Search results

1

Investigation of Phosphorus Release during Annealing of Au Contacts to InP

100%

Piotrowska A., Kamińska E., Kwiatkowski S., Turos A.

Acta Physica Polonica A

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1992

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vol. 82

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issue 5

849-852

EN

The analysis of phosphorus release from Au/InP contacts heat treated at temperature from the range 360-480°C showed that P evaporation accompanies any stage of contact reaction. The use of encapsulating layer during contact annealing suppresses the loss of phosphorus and changes the kinetics of thermally activated interfacial reaction.

2

Heterogeneous Amorphization of P and As Implanted GaAs at Low Temperatures

100%

Krynicki J., Rzewuski H., Turos A.

Acta Physica Polonica A

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1992

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vol. 82

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issue 5

871-875

EN

Amorphization of P and As implanted GaAs at liquid nitrogen temperature has been investigated. The post-implantation damage was measured by means of Rutherford Backscattering (RBS) He^{+} channeling technique. The critical dose and critical energy densities for amorphization were determined. From the results obtained it is concluded that for both ions the amorphization process can be satisfactorily described by the heterogeneous model.

3

X-ray Standing Waves and Rutherford backscattering Studies of the Structure of Si Single Crystals Implanted with Fe Ions

88%

Vartanyantz I., Auleytner J., Nowicki L., Kwiatkowski S., Turos A.

Acta Physica Polonica A

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1996

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vol. 89

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issue 5-6

625-633

EN

The X-ray standing wave and Rutherford backscattering spectroscopy in channelling geometry were applied for the investigation of the structure of silicon single crystals implanted with 80 keV Fe ions. Both methods were used for the determination of crystal damage and lattice location of implanted metal atoms before and after thermal annealing. Both methods gave consistent results regarding the amorphization of Si due to the Fe-ion implantation. Moreover, using both methods some Fe substitution fraction was determined. The depth profiles of implanted atoms were compared to the results of computer simulations. Complementary use of X-ray standing wave and Rutherford backscattering spectroscopy channelling techniques for studies of radiation damage and lattice location of implanted atoms is discussed.

4

Lattice Deformation in Al_{x}Ga_{1-x}As Epitaxial Layers Caused by Implantation with High Doses of 1 Mev Si Ions

88%

Wieteska K., Wierzchowski W., Graeff W., Turos A., Grötzschel R.

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vol. 96

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issue 2

289-293

EN

A series of highly perfect Al_{0.45}Ga_{0.55} As epitaxial layers implanted with 1 MeV Si ions to the doses in a range 7×10^{13}-2×10^{15} ions/cm^{2} were studied with various conventional and synchrotron X-ray diffraction methods. The presently used methods allowed both the measurement of lattice parameter changes and strain induced deformation. The evaluation of complete strain profiles was also performed by numerical simulation of diffraction curves. It was found that the implantation induced considerable change of lattice parameter reached the maximum at the dose 3×10^{14} ions/cm^{2}. The recorded curves proved also that the lattice parameter is almost constant in the near surface region of the implanted layers. The applied doses did not cause lattice amorphisation at room temperature.

5

Defect Transformations in Ion Bombarded InGaAsP

88%

Ratajczak R., Turos A., Stonert A., Nowicki L., Strupiński W.

Acta Physica Polonica A

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2011

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vol. 120

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issue 1

136-139

EN

Damage buildup and defect transformations at temperatures ranging from 15 K to 300 K in ion bombarded InGaAsP epitaxial layers on InP were studied by in situ Rutherford backscattering/channeling measurements using 1.4 MeV ^4He ions. Ion bombardment was performed using 150 keV N ions and 580 keV As ions to fluences ranging from 5 × 10^{12} to 6 × 10^{14} at./cm^2. Damage distributions were determined using the McChasy Monte Carlo simulation code assuming that they consist of randomly displaced lattice atoms and extended defects producing bending of atomic planes. Steep damage buildup up to amorphisation with increasing ion fluence was observed. Defect production rate increases with the ion mass and decreases with the implantation temperature. Parameters of damage buildup were evaluated in the frame of the multi-step damage accumulation model. Following ion bombardment at 15 K defect transformations upon warming up to 300 K have also been studied. Defect migration beginning above 100 K was revealed leading to a broad defect recovery stage with the activation energy of 0.1 eV for randomly displaced atoms and 0.15 eV for bent channels defects.

