Role of Self-Heating and Polarization in AlGaN/GaN-Based Heterostructures

Ahmeda, K.; Ubochi, Brendan; Benbakhti, B.; Duffy, Steven J.; Soltani, A.; Zhang, W.; Kálna, K.

doi:10.1109/access.2017.2755984

Cited by 19 publications

(14 citation statements)

References 30 publications

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“…The simulations of 4H‐SiC MOSFET are carried out using the drift‐diffusion (DD) transport mode, Poisson equation and heat transport equation [7, 8]. These equations allow the calculation of electrostatic potential, the concentrations of electrons and holes, current and lattice temperature.…”

Section: Methodsmentioning

confidence: 99%

“…At a low field, we used analytic mobility which is based on Caughey–Thomas [7, 10, 11]

μ_{n} false(n, T_{normalL} false) = μ_{1} {(\frac{T_{L}}{300})}^{a} + \frac{μ_{2} {false(T_{normalL} / 300 false)}^{b} - μ_{1} {false(T_{normalL} / 300 false)}^{a}}{1 + {false(T_{normalL} / 300 false)}^{c} {false(n / NCR false)}^{d}}

where n is the total doping concentration; T L is the lattice temperature in Kelvin;

μ_{1}

and

μ_{2}

are the mobilities of undoped samples; NCR is the doping concentration when the mobility has an average value between

μ_{1}

and

μ_{2}

; d shows the rate of changing mobility from

μ_{1}

μ_{2}

; and a , b , c and d are temperature‐dependent coefficients [7, 10, 11].…”

Section: Methodsmentioning

confidence: 99%

“…The heat generation equation is given by [7, 23]

\begin{matrix} right leftthickmathspace.5em \\ h & = \frac{q {|j_{n}|}^{2}}{μ_{n} n} + \frac{q {(||, {bold-italicj}_{p})}^{2}}{μ_{p} p} + q (R - G) [ϕ_{p} - ϕ_{n} \\ + T_{L} (P_{n} + P_{p})] - q T_{L} (j_{n} \nabla P_{n} - j_{n} \nabla P_{p}) \end{matrix}

where

| {bold-italicj}_{n} |

| {bold-italicj}_{p} |

are the particle current densities of electrons and holes;

μ_{n}, μ_{p}

are the mobility of electrons and holes;

n, p

are the electron and hole concentrations;

ϕ_{n}, ϕ_{p}

are the quasi‐Fermi levels of electrons and holes;

P_{p}, P_{n}

are the thermoelectric powers of electrons and holes; R is the bulk recombination rate of carriers; G is the carrier generation rate;

T_{normalL}

is the local lattice temperature; and q is the elementary charge of an electron.…”

Section: Methodsmentioning

confidence: 99%

“…where n is the total doping concentration; T L is the lattice temperature in Kelvin; μ 1 and μ 2 are the mobilities of undoped samples; NCR is the doping concentration when the mobility has an average value between μ 1 and μ 2 ; d shows the rate of changing mobility from μ 1 to μ 2 ; and a, b, c and d are temperature-dependent coefficients [7,10,11]. SiC is an anisotropic material, therefore, its mobility needs to be represented by a tensor (a 3 × 3 matrix) [12].…”

Section: Drift Diffusion and Mobility Transport Modelsmentioning

confidence: 99%

See 3 more Smart Citations

Impact of interface traps/defects and self‐heating on the degradation of performance of a 4H‐SiC VDMOSFET

Alqaysi

Martı́nez

Ahmeda

et al. 2019

IET Power Electronics

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The reliability of silicon carbide metal oxide semiconductor field-effect transistors remains a challenge in power applications and relates to the SiO 2-SiC interface. The presence of unwanted interface traps/defects degrades the device performance. The impact of acceptor traps/defects on the performance of a 4H-SiC vertical Diffused Metal Oxide Semiconductor Field Effect Transistor (DMOSFET) with a breakdown voltage of 1700 V is investigated.-and-characteristics were simulated, using a drift-diffusion model coupled to Fourier heat equations, and are in a good agreement with experimental results. The presence of interface traps/defects were shown to produce degradation of threshold voltage, but the impact diminishes as temperature increases. A threshold voltage shift of 3.5 V occurs for a trap concentration of 2 × 10 13 cm-2 /eV at room temperature. The transfer characteristics obtained from electro-thermal modelling show a larger degradation than those at a constant temperature. This degradation increases with the drain bias increase. The threshold voltage from the electro-thermal simulations is 5 V compared to 4 V observed in constant 423 K temperature simulations at. Finally, the interface traps/defects increases breakdown voltage exhibiting a strong dependency on the trap density and their energy decay characteristics.

