Improvement of breakdown and current collapse characteristics of GaN HEMT with a polarization-graded AlGaN buffer

We present the stable transconductance operation of InGaN/GaN composite channel based HEMTs. LG = 55 nm AlGaN/InGaN/GaN (Device A) and InAlN/InGaN/GaN (Device B) HEMTs were proposed and investigated its operational characteristics using numerical simulation. Existence of deeper potential well, the proposed HEMTs possesses high 2DEG (two-dimensional electron gas) density, enhanced electron confinement, and improved electron mobility. As a result, the device shows enhanced current density, and high linearity operation. Furthermore, Al0.04Ga0.96N superlative back-barrier significantly reduces the buffer leakage current resulting in improved breakdown voltage (VBR). The proposed device A (device B) exhibited 2.81 (5) A/mm of output current density, 0.669 (0.7273) S/mm, 4 (7) V of GVS (gate voltage swing), 55.3 (43.5) V of breakdown voltage, and 252/263 (275/289) GHz of FT/FMAX. This excellent device performances illustrates the potential of InGaN/GaN channel HEMTs for future wide-band telecommunication, radio astronomy, radar and space applications.

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“…The interface charge density is given by [36][37]: [39]. Table 1 presents the polarization parameters of III-nitride binary alloys.…”

Section: Device Description Simulation Models and Materials Parametersmentioning

confidence: 99%

Design and Analysis of AlGaN/InGaN/GaN and InAlN/InGaN/GaN HEMTs for High-Power Wide Bandwidth Applications

Revathy

Boopathi

Nirmal

2021

Preprint

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“…A space polarization-induced charge would be generated by a gradient of polarization of the Al x Ga 1−x N back barrier which varies along the growth direction. The corresponding density is given by [42,43]:…”

Section: Device Description and Physical Modelsmentioning

confidence: 99%

Theoretical Study of InAlN/GaN High Electron Mobility Transistor (HEMT) with a Polarization-Graded AlGaN Back-Barrier Layer

Chang

Sun

et al. 2019

Electronics

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An inserted novel polarization-graded AlGaN back barrier structure is designed to enhance performances of In0.17Al0.83N/GaN high electron mobility transistor (HEMT), which is investigated by the two-dimensional drift-diffusion simulations. The results indicate that carrier confinement of the graded AlGaN back-barrier HEMT is significantly improved due to the conduction band discontinuity of about 0.46 eV at interface of GaN/AlGaN heterojunction. Meanwhile, the two-dimensional electron gas (2DEG) concentration of parasitic electron channel can be reduced by a gradient Al composition that leads to the complete lattice relaxation without piezoelectric polarization, which is compared with the conventional Al0.1Ga0.9N back-barrier HEMT. Furthermore, compared to the conventional back-barrier HEMT with a fixed Al-content, a higher transconductance, a higher current and a better radio-frequency performance can be created by a graded AlGaN back barrier.

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“…25 Chuanhao Li et al show the breakdown and current collapse characteristics of graded AlGaN buffer. 26 This paper has designed and investigated the DC and microwave performance of ultra-scaled 10 nm Tgate InAlN/AlN E-mode HEMT with heavily doped source/drain region and polarization doped buffer. The higher f T /f max , high breakdown voltage, and tighter 2DEG confinement have been achieved for the proposed HEMT.…”

Section: Introductionmentioning

confidence: 99%

Ultrascaled 10 nm T‐gate E‐mode InAlN / AlN HEMT with polarized doped buffer for high power microwave applications

Sharma

Chaujar

2022

Int J RF Mic Comp-Aid Eng

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The DC and RF performance of ultra-scaled 10 nm E mode InAlN/AlN HEMT with polarized doped buffer has been investigated. The proposed device has the feature of polarized doped buffer, heavily doped source/drain region, and recessed T-gate structure. The polarization-induced doping in the buffer layer bent the conduction band upwardly convex, which enhanced the 2DEG confinement, reduced the buffer leakage current, and significantly uplifted the breakdown voltage (33 V), which is 5 times higher than the conventional InAlN/AlN GaN buffer HEMT (8 V). The short channel effect was further reduced by the recessed gate engineering (high on/off ratio 10 9 , subthreshold swing 78 mV/dec, and DIBL 100 mV/V), and smaller 10 nm foot length of Tgate reduced the parasitic capacitance, which uplifts the RF parameters of the proposed device. The proposed device exhibits a high current density of 2.8 A/ mm, transconductance 1.55 S/mm, cutoff frequency f T (583 GHz), and maximum oscillation frequency f max (840 GHz). At room temperature, the calculated carrier density and mobility are 2.8 Â 10 13 cm À2 and 1250 cm 2 /Vs. The large Jhonson figure of merit (f T . V BR ) 19.23 THz and (f T . f max ) 1/2 699 GHz shows the potential of the proposed device for high-power millimeter-wave applications.

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Improvement of breakdown and current collapse characteristics of GaN HEMT with a polarization-graded AlGaN buffer

Cited by 26 publications

References 27 publications

Design and Analysis of AlGaN/InGaN/GaN and InAlN/InGaN/GaN HEMTs for High-Power Wide Bandwidth Applications

Design and Analysis of AlGaN/InGaN/GaN and InAlN/InGaN/GaN HEMTs for High-Power Wide Bandwidth Applications

Theoretical Study of InAlN/GaN High Electron Mobility Transistor (HEMT) with a Polarization-Graded AlGaN Back-Barrier Layer

Ultrascaled 10 nm T‐gate E‐mode InAlN / AlN HEMT with polarized doped buffer for high power microwave applications

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