Variation of Dominant Degradation Mechanism in AlGaN Barrier Layer With Different Voltage Stress on the Gate of AlGaN/GaN High Electron Mobility Transistors

2015 ◽  
Vol 36 (4) ◽  
pp. 321-323 ◽  
Author(s):  
Lei Shi ◽  
Shiwei Feng ◽  
Yamin Zhang ◽  
Bangbing Shi ◽  
Kun Liu
Keyword(s):  
Barrier Layer ◽  
Electron Mobility ◽  
Degradation Mechanism ◽  
High Electron Mobility Transistors ◽  
High Electron ◽  
High Electron Mobility ◽  
Electron Mobility Transistors ◽  
Algan Barrier ◽  
Voltage Stress ◽  
Algan Barrier Layer

scholarly journals Низкоэнергетическое бездефектное сухое травление барьерного слоя HEMT AlGaN/AlN/GaN

2018 ◽  
Vol 44 (10) ◽  
pp. 61
Author(s):  
С.В. Михайлович ◽  
А.Ю. Павлов ◽  
К.Н. Томош ◽  
Ю.В. Федоров
Keyword(s):  
Barrier Layer ◽  
High Electron Mobility Transistors ◽  
High Electron ◽  
High Electron Mobility ◽  
Inductively Coupled ◽  
Enhancement Mode ◽  
Electron Mobility Transistors ◽  
Algan Barrier ◽  
Algan Barrier Layer ◽  
First Time

AbstractA method of defectless dry etching of an AlGaN barrier layer is proposed, which consists in repeated plasmachemical oxidation of AlGaN and removal of the oxide layer by means of reactive ion etching in inductively coupled BCl_3 plasma. Using the proposed etching technology, AlGaN/AlN/GaN high-electron-mobility transistors (HEMTs) with a buried gate have been successfully fabricated for the first time. It is shown that the currents of obtained HEMTs are independent of the number of etching cycles, while the gate operating point shifts toward positive voltages up to obtaining transistors operating in the enhancement mode.

scholarly journals Channel Characteristics of InAs/AlSb Heterojunction Epitaxy: Comparative Study on Epitaxies with Different Thickness of InAs Channel and AlSb Upper Barrier

Coatings ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 318 ◽  
Author(s):  
He Guan ◽  
Shaoxi Wang ◽  
Lingli Chen ◽  
Bo Gao ◽  
Ying Wang ◽  
...  
Keyword(s):  
Barrier Layer ◽  
Electron Mobility ◽  
High Electron Mobility Transistors ◽  
Electron Velocity ◽  
High Electron ◽  
High Electron Mobility ◽  
Electron Mobility Transistors ◽  
Channel Thickness ◽  
The Impact ◽  
Different Thickness

Because of the high electron mobility and electron velocity in the channel, InAs/AlSb high electron mobility transistors (HEMTs) have excellent physical properties, compared with the other traditional III-V semiconductor components, such as ultra-high cut-off frequency, very low power consumption and good noise performance. In this paper, both the structure and working principle of InAs/AlSb HEMTs were studied, the energy band distribution of the InAs/AlSb heterojunction epitaxy was analyzed, and the generation mechanism and scattering mechanism of two-dimensional electron gas (2DEG) in InAs channel were demonstrated, based on the software simulation in detail. In order to discuss the impact of different epitaxial structures on the 2DEG and electron mobility in channel, four kinds of epitaxies with different thickness of InAs channel and AlSb upper-barrier were manufactured. The samples were evaluated with the contact Hall test. It is found the sample with a channel thickness of 15 nm and upper-barrier layer of 17 nm shows a best compromised sheet carrier concentration of 2.56 × 1012 cm−2 and electron mobility of 1.81 × 104 cm2/V·s, and a low sheet resistivity of 135 Ω/□, which we considered to be the optimized thickness of channel layer and upper-barrier layer. This study is a reference to further design InAs/AlSb HEMT, by ensuring a good device performance.

