A5040431813- Radio Frequency Integrated Circuit Design
- GaN-based semiconductor devices and materials
- Semiconductor Quantum Structures and Devices
- Semiconductor materials and devices
- Ga2O3 and related materials
- Photonic and Optical Devices
- Advanced Power Amplifier Design
- Acoustic Wave Resonator Technologies
- Microwave Engineering and Waveguides
- ZnO doping and properties
- Microwave and Dielectric Measurement Techniques
- Advanced Photonic Communication Systems
- Semiconductor Lasers and Optical Devices
- Superconducting and THz Device Technology
- Semiconductor materials and interfaces
- Advancements in Semiconductor Devices and Circuit Design
- Induction Heating and Inverter Technology
- Silicon Carbide Semiconductor Technologies
ETH Zurich
2010-2022
Board of the Swiss Federal Institutes of Technology
2011
We report a new generation of high-performance AlGaN/GaN high-electron-mobility transistors (HEMTs) grown on high-resistivity Si (111) substrates. map out small- and large-signal device performances against technological parameters such as the gate length source-drain contact separation. first performance for GaN-on-Si technology offering an output power 2 W/mm associated peak power-added efficiency 13.8% (peak 18.5%) at 40 GHz without any field plate. The offers measured transconductances...
Small-signal equivalent circuit (SSEC) models prove indispensable to a broad range of activities, ranging from the understanding device physics, analysis performance, characterization and comparison fabrication processes, bottom-up construction large-signal models, extraction intrinsic noise parameters, design monolithic microwave integrated circuits (MMICs). Because SSEC model links physical structure its behavior, it allows performance as function geometry. A physically representative can...
We report a new InP/GaAsSb double heterojunction bipolar transistor (DHBT) emitter fin architecture with record <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${f}_{\mathrm {MAX}} =1.2$ </tex-math></inline-formula> THz, simultaneous {T}} =475$ GHz, and notation="LaTeX">$BV_{\mathrm {CEO}} =5.4$ V. The resulting {CEO}}\,\times \,{f}_{\mathrm =6.48$ THz-V is unparalleled in semiconductor technology. Devices...
We report the fabrication and characterization of 30-nm-gate fully passivated AlInN/GaN high-electron mobility transistors (HEMTs) with cutoff frequencies <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f</i> <sub xmlns:xlink="http://www.w3.org/1999/xlink">T</sub> xmlns:xlink="http://www.w3.org/1999/xlink">MAX</sub> simultaneously exceeding 200 GHz at a given bias point. The current gain frequency does not vary significantly for 2.5 <;...
We report the first 94-GHz (W-band) large-signal performance of AlInN/GaN high-electron-mobility transistors (HEMTs) grown on high-resistivity silicon (111) substrates. A maximum output power density 1.35 W/mm and peak power-added-efficiency 12% are measured at 94 GHz. The devices exhibit a dc current drain 1.6 A/mm transconductance 650 mS/mm. In small-signal operation, cutoff frequencies f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</sub>...
We report high-speed fully passivated deep submicrometer (Al,Ga)N/GaN high-electron mobility transistors (HEMTs) grown on (111) high-resistivity silicon with current gain cutoff frequencies of as high f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</sub> = 107 GHz and maximum oscillation reaching xmlns:xlink="http://www.w3.org/1999/xlink">MAX</sub> 150 GHz. Together, these are the highest values achieved for GaN-based HEMTs implemented...
The major mm and sub-mm radio-astronomy observatories are prioritizing instantaneous bandwidth widening for their current or planned upgrades this decade. We present an ultra-wide-band ultra-low-noise cryogenic hybrid amplifier with 4 K (NF = 0.06 dB) average noise temperature in the 2-18 GHz band when cooled to 6 K. It is based on a 100 nm gate pseudomorphic InP HEMT outstanding characteristics. This demonstration meets IF demands of ALMA next generation receivers, doubling maximum...
We report the large-signal performance of high electron mobility transistors (HEMTs) fabricated on GaN- and AlN-capped AlInN/GaN epilayers grown semi-insulating SiC substrates. Large-signal measurements at 10 40 GHz are presented with both gate drain dynamic loadlines to clarify factors limiting high-power performance. Devices show a marginal advantage in terms higher current reduced dispersion, but GaN-capped perform better short-channel effects channel control. In operation GHz, device...
We report on the low-temperature growth of heavily Si-doped (&gt;1020 cm−3) n+-type GaN by N-rich ammonia molecular beam epitaxy (MBE) with very low bulk resistivity (&lt;4 × 10−4 Ω·cm). This is applied to realization regrown ohmic contacts InAlN/GaN high electron mobility transistors. A n+-GaN/2 dimensional gas contact 0.11 Ω·mm measured, provided an optimized surface preparation procedure, which shown be critical. proves great potentials MBE for performance electronic devices.
A new W-band active load-pull system is presented. It the first to implement a 94 GHz load by means of an loop exploiting frequency conversion techniques. The configuration demonstrates number advantages that overcome typical limitations passive tuners or conventional open-loop techniques in cost-effective way: reflection coefficients Γ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">L</sub> as high 0.95 magnitude can be achieved at GHz, thus...
We characterize the microwave loss in coplanar waveguides (CPWs) on AlGaN/GaN high-electron mobility transistor (HEMT) buffer layers high-resistivity silicon (HR-Si) substrates, up to 110 GHz. To our knowledge, this is first broadband characterization of CPWs GaN-on-Si. Conventional commercially available HR-Si HEMT show a as low 0.8 dB/mm at Losses are further reduced by etching trenches between CPW conductors, reaching 0.47 The work shows that GaN-on-Si exhibit performances comparable...
