The AlInGaN back barrier effect on DC characteristics of AlGaN/GaN high electron mobility transistor

2019 ◽  
Vol 33 (18) ◽  
pp. 1950190
Author(s):  
Hai Li Wang ◽  
Peng Yang ◽  
Kun Xu ◽  
Xiang Yang Duan ◽  
Shu Xiang Sun
Keyword(s):  
Mole Fraction ◽  
Electron Mobility ◽  
Transport Model ◽  
High Electron Mobility Transistors ◽  
High Electron Mobility Transistor ◽  
High Electron ◽  
High Electron Mobility ◽  
Conduction Band Offset ◽  
Electron Mobility Transistors ◽  
The Impact

In this paper, we investigated the impact of thickness and mole fraction AlInGaN back barrier on the DC performance of AlGaN/GaN high electron mobility transistors (HEMTs) by numerical simulation. The simulations are performed using the hydrodynamic transport model (HD). The simulation results indicated that an inserted AlInGaN back barrier with increasing thickness and mole fraction could effectively confine the electron in the channel, resulting in a significant improvement of the channel current and transconductance. Additionally, the variation of conduction band offset and the increase of total number electron in the channel led to the threshold voltage moving toward a more negative value.

scholarly journals The Impact of AlxGa1−xN Back Barrier in AlGaN/GaN High Electron Mobility Transistors (HEMTs) on Six-Inch MCZ Si Substrate

Coatings ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 570
Author(s):  
H.Y. Wang ◽  
H.C. Chiu ◽  
W.C. Hsu ◽  
C.M. Liu ◽  
C.Y. Chuang ◽  
...  
Keyword(s):  
Mole Fraction ◽  
Electron Mobility ◽  
Heat Dissipation ◽  
Surface Defects ◽  
Lattice Mismatch ◽  
High Electron Mobility Transistors ◽  
High Electron ◽  
High Electron Mobility ◽  
Electron Mobility Transistors ◽  
The Impact

In this study, AlGaN/GaN high electron mobility transistors (HEMTs) with AlGaN back barriers (B.B.) were comprehensively investigated based on the different Al mole fractions and thicknesses in the design of the experiments. It was shown that the off-state leakage current can be suppressed following an increase of the Al mole fraction due to the enhancement of the back barrier height. Increasing the AlGaN thickness deteriorated device performance because of the generation of lattice mismatch induced surface defects. The dynamic on-resistance (RON) measurements indicated that the Al mole fraction and thickness of the B.B. both affected the buffer trapping phenomenon. In addition, the thickness of B.B. also influenced the substrate heat dissipation ability which is also a key index for high power RF device applications.

scholarly journals AlGaN/GaN High Electron Mobility Transistors on Semi-Insulating Ammono-GaN Substrates with Regrown Ohmic Contacts

Micromachines ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 546 ◽  
Author(s):  
Wojciech Wojtasiak ◽  
Marcin Góralczyk ◽  
Daniel Gryglewski ◽  
Marcin Zając ◽  
Robert Kucharski ◽  
...  
Keyword(s):  
Electron Mobility ◽  
Ohmic Contacts ◽  
High Electron Mobility Transistors ◽  
High Electron Mobility Transistor ◽  
Maximum Output ◽  
High Electron ◽  
Output Current ◽  
High Electron Mobility ◽  
Electron Mobility Transistors ◽  
Access Resistance

AlGaN/GaN high electron mobility transistors on semi-insulating bulk ammonothermal GaN have been investigated. By application of regrown ohmic contacts, the problem with obtaining low resistance ohmic contacts to low-dislocation high electron mobility transistor (HEMT) structures was solved. The maximum output current was about 1 A/mm and contact resistances was in the range of 0.3–0.6 Ω ·mm. Good microwave performance was obtained due to the absence of parasitic elements such as high access resistance.

Applications of GaN-Based High Electron Mobility Transistors in Large-Size Devices

2015 ◽  
Vol 764-765 ◽  
pp. 486-490
Author(s):  
Chih Hao Wang ◽  
Liang Yu Su ◽  
Finella Lee ◽  
Jian Jang Huang
Keyword(s):  
Electron Mobility ◽  
High Electron Mobility Transistors ◽  
High Electron Mobility Transistor ◽  
High Electron ◽  
Saturation Current ◽  
High Electron Mobility ◽  
Enhancement Mode ◽  
Electron Mobility Transistors ◽  
Large Size ◽  
Novel Design

We demonstrate a novel design of large-size device in AlGaN/GaN high-electron-mobility transistor (HEMT). Depletion mode (D-mode) HEMTs and enhancement mode (E-mode) HEMTs are fabricated in our research. The saturation current of D-mode HEMTs is over 6A. By using Cascode structure, the D-mode HEMT becomes a normally-off device efficiently, and the threshold voltage of it rises from-7V to 2V. By using BCB (Benzocyclobutene) as the passivation, the E-mode HEMT shows an excellent characteristic. Also, when the VGS of the E-mode HEMT is over 9V, it still shows a good performance.

