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.

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 Effect of Electric Field On Electron Mobility in Sub-100 nm InAlN/GaN High Electron Mobility Transistors

2021 ◽  
Author(s):  
Peng Cui ◽  
Yuping Zeng
Keyword(s):  
Electric Field ◽  
Electron Mobility ◽  
Scattering Theory ◽  
Field Effect Transistors ◽  
High Electron Mobility Transistors ◽  
Electron Velocity ◽  
High Electron ◽  
Current Output ◽  
High Electron Mobility ◽  
Electron Mobility Transistors

Abstract Electron mobility is important for electron velocity, transport current, output power, and frequency characteristics. In conventional mobility extraction methods, electron mobility is usually extracted directly from the measured gate capacitance (CG) and current-voltage characteristics. When device gate length (LG) scales to sub-100 nm, the determination of CG becomes more difficult not only for the measure equipment but also the enhanced effect from parasitic capacitance. Here in this paper, the CG extracted from high-frequency small-signal equipment circuit is used for the InAlN/GaN high electron mobility transistors (HEMTs). Electron mobility of the device with LG of 60-nm under VDS of 0.1 V and 10 V is extracted using two-dimensional scattering theory, respectively. The obtained results show that under a high electric field, the electron temperature (Te) and addition polarization charges (∆σ) increase, resulting in the enhanced polar optical phonon (POP) as well as polarization Coulomb field (PCF) scatterings and degradation of the electron mobility. This study makes it possible to improve the electron mobility by reducing Te and ∆σ for the InAlN/GaN HEMTs application.AlGaN/GaN heterostructure field-effect transistors with different gate lengths were fabricated. Based on the chosen of the Hamiltonian of the system and the additional polarization charges, two methods to calculate PCF scattering by the scattering theory were presented. By comparing the measured and calculated source-drain resistances, the influence of the different gate lengths on the PCF scattering potential was confirmed.

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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