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Section: Methodsmentioning

confidence: 99%

“…At a low field, we used analytic mobility which is based on Caughey–Thomas [7, 10, 11]

μ_{n} false(n, T_{normalL} false) = μ_{1} {(\frac{T_{L}}{300})}^{a} + \frac{μ_{2} {false(T_{normalL} / 300 false)}^{b} - μ_{1} {false(T_{normalL} / 300 false)}^{a}}{1 + {false(T_{normalL} / 300 false)}^{c} {false(n / NCR false)}^{d}}

where n is the total doping concentration; T L is the lattice temperature in Kelvin;

μ_{1}

and

μ_{2}

are the mobilities of undoped samples; NCR is the doping concentration when the mobility has an average value between

μ_{1}

and

μ_{2}

; d shows the rate of changing mobility from

μ_{1}

μ_{2}

; and a , b , c and d are temperature‐dependent coefficients [7, 10, 11].…”

Section: Methodsmentioning

confidence: 99%

“…The heat generation equation is given by [7, 23]

\begin{matrix} right leftthickmathspace.5em \\ h & = \frac{q {|j_{n}|}^{2}}{μ_{n} n} + \frac{q {(||, {bold-italicj}_{p})}^{2}}{μ_{p} p} + q (R - G) [ϕ_{p} - ϕ_{n} \\ + T_{L} (P_{n} + P_{p})] - q T_{L} (j_{n} \nabla P_{n} - j_{n} \nabla P_{p}) \end{matrix}

where

| {bold-italicj}_{n} |

| {bold-italicj}_{p} |

are the particle current densities of electrons and holes;

μ_{n}, μ_{p}

are the mobility of electrons and holes;

n, p

are the electron and hole concentrations;

ϕ_{n}, ϕ_{p}

are the quasi‐Fermi levels of electrons and holes;

P_{p}, P_{n}

are the thermoelectric powers of electrons and holes; R is the bulk recombination rate of carriers; G is the carrier generation rate;

T_{normalL}

is the local lattice temperature; and q is the elementary charge of an electron.…”

Section: Methodsmentioning

confidence: 99%

Section: Drift Diffusion and Mobility Transport Modelsmentioning

confidence: 99%

See 2 more Smart Citations

Impact of interface traps/defects and self‐heating on the degradation of performance of a 4H‐SiC VDMOSFET

Alqaysi

Martı́nez

Ahmeda

et al. 2019

IET Power Electronics

Self Cite

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“…Simin G. et al [10] revealed that gate bias-induced inhomogeneous strain in the AlGaN barrier will cause a decrease in polarization charge and reduction in 2DEG in normally-on HEMT device by experiments. Ahmeda K. et al [11] found that applying strain in drain region will cause changes in the total polarization, thus affecting 2DEG density in the channel. However, as far as we known, there are few reports on the strain effect in the AlGaN barrier of normally-off HEMT with a p-GaN gate.…”

Section: Introductionmentioning

confidence: 99%

Simulation of Electrical Characteristics on Inhomogeneous Strains in Normally-off HEMTs with p-GaN Gate

et al. 2020

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Strain is one of the important factors affecting the two-dimensional electron gas (2DEG) transform in AlGaN/GaN material based high electron mobility transistors (HEMTs) by polarization effects. In this paper, the effects of inhomogeneous biaxial strain in different regions of the AlGaN barrier layer on electrical properties of normally-off HEMTs with p-GaN gate were discussed. The results show that biaxial strain applied in three regions has different influence on transfer, output and breakdown characteristics of the device. The strain applied in region under gate has the most significant impact on threshold voltage and drain saturation current with a decreasing of 39% and an increasing of 97% respectively as the strained lattice constant increases from 3.173061Å to 3.187229Å.While, strain applied between gate and drain electrode can improve the off-state breakdown voltage by 12% with the increasing of strained lattice constant.

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Performance analysis of gallium nitride-based DH-HEMT with polarization-graded AlGaN back-barrier layer

2023

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In this paper, polarization-graded AlGaN back-barrier nanolayer has been introduced to improve the DC and RF parameters of gallium nitride-based high electron mobility transistors (HEMT). To explore the characteristics, both graded and non-graded double heterojunction high electron mobility transistor (DH-HEMT) structures are optimized using SILVACO-ATLAS physical simulator. Enhanced DC and RF parameters have been observed in the optimized graded DH-HEMT. In this paper, we have also studied the development of the quantum wells at the AlGaN/GaN interfaces due to the conduction band discontinuity in both structures.

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Role of Self-Heating and Polarization in AlGaN/GaN-Based Heterostructures

Cited by 19 publications

References 30 publications

Impact of interface traps/defects and self‐heating on the degradation of performance of a 4H‐SiC VDMOSFET

Impact of interface traps/defects and self‐heating on the degradation of performance of a 4H‐SiC VDMOSFET

Simulation of Electrical Characteristics on Inhomogeneous Strains in Normally-off HEMTs with p-GaN Gate

Performance analysis of gallium nitride-based DH-HEMT with polarization-graded AlGaN back-barrier layer

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