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A comprehensive model for the electron mobility in AlGaN lattices-matched to GaN is developed. A large number of experimental and theoretical mobility data and the results of Monte Carlo transport simulations in previous literature have been evaluated and referred as the basis for the model development. The proposed model describes the variation of the field-dependent mobility with carrier concentration,...
A Magnesium Doped Layer (MDL) under the 2-DEG channel and a Drain Metal Extension (DME) are proposed to provide a new degree of freedom in the optimization between breakdown voltage (BV) and specific-on-resistance (Ron-sp) in AlGaN/GaN HEMTs. The surface electric field of the proposed structure is distributed more evenly when compare to the MDL-only structure with the same dimensions. A breakdown...
Thermal transient measurement of the 808 nm GaAs-Based laser diodes (LDs) before and after the constant current stress are presented and discussed in this paper. Aging tests are carried out under the conditions of the constant current stress (1 A) for 255 hours. The total thermal resistance increases from 7.0 to 8.8°C/W before and after degradation. Furthermore, the contribution of each component...
In this paper, ZnO nanorod arrays used as transparent conducting oxide(TCO) were fabricated on ZnO seed layers though a hydrothermal method and the seed layers were prepared by sol-gel method. Different pre-annealing temperature varying from 300°C to 400°C and different hydrothermal precursor concentration varying from 0.005 to 0.15M were studied. The effects of seed layers pre-annealing temperature...
The terahertz frequency GaN Gunn diodes with GaN and AlGaN electron launchers are investigated by using an improved NDM model of GaN. The simulations demonstrate that there exists a shift of the oscillation mode from dipole domain mode toward accumulation mode with increased temperature, and the AlGaN launcher GaN Gunn diode can generate better power performance at stable oscillation mode than the...
Well-aligned ZnO nanorods were grown on the p-GaN substrate by a hydrothermal method and n-ZnO nanorods/p-GaN heterojunction LED structures were formed. The electroluminescence (EL) properties of this structure were studied under both forward and reverse bias. The nanorod LED device only has light output under reverse bias. The I-V characteristic results show that the nanosized junction can increase...
Dual gate AlGaN/GaN MOS HFET with Al2O3 as gate oxide layer was fabricated. In comparison with normal dual gate Schottky HFET, dual gate MOS HFET exhibits much lower gate leakage current, larger transconductance and output current. Besides, the dual gate MOS HFET shows excellent breakdown characteristic.
The high breakdown voltage AlGaN/GaN HEMTs with source-terminated field plate was firstly fabricated for high frequency and high power application, employing by CF4 plasma treatment for enhancement-mode (E-mode). The results showed that by adding the distance of gate to drain, LGD from 5 um to 15um, the breakdown voltage of the device was rapidly increased 350V, whose value is from 50V to 400V while...
We report on study of the scattering mechanisms in the system of AlGaAs/GaAs two-dimensional electron gas (2DEG) with nearby embedded GaSb/GaAs type-II quantum dots (QDs), which directly affect its transport properties. Mobilities were measured as functions of electron density N2D in the QDs contained sample and reference sample at 4.2K, respectively. In the framework of Born approximation, a short-range...
The influence of neutron irradiation on the deep levels in GaN epilayer is studied. Thermal stimulated current (TSC) and low temperature photoluminescence (PL) techniques are used to determine the position of deep levels. Four traps are found in irradiated GaN and five traps in unirradiated sample by resolving TSC spectrum. The activation energy (Et), capture cross section (St), and concentration...
We would like to report our approaches to realize epitaxially grown source toward high drain current in III-V MISFET. One approach is an InP/InGaAs composite channel MISFET with regrown InGaAs source/drain. When gate length of 150 nm was fabricated, Id at Vd = 0.8 V was 0.8 A/mm and maximum gm was 0.38 S/mm at Vd = 0.5 V. The other approach is vertical FET. In case of vertical FET with dual gate,...
In this work, the metal gate effective work function (EWF) modulation for the TiN/Ta/TiN/SiO2/p-Si(100) structure was investigated. Comparing with TiN/SiO2/p-Si(100) structure, after annealing the introduction of Ta can effectively reduce the flat band voltage. It is also revealed that although as the thermal budget increases the flat band voltage obviously shifts toward the negative bias direction,...
In this paper, a dual mode GaAs HBT power amplifier for LTE band I applications is present. The amplifier is designed to operate from 1.92 GHz to 1.98 GHz with 28 dB of gain, enough to work with transmitter chips with relative low output power. The amplifier deliveries 28 dBm of linear power at 3.4 V supply to satisfy the linearity requirement for the LTE application. To improve the average efficiency...
CMOS utilizing high mobility III-V/Ge channels on Si substrates is expected to be one of key devices for high performance and low power advanced LSIs in the future. In addition, the heterogeneous integration of these materials on the Si platform can provide a variety of applications from high speed logic CMOS to versatile SoC chips, where various functional devices can be co-integrated. In this presentation,...
High-performance implant-free In0.53Ga0.47As-channel MOSFETs grown on GaAs substrates by Metalorganic Chemical Vapor Deposition (MOCVD) are demonstrated. Atomic-layer-deposited (ALD) Al2O3 was used as gate dielectric on top of a δ-doped In0.53Ga0.47As/In0.51Al0.49As metamorphic heterojunction structures grown on GaAs substrates. A 1-μm gate-length MOSFET with 15nm Al2O3 shows a maximum drain current...
One way to increase the breakdown voltage in heterojunction field-effect-transistors (HFETs) on silicon substrate is to introduce a transition (buffer) layer made of a sandwich of thin AlN/AlGaN layers between the silicon substrate and the GaN well. The effect of this transition layer is to average out and, in this way, to reduce the local mechanical stress that appears between the silicon substrate...
InGaN/GaN multi-quantum-well (MQW) nanowires and accordingly light-emitting-diodes (LEDs) were fabricated on the n-GaN/sapphire substrate with a nano-patterned SiO2 film as growth mask. The structural characteristics, optical and electrical properties were investigated. the observed results show that a InGaN/GaN MQW nanowire has smooth surface morphologies and triangular cross sectional structure...
Fabrication and performance of high-frequency 0.3-μm gate-length depletion-mode metamorphic Al0.50In0.50As/Ga0.47In0.53As high electron mobility transistors (mHEMT) grown by Metalorganic Chemical Vapor Deposition (MOCVD) on n-type silicon substrates is reported. Using a combined optical and e-beam photolithography technology, submicron mHEMT devices on Si have been achieved. A maximum trans-conductance...
This paper describes 0.18um CMOS silicon-on-insulator (SOI) technology and design techniques for SOI RF switch designs for wireless applications. The measured results of SP4T (single pole four throw) and SP8T (single pole eight throw) switch reference designs are presented. It has been demonstrated that SOI RF switch performance, in terms of power handling, linearity, insertion loss and isolation,...
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