Search results

1

Quantity-based flow control strategy for connection-oriented communication networks

100%

Karbowańczyk M., Żuk J.

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2012

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issue 2

2

Effect of Epitaxial Layer Thickness on Built-in Electric Field in Region of AlGaAs/SI-GaAs Interface: A Photoreflectance Study

81%

Ochalski T., Żuk J., Vlasukova L.

Acta Physica Polonica A

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1997

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vol. 92

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issue 5

935-939

EN

We present a study of detailed line shapes of photoreflectance spectra for Al_{0.3}Ga_{0.7} As/SI-GaAs epitaxial layers grown by MBE. All measurements were performed at 80 K under UHV conditions with a special care for the samples surface quality. A set of the photoreflectance spectra was collected for photon energies close to the GaAs and Al_{0.3}Ga_{0.7}As band gaps (E_{0}). The photoreflectance spectra originated in the vicinity of the Al_{0.3}Ga_{0.7}As/SI-GaAs interface were analyzed using the complex Airy function model of Franz-Keldysh oscillations. To examine the effect of the epitaxial layer thickness on parameters characterizing the interface, a step-by-step chemical etching was applied for stripping the top layers. The built-in electric field intensity, field inhomogeneity and phenomenological broadening parameter for interface regions were determined as a function of the epilayer thickness.

3

Photoreflectance Studies of InGaAs/GaAs/AlGaAs Single Quantum Well Laser Structures

81%

Ochalski T., Żuk J., Regiński K., Bugajski M.

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EN

We report on photoreflectance investigations of strained-layer In_{0.2}Ga_{0.8}As/GaAs/Al_{0.3}Ga_{0.7}As single quantum well laser structures grown by molecular beam epitaxy. All the observed photoreflectance spectral features were assigned to the e-hh transitions with Δn=0. The transition energies were determined and compared to their values calculated within the envelope function approximation. Assuming that one third of the total strain in the central In_{0.2}Ga_{0.8}As layer is relaxed by biaxial deformation of surrounding thin GaAs layers, it is possible to explain reasonably the results of our photoreflectance experiment.

4

Chemical Composition of Native Oxide Layers on In^{+} Implanted and Thermally Annealed GaAs

71%

Kulik M., Kołodyńska D., Żuk J., Komarov F., Filiks J.

Acta Physica Polonica A

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2013

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vol. 123

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issue 5

943-947

EN

Semi-insulating GaAs wafers have been implanted with 250 keV In^{+} ions at a fluence of 3 × 10^{16} cm^{-2}. The samples prepared in this way were subsequently annealed at a temperature of 600°C or 800°C for 2 h. Thicknesses of the native oxide layers on implanted GaAs after samples storage in air were evaluated using the Rutherford backscattering spectrometry with the nuclear reaction O^{16}(α,α)O^{16} method. The chemical composition of native oxide layers on In^{+} implanted and annealed GaAs has been studied using X-ray photoelectron spectroscopy. As_{2}O_{3}, As_{2}O_{5}, Ga_{2}O_{3}, GaAs, InAs and InAsO_4 compounds were detected in these layers.

5

Depth Profile Analysis of Phosphorus Implanted SiC Structures

61%

Konarski P., Król K., Miśnik M., Sochacki M., Szmidt J., Turek M., Żuk J.

Acta Physica Polonica A

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2015

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vol. 128

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issue 5

864-866

EN

Secondary ion mass spectrometry depth profile analyses were performed on two sets of 4H-SiC(0001) substrate samples implanted with phosphorus. Both sets were processed under the same conditions. We implanted the samples with 100 keV (10¹¹-10¹⁴ cm¯²) phosphorus ions through the thin chemical vapor deposition deposited silicon dioxide stopping mask in order to obtain an ultra-shallow implantation profile. After phosphorus implantation, secondary ion mass spectrometry depth profile analysis was performed on the first set of samples and the second set was subjected to thermal oxidation procedure at 1200°C in order to create a dielectric layer. The aim of the oxidation process was formation of the silicon dioxide layer enriched with phosphorus: the element, which is considered to be suitable for trap density reduction. Ion implantation parameters as well as oxidation and chemical etching procedures were examined for the proper incorporation of phosphorus into the subsurface structure of the silicon oxide. Secondary ion mass spectrometry depth profile analysis was performed with Physical Electronics 06-350E sputter ion gun and QMA-410 Balzers quadrupole mass analyser. The analytical parameters such as: 1.7 keV Ar⁺ ion beam digitally scanned over 3×3 mm² area and ion erosion rate of 1.4 nm/min and sampling rate of 0.3 nm, were suitable for samples oxidized after ion implantation.

6

Thermal Desorption of Helium from Defected Silicon

52%

Turek M., Droździel A., Pyszniak K., Wójtowicz A., Mączka D., Yuschkevich Y., Vaganov Y., Żuk J.

