AlGaN-GaN heterojunction field-effect transistors (HFETs) with a field modulating plate (FP) were fabricated on an SiC substrate. The gate-drain breakdown voltage (BV/sub gd/) was significantly improved by employing FP electrode, and the highest BV/sub gd/ of 160 V obtained length (L/sub FP/) 1 μm. maximum drain current achieved 750 mA/mm, together negligibly small collapse. A 1-mm-wide FP-FET FP/=1 μm) biased at 65 demonstrated continuous wave saturated output power 10.3 W linear gain 18.0...

Abstract In this paper, we give an overview of the recent progress in GaN-based high-electron-mobility transistors (HEMTs) developed for mainstream acceptance power electronics field. The comprehensive investigation AlGaN/GaN HEMTs fabricated on a free-standing semi-insulating GaN substrate reveals that extracted effective lateral breakdown field approximately 1 MV/cm is likely limited by premature device originating from insufficient structural and electrical quality buffer layers and/or...

This paper describes recent technological advances on III-nitride-based transistors for power switching applications. Focuses are placed the progress toward enhancing breakdown voltage, lowering ON-resistance, suppressing current collapse, and reducing leakage in AlGaN/GaN high-electron mobility (HEMTs). Recent publications revealed that tradeoff relation between ON-resistance voltage HEMTs exceeded SiC limit was getting close to GaN limit; however, achieved still lower than theoretical...

Current collapse measurements have been performed for AlGaN/GaN high-electron-mobility transistors having identical breakdown voltages but with different field plate (FP) lengths. The results indicated that applying more positive ON-state gate biases resulted in pronounced recovery the dynamic ON-resistance FP device, whereas no gate-bias effects were observed device without FP. mechanism responsible reduced current by is proposed, which key role played during quick field-effect of partial...

AlGaN-channel high-electron-mobility transistor (HEMT) with high Al composition of 0.51 has been developed. The epitaxial layers were grown on a free-standing AlN substrate to improve crystalline quality. fabricated device exhibited maximum drain current (Idsmax) 25.2 mA/mm transconductance (gmmax) 4.7 mS/mm. characteristic features the source-to-drain breakdown voltage 1800 V and applicable gate-to-source 4 in forward direction. Temperature dependence DC characteristics demonstrated that...

An AlN/AlGaN high-electron-mobility transistor (HEMT) fabricated on a free-standing AlN substrate is demonstrated. A metal stack, composed of Zr/Al/Mo/Au, was found to show low contact resistivity for source and drain ohmic contacts. The HEMT exhibited maximum current 38 mA/mm with threshold voltage −3.4 V. Negligible degradation observed at temperatures from 300 573 K, demonstrating that an approach promising stable high-temperature operation.

We review the features of GaN-based FETs and describe their expected development direction, GaN has a high breakdown field, but this does not necessarily mean it is suitable for high-voltage high-power applications. The main advantage that enables scaling down beyond silicon MOSFET miniaturization limitation from Maxwell-Boltzmann distribution. Thus, fine gate patterns together with carrier velocity make be suited millimeter near wavelength In addition, by using large-area sapphire...

A recessed-gate AlGaN-GaN field-modulating plate (FP) field-effect transistor (FET) was successfully fabricated on an SiC substrate. By employing a structure FP FET, the transconductance increased from 150 to 270 mS/mm, leading improvement in gain characteristics, and current collapse minimized. At 2 GHz, 48-mm-wide recessed FET exhibited record output power of 230 W (4.8 W/mm) with 67% power-added efficiency 9.5-dB linear drain bias 53 V.

We report on an Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> /AlGaN/GaN metalinsulator-semiconductor high-electron-mobility transistor (MIS-HEMT) with recessed-gate structure and regrown AlGaN barrier. After analyzing the possibility of obtaining high threshold voltage (V xmlns:xlink="http://www.w3.org/1999/xlink">th</sub> ) within framework Tapajna Kuzmik model from preliminary...

Conditions for post-implantation capless annealing of GaAs, called infrared rapid thermal (IRTA) using halogen lamps, were investigated. Si-implanted GaAs (5×1012 cm−2, 150 keV) was annealed at temperatures ranging from 700 to 1100 °C various times. Annealed 950 2–4 s shows about 75% electrical activation and 3700 cm2/Vs electron mobility without noticeable dopant diffusion surface decomposition. Planar metal-semiconductor field-effect transistors (MESFET’s) fabricated on the active layer...

A very high optical gain (∼900) was obtained near the 1.1-µm wavelength by InGaAsP-InP heterojunction phototransitor. The light amplifier, which is an integral device of a phototransistor and double-heterojunction laser (or light-emitting diode with confining layers), presented. bias method described for amplification weak incident light.

Abstract We demonstrate normally-off operation in Al 2 O 3/AlGaN/GaN MIS-HEMTs with a high two dimensional electron gas (2DEG) mobility enabled by shallow recess channel structure and oxygen plasma treatment. In the region, original 25-nm-thick AlGaN barrier layer was thinned down to 9 nm, which principle, should yield normally-on operation. However, we show that pre-insulator deposition treatment shifts threshold voltage +1.4 V. The relatively thick facilitated minimal sacrifice of 2DEG...

This paper reports novel high power AlGaAs/GaAs heterostructure FET with a field-modulating plate (FP-HFET), which accomplished dramatic increase of the gate-drain breakdown voltage greatly suppressed drain-current pulse-dispersion characteristics. The fabricated FETs exhibited excellent performance up to 35 V at L-band, delivering maximum density 1.7 W/mm.

