In this paper, we report state-of-the-art high frequency performance of GaN-based electron mobility transistors (HEMTs) and Schottky diodes achieved through innovative device scaling technologies such as vertically scaled enhancement depletion mode (E/D mode) AlN/GaN/AlGaN double-heterojunction HEMT epitaxial structures, a low-resistance <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex...

This letter reports record RF performance of deeply scaled depletion-mode GaN-high-electron-mobility transistors (GaN-HEMTs). Based on double heterojunction AlN/GaN/AlGaN epitaxial structure, fully passivated devices were fabricated by self-aligned-gate technology featuring recessed n <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> -GaN ohmic contact regrown molecular beam epitaxy. Record-high f <sub...

One-dimensional microcavities are optical resonators with coplanar reflectors separated by a distance on the order of wavelength. Such structures quantize energy photons propagating along axis cavity and thereby strongly modify spontaneous emission properties photon-emitting medium inside microcavity. This report concerns semiconductor light-emitting diodes active region placed These devices shown to have modified including experimental efficiencies that higher more than factor 5 theoretical...

Resonant-cavity light-emitting diodes (RCLED) are novel, high-efficiency which employ optical microcavities. These have higher intensities and spectral purity as compared to conventional LEDs. Analytical formulas derived for the enhancement of spontaneous emission along axis cavity. The design rules operation RCLEDs established. temperature dependence intensity is analyzed in range 20-80/spl deg/ it described by an exponential with a characteristic 112 K. modulation characteristics exhibit 3...

The presence of thin ordered layers Si within the interface region AlAs-GaAs heterostructures is found to tune valence-band offset throughout 0.02--0.78 eV range. High-resolution x-ray-photoemission studies prepared in situ by molecular-beam epitaxy as a function substrate temperature, arsenic flux, concentration Si, and growth sequence (AlAs on GaAs versus AlAs) indicate that this tunability associated with Si-related local dipole which can be added or subtracted from intrinsic 0.40 eV.

We report deep-submicrometer gate-recessed and field-plated AlGaN-GaN HEMTs their state-of-the-art continuous wave (CW) power performance measured at 30 GHz. The exhibit a CW density of 5.7 W/mm with power-added efficiency (PAE) 45% drain-efficiency 58% V/sub ds/=20 V. At ds/=28 V, the output is as high 6.9 both PAE increasing input level. Compared to conventional T-gated HEMTs, HFETs are improved greatly, along excellent pulsed IVs. attribute improvement field-plating effect vertical...

We report small- and large-signal performances of 140-nm gatelength field-plated GaN HEMTs at Ka-band frequencies, in which the were fabricated with n+ source contact ledge. The parasitic channel resistance is reduced by ~ 50%, whereas peak extrinsic transconductance improved 20% from 370 to 445 mS/mm. ledge exhibit improvement maximum stable gain least 0.7 dB over reference devices without At 30 GHz, CW output power density 10 W/mm measured PAE 40% associated 8.4 Vds = 42 V. V, as 7.3 DE...

We report the test results of a family 92-96 GHz GaN power amplifiers (PA) with increasing gate peripheries (150 µm to 1200 µm). The µm, 3-stage PA produces 2.138 W output (Pout) an associated PAE 19% at 93.5 (V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">D</inf> =14V). amplifier offers Pout over 1.5W 17.8% in 92–96 bandwidth. measured data show that maximum scales linearly periphery almost constant around 20%. This demonstrates high...

We report record DC and RF performance in deeply-scaled self-aligned gate (SAG) GaN-HEMTs operating both depletion-mode (D-mode) enhancement-mode (E-mode). Through aggressive lateral scaling of the length (L <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">g</inf> ) source-drain distance xmlns:xlink="http://www.w3.org/1999/xlink">sd</inf> using a novel technology engineering thin top barrier layer, 20-nm AlN/GaN/AlGaN double-heterojunction (DH)...

Highly scaled GaN T-gate technology offers devices with high f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t</sub> /f xmlns:xlink="http://www.w3.org/1999/xlink">MAX</sub> , and low minimum noise figure while still maintaining breakdown voltage linearity typical for technology. In this paper we report an E-band power amplifier (PA) output (P xmlns:xlink="http://www.w3.org/1999/xlink">out</sub> ) of 1.3 W at added efficiency (PAE) 27% a 65-110...

We provide an overview of key challenges and technical breakthroughs that led to development highly scaled GaN HEMT's having ft > 400 GHz fmax 550 the corresponding IC process. These devices have 5 times higher breakdown voltage than transistors with similar high frequency RF power gain in other semiconductor systems (Si, SiGe, InP, GaAs). also report performance first generation MMIC amplifiers (PAs) utilize these devices. The added efficiency (PAE) 59% measured at a 32 GHz, bias 3 V output...

The performance of 50 nm gate length GaN/AlGaN HEMTs is reported. device layers were grown by MBE directly onto an SiC substrate. Devices exhibit a maximum drain current density 1.2 A/mm, extrinsic fτ 110 GHz and fmax over 140 GHz. the highest reported to date for HEMT, nearly 50% increase previous record.

In this paper we report high frequency GaN power device and measured performance of the first W-band (75 GHz-110 GHz) MMIC fabricated in material system. The with 150 mum output gate periphery produces 316 mW continuous wave (power density =2.1 W/m) at a 80.5 GHz has associated gain 17.5 dB. By comparison reported state art for other solid technologies is 427 pulsed mode on an InP HEMT 1600 = 0.26 W/mm). result demonstrates tremendous superiority technology applications frequencies greater than 75

In this letter, we report the first experimental observation of electron velocity enhancement by aggressive lateral scaling GaN HEMTs. Through reduction source-drain distance down to 170 nm using <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i> <sup xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> -GaN ohmic regrowth, 45-nm gate AlN/GaN/Al <sub xmlns:xlink="http://www.w3.org/1999/xlink">0.08</sub> Ga...