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.

scholarly journals An Overview of Normally-Off GaN-Based High Electron Mobility Transistors

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1599 ◽  
Author(s):  
Fabrizio Roccaforte ◽  
Giuseppe Greco ◽  
Patrick Fiorenza ◽  
Ferdinando Iucolano
Keyword(s):  
Power Electronics ◽  
Electron Mobility ◽  
Wide Band ◽  
High Electron Mobility Transistors ◽  
High Electron Mobility Transistor ◽  
Special Focus ◽  
High Electron ◽  
High Electron Mobility ◽  
Advantages And Disadvantages ◽  
Electron Mobility Transistors

Today, the introduction of wide band gap (WBG) semiconductors in power electronics has become mandatory to improve the energy efficiency of devices and modules and to reduce the overall electric power consumption in the world. Due to its excellent properties, gallium nitride (GaN) and related alloys (e.g., AlxGa1−xN) are promising semiconductors for the next generation of high-power and high-frequency devices. However, there are still several technological concerns hindering the complete exploitation of these materials. As an example, high electron mobility transistors (HEMTs) based on AlGaN/GaN heterostructures are inherently normally-on devices. However, normally-off operation is often desired in many power electronics applications. This review paper will give a brief overview on some scientific and technological aspects related to the current normally-off GaN HEMTs technology. A special focus will be put on the p-GaN gate and on the recessed gate hybrid metal insulator semiconductor high electron mobility transistor (MISHEMT), discussing the role of the metal on the p-GaN gate and of the insulator in the recessed MISHEMT region. Finally, the advantages and disadvantages in the processing and performances of the most common technological solutions for normally-off GaN transistors will be summarized.

scholarly journals The impact of dislocations on AlGaN/GaN Schottky diodes and on gate failure of high electron mobility transistors

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Sven Besendörfer ◽  
Elke Meissner ◽  
Farid Medjdoub ◽  
Joff Derluyn ◽  
Jochen Friedrich ◽  
...  
Keyword(s):  
Electron Mobility ◽  
Reverse Bias ◽  
Schottky Diodes ◽  
Forward Bias ◽  
High Electron Mobility Transistors ◽  
High Electron ◽  
Conductive Atomic Force Microscopy ◽  
High Electron Mobility ◽  
Electron Mobility Transistors ◽  
The Impact

Abstract GaN epitaxially grown on Si is a material for power electronics that intrinsically shows a high density of dislocations. We show by Conductive Atomic Force Microscopy (C-AFM) and Defect Selective Etching that even for materials with similar total dislocation densities substantially different subsets of dislocations with screw component act as current leakage paths within the AlGaN barrier under forward bias. Potential reasons are discussed and it will be directly shown by an innovative experiment that current voltage forward characteristics of AlGaN/GaN Schottky diodes shift to lower absolute voltages when such dislocations are present within the device. A local lowering of the Schottky barrier height around conductive dislocations is identified and impurity segregation is assumed as responsible root cause. While dislocation related leakage current under low reverse bias could not be resolved, breakdown of AlGaN/GaN Schottky diodes under high reverse bias correlates well with observed conductive dislocations as measured by C-AFM. If such dislocations are located near the drain side of the gate edge, failure of the gate in terms of breakdown or formation of percolation paths is observed for AlGaN/GaN high electron mobility transistors.

scholarly journals Effect of the High-Temperature Off-State Stresses on the Degradation of AlGaN/GaN HEMTs

Electronics ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1339
Author(s):  
Jinfu Lin ◽  
Hongxia Liu ◽  
Shulong Wang ◽  
Chang Liu ◽  
Mengyu Li ◽  
...  
Keyword(s):  
High Temperature ◽  
Electric Field ◽  
Electron Mobility ◽  
High Electron Mobility Transistors ◽  
Simultaneous Action ◽  
High Electron ◽  
High Electron Mobility ◽  
Electron Mobility Transistors ◽  
Significant Difference ◽  
The Impact

GaN-based high electron mobility transistors offer high carrier density combined with high electron mobility and often require operation at high frequencies, voltages, and temperatures. The device may be under high temperature and high voltage at the same time in actual operation. In this work, the impact of separate off-state stresses, separate high-temperature stresses, and off-state stresses at high temperatures on AlGaN/GaN high electron mobility transistors (HEMTs) grown on Si substrates was investigated. The output current and gate leakage of the device degenerated to different degrees under either isolated off-state or high-temperature stress. The threshold voltage of the device only exhibited obvious negative drift under the action of high-temperature and off-state stresses. The parameter at high temperature (or room temperature) before stress application was the reference. We found that there was no significant difference in the degradation rate of drain current and transconductance peak when the same off-state stress was applied to the device at different temperatures. It was concluded that, under the high-temperature off-state electric field pressure, there were two degradation mechanisms: one was the inverse piezoelectric polarization mechanism only related to the electric field, and the other was the degradation mechanism of the simultaneous action of temperature and electric field.

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