Growth conditions of semi and non-polar GaN on Si with Er2O3 buffer layer

Grinys, Tomas; Drunga, Tomas; Badokas, Kazimieras; Dargis, Rytis; Clark, Andrew; Malinauskas, T.

doi:10.1016/j.jallcom.2017.07.189

Cited by 5 publications

(3 citation statements)

References 22 publications

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“…Hydrogen (H 2 ) was used as a gas carrier throughout the growth. as temperature [21], V/III ratio [22] and reactor pressure [23,24], have been widely discussed to understand the influence of the growth process. To achieve a good GaN layer researchers will normally combine the growth parameters utilizing a two-step process to achieve 3D layers first using a rather lower V/III ratio and temperature and then a higher V/III ratio and temperature for surface smoothing [25].…”

Section: Experimental Methodsmentioning

confidence: 99%

“…Numerous efforts, such as epitaxial lateral overgrowth (ELOG) [16], AlN/GaN multilayer, silicon nitride (SiN x ) interlayer [17], double AlN or GaN nucleation layers [18], patterned sapphire substrates [19] and graded superlattices [20] have been explored to solve this problem to achieve an enhanced crystal quality and surface morphology. Growth parameters, such as temperature [21], V/III ratio [22] and reactor pressure [23,24], have been widely discussed to understand the influence of the growth process. To achieve a good GaN layer researchers will normally combine the growth parameters utilizing a two-step process to achieve 3D layers first using a rather lower V/III ratio and temperature and then a higher V/III ratio and temperature for surface smoothing [25].…”

Section: Introductionmentioning

confidence: 99%

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Effect of Flux Rate Variation at Fixed V/III Ratio on Semi-Polar (112¯2) GaN: Crystal Quality and Surface Morphology Study

et al. 2022

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We report on the crystal improvement of semi-polar (112¯2) gallium nitride epitaxy layer on m-plane (101¯0) sapphire substrate by changing the flux rate at a fixed V/III ratio. The high-resolution X-ray diffraction (HR-XRD) analysis showed that lower flux rate enhanced the crystal quality of GaN epitaxy with the lowest FWHM values of 394 and 1173 arc seconds at [11¯23] and [11¯00] planes, respectively. In addition, Raman spectroscopy showed that flux rate did not affect the stress state of the GaN crystal. However, atomic force microscopy (AFM) micrograph depicted an anomalous trend where the lowest flux rate produces roughest surface with RMS roughness of 40.41 nm. Further analysis of AFM results on the undulation period length along [11¯23] and [11¯00] directions is carried out. It shows that as the growth rate decreases, the average undulation period along [11¯23] and [11¯00] directions increases from 2.59 µm and 1.90 µm to 3.52 µm and 3.52 µm, respectively. The mechanism for the surface roughening at the lower flux rate is then explained by using the adatom surface diffusion relation L ~ Dτ.

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Section: Experimental Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effect of Flux Rate Variation at Fixed V/III Ratio on Semi-Polar (112¯2) GaN: Crystal Quality and Surface Morphology Study

et al. 2022

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“…The difference in electronegativity leads to the formation of electric dipoles, which in turn results in spontaneous polarization. In order to avoid/overcome the polarization effect caused by the polar GaN, the research focusing on the growth of nonpolar GaN is gradually increasing, with one-dimensional nanomaterials being a significant component. − One-dimensional nanomaterials such as nanowires and nanorods are considered as promising candidates for next-generation high-performance devices because of their huge surface–volume ratio and highly regulable structure compared to bulk GaN crystal materials. , Various growth techniques have been applied to the growth of nonpolar GaN nanowires, including metal-catalyzed metal-organic chemical vapor deposition (MOCVD), direct nitridation/vapor transport, , and catalyst-free selective-area molecular beam epitaxy (SA-MBE) . And among the increasingly sophisticated preparation systems, the convenient chemical vapor deposition (CVD) method is one representative of the ways to prepare nanomaterials.…”

Section: Introductionmentioning

confidence: 99%

Highly Controllable Epitaxial Growth of High-Density Nonpolar GaN Nanorod Arrays

Li,

Wang,

Chen

et al. 2024

Crystal Growth & Design

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The undesirable effects of the degraded device performance and shorter lifetime caused by the polarization electric field induced by polar GaN have contributed to an increasing interest in the fundamental research and promising applications of nonpolar GaN. Herein, we demonstrate a strategy to construct high-quality arrays of well-aligned nonpolar GaN nanorods on the Au-coated (100) γ-LiAlO 2 substrates by the chemical vapor deposition method. During the growth process, the Au particles that were originally at the tips of the nanorods were found to gradually disappear with time. The disappearance of Au particles solved the problem of catalyst contamination and also demonstrated an interesting growth mechanism: whereas the traditional vapor−liquid− solid dominated the initial growth stage, the Au catalyst began to migrate and detach under the relatively Ga-rich condition, and then the vapor−solid controlled the subsequent growth. The E 2 (high) phonon peak (567.7 cm −1 ) and the strong ultraviolet emission peak (362.0 nm) indicate that the nonpolar GaN nanorods are virtually strain-free and have a high crystallization quality. Additionally, the effects of NH 3 and the thickness of Au films on the growth of GaN nanorods were thoroughly investigated. The well-arranged nonpolar GaN nanorod arrays with excellent crystal quality will provide a referable nanomaterial choice for highperformance, high-efficiency nonpolar nanodevices.

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