Use of related parameters in X-ray diffraction analysis of multilayer structures with allowance for the layer growth time

Yunin, P. A.; Drozdov, Yu. N.; Дроздов, М. Н.; Новиков, А. В.; Yurasov, D. V.; Zakharov, N. D.; Korolev, S. A.

doi:10.1134/s1063784214030293

Cited by 3 publications

(4 citation statements)

References 2 publications

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“…Quantitative assessment of the match between measured and simulated XRD diffraction curves was evaluated using the DIFFRAC.Leptos builtin normalized logarithmic discrepancy functional χ 2 [29]: 2 , where I exp is measured intensity and I sim is simulated one. The sum is taken over the all spectrum data points N. Minimization of normalized logarithmic χ 2 is a conventional approach to fitting of XRD spectra [55,56].…”

Section: Resultsmentioning

confidence: 99%

Matched characterization of super-multiperiod superlattices

Goray¹,

Pirogov²,

Sobolev³

et al. 2020

J. Phys. D: Appl. Phys.

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Heterostructures with multiple strongly coupled quantum wells, such as super-multiperiod (SMP) superlattices (SLs), are promising semiconductor devices, which may contain hundreds or even thousands of layers with 100 or more periods synthesized by molecular beam epitaxy (MBE) to high structural perfection. The proposed characterization method employs matched application of high-resolution x-ray diffractometry (XRD), reflectometry (XRR), and, for the first time, the deep XRR (DXRR) allows the study of SMP structures, as well as high-accuracy determination of the thicknesses of layers, roughness/diffuseness of boundaries using the rigorous scattering theory, and composition of solid solutions. Combining these methods with scanning transmission electron microscopy (STEM) enables characterization of SMP SLs and independent determination of these same parameters. The differences between the expected and obtained layer thicknesses by XRD and XRR were 1%-3% for AlGaAs/GaAs structures. The samples were characterized by sharp interfaces with the root-mean-square width of the transition layers of the order of a few Å, which is consistent with the XRR/DXRR and STEM analysis. Based on the data obtained for the thicknesses of layers, the composition of Al 0.3 Ga 0.7 As has been accurately determined by the x-ray methods. These results may be considered as the first step in the analysis of MBE-grown SMP structures with a number of periods up to 1000.

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Section: Resultsmentioning

confidence: 99%

Matched characterization of super-multiperiod superlattices

Goray¹,

Pirogov²,

Sobolev³

et al. 2020

J. Phys. D: Appl. Phys.

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“…To this end, we used a widespread approach to the profile reconstruction with allowance for the depth resolution function (DRF). In the literature, this approach was used many times for processing of the results of SiGe, AlGaAs, and diamond heterostructures sputter depth profiling. The reconstruction procedure requires knowledge of the experimental profile distortion, which is characterized by the DRF.…”

Section: Resultsmentioning

confidence: 99%

“…In particular, for the SIMS method it is possible to carry out additional operations for experimental data processing, which permit one, preserving the advantages of this technique, to fight its main disadvantage—inability for direct quantitative analysis of the thickness and composition of the layers in the heterostructure. In the first place, quantitative analysis of the AlGaN composition is complicated by the nonlinear correlation between the intensity of detected secondary ions and the element concentration in the specimen, the so‐called matrix effects. This problem is solved relatively simply by using special calibration dependences obtained by measuring a series of test structures.…”

Section: Introductionmentioning

confidence: 99%

“… However, precise quantitative analysis of thin layers is additionally complicated by the shift and broadening of the measured profiles. The SIMS depth resolution is limited both by the features of the specimen and the essential influence of the primary sputtering‐ion beam. The SIMS experimental distortions become especially crucial in the analysis of GaN‐based HEMT structures with nanometer‐thin layers, whose thickness is comparable with the depth resolution.…”

Section: Introductionmentioning

confidence: 99%

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Quantitative SIMS depth profiling of Al in AlGaN/AlN/GaN HEMT structures with nanometer-thin layers

Yunin

Drozdov

Дроздов

et al. 2016

Surf. Interface Anal.

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The possibilities of quantitative secondary ion mass spectrometry (SIMS) depth profiling of Al in AlxGa1 − xN/AlN/GaN transistor heterostructures are shown. Using a series of test structures for a TOF.SIMS‐5 time‐of‐flight mass spectrometer, we obtained a refined linear calibration dependence of the secondary‐ion yield on the composition ×, namely, Y(CsAl+)/Y(CsGa+) = K × x/(1 − x), with a high linear correlation coefficient, Rl = 0.9996, which permits quantitative SIMS analysis of relatively thick AlGaN barrier layers. The method of profile reconstruction with allowance for the main artifacts of ion sputtering has been first applied for the analysis of GaN/AlGaN/AlN/GaN high electron mobility transistor structure. This method permits to perform quantitative analysis of the thickness and composition of a nanometer‐thin AlN sublayer and to estimate the measurement error. For the structure being studied, the AlN sublayer is 1.2 ± 0.2 nm thick. Copyright © 2016 John Wiley & Sons, Ltd.

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