A Study of Defects and Surface Properties in AlGaN/GaN High Electron Mobility Transistors (HEMTs) Grown by MOCVD on Semi-Insulating SiC Substrates

2006 ◽  
Vol 955 ◽  
Author(s):  
Yongkun Sin ◽  
Hyun I Kim ◽  
Paul Adams ◽  
Gary Stupian
Keyword(s):  
Surface Properties ◽  
Hall Mobility ◽  
Electron Mobility ◽  
High Electron Mobility Transistors ◽  
High Electron ◽  
Plan View ◽  
High Electron Mobility ◽  
Electron Mobility Transistors ◽  
Algan Barrier ◽  
Sheet Density

ABSTRACTAlGaN/GaN HEMTs (High Electron Mobility Transistors) grown on semi-insulating (SI) SiC substrates are very promising for high power, high speed, and high temperature operation with great potential for both military and commercial applications. These high performance characteristics are possible due to presence of high two-dimensional electron gas (2 DEG) charge sheet density maintaining a high Hall mobility at the AlGaN barrier/GaN buffer hetero-interface. However, reliability of AlGaN HEMTs still remains a major concern because of the large number of defects and traps present both in the bulk as well as at the surface leading to current collapse. We report on the study of defects and surface properties in MOCVD-grown Al0.27Ga0.73N HEMT structures on SI SiC substrates. Our HEMT structures consist of a 25nm thick undoped AlGaN barrier layer and a 3μm thick undoped GaN buffer layer grown on a 100nm thick AlN nucleation layer. Hall measurements showed a charge sheet density of ∼1013/cm2 and a Hall mobility of ∼1500cm2/V·sec. Both cross-sectional and plan view TEMs were employed to study defects in the heterostructures and XPS (X-ray Photoelectron Spectroscopy) and AES (Auger Electron Spectroscopy) employed to study surface properties in both GaN and AlGaN layers. DC characterization results from AlGaN Schottky diodes with Pt/Au Schottky contacts are also reported along with results from AlGaN/GaN HEMT devices.

AlGaN/GaN High Electron Mobility Transistors on Si/SiO2/poly-SiC Substrates

2006 ◽  
Vol 955 ◽  
Author(s):  
Travis Anderson ◽  
Fan Ren ◽  
Lars Voss ◽  
Mark Hlad ◽  
Brent P Gila ◽  
...  
Keyword(s):  
Electron Mobility ◽  
High Electron Mobility Transistors ◽  
Parameter Extraction ◽  
High Electron ◽  
High Electron Mobility ◽  
Drain Spacing ◽  
Electron Mobility Transistors ◽  
Algan Barrier ◽  
Rf Performance ◽  
Spacing Parameter

ABSTRACTThe dc and rf performance of AlGaN/GaN High Electron Mobility Transistors (HEMTs) grown by Molecular Beam Epitaxy on Si-on-poly (SopSiC) substrates is reported. The HEMT structure incorporated a 7 period GaN/AlN superlattice between the AlGaN barrier and GaN channel for improved carrier confinement. The knee voltage of devices with 2 μm gate-drain spacing was 2.12 V and increased to 3 V at 8 μm spacing. The maximum frequency of oscillation, fMAX, was ∼40 GHz for devices with 0.5 μm gate length and 2 μm gate-drain spacing. Parameter extraction from the measured rf characteristics showed a maximum intrinsic transconductance of 143 mS.mm−1.

DEPENDENCE OF RF PERFORMANCE OF GaN/AlGaN HEMTS UPON AlGaN BARRIER LAYER VARIATION

2004 ◽  
Vol 14 (03) ◽  
pp. 750-755 ◽  
Author(s):  
ELIAS FARACLAS ◽  
RICHARD T. WEBSTER ◽  
GEORGE BRANDES ◽  
A. F. M. ANWAR
Keyword(s):  
Elevated Temperatures ◽  
High Electron Mobility Transistors ◽  
High Electron ◽  
Gate Bias ◽  
High Electron Mobility ◽  
Electron Mobility Transistors ◽  
Algan Barrier ◽  
Unity Gain ◽  
Algan Barrier Layer ◽  
Rf Performance

The dependence of microwave performance of GaN/AlGaN High Electron Mobility Transistors (HEMTs), namely the unity gain current cut-off frequency (fT) and the maximum oscillation frequency (fMAX), are reported as a function of the mole fraction of Al and the thickness of the barrier AlGaN layer. The parameters are computed using a physics-based model and compared to experimental results. Schrödinger and Poisson's equations are solved self-consistently to relate the applied gate bias to the channel electron concentration. The contributions of both spontaneous and piezoelectric polarizations towards f T are explored. Finally, because of interest in using this family of devices at elevated temperatures, each simulation was repeated between 300K and 500K for comparison.

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