Abstract A new, semi‐self‐limiting, digital etch process using separate oxygen (O 2 ) and boron trichloride (BCl 3 plasmas to sequentially remove layers of material from AlGaN/GaN high electron mobility transistors (HEMTs) on the order a few angstroms per cycle is presented. This novel or atomic layer etching (ALE) technique was used for conversion HEMT devices depletion mode (normally‐on operation) enhancement (normally‐off operation). For fixed BCl time 60 sec cycle, rate increased 1.4...

We report W-band GaN MMIC's that produce 96% more power at a frequency of 88 GHz in continuous wave (CW) operation than the highest reported this band for best competing solid state technology, InP HEMT. module containing single three stage MMIC chip with 600 μm wide output produced over 842 mW CW-mode, associated PAE 14.7% and gain 9.3 dB. This performance was measured drain bias 14 V.

We report our second-generation mm-wave GaN double-heterostructure FET (DHFET) device technology which uses MBE regrowth of n+ ohmic regions to reduce parasitic resistance, and an improved T-gate process demonstrated reduced current-collapse. These devices were utilized in a MMIC with 600 μm wide output stage achieved 1024 mW power (1.7 W/mm) PAE 19.1% at 95 GHz bias 14V. This combination represents substantial improvement over competing technologies, such as InP HEMTs, well own previous...

We report record DC and RF performance obtained in deeply-scaled self-aligned-gate GaN-HEMTs with heavily-doped n <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> -GaN ohmic contacts to two-dimensional electron-gas (2DEG). High density-of-states of three-dimensional (3D) source near the gate mitigates "source-starvation," resulting a dramatic increase maximum drain current (I <sub xmlns:xlink="http://www.w3.org/1999/xlink">dmax</sub> )...

High performance GaN/AlGaN MODFETs grown by MBE directly on SiC substrate have been successfully fabricated and characterised. The epitaxial layers of the device were RF-assisted MBE. Excellent uniformity, reproducibility scalability obtained. A maximum output density 6.5 W/mm was obtained for a 0.1 mm device. On scaling to 1.0 gate-width, total power 6.3 W with 38% PAE at 10 GHz achieved. These results demonstrate excellent potential GaN-based FETs as cells practical microwave applications.

We report development of a novel AlGaN/GaN/AlGaN double heterojunction field effect tansistor (DHFET) with improved device performance over the conventional single GaN FET (SHFET). The DHFETs low Al content Al/sub 0.04/Ga/sub 0.96/N buffer layer exhibit three orders magnitude lower subthreshold drain leakage current and almost higher isolation than corresponding SHFET devices (600 M/spl Omega//sq. vs. 1 Omega//sq.). In DHFET's 0.15 /spl mu/m T-gates we observed 30% improvement in saturated...

This paper reports a W-band solid-state power amplifier with an output of 5.2W at 95 GHz and greater than 3 watts over the 94 to 98.5 band. These SOA results were achieved by combining 12 GaN MMICs in low-loss radial-line combiner network. The 12-way demonstrates overall efficiency 87.5%, excluding conductor losses (0.3 dB), exhibits 93.7% 95GHz. size amplifier/combiner is only 2.39" dia. × 1.5" length. work represents first application configuration applications frequencies, establishes new...

An enhancement-mode (E-mode) AlN/GaN/AlGaN double-heterojunction field-effect transistor (DHFET) with record high-frequency performance is reported. E-mode operation was achieved through vertical scaling of the AlN barrier layer. Parasitic resistances were reduced ohmic contact recess etching followed by regrowth n+ GaN molecular-beam epitaxy and SiN deposition to increase sheet charge density in access regions device, resulting an extremely low on-resistance 1.06 Ω · mm. A DHFET 80-nm gate...

We report record RF performance in 40nm-gate GaN-HEMT technology. Through vertical scaling an AlN/GaN/AlGaN double heterojunction (DH) HEMT structure and reduction of access resistance using MBE re-growth n <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> -GaN ohmic contacts, fully-passivated 40-nm devices exhibited excellent DC characteristics, such as R <sub xmlns:xlink="http://www.w3.org/1999/xlink">on</sub> 0.81Ω·mm, I...

We report the first generation of GaN MMIC circuits that are based on latest (ft > 320 GHz and fmax 580 GHz) [1] Transistors. The reported broadband Ka-band (27 - 40 LNA MMIC's have Noise Figure (NF) as low 1 dB measured at a frequency 37 GHz, NF <; 2 with >24dB gain across 28 GHz- 39.2 range, very broad range usable DC bias conditions (Vd: 0.6V 4V; Pdc: 5 mW- 310 mW). This is to best our knowledge lowest for in this band.

In this paper we demonstrate the merits of GaN MMIC technology for high bandwidth millimeter-wave power applications and microwave robust LNA receiver applications. We report development a broadband two-stage microstrip Ka-band amplifier, with 15dB flat small signal gain over 27.5GHz to 34.5GHz frequency range 4W saturated output at 28GHz, added efficiency 23.8%. This is best our knowledge combination power, reported in range. also wideband (0.5GHz-12GHz) MMIC, which can survive incident...