Semipolar GaInN quantum well structures on large area substrates

Scholz, F.; Schwaiger, Stephan; Däubler, Jürgen; Tischer, Ingo; Thonke, Klaus; Neugebauer, Silvio; Metzner, Sebastian; Bertram, F.; Christen, J.; Lengner, Holger; Thalmair, Johannes; Zweck, Josef

doi:10.1002/pssb.201100342

Cited by 8 publications

(9 citation statements)

References 16 publications

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“…In order to achieve fairly long wavelength above 500 nm, the QWs have been deposited at a temperature of typically 720 °C, while the temperature was increased by about 35 K for the barrier growth. When comparing the

{11 \overset{2}{true} 2}

and

{10 \overset{1}{true} 1}

samples, fairly similar results have been obtained ().…”

Section: Trench Approachsupporting

confidence: 70%

“…After dry etching and complete removal of the remaining mask material, we typically perform a directed sputtering of

{SiO}_{2}

in order to cover all other planes of the structured sapphire surface except the inclined c ‐plane‐like side facet of the trenches (see Fig. ), thus preventing parasitic nucleation on the other facets in the subsequent MOVPE process .…”

Section: Trench Approachmentioning

confidence: 99%

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Semipolar GaN‐based heterostructures on foreign substrates

Scholz

Caliebe

Gahramanova

et al. 2015

Physica Status Solidi (b)

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This paper reviews our recent investigations about semipolar GaN‐based optoelectronic heterostructures grown on foreign substrates. Two basically different approaches are discussed, both making use of epitaxial growth in the polar c‐direction to minimize any crystalline defects. By selective area growth, stripes with triangular cross‐section have been formed with semipolar side‐facets, on which quantum well and electroluminescence test structures have been deposited. By careful optimisation of many growth parameters, we could drastically increase the growth temperature of GaInN quantum wells emitting beyond 500 nm. In the second approach, the GaN growth starts on inclined sapphire c‐planes, which form the side facets of trenches etched into the substrates. After coalescence, planar semipolar GaN layers can be achieved. We investigated various sapphire wafer orientations leading to {112‾2}, {101‾1}, and {202‾1} layers. After careful optimisation with a major focus on the decrease of the stacking fault density, we have also investigated the doping behaviour of such semipolar structures. Eventually, full electroluminescence test structures could be grown.

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{11 \overset{2}{true} 2}

and

{10 \overset{1}{true} 1}

samples, fairly similar results have been obtained ().…”

Section: Trench Approachsupporting

confidence: 70%

“…After dry etching and complete removal of the remaining mask material, we typically perform a directed sputtering of

{SiO}_{2}

Section: Trench Approachmentioning

confidence: 99%

Semipolar GaN‐based heterostructures on foreign substrates

Scholz

Caliebe

Gahramanova

et al. 2015

Physica Status Solidi (b)

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“…(b)). If the large number of structural defects inside this – c ‐wing of the isolated GaN stripe would reach the surface, this might have a huge impact on the properties of active regions for light emission (e.g., in quantum wells) and has to be avoided.…”

Section: Resultsmentioning

confidence: 99%

“…Despite these promising advantages, semi‐ and also nonpolar nitride orientations are handicapped by the appearance of structural defects like different types of basal plane stacking faults (BSF), prismatic stacking faults (PSF), and partial dislocations (PD) when grown heteroepitaxially . These defects strongly influence the active region of optoelectronic devices . Some techniques have been developed to reduce these huge densities of structural defects.…”

Section: Introductionmentioning

confidence: 99%

Direct microscopic correlation of real structure and optical properties of semipolar GaN based on pre‐patterned r‐plane sapphire

Metzner

Bertram

Hempel

et al. 2015

Physica Status Solidi (b)

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Spatially resolved cathodoluminescence (CL) microscopy is used to study semipolar {112¯2} gallium nitride (GaN) grown out of trenches with c‐plane‐like sidewalls etched into the r‐plane {11¯02} sapphire substrate. The beneficial effect of growing locally c‐GaN on c‐sapphire and subsequent switching to the semipolar growth mode manifests in bending of threading dislocations (TDs) and a +c‐wing of excellent material properties represented by pure donor‐bound‐exciton emission. The −c‐wing, on the other hand, is strongly affected by a huge number of stacking faults and other structural defects. An optimized growth process leads to a delayed coalescence of the single GaN stripes which allows to block the complete −c‐wing including all the defects by a void, and coalescence occurs only between the +c‐wings consisting of GaN with excellent material quality. The final semipolar {112¯2} GaN surface shows exclusively CL of the donor‐bound exciton (D0, X) recombination and no other spectral contribution of structural defects and a reduced TD density. After coalescence and further growth a significant increase of the homogeneity of the CL intensity and emission wavelength is observed for thick samples. CL of an InGaN/GaN active region deposited on top reveals homogeneous luminescence properties over the coalesced region showing no modulation related to the pre‐structured growth mode as the defect containing growth domains are effectively blocked.

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“…By carefully optimizing the growth conditions and applying various defect reduction methods already known from c-plane growth, we were able to minimize substantially the formation of the commonly observed defects like dislocations and stacking faults. Particularly for the (10)(11) and (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) samples, excellent structural properties have been obtained, being evident from very narrow X-ray diffraction peaks in the range of 200 -300 arcsec and photoluminescence spectra dominated by the excitonic peaks, whereas only comparably weak signals of the stacking fault related signals were visible (9). In particular, (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) layers grown with an in-situ deposited SiN nanomask layer have shown very low stacking fault densities down to mid 10 3 cm -1 (10).…”

Section: Resultsmentioning

confidence: 99%

(Invited) Large Area Semipolar GaN Grown on Foreign Substrates

Scholz¹,

Caliebe²,

Meisch³

et al. 2014

ECS Trans.

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By nucleation of GaN stripes on the c-plane-like side facets of trench-patterned sapphire wafers and their subsequent coalescence, we have realized various semipolar planar GaN layers by metalorganic vapor phase epitaxy. A variation of the miscut of r-plane sapphire wafers did not lead to improved (11-22) GaN layers despite the slight off-orientation between the GaN (11-22) plane and the sapphire r-plane. For (20-21) GaN grown on s-plane sapphire, we only obtained nicely coalesced layers after overgrowth by hydride vapor phase epitaxy (HVPE). However, increased parasitic oxygen incorporation was observed in HVPE growth of such semipolar layers. On the other hand, the Mg incorporation was reduced by about a factor of 8 on (11-22) planes as compared to the polar c-plane.

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Semipolar GaInN quantum well structures on large area substrates

Cited by 8 publications

References 16 publications

Semipolar GaN‐based heterostructures on foreign substrates

Semipolar GaN‐based heterostructures on foreign substrates

Direct microscopic correlation of real structure and optical properties of semipolar GaN based on pre‐patterned r‐plane sapphire

(Invited) Large Area Semipolar GaN Grown on Foreign Substrates

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