Breaking Through the Multi-Mesa-Channel Width Limited of Normally Off GaN HEMTs Through Modulation of the Via-Hole-Length

Chien, Chin-Cheng; Wu, Wen-Hsin; You, Yao-Hong; Lin, Jun-Huei; Lee, Chia-Yu; Hsu, Wen Dung; Kuan, Chieh-Hsiung; Lin, Ray–Ming

doi:10.1186/s11671-017-2189-3

Cited by 5 publications

(2 citation statements)

References 29 publications

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“…In the case of the NC-HEMTs, the I DMAX (W NC ) with the gate annealing treatment (400 • C) rose to 785 mA mm −1 (800 nm), 720 mA mm −1 (600 nm), 625 mA mm −1 (400 nm), and 470 mA mm −1 (200 nm). Generally, increasing the etching area reduces the maximum drain current due to a reduction in the sheet carrier density [50]. After the gate annealing treatment, the incremental increases in electron saturation velocity (⃗ v ), as shown in figure 4(c), caused the peak transconductance and I DMAX to increase significantly [48].…”

Section: Resultsmentioning

confidence: 99%

DC performance improvement of nanochannel AlGaN/AlN/GaN HEMTs with reduced OFF-state leakage current by post-gate annealing modulation

Mazumder

Pan

et al. 2021

Semicond. Sci. Technol.

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In this work, the effects of a post-gate annealing (PGA) treatment on the electrical performance of AlGaN/AlN/GaN nanochannel high electron mobility transistors (NC-HEMTs) were analyzed, with various channel widths of 200, 400, 600, and 800 nm for a constant fill factor of 0.45. A systematic improvement in the DC parameters was observed in the NC-HEMTs after PGA treatment at 400 • C for 10 min. Secondary ion mass spectroscopy was performed on the 300 • C, 400 • C, and 500 • C for 10 min annealed and as-deposited NC-HEMT to optimize the PGA conditions. It was also verified that annealing at higher temperatures (>400 • C) can cause the diffusion of the gate metal (Ni/Au) into the AlGaN/AlN/GaN active layer, which subsequently degrades the device performance. The removal of shallow traps after the PGA treatment, which were created by ICP dry etching, improved the Schottky barrier height (∅ B ) from 0.42 eV to 1.40 eV and resulted in a significant reduction in the reverse gate leakage current (I G ) of approximately more than three orders of magnitude in the NC-HEMT with a channel width of 200 nm. The reduction in the channel resistance after the PGA treatment, correspondingly improved the drift velocity, resulting in a marked improvement in the maximum transconductance (G MMAX ) of 34% and considerable incremental increases in the maximum drain current (I DMAX ). The NC-HEMT (W NC = 200 nm) with PGA treatment exhibited decent performance, with an I G of 9 × 10 −9 A mm −1 , an I DMAX of 470 mA mm −1 , a G MMAX of 140 mS mm −1 , and an ON/OFF ratio (I ON /I OFF ) of approximately 1.1 × 10 7 along with improved gate controllability, i.e. lowering of the subthreshold swing to 69 mV dec −1 .

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Section: Resultsmentioning

confidence: 99%

DC performance improvement of nanochannel AlGaN/AlN/GaN HEMTs with reduced OFF-state leakage current by post-gate annealing modulation

Mazumder

Pan

et al. 2021

Semicond. Sci. Technol.

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“…Recently, fin-shaped tri-gate structures, formed by structuring parts of the gate region [10], have been developed to demonstrate high-voltage GaN MOS-HEMTs with superior gate control, leading to large ON-OFF ratios and small subthreshold slopes (SS), along with much reduced leakage current, and significantly increased breakdown voltages [15]- [17]. In addition, an excellent control of the threshold voltage (V TH ) in tri-gates, achieved by changing the fin width (w), offers an additional device design tool [17] and has been explored to reach E-mode operation in previous works [18]- [21]. This approach relies only on one lithography step to achieve positive threshold voltage through strain relaxation of the barrier layer and electron depletion from the fin sidewalls, and does not require any critical etching as for gate recess or p-GaN gates.…”

Section: Introductionmentioning

confidence: 99%

High-Performance Nanowire-Based E-Mode Power GaN MOSHEMTs With Large Work-Function Gate Metal

Nela

Zhu

et al. 2019

IEEE Electron Device Lett.

