Dislocations at coalescence boundaries in heteroepitaxial GaN/sapphire studied after the epitaxial layer has completely coalesced

O'Hanlon, Thomas J.; Zhu, Tongtong; Massabuau, Fabien; Oliver, Rachel A.

doi:10.1016/j.ultramic.2021.113258

Cited by 4 publications

(1 citation statement)

References 32 publications

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“…There have been very few reports of AlGaN/GaN HEMTs with sheet resistivity of near or less than 250 Ω/ [6,8] with a single AlGaN barrier, with most of them on SiC substrates. It is challenging to achieve low sheet resistivity in AlGaN/GaN HEMT structures deposited on sapphire substrates due to the high density of defects and dislocations generated due to lattice mismatch (16%) between GaN and sapphire [9,10]. Also, it is well known that due to high optical phonon scattering and scattering due to polarization-induced charges at the interface, it is very difficult to achieve sheet resistivity below 250 Ω/ [11].…”

Section: Introductionmentioning

confidence: 99%

Crack-Free High-Composition (>35%) Thick-Barrier (>30 nm) AlGaN/AlN/GaN High-Electron-Mobility Transistor on Sapphire with Low Sheet Resistance (<250 Ω/□)

Mukhopadhyay,

Liu,

Chen

et al. 2023

Crystals

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In this article, a high-composition (>35%) thick-barrier (>30 nm) AlGaN/AlN/GaN high-electron-mobility transistor (HEMT) structure grown on a sapphire substrate with ultra-low sheet resistivity (<250 Ω/□) is reported. The optimization of growth conditions, such as reduced deposition rate, and the thickness optimization of different epitaxial layers allowed us to deposit a crack-free high-composition and thick AlGaN barrier layer HEMT structure. A significantly high two-dimensional electron gas (2DEG) density of 1.46 × 1013 cm−2 with a room-temperature mobility of 1710 cm2/V·s was obtained via Hall measurement using the Van der Pauw method. These state-of-the-art results show great potential for high-power Ga-polar HEMT design on sapphire substrates.

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Section: Introductionmentioning

confidence: 99%

Crack-Free High-Composition (>35%) Thick-Barrier (>30 nm) AlGaN/AlN/GaN High-Electron-Mobility Transistor on Sapphire with Low Sheet Resistance (<250 Ω/□)

Mukhopadhyay,

Liu,

Chen

et al. 2023

Crystals

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The effect of GaN single crystal substrate characteristics on homo-epitaxial GaN films

Li,

Liu,

Wang

et al. 2025

Surfaces and Interfaces

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Study on the processing characteristics of sapphire wafer polished with different properties plates

Chen

Wang

2022

AIP Advances

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To realize the processing demands of the sapphire wafer surface with scratch-free and nano-scale roughness by mechanical polishing, a novel flexible polishing plate was developed by using soft unsaturated resin. The surface characteristics, material removal rate, and residual stress of the sapphire wafer after the flexible polishing process have been compared with those of the sapphire wafer after the rigid polishing process. Both theoretical and simulation analysis results show that the abrasive particles in the flexible polishing exhibit an apparent yielding effect during the polishing course, which contributes to the achievement of plastic flow removal for the wafer surface. The experimental results show that the surface roughness and subsurface damage of the sapphire wafer polished by the flexible polishing process can be decreased by 18.7% and 57.3%, respectively, compared with those of the sapphire wafer polished by the rigid polishing process.

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Dislocations at coalescence boundaries in heteroepitaxial GaN/sapphire studied after the epitaxial layer has completely coalesced

Cited by 4 publications

References 32 publications

Crack-Free High-Composition (>35%) Thick-Barrier (>30 nm) AlGaN/AlN/GaN High-Electron-Mobility Transistor on Sapphire with Low Sheet Resistance (<250 Ω/□)

Crack-Free High-Composition (>35%) Thick-Barrier (>30 nm) AlGaN/AlN/GaN High-Electron-Mobility Transistor on Sapphire with Low Sheet Resistance (<250 Ω/□)

The effect of GaN single crystal substrate characteristics on homo-epitaxial GaN films

Study on the processing characteristics of sapphire wafer polished with different properties plates

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