AlGaN/GaN 70-nm-gate high-electron mobility transistors (HEMTs) fabricated using either ion implantation or conventional mesa isolation are compared. Although the resulting devices display comparable dc characteristics, process influences RF and pulsed <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">I</i> - xmlns:xlink="http://www.w3.org/1999/xlink">V</i> characteristics. others have described implant-isolated GaN HEMTs, published reports focused...
We report the first microwave performance for AlGaN/GaN HEMT structures grown by molecular beam epitaxy on Si(110) high-resistivity substrates. Transistors were fabricated with gate lengths of 50, 75, and 100 nm, achieving short-circuit current cutoff frequencies as high fT = 70 GHz maximum oscillation fMAX(U) 93 GHz. Because complementary metal–oxide–semiconductor (CMOS) technology is compatible (110) substrates, this demonstration establishes a foundation future integration GaN devices...
We demonstrate W-band monolithic microwave integrated circuit (MMIC) amplifiers based on AlInN/GaN high electron mobility transistors (HEMTs) grown Silicon. Our MMIC process was fully characterized to 110 GHz and a design kit generated enable design. A fabricated two-stage amplifier with an output device width of 100 μm shows saturated power 18.3 dBm gain 8.2 dB at 94 input/output return losses -10 or better from 90 GHz. model confirmed by experimental data revealed that the performance is...
We report the 94 GHz large-signal load-pull performance of (0.3 × 9) μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> InP/Ga(In)AsSb double heterojunction bipolar transistors (DHBTs) in common-emitter (CE) and common-base (CB) configurations. Both configurations were implemented side-by-side on either 20-nm-thick graded GaAsSb- or GaInAsSb-base layers. A measured record saturated output power <italic...
We report uniform Type-II GaInAsSb/InP UTC-PDs, and compare their performance to devices fabricated with GaAsSb graded (composition doping) absorbers of the same thickness. The quaternary UTC-PDs show a transit limited bandwidth 274 GHz in contrast 107 185 for absorber UTC-PDs. Because ternary only differ material, findings conclusively demonstrate enhanced transport GaInAsSb. Performance comparison GaInAs-based from literature suggest that GaInAsSb is superior material λ = 1.55 μm...
A comparison of the microwave small-signal performance 0.1 µm AlGaN/GaN high electron mobility transistors (HEMTs) grown on (111) high-resistivity (HR) Si and insulating sapphire substrates is performed. With resistivities <20 kΩ·cm, HR-Si not semi-insulating, potential substrate loading effects and/or parasitic conduction through buffer layers might affect device performance. The extracted equivalent circuit models reveal no differences attributable to different substrates. Coplanar...
We review the AlGaN/GaN high electron mobility transistor (HEMT) activities in Millimeter-Wave Electronics Group at ETH-Zürich. Our group's main thrust arena is extension of device bandwidth to higher frequency bands. demonstrated surprising performances for HEMTs grown on high-resistivity (HR) silicon (111) substrates, and extended cutoff frequencies 100 nm gate devices well into millimeter (mm)-wave domain. results narrow performance gap between GaN-on-SiC (or sapphire) GaN-on-silicon...
The present work characterizes the 94 GHz class-A large-signal load-pull performance of mm-wave InP/GaAsSb double heterojunction bipolar transistors (DHBTs) with different emitter lengths LE. When matched for maximum power, a 10.3 dBm (1.09 mW/μm) output is realized in 10 μm transistor 24.5 % power-added efficiency (PAE). PAE, 30% Class-A PAE achieved 7.5 long device, simultaneous power and gain 9.0 5.9 dB. contours exhibit combination good high wide range load impedances vicinity 50 Ohm....
We report the characterization of GaN high electron mobility transistors (HEMTs) using a new AlN-capped AlInN/GaN epilayer structure developed to achieve current densities and reduced gate leakage currents. Devices with lengths 75 200 nm various source–drain separations were fabricated simultaneously, allowing selection most favorable configuration for power performance. show that, as anticipated, aggressive scaling spacing gatelength does not benefit performance because early breakdown more...
Abstract— Linear power amplifiers (PAs) are critical in high-capacity modern telecom systems. We characterize the linearity of common-emitter (CE) and common-base (CB) mm-wave InP/GaAsSb double heterojunction bipolar transistors (DHBTs) at 18/45 GHz. When matched for maximum linearity, 3 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rd</sup> order intercepts (OIP3) 23.4 18.2 dBm found single-finger (0.3 × 10) μm...
With 5G implementation details still remaining to be defined, it is already clear that the corresponding handset power amplifiers (PAs) will require high-linearity, high-efficiency performance. In this context, present paper first examines PA landscape of available candidate technologies and then shows InP/GaAsSb Double Heterojunction Bipolar Transistors (DHBTs) offer performance differentiating features. Indeed, DHBTs exhibit weaker C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML"...
The present work compares single-gate (SG) and dual-gate (DG) HEMTs from a low-noise amplification perspective. Experimental results, obtained through RF noise measurements in the 5 to 50 GHz range, reveal significant boost of ~6 dB associated gain for DG-HEMT compared conventional SG-HEMT. biasing characteristics offer an additional degree freedom, relaxing traditionally rigid constraints on relationship between minimum figure gain.
We report a new InP/GaAsSb Double Heterostructure Bipolar Transistor (DHBT) emitter fin architecture with record f <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">MAX</inf> = 1.2 THz, simultaneous xmlns:xlink="http://www.w3.org/1999/xlink">T</inf> 475 GHz and BV xmlns:xlink="http://www.w3.org/1999/xlink">CEO</inf> 5.4 V. The resulting x 6.48 THz-V is unparalleled in semiconductor technology. performance arises because the process allows: i) an...