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In this work, we demonstrate high-performance Enhancement-mode (E-mode) GaN Metal-Oxide-Semiconductor High Electron Mobility Transistors (MOS-HEMTs) on Si substrate based on sidewall depletion achieved by nanostructured gate with large work-function metal. The devices presented threshold voltage (VTH) over 0.6 V at 1 μA/mm, large current density (IDS) up to 590 mA/mm, low specific on resistance (RON,SP) of 1.33 mΩ•cm 2 , high ON/OFF ratio over 10 10 and large breakdown voltage (VBR) of 1080 V at 1 μA/mm with grounded substrate. The excellent high power FOM of 877 MW/cm 2 reveals the potential of our approach to obtain E-mode operation, while maintaining exceptional on-state performance and high VBR.

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GaN-based power devices: Physics, reliability, and perspectives

Meneghini

Santi

Abid

et al. 2021

Journal of Applied Physics

298

126

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Over the last decade, gallium nitride has emerged as an excellent material for the fabrication of power devices. Among the semiconductors for which power devices are already available on the market, GaN has the widest energy gap, the largest critical field, the highest saturation velocity, thus representing an excellent material for the fabrication of high speed/high voltage components.The presence of spontaneous and piezoelectric polarization allows to create a 2-dimensional electron gas, with high mobility and large channel density, in absence of any doping, thanks to the use of AlGaN/GaN heterostructures. This contributes to minimize resistive losses; at the same time, for GaN transistors switching losses are very low, thanks to the small parasitic capacitances and switching charges. Device scaling and monolithic integration enable high frequency operation, with consequent advantages in terms of miniaturization.For high power/high voltage operation, vertical device architectures are being proposed and investigated, and 3-dimensional structuresfin-shaped, trench-structured, nanowire-basedare demonstrating a great potential. Contrary to silicon, GaN is a relatively young material: trapping and degradation processes must be understood and described in detail, with the aim of optimizing device stability and reliability. This tutorial paper describes the physics, technology and reliability of GaN-based power devices: in the first part of the article, starting from a discussion of the main properties of the material, the characteristics of lateral and vertical GaN transistors are discussed in detail, to provide guidance in this complex and interesting field. The second part of the paper focuses on trapping and reliability aspects: the physical origin of traps in GaN, and the main degradation mechanisms are discussed in detail. The wide set of referenced papers and the insight on the most relevant aspects gives the reader a comprehensive overview on present and next-generation GaN electronics. IntroductionOver the past decade, gallium nitride has emerged as an excellent material for the fabrication of power semiconductor devices. Thanks to the unique properties of GaN, diodes and transistors based on this material have excellent performance, compared to their silicon counterparts, and are expected to find wide application in the next-generation power converters. Owing to the flexibility and the energy efficiency of GaN-based power converters, the interest towards this technology is rapidly growing: the aim of this tutorial is to review the most relevant physical properties, the operating principles, the fabrication parameters, and the stability/reliability issues of GaN-based power transistors. For introductory purposes, we start summarizing the physical reasons why GaN transistors achieve a much better performance than the corresponding silicon devices, to help the reader understanding the unique advantages of this technology.The properties of GaN devices allow the fabrication of high-efficiency (near or above 99 %)...

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Breaking Through the Multi-Mesa-Channel Width Limited of Normally Off GaN HEMTs Through Modulation of the Via-Hole-Length

Cited by 5 publications

References 29 publications

DC performance improvement of nanochannel AlGaN/AlN/GaN HEMTs with reduced OFF-state leakage current by post-gate annealing modulation

DC performance improvement of nanochannel AlGaN/AlN/GaN HEMTs with reduced OFF-state leakage current by post-gate annealing modulation

High-Performance Nanowire-Based E-Mode Power GaN MOSHEMTs With Large Work-Function Gate Metal

GaN-based power devices: Physics, reliability, and perspectives

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