Growth of Bulk Nitrides from a Na Flux

Mori, Yusuke; Imade, Mamoru; Maruyama, Mihoko; Yoshimura, Masashi; Yamane, Hisanori; Kawamura, Fumio; Kawamura, Takahiro

doi:10.1016/b978-0-444-63303-3.00013-4

Cited by 20 publications

(26 citation statements)

References 41 publications

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“…It is interesting to note some separation of the ternary nitride materials synthesized in bulk and thin film forms. For example, some Mg-based Mg– M –N have been synthesized only in the thin film form, , whereas there are only bulk synthesis reports of some Ca-, Sr-, and Ba-containing materials. , Within the Zn-based Zn– M –N material family, Zn 2 SbN 3 has been synthesized only in thin film form, and Zn 2 PN 3 is an example of material synthesized only in bulk . Some of this material separation between film and bulk forms may be related to the synthesis considerations and preferences.…”

Section: Experimental Synthesismentioning

confidence: 99%

Experimental Synthesis of Theoretically Predicted Multivalent Ternary Nitride Materials

2022

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Multivalent ternary nitride materials, which combine two metal cations with a nitrogen anion in equal amounts and charge balanced stoichiometry, tend to have relatively simple structures and promising properties for a broad range of applications. Historically, discovery of such new nitrides has been a bulk synthesis endeavor, following chemical intuition. In the past decade experimental synthesis of theoretically predicted materials, including as thin films, has changed this approach. In this perspective, we discuss progress in the experimental synthesis of theoretically predicted multivalent ternary nitrides, with the focus on Zn-and Mg-based materials. First-principles theoretical calculations predicted structures and properties of many new Zn−M−N and Mg−M−N materials and offered insights into the effects of cation ordering. Thin film and bulk experiments were used to synthesize some of these predicted multivalent ternary nitride compounds such as Zn 3 MoN 4 , Zn 2 SbN 3 , and Zn 2 NbN 3 , as well as MgZrN 2 , Mg 2 NbN 3 , and Mg 2 SbN 3 , and many others. These multivalent ternary nitride success stories should inspire experimental synthesis of other underexplored materials predicted by theoretical calculations.

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Section: Experimental Synthesismentioning

confidence: 99%

Experimental Synthesis of Theoretically Predicted Multivalent Ternary Nitride Materials

2022

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“…Fabrication of bulk GaN has been attempted using several growth techniques: the hydride vapor phase epitaxy (HVPE) method, 5,6 the ammonothermal method, 7,8 the high nitrogen pressure solution method, 9 and the Na-flux method. 10,11 However, there is as yet no way to fabricate bulk GaN that achieves low dislocation density (< ∼10 5 cm −2 ), large diameter (>4 in. ), low curvature (radius of curvature >20 m), and a high growth rate (>1 mm/h).…”

Section: ■ Introductionmentioning

confidence: 99%

“…freestanding GaN wafer. 11 The threading dislocation density (TDD) of the wafer was on the order of 10 2 cm −2 to 10 5 cm −2 , and the radius of lattice curvature is more than 100 m. However, the growth rate along the c axis was 50 μm/h, which is still low for the mass production, and further improvement of the growth rate is necessary. On the other hand, ultrahigh-speed growth along the c axis, more than 1 mm/h, was accomplished with HVPE growth by Yoshida et al 14 Thus, in the present study, we propose HVPE growth on the Na-flux-grown wafer, that is, a hybrid growth method.…”

Section: ■ Introductionmentioning

confidence: 99%

Homoepitaxial Hydride Vapor Phase Epitaxy Growth on GaN Wafers Manufactured by the Na-Flux Method

Imanishi

Yoshida

Kitamura

et al. 2017

Crystal Growth & Design

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Homoepitaxial hydride vapor phase epitaxy (HVPE) growth on GaN substrates grown with a Na-flux method, which is the most promising approach for fabrication of large-diameter, low-dislocation-density, fast-growing GaN wafers, was attempted for the first time. We found that, when different growth methods are combined, the differences in oxygen concentrations between a seed and grown crystal must be eliminated to maintain the crystallographic quality of the seed. Two kinds of Na-flux-grown seed crystals were prepared; one had a surface composed of c, {101̅2}, and {101̅1} planes, the other a surface composed entirely of c-planes. Both crystals were sliced, ground, mirror-polished, and applied for 500-μm-thick HVPE growth. In the former sample, the seed crystal generated fine cracks, and the epitaxially grown layer had a rough surface and included many dislocations; the latter sample showed no fault. For clarifying the mechanism of crystal degradation, we investigated the lattice constants of each growth sector using an X-ray microbeam and found that lattice constants in the {101̅1}-growth sector were expanded compared to those in other growth sectors due to oxygen impurities. These values were estimated to be much larger than those of HVPE crystals, resulting in the crystal degradation after the HVPE growth by a lattice mismatch.

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“…[60] Typical dislocation densities in these crystals are 10 6 -10 11 cm −2 . These pre-existing defects in the seed crystal will transfer into the bulk grown layers leading to numerous problems.…”

Section: Progress Reportmentioning

confidence: 99%

Defects in Single Crystalline Ammonothermal Gallium Nitride

Suihkonen

Pimputkar

Sintonen

et al. 2017

Adv Elect Materials

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Native bulk gallium nitride (GaN) has emerged as an alternative for sapphire and silicon as a substrate material for III‐N devices. While quasi‐bulk GaN substrates are currently commercially available, single crystal GaN substrates are considered essential for future high performance light emitters and power devices. The ammonothermal method is currently considered one of the most feasible methods to grow large truly bulk crystals of GaN at low cost and high structural quality. High crystalline quality GaN substrates sliced from ammonothermally grown crystals have been demonstrated and utilized in homoepitaxy for III‐N devices. However, despite the high crystalline quality the properties of as‐grown ammonothermal GaN crystals and substrates are affected by the presence of impurities and other defects that hinder their use for device applications. Here, the main developments of ammonothermal growth of GaN and the effects of impurities, native point defects, and dislocations on the material properties are summarized. Additionally, measurement techniques that enable the evaluation of point defect concentration and low dislocation density distribution over a large area on bulk GaN substrates are reviewed.

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Growth of Bulk Nitrides from a Na Flux

Cited by 20 publications

References 41 publications

Experimental Synthesis of Theoretically Predicted Multivalent Ternary Nitride Materials

Experimental Synthesis of Theoretically Predicted Multivalent Ternary Nitride Materials

Homoepitaxial Hydride Vapor Phase Epitaxy Growth on GaN Wafers Manufactured by the Na-Flux Method

Defects in Single Crystalline Ammonothermal Gallium Nitride

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