Acta Physica Polonica A

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2015

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vol. 128

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issue 5

849-852

EN

The thermal desorption spectroscopy measurements of He implanted silicon samples are reported. The He implantation energy was 90 keV (at 45° tilt) while the fluence was 10¹⁶ cm¯². Additionally, the influence of Si pre-implantation (fluences in the range 10¹⁴-10¹⁶ cm¯², E=260 keV) was under investigation. The He releases from both interstitials/vacancies (β peak) and cavities (α peak or rather band consisting probably of at least two peaks) were observed. The α peak disappears for the pre-implantation fluences larger than 10¹⁵ cm¯², while β peak becomes broader and shifts toward higher temperatures. The thermal desorption spectra were collected using heating ramp rates in the range 0.3-0.7 K/s. Desorption activation energy of the β peak for different pre-implantation fluences was found using the Redhead analysis of the β peak shift. It varies from 0.97 eV for the sample that was not pre-implanted up to 1.3 eV for the sample pre-implanted with the fluence 10¹⁶ cm¯².

7

III-V Quantum Dots in Dielectrics Made by Ion Implantation and Flash Lamp Annealing

52%

Prucnal S., Turek M., Gao K., Zhou S., Pyszniak K., Droździel A., Żuk J., Skorupa W.

Acta Physica Polonica A

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2013

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vol. 123

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issue 5

935-938

EN

Different semiconductor nanocrystals synthesized in dielectrics on silicon are very interesting for applications in non-volatile memories and photovoltaics. In this paper we present an overview of microstructural and opto-electronic properties of different III-V quantum dots embedded in SiO_2 and Si_3N_4 made by sequential ion implantation and millisecond range flash lamp annealing. It is shown that within 20 ms post-implantation annealing high quality crystalline III-V quantum dots can be formed in different matrices. Formation of crystalline III-V quantum dots was confirmed by cross-section transmission electron microscopy, photoluminescence and μ-Raman spectroscopy. Flash lamp annealing is essentially a single-flash-single-wafer technique whose main attributes are the ease and control of processing over large wafer batches.

8

Influence of Hot Implantation on Residual Radiation Damage in Silicon Carbide

52%

Rawski M., Żuk J., Kulik M., Droździel A., Lin L., Prucnal S., Pyszniak K., Turek M.

Acta Physica Polonica A

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2011

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vol. 120

|

issue 1

192-195

EN

Remarkable thermomechanical and electrical properties of silicon carbide (SiC) make this material very attractive for high-temperature, high-power, and high-frequency applications. Because of very low values of diffusion coefficient of most impurities in SiC, ion implantation is the best method to selectively introduce dopants over well-defined depths in SiC. Aluminium is commonly used for creating p-type regions in SiC. However, post-implantation radiation damage, which strongly deteriorates required electric properties of the implanted layers, is difficult to anneal even at high temperatures because of remaining residual damage. Therefore implantation at elevated target temperatures (hot implantation) is nowadays an accepted method to decrease the level of the residual radiation damage by avoiding ion beam-induced amorphization. The main objective of this study is to compare the results of the Rutherford backscattering spectroscopy with channeling and micro-Raman spectroscopy investigations of room temperature and 500°C Al^{+} ion implantation-induced damage in 6H-SiC and its removal by high temperature (up to 1600°C) thermal annealing.

9

Influence of Ion Implantation on Magnetic Structural and Optical Properties of (Ga,Mn)As Epitaxial Films

52%

Yastrubchak O., Kulik M., Żuk J., Domagała J., Szymczak R., Wosiński T., Sadowski J., Tóth A.

Acta Physica Polonica A

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2008

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vol. 114

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issue 5

1445-1450

EN

We performed implantation experiments, applying both the chemically active oxygen ions and inactive ions of neon noble gas, to thin epitaxial films of (Ga,Mn)As ferromagnetic semiconductor. Inspection of their magnetic properties by means of a superconducting quantum interference device magnetometer revealed that the implantation with a low dose of either O or Ne ions completely suppressed ferromagnetism in the films. Both the high resolution X-ray diffraction technique and the Raman spectroscopy showed significant changes in the structural and optical properties of the films caused by oxygen implantation and confirmed the preservation of high structural and optical quality of the neon implanted (Ga,Mn)As films.

Refine search results

Quantity-based flow control strategy for connection-oriented communication networks

Effect of Epitaxial Layer Thickness on Built-in Electric Field in Region of AlGaAs/SI-GaAs Interface: A Photoreflectance Study

Photoreflectance Studies of InGaAs/GaAs/AlGaAs Single Quantum Well Laser Structures

Chemical Composition of Native Oxide Layers on In^{+} Implanted and Thermally Annealed GaAs

Depth Profile Analysis of Phosphorus Implanted SiC Structures

Thermal Desorption of Helium from Defected Silicon

III-V Quantum Dots in Dielectrics Made by Ion Implantation and Flash Lamp Annealing

Influence of Hot Implantation on Residual Radiation Damage in Silicon Carbide

Influence of Ion Implantation on Magnetic Structural and Optical Properties of (Ga,Mn)As Epitaxial Films