Recessed-gate AlGaN-GaN heterojunction field-effect transistors (FETs) with a field-modulating plate (FP) have been successfully fabricated for high-voltage and high-power microwave applications. The developed recessed-gate FP-FET gate length of 1 /spl mu/m exhibited an increased transconductance 200 mS/mm. A series current collapse measurements revealed that the is highly desirable collapse-free power operation. Equivalent circuit analysis demonstrated gain loss due to additional feedback...

The out-diffusion of Ga atoms during thermal annealing from a GaAs substrate into an SiOxNy encapsulating film has been studied using secondary ion mass spectrometry. concentration detected within the encapsulant annealed at 850 °C is found to increase with increasing oxygen content encapsulant. results are well correlated change electron trap EL5 (Ec−ET =0.42 eV) evaluated deep-level transient spectroscopy. We conclude that controlled by capped causes enhanced electrical activation Si...

In this paper, we report on AlGaN/GaN metal–insulator–semiconductor high-electron-mobility transistors (MIS-HEMTs) fabricated using ZrO2/Al2O3 as a gate dielectric stack. Gate leakage characteristics well dynamic on-resistance due to current collapse have been studied for ZrO2 (2 nm)/Al2O3 nm)/AlGaN/GaN MIS-HEMT and compared with those MIS-HEMTs single insulator of Al2O3 (4 nm) nm). It was found that an effective in reducing the forward suppressing collapse, whereas use resulted suppressed...

This paper describes the small-signal characterization through delay-time analysis and high-power operation of Ka-band AlGaN/GaN heterojunction field-effect transistors (FETs). An FET with a gatewidth 100 /spl mu/m gate length 0.09 has exhibited current gain cutoff frequency (f/sub T/) 81 GHz, maximum oscillation (fmax) 187 stable 10.5 dB at 30 GHz (8.3 60 GHz). Delay-time demonstrated channel electron velocities 1.50/spl times/10/sup 7/ to 1.75/spl cm/s in gate-length range 0.09-0.25 mu/m....

A new post-implantation annealing technique, called infrared rapid thermal (IRTA), is discussed for fabricating GaAs devices using ion implantation technology. The IRTA apparatus and capless conditions are described. Also, electrical property its uniformity of n or n+ type layers made by Si to semi-insulating followed presented, compared with those Si3N4 capped furnace annealing. steeper carrier concentration profile a higher peak in the active layer results transconductance without any...

Hall electron mobility (μH) and sheet concentration (ns) in AlGaN/GaN heterostructures have been measured from 77 to 1020 K. The effect of the deposited Al2O3 layer is also investigated with varying its thickness. It found that μH decreases monotonously temperature (T) dependence well approximated function μH=4.5×103 exp(−0.004T) temperatures over 350 different commonly used one μH=AT−α (α∼1.5), which indicates not only governed by polar optical phonon scattering but deformation potential...

We have demonstrated for the first time a remarkable reduction of current collapse in AlGaN/GaN high-electron-mobility transistors (HEMTs) by high-pressure water vapor annealing (HPWVA). The device subjected to HPWVA exhibited considerably low dynamic ON-resistance (R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ON</sub> ), suggesting highly improved performance these devices. Analyses results on normalized R experiments shown elimination...

The microwave power performance of double-doped AlGaAs/InGaAs/GaAs pseudomorphic heterojunction field-effect transistors (HJFETs) operated at a DC drain bias 3 V is presented. fabricated 1.1- mu m-gate-length HJFET with an undoped AlGaAs Schottky layer exhibited maximum current 220 mA/mm, peak transconductance 200 mS/mm, and gate-to-drain breakdown voltage 21 V. Power evaluated 3-V for 12-mm-gate-periphery device demonstrated output 1.4 W 61% power-added efficiency 950 MHz. results indicate...

Electron traps in n-GaAs resulting from infrared rapid thermal annealing (IRTA) have been studied by deep-level transient spectroscopy (DLTS). An electron trap with an activation energy of 0.20 eV the conduction band, termed EN1, is introduced IRTA above 800 °C. This formation closely related to a heating stage process. The EN1 concentration changes similarly dominant midgap EL2 versus variation temperature, time, or encapsulating films. It proposed that IRTA-related ascribed defect...

Compact DC-60-GHz heterojunction field-effect transistor (HJFET) monolithic-microwave integrated-circuit (MMIC) switches have been demonstrated for millimeter-wave communications and radar systems. To reduce the MMIC chip size, a novel ohmic electrode-sharing technology (OEST) has developed with series-shunt FET configuration. Four FET's of single-pole double-throw (SPDT) switch were integrated into an area approximately 0.018 mm/sup 2/. The high power-handling capability low insertion loss...

A novel GaAs power FET with a field-modulating plate (FP-FET) and operated at drain bias voltage of 24 V was developed. Regarding the performance an FP-FET under wideband code division multiple access (WCDMA) operation, its peak output significantly degraded in saturated-output-power region when FP length short. However, by introducing sufficiently large length, it demonstrated that peak-power degradation can be suppressed. In particular, amplifier fabricated 1.5 /spl mu/m exhibited no WCDMA...

S-implanted GaAs at room temperature was annealed by several seconds radiation from halogen lamps. Differential Hall effect/sheet resistivity measurements have been used to study the annealing behavior and electrical carrier concentration profiles of GaAs. Electrical activation found increase with increasing up 1100 °C. A maximum 78% obtained for a dose 5×1013 cm−2. Also, more than 5×1018 cm−3 peak 1×1014 cm−2, indicating about three times higher that after conventional furnace annealing....