Quantitative x-ray diffraction analysis of bimodal damage distributions in Tm implanted Al<sub>0.15</sub>Ga<sub>0.85</sub>N

Magalhães, S.; Fialho, M.; Peres, M.; Lorenz, K.; Alves, E.

doi:10.1088/0022-3727/49/13/135308

Cited by 19 publications

(25 citation statements)

References 31 publications

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“…Also, after each processing stage, there are no visible Q x shift of the Al x Ga 1-x N and GaN peak position, which indicates that implantation does not introduce notable strain along the a-axis of the crystal lattice. It is in agreement with previous reports [8,[22][23][24]. The high-temperature annealing resulted in a remarkable lattice recovery; however, some residual с-lattice extension is still observed in both the GaN and Al x Ga 1-x N layers ( Fig.…”

Section: Resultssupporting

confidence: 93%

The effect of ion implantation on structural damage of сompositionally graded AlGaN layers

Liubchenko¹

2019

Semicond. Phys. Quantum Electron. and Optoelectron.

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Compositionally graded Al x Ga 1-x N alloys with the Al concentration in the (7 ≤ x ≤ 32) range were implanted with Ar + ions to study the structural and strain changes (strain engineering). It was shown that ion implantation leads to ~0.3…0.46% hydrostatic strains and a relatively low damage of the crystal structure. The ion-implantation leads mainly to an increase of the density of point defects, while the dislocation configuration is almost unaffected. The density of microdefects is sufficiently reduced after the postimplantation annealing. The structural quality of the Al x Ga 1-x N layers strongly depends on the Al concentration and is worsen with increasing Al. The implantation induced structural changes in highly dislocated Al x Ga 1-x N layers are generally less pronounced. Based on the X-ray diffraction, a model is developed to explain the strain field behavior in the Al x Ga 1-x N/GaN heterostructures by migration of point defects and strain field redistribution. The approach to simulate 2θ/ω scans using statistical dynamical theory of X-ray diffraction for implanted compositionally graded structures AlGaN has been developed.

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Section: Resultssupporting

confidence: 93%

The effect of ion implantation on structural damage of сompositionally graded AlGaN layers

Liubchenko¹

2019

Semicond. Phys. Quantum Electron. and Optoelectron.

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“…This saturation was attributed to the formation of a dense network of extended defects leading to plastic deformation and strain relaxation. Many authors have reported similar strain formation in GaN for different implantation conditions 42,43,44 . In fact, it was suggested that strain induced by implantation defects is the driving force behind the defect mobility and dynamic annealing in GaN leading to the change of defect microstructure as the fluence increases 45 .…”

Section: Strain and Morphologymentioning

confidence: 81%

Incorporation of Europium into GaN Nanowires by Ion Implantation

et al. 2019

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Rare earth (RE) doped GaN nanowires (NWs), combining the well-defined and controllable optical emission lines of trivalent RE ions with the high crystalline quality, versatility and small dimension of the NW host, are promising building blocks for future nanoscale devices in optoelectronics and quantum technologies. Europium doping of GaN NWs was performed by ion implantation and structural and optical properties were assessed in comparison to thin film reference samples. Despite some surface degradation for high implantation fluences, the NW core remains of high crystalline quality with lower concentrations of extended defects than observed in ion implanted thin films. Strain introduced by implantation defects is efficiently relaxed in NWs and the measured deformation stays much below that in thin films implanted in the same conditions. Optical activation is achieved for all samples after annealing and, while optical centres are similar in all samples, Eu 3+ emission from NW samples is shown to be less affected by residual implantation damage than for the case of thin films. The incorporation of Eu in GaN NWs was further investigated by nano-cathodoluminescence and X-ray absorption spectroscopy (XAS). Maps of the Eu-emission intensity within a single NW agree well with the Eu-distribution predicted by Monte Carlo simulations suggesting that no pronounced Eu-diffusion takes place. XAS shows that 70-80% of Eu is found in the 3+ charge state while 20-30% is 2+ attributed to residual implantation defects. A similar local environment was found for Eu in NWs and thin films: for low fluences, Eu is mainly incorporated on substitutional Ga-sites while for high fluences XAS points at the formation of a local EuN-like next neighbour structure. Results reveal the high potential of ion implantation as a processing tool at the nano-scale.

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“…41 The calculation of diffracted intensities uses the Takagi-Taupin differential equations solved by the recursion formula of Bartels. [41][42][43] The attenuation static Debye-Waller (DW) factor is introduced in the static structure factor calculations to account for the decrease of the reflected amplitude associated with mean atomic displacements, hu 2 i 1/2 . According to Sousbie et al, 44 the mean atomic displacement is assumed to be proportional to the perpendicular deformation, and hence, a measure for the crystal implantation damage is extracted via the a parameter.…”

Section: Methodsmentioning

confidence: 99%

Impact of implantation geometry and fluence on structural properties of AlxGa1-xN implanted with thulium

Fialho

Magalhães

Chauvat

et al. 2016

Journal of Applied Physics

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Al x Ga 1-x N (x ¼ 0.15 and 0.77) films, grown by halide vapor phase epitaxy, were implanted with 300 keV Tm ions. Implantation damage accumulation is investigated with Rutherford backscattering spectrometry/channeling (RBS/C), transmission electron microscopy (TEM), and high resolution X-ray diffraction (XRD). Distinct damage behavior for samples with different AlN contents was found. Surface nanocrystallization occurs for samples with x ¼ 0.15, similar to implantation effects observed in GaN. Samples with x ¼ 0.77 approach the behavior of AlN. In particular, surface nanocrystallization is suppressed and the depth range of the stacking fault network, typical for implanted III-nitrides, is decreased. The crystalline quality of the sample with x ¼ 0.15 was investigated to compare random and channeled implantation, showing less concentration of damage but with a higher range for channeled implantation. Surprisingly, the strain field caused by the implantation reaches much deeper into the sample than the defect profiles measured by RBS/C and TEM. This is attributed to the fact that XRD is much more sensitive to low defect densities caused by ions which are channeled to deep regions of the sample. Published by AIP Publishing.

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Quantitative x-ray diffraction analysis of bimodal damage distributions in Tm implanted Al_0.15Ga_0.85N

Cited by 19 publications

References 31 publications

The effect of ion implantation on structural damage of сompositionally graded AlGaN layers

The effect of ion implantation on structural damage of сompositionally graded AlGaN layers

Incorporation of Europium into GaN Nanowires by Ion Implantation

Impact of implantation geometry and fluence on structural properties of AlxGa1-xN implanted with thulium

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Quantitative x-ray diffraction analysis of bimodal damage distributions in Tm implanted Al0.15Ga0.85N

Cited by 19 publications

References 31 publications

The effect of ion implantation on structural damage of сompositionally graded AlGaN layers

The effect of ion implantation on structural damage of сompositionally graded AlGaN layers

Incorporation of Europium into GaN Nanowires by Ion Implantation

Impact of implantation geometry and fluence on structural properties of AlxGa1-xN implanted with thulium

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Quantitative x-ray diffraction analysis of bimodal damage distributions in Tm implanted Al_0.15Ga_0.85N