Defect reduction in (11–22) semipolar GaN with embedded InN islands on m-plane sapphire

Jung, Chil-Sung; Jang, Jongjin; Hwang, Jongkook; Jeong, Joocheol; Kim, Jinwan; Lee, Kyung-Jae; Nam, Okhyun

doi:10.1016/j.jcrysgro.2012.09.022

Cited by 10 publications

(13 citation statements)

References 28 publications

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“…An M-shaped azimuthal dependence of FWHM values over 360° angle range was observed in Fig. 2(d) , which is similar to the observation reported for MOCVD a-GaN 29 and (11–22) GaN 22 30 31 32 33 . The broadening of (11–22) XRC FWHM along the [1–100] direction is caused by the larger distortion of the GaN lattice due to higher density of defects such as threading dislocations, stacking faults (SFs), as well as a larger mosaic tilt and/or a reduced coherent length (smaller size of the mosaic blocks) 32 34 .…”

Section: Resultssupporting

confidence: 86%

Anisotropic structural and optical properties of semi-polar (11–22) GaN grown on m-plane sapphire using double AlN buffer layers

Zhao

Wang

Yang

et al. 2016

Sci Rep

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We report the anisotropic structural and optical properties of semi-polar (11–22) GaN grown on m-plane sapphire using a three-step growth method which consisted of a low temperature AlN buffer layer, followed by a high temperature AlN buffer layer and GaN growth. By introducing double AlN buffer layers, we substantially improve the crystal and optical qualities of semi-polar (11–22) GaN, and significantly reduce the density of stacking faults and dislocations. The high resolution x-ray diffraction measurement revealed that the in-plane anisotropic structural characteristics of GaN layer are azimuthal dependent. Transmission electron microscopy analysis showed that the majority of dislocations in the GaN epitaxial layer grown on m-sapphire are the mixed-type and the orientation of GaN layer was rotated 58.4° against the substrate. The room temperature photoluminescence (PL) spectra showed the PL intensity and wavelength have polarization dependence along parallel and perpendicular to the [1–100] axis (polarization degrees ~ 0.63). The realization of a high polarization semi-polar GaN would be useful to achieve III-nitride based lighting emission device for displays and backlighting.

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Section: Resultssupporting

confidence: 86%

Anisotropic structural and optical properties of semi-polar (11–22) GaN grown on m-plane sapphire using double AlN buffer layers

Zhao

Wang

Yang

et al. 2016

Sci Rep

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“…Different interlayer methods have been tried to reduce threading dislocations by promoting 3D growth. Exotic elements have been tried like ScN (), CrN (), as well as more common elements like InN quantum dots (), or SiN x interlayers . While these reduce XRD

ω

FWHM, they often lead to very rough surfaces.…”

Section: Introductionmentioning

confidence: 99%

“…Exotic elements have been tried like ScN [7], CrN [8], as well as more common elements like InN quantum dots [9], or SiN x interlayers [10,11]. While these reduce XRD ω FWHM, they often lead to very rough surfaces.…”

mentioning

confidence: 99%

Optimizing GaN () hetero‐epitaxial templates grown on () sapphire

Pristovsek

Frentrup

Han

et al. 2015

Physica Status Solidi (b)

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The hetero‐epitaxy of (11true2‾2) GaN on (10true1‾0) sapphire was optimized in metal–organic vapor phase epitaxy. Best results were obtained from an AlN nucleation followed by AlN and AlGaN layers, and inserting low‐temperature AlN interlayers (ILs) as well as a SiNx IL. X‐ray diffraction (XRD) of ω scans of the symmetric (11true2‾2) reflection yielded an ω FWHM <450″ along [11true2‾true3‾] and <900″ along [10true1‾0] together with a 100×100thinmathspaceμm2 rms roughness below 10 nm as determined by atomic force microscopy. The lowest threading dislocation density achieved was ≈109cm−2 while the basal plane stacking fault density was in the lower 105cm−1 range as determined by transmission electron microscopy. The suppression of the unwanted (10true1‾true3‾) phase was lower than 1 in 10,000 as judged from XRD.

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“…But such layers have a huge density of dislocations in the

10^{10} {cm}^{- 2}

range and basal‐plane stacking faults (BSFs) in the

10^{5} {cm}^{- 1}

range . To reduce defects by promoting three dimensional growth several interlayers have been used like ScN (), CrN (), InN quantum dot (), or SiN

_{x}

interlayers. Still these do not reduce BSFs below

10^{5}

^{- 1}

.…”

Section: Introductionmentioning

confidence: 99%

Low defect large area semi‐polar (112) GaN grown on patterned (113) silicon

Pristovsek

Han

Zhu

et al. 2014

Physica Status Solidi (b)

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We report on the growth of semi-polar GaN (112) templates on patterned Si (113) substrates. Trenches were etched in Si (113) using KOH to expose Si {111} sidewalls. Subsequently an AlN layer to prevent meltback etching, an AlGaN layer for stress management, and finally two GaN layers were deposited. Total thicknesses up to 5 m were realised without cracks in the layer. Transmission electron microscopy showed that most dislocations propagate along [0001] direction and hence can be covered by overgrowth from the next trench. The defect densities were below and stacking fault densities less than 100 cm . These numbers are similar to reports on patterned r-plane sapphire. Typical X-ray full width at half maximum (FHWM) were 500” for the asymmetric (00.6) and 450” for the (11.2) reflection. These FHWMs were 50 % broader than reported for patterned r-plane sapphire which is attributed to different defect structures and total thicknesses. The surface roughness shows strong variation on templates. For the final surface roughness the roughness of the sidewalls of the GaN ridges at the time of coalescence are critical.

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Defect reduction in (11–22) semipolar GaN with embedded InN islands on m-plane sapphire

Cited by 10 publications

References 28 publications

Anisotropic structural and optical properties of semi-polar (11–22) GaN grown on m-plane sapphire using double AlN buffer layers

Anisotropic structural and optical properties of semi-polar (11–22) GaN grown on m-plane sapphire using double AlN buffer layers

Optimizing GaN () hetero‐epitaxial templates grown on () sapphire

Low defect large area semi‐polar (112) GaN grown on patterned (113) silicon

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