Indium incorporation processes investigated by pulsed and continuous growth of ultrathin InGaN quantum wells

Rossów, U.; Hoffmann, Lars; Bremers, Heiko; Buß, E. R.; Ketzer, Fedor Alexej; Langer, Torsten; Hangleiter, A.; Mehrtens, Thorsten; Schowalter, Marco; Rosenauer, A.

doi:10.1016/j.jcrysgro.2014.11.040

Cited by 7 publications

(7 citation statements)

References 33 publications

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“…The boundary of formation for gallium droplets is strongly related to the formation of the gallium wetting layer (adatom layer) on the surface of samples. Recently, Rossow et al 36 have also identified the importance of the metal wetting layer and have pointed out that there is some variation in published results for the maximum thickness of metal wetting layers used for nitride deposition. Butcher identified this importance earlier in patent applications.…”

Section: -9mentioning

confidence: 99%

DC voltage fields generated by RF plasmas and their influence on film growth morphology through static attraction to metal wetting layers: Beyond ion bombardment effects

Butcher

Terziyska

Gergova

et al. 2017

Journal of Applied Physics

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It is shown that attractive electrostatic interactions between regions of positive charge in RF plasmas and the negative charge of metal wetting layers, present during compound semiconductor film growth, can have a greater influence than substrate temperature on film morphology. Using GaN and InN film growth as examples, the DC field component of a remote RF plasma is demonstrated to electrostatically affect metal wetting layers to the point of actually determining the mode of film growth. Examples of enhanced self-seeded nanopillar growth are provided in the case where the substrate is directly exposed to the DC field generated by the plasma. In another case, we show that electrostatic shielding of the DC field from the substrate can result in the growth of Ga-face GaN layers from gallium metal wetting layers at 490 C with root-mean-square roughness values as low as 0.6 nm. This study has been carried out using a migration enhanced deposition technique with pulsed delivery of the metal precursor allowing the identification of metal wetting layers versus metal droplets as a function of the quantity of metal source delivered per cycle. It is also shown that electrostatic interactions with the plasma can affect metal rich growth limits, causing metal droplet formation for lower metal flux than would otherwise occur. Accordingly, film growth rates can be increased when shielding the substrate from the positive charge region of the plasma. For the example shown here, growth rates were more than doubled using a shielding grid.

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Section: -9mentioning

confidence: 99%

DC voltage fields generated by RF plasmas and their influence on film growth morphology through static attraction to metal wetting layers: Beyond ion bombardment effects

Butcher

Terziyska

Gergova

et al. 2017

Journal of Applied Physics

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“…the GaN barrier 0.83 nm min À1 . [21] The V/III ratio was varied between that used for Ga-face growth and reduced by a factor 5 to improve the quality of the QW structure, which follows the results reported in Keller et al [14] All temperatures were readings of a thermocouple placed inside a SiCcoated graphite susceptor. The sample was placed on a disc, which rotated in a circular opening of the susceptor.…”

Section: Methodsmentioning

confidence: 99%

Pyramid Formation by Etching of InxGa1−xN/GaN Quantum Well Structures Grown on N‐face GaN for Nanooptical Light Emitters

Rossów

Sidikejiang

Hagag

et al. 2021

Physica Status Solidi (b)

