Ellipsometric studies of porous silicon

Макара, В. А.; Odarych, Volodymyr; Vakulenko, O. V.; Dacenko, O.I.

doi:10.1016/s0040-6090(98)01163-8

Cited by 13 publications

(5 citation statements)

References 17 publications

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“…Not taking into account the short-time intensity drop for the first minutes of the experiment (Fig.1) and the meaningful anomalies related to breaks of laser beam action, one can conclude that the luminescence quantum yield monotonously rises and flattens out during the experiment. In principle, this correlates with the most of data for the PL intensity behaviour when ageing a PS sample in the air (see, e.g., [3,4,6,9,11]). The causes for the rise of PS PL intensity in the air are associated with the atmospheric oxidation of the nanostructure [10]: increase of the sensitizer mass (which is the Si oxide for UV region of excitation [12]), effective saturation of the silicon dangling bonds (nonradiative recombination cen- ters [2]) by oxygen, and the nanostructure modification due to the oxidation.…”

Section: Resultssupporting

confidence: 71%

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Evidence for photochemical transformations in porous silicon

Shevchenko¹

1999

Semicond. Phys. Quantum Electron. Optoelectron.

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The dynamics of the variation of photoluminescence intensity (PLI) of porous silicon (PS) samples subjected to laser irradiation (337 nm, 3.7 mW) during their ageing in air has been studied. The PLI turned out to increase rapidly under UV irradiation and to flatten out in several hours. The subsequent irradiation leads to intensity degradation, which may be explained by the luminescence fatigue effect. At the same time, the PLI of the unilluminated sample almost does not change during the experiment. It turned out that the anomaly as a small surge down is observed on the PLI evolution curve at the stage of the initial monotonous increase of PLI after a short-time (1 to 2 minutes) interruption of the laser illumination of the sample, whereas this anomaly is a surge up at the stage of the monotonous fall of the PLI curve. In the case of a long-time (tens of hours) discontinuation of illumination, the anomaly was similar for all the portions of the PLI curve. The described results are explained by effect of two competing factors which are the luminescence fatigue and light-induced formation of unstable (molecular) chemical bonds that can transform to the stable atomic ones.

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Section: Resultssupporting

confidence: 71%

“…After anodizing, the samples were kept in the air for 3 months. Their luminescence intensities essentially increased during that period of time, which occurred, probably, due to effects of porous layer oxidation [9,10]. Immediately before the experiment, the samples were chemically etched in HF for 3 seconds.…”

Section: Methodsmentioning

confidence: 99%

Evidence for photochemical transformations in porous silicon

Shevchenko¹

1999

Semicond. Phys. Quantum Electron. Optoelectron.

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“…This film may contain pore remnants (the silicon frame) that are partially or completely filled with reaction products; the latter are mainly silicon oxides of various compositions. There are spectro-ellipsometric data that show that this film is not homogeneous across its thickness [4], but may be composed of two components [5].…”

Section: Introductionmentioning

confidence: 99%

The Structure of Oxide Film on the Porous Silicon Surface

Zavalistyi¹,

Makarenko

Odarych

et al. 2020

Ukr. J. Phys.

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A prolonged stay of porous silicon in the air environment gives rise to structural changes in its surface layer, and the standard single-layer model is not sufficiently accurate to describe them. In this work, the structure of the near-surface layer in porous silicon is studied using the polygonal ellipsometry method. A combined approach is proposed to analyze the angular ellipsometry data for the parameters ф and Δ. It consists in the application of the multilayer medium model and the matrix method, while simulating the propagation of optical radiation in this medium in order to obtain the theoretical angular dependences of tan ф and cosΔ. In this method, the dependence of the sought optical profile on the specimen depth is an additional condition imposed on the multilayer model. Evolutionary numerical methods are used for finding the global minimum of the mean squared error (MSE) between the corresponding theoretical and experimental dependences, and the parameters of an optical profile are determined. A model in which the inner non-oxidized layer of porous silicon is homogeneous, whereas the refractive index in the outer oxidized layer has a linear profile, is analyzed. It is shown that the linear and two-step models for the refractive index of an oxidized film provided the best agreement with the experimental ellipsometric functions. The adequacy of the theoretical model is also confirmed by determining the color coordinates of the specimen.

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“…The thickness and porosity of a PS layer may be determined with the use of contemporary atomic-force, tunnel and electron microscopes, as well as by ellipsometry [14][15][16]. All these methods are rather complicated; they are suitable for minute studies of already obtained samples with optimum characteristics.…”

Section: Introductionmentioning

confidence: 99%

Determination of basic parameters of porous silicon

Adamyan¹,

Adamian²,

Aroutiounian³

2006

J. Phys. D: Appl. Phys.

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A new simple nondestructive capacitance method is proposed for determination of the basic parameters of porous silicon such as layer thickness, porosity and dielectric permittivity. The method is based on two measurements of the capacitance of a metal/porous silicon/single crystalline silicon/metal (M/PS/c-Si/M) structure, one measurement being performed with empty pores, and the other measurement with pores filled by an organic compound with a high value of dielectric permittivity. A comparison of results obtained by the ball lap and gravimetric techniques before and after anodization with the capacitance data measurements carried out with the same samples prior to their destruction shows sufficiently good agreement.

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Ellipsometric studies of porous silicon

Cited by 13 publications

References 17 publications

Evidence for photochemical transformations in porous silicon

Evidence for photochemical transformations in porous silicon

The Structure of Oxide Film on the Porous Silicon Surface

Determination of basic parameters of porous silicon

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