Scaling of AlN/GaN HEMT for millimeter-wave power applications

International audienceIn this paper, we report on AlN/GaN HEMTs for high frequency applications. Various gate lengths have been studied as a function of the gate-drain distance in order to analyze the impact on the DC, RF and power performances. Electrical characteristics of this structure for 110 nm gate length show a maximum drain current of 1.2 A/mm, an extrinsic transconductance Gm of 400 mS/mm and a FT/Fmax of 63/300 GHz at a drain bias voltage VDS = 20V. An excellent electron confinement with a low leakage current below 10 µA/mm is achieved. Furthermore, a breakdown voltage of 55 V for GD0.5 and up to 140 V for GD2.5 are observed when using a 110 nm short gate length. Large signal characteristics at 40 GHz reveal a state-of-the-art combination of power added efficiency (PAE) (50%) with an output power density (Pout) of 3.6 W/mm at VDS = 20 V in continuous wave mode (CW) and PAE of 50% associated with a Pout of 8.3 W/mm at 40V in pulsed mode. It can be noticed that the 110 nm gate length GD0.5 showed no degradation after semi-on robustness tests and large signal measurements up-to VDS = 20V

GaN-based transistors using buffer-free heterostructures for next generation RF devices

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Demonstration of GaN-on-silicon material system operating up to 3 kilovolts with reduced trapping effects

International audienceWe report on the first demonstration of low trapping effects up to 3000 V within GaN-on-silicon epitaxial layers using a local substrate removal (LSR) followed by a thick backside ultra-wide-bandgap AlN deposition. The fabricated AlGaN/GaN devices deliver low specific on-resistance below 10 mΩcm 2 together with unprecedented 3-terminal blocking voltage while substrate ramp measurements show reduced hysteresis up to 3000 V. These results pave the way for beyond 1200 V applications using large wafer diameter GaN-on-Si high electron mobility transistors

AlGaN/GaN High Electron Mobility Transistors with Ultra -Wide Bandgap AlN buffer

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The Palm oil from seed of Phoenix dactylifera (Oil of both Deglet Nour and Kentichi) as a natural antioxidants and Environment-Friendly inhibitors on the Corrosion of mild Steel in HCl 1M

The flora of Republic of Algeria comprises a lot of Palm species, including Phoenix dactylifera. In this work, we used the Palm oil from seed of Phoenix dactylifera (Oil of both Deglet Nour and Kentichi). The objective of this study is divided into two parts. Firstly, determine the antioxidant activity of Palm oil from seed of Phoenix dactylifera (Oil of both Deglet Nour and Kentichi) according to the DPPH radical scavenging assay to suggest it as a new potential source of natural antioxidants, secondly, study the effect of inhibiting Palm oil from seed of Phoenix dactylifera (Oil of both Deglet Nour and Kentichi) on corrosion of mild steel in hydrochloric acid by electrochemical methods. Furthermore, The DPPH scavenging activity of Oil of both Deglet Nour and Kentichi increased in the order, Deglet Nour Oil < Kentichi Oil < ascorbic acid. The results of the polarization curves show that the corrosion current density decreases 577.9 μA/cm2 to 58μA/cm2 and to 59.3 μA/cm2 after addition of the inhibitor (oil of Deglet Nour and Kentichi respectively). The charge transfer resistance increases 21.69 ohm.cm2 to 186.5 ohm.cm2 and to 222.8 ohm.cm2 in the electrochemical impedance spectrum after addition of oil of Deglet Nour and Kentichi respectively. The inhibition of the compound effect is attributed to the formation of a film on the surface of the steel.

Antibacterial Activity and Chemical Composition of Essential Oil of Athamanta sicula L. (Apiaceae) from Algeria

Essential oil extracted from fresh aerial parts of Athamanta sicula L. (syn. Tingara sicula) was analysed by gas phase chomatography coupled to mass spectrometry (GC-MS). The main constituents were: germacrene B (88.5%) and apiol (4.9%). Comparing with the tested bacteria, the growth of Escherichia coli and Klebsiella pneumoniae strains was more inhibited by the essential oil of A. sicula

Antibacterial activity and chemical composition of essential oil of Ammi visnaga L. (Apiaceae) from Constantine, Algeria.

Abstract: Essential oil extracted from fresh aerial parts of Athamanta sicula L. (syn. Tingara sicula) was analysed by gas phase chomatography coupled to mass spectrometry (GC-MS). The main constituents were: germacrene B (88.5%) and apiol (4.9%). Comparing with the tested bacteria, the growth of Escherichia coli and Klebsiella pneumoniae strains was more inhibited by the essential oil of A. sicula

Novel heterostructures for millimeter-wave GaN devices

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Short-term reliability of high performance Q-band AlN/GaN HEMTs

International audienceWe report on an on-wafer short-term 40 GHz RF reliability stress test comparison between a 3 nm versus 4 nm barrier thickness AlN/GaN HEMT technology showing state-ofthe-art power performances in the millimeter wave range. It is found that the barrier thickness in this highly strain heterostructure has a major impact on the device reliability. The superior robustness when using thinner barrier (closer to the critical thickness) is attributed to the reduced strain

C-doped AlN/GaN HEMTs for High efficiency mmW applications

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