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Nanooptical light emitters based on semiconductors are very promising for a broad range of applications such as single-photon sources or optical sensors of nanoobjects. The group-III nitrides are especially interesting in this respect as light emitters in the visible range with high efficiency are nowadays commercially available. By changing the indium content, the bandgap of In x Ga 1Àx N can in principle be tuned over the whole wavelength range from the near-IR region to the near-UV region. In most studies, three routes are followed to produce nanooptical light emitters: 1) the self-assembled growth of quantum dots (QDs), [1,2] 2) the growth of pyramids by applying masks of, for example, SiO 2 , [3] or 3) the growth [4,5] or topÀdown fabrication [6] of nanorods. The first one suffers from the high defect density in group-III nitride growth when using conventional sapphire, SiC, or silicon substrates, [7] that the sites of the QDs are unknown (unless further steps are taken), the properties are critically dependent on the growth conditions, and that it is difficult to stabilize the QDs in further growth. The second one has the problem that indium incorporation on different parts of the pyramid, side facets, edges, and tip, varies and is difficult to control, which typically result in an inhomogeneous emission. Furthermore, defects may form, induced by the mask, which reduce the efficiency. The insertion of QDs in nanorods during growth shows, up to now, low efficiency. A topÀdown approach to realize QDs in etched nanorods would be quite a challenge due to the length of the nanorods and the small required diameters.Hence, for the generation of a large array of as similar as possible nanooptical light emitters, we propose another solution. A single or multiquantum well (SQW, MQW) structure is grown on N-face GaN and in a second step pyramids are formed by wet chemical etching. This has the advantage that the QW can be optimized independently of pyramid formation. However, in contrast to the N face, the Ga face is chemically inert and plasma etching processes may create damage, which reduces the efficiency. Another advantage of using N-face GaN is that the

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“…Generally speaking, fabrication of blue or green LEDs requires relatively high indium composition of InGaN layer [11, 12]. Although the reduction of growth temperature and the increase of growth rate of the quantum well (QW) can alleviate indium atom desorption to obtain high indium content, these methods also deteriorate the optical performance of InGaN/GaN multiple quantum wells (MQWs) by worsening interface abruptness and introducing more defects [13, 14].…”

Section: Introductionmentioning

confidence: 99%

“…InGaN/GaN-based high-brightness light-emitting diodes (LEDs) and laser diodes, as the representative devices of III-nitrides, have attracted much attention owing to their important role in digital signage, high-density optical storage, and general illumination [ 1 – 10 ]. Generally speaking, fabrication of blue or green LEDs requires relatively high indium composition of InGaN layer [ 11 , 12 ]. Although the reduction of growth temperature and the increase of growth rate of the quantum well (QW) can alleviate indium atom desorption to obtain high indium content, these methods also deteriorate the optical performance of InGaN/GaN multiple quantum wells (MQWs) by worsening interface abruptness and introducing more defects [ 13 , 14 ].…”

Section: Introductionmentioning

confidence: 99%

Surface Morphology Evolution Mechanisms of InGaN/GaN Multiple Quantum Wells with Mixture N2/H2-Grown GaN Barrier

et al. 2017

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Surface morphology evolution mechanisms of InGaN/GaN multiple quantum wells (MQWs) during GaN barrier growth with different hydrogen (H2) percentages have been systematically studied. Ga surface-diffusion rate, stress relaxation, and H2 etching effect are found to be the main affecting factors of the surface evolution. As the percentage of H2 increases from 0 to 6.25%, Ga surface-diffusion rate and the etch effect are gradually enhanced, which is beneficial to obtaining a smooth surface with low pits density. As the H2 proportion further increases, stress relaxation and H2 over- etching effect begin to be the dominant factors, which degrade surface quality. Furthermore, the effects of surface evolution on the interface and optical properties of InGaN/GaN MQWs are also profoundly discussed. The comprehensive study on the surface evolution mechanisms herein provides both technical and theoretical support for the fabrication of high-quality InGaN/GaN heterostructures.

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Indium incorporation processes investigated by pulsed and continuous growth of ultrathin InGaN quantum wells

Cited by 7 publications

References 33 publications

DC voltage fields generated by RF plasmas and their influence on film growth morphology through static attraction to metal wetting layers: Beyond ion bombardment effects

DC voltage fields generated by RF plasmas and their influence on film growth morphology through static attraction to metal wetting layers: Beyond ion bombardment effects

Pyramid Formation by Etching of InxGa1−xN/GaN Quantum Well Structures Grown on N‐face GaN for Nanooptical Light Emitters

Surface Morphology Evolution Mechanisms of InGaN/GaN Multiple Quantum Wells with Mixture N2/H2-Grown GaN Barrier

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