 200°C for 25 min resulted in partial recovery of transport properties and device performance.

The effects of proton irradiation on optical and electrical performances of InGaN/GaN blue light-emitting diodes (LEDs) were investigated. The InGaN/GaN blue LEDs were irradiated with protons at a fixed energy of 340 keV and doses ranging from 5 × 1010 to 1 × 1014/cm2. Both current–voltage (I-V) and light output–current (L-I) characteristics of InGaN/GaN blue LEDs were gradually degraded as increasing the proton doses. The optical performances of LED were much more sensitive to the proton irradiation than that of electrical performances. The electroluminescence spectra and the light output performances before and after proton irradiations had similar trends in degradation. Then, the reverse recovery time before and after 1 × 1014/cm2 proton irradiation slightly decreased from 31.0 to 27.6 ns.

Articles you may be interested inStudy on the effects of proton irradiation on the dc characteristics of AlGaN/GaN high electron mobility transistors with source field plate

Articles you may be interested inMethane detection using Pt-gated AlGaN/GaN high electron mobility transistor based Schottky diodes J. Vac. Sci. Technol. B 31, 032203 (2013); 10.1116/1.4803743 Effect of humidity on hydrogen sensitivity of Pt-gated AlGaN/GaN high electron mobility transistor based sensors AlGaN/GaN-based metal-oxide-semiconductor diode-based hydrogen gas sensorThe hydrogen detection response time of Pt-gated diode sensors fabricated on AlGaN/GaN heterostructure as a function of the hydrogen concentration was investigated. A new method to extract the response time, taking the derivative of diode current, was proposed and shown to reduce the response time of detecting 1% hydrogen by about 60% as compared to the response time defined as the diode current reaching 90% of its total changes, t 90 . Hydrogen-sensing experiments were conducted at different temperatures, and an Arrhenius plot of the data determined an activation energy of 17.7 kJ/mole for the sensing process.