6

Dual Role of TiN Reaction Barrier in Gold Based Metallization to GaAs

76%

Piotrowska A., Kamińska E., Guziewicz M., Adamczewska J., Kwiatkowski S., Turos A.

Acta Physica Polonica A

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1992

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vol. 82

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issue 5

857-860

EN

Reactively sputtered TiN films were evaluated as annealing cap improving the formation of Au(Zn) ohmic contact and as antidiffusion barrier protecting contact metallization and underlying GaAs against reaction with Au overlayers.

7

Stopping Power and Energy Straggling of Channeled He-Ions in GaN

76%

Turos A., Ratajczak R., Pągowska K., Nowicki L., Stonert A., Caban P.

Acta Physica Polonica A

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2011

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vol. 120

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issue 1

163-166

EN

GaN epitaxial layers are usually grown on sapphire substrates. To avoid disastrous effect of the large lattice mismatch a thin polycrystalline nucleation layer is grown at 500°C followed by the deposition of thick GaN template at much higher temperature. Remnants of the nucleation layer were visualized by transmission electron microscopy as defect agglomeration at the GaN/sapphire interface and provide a very useful depth marker for the measurement of channeled ions stopping power. Random and aligned spectra of He ions incident at energies ranging from 1.7 to 3.7 MeV have been measured and evaluated using the Monte Carlo simulation code McChasy. Impact parameter dependent stopping power has been calculated for channeling direction and its parameters have been adjusted according to experimental data. For virgin, i.e. as grown, samples, the ratio of channeled to random stopping power is constant and amounts to 0.7 in the energy range studied. Defects produced by ion implantation largely influence the stopping power. For channeled ions the variety of possible trajectories leads to different energy loss at a given depth, thus resulting in much larger energy straggling than that for the random path. Beam energy distributions at different depths have been calculated using the McChasy code. They are significantly broader than those predicted by the Bohr formula for random direction.

8

The Use of Analytical Methods in Evaluation of Coptic Wall Paintings Conservation - A Case Study

76%

Ali M., Abd El Aal S., Mahgoub G., Sihame A., Turos A., Korman A., Stonert A.

Acta Physica Polonica A

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2011

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vol. 120

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issue 1

171-176

EN

Egypt has a lot of ancient monasteries and churches, which were decorated with different kinds of wall paintings. Structure of these wall paintings consists of support, plaster and painting layers. Paintings deterioration is primarily due to physicochemical, natural and human factors. The most detrimental factors are bat patches, old varnish and organic waste of birds. All these lead to the gradual disappearance of paintings. Modern technology of conservation is focused on application of new materials for cleaning of wall paintings. Here we report on the use of enzymes, for cleaning surface of coptic wall paintings. Analytical techniques such as particle induced X-ray emission, Fourier transform infrared and optical microscopy were used to evaluate the enzymatic cleaning processes of coptic wall paintings and to identify the chemical composition of red, yellow and white pigments. Particle induced X-ray emission results indicated that there is no change in the chemical composition of the materials and pigments due to enzymatic cleaning. Fourier transform infrared and optical microscopy results confirmed the stability of organic medium before and after treatment of different kind of patches.

9

Electron Microscopy and X-ray Diffraction Study of AlN Layers

76%

Kowalczyk A., Jagoda A., Mücklich A., Matz W., Pawłowska M., Ratajczak R., Turos A.

Acta Physica Polonica A

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2002

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vol. 102

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issue 2

221-225

EN

AlN nanocrystalline layers and superstructures are used in the modern optoelectronic technology as reflecting mirrors in semiconductor lasers. In the present work the properties of AlN films prepared by sputtering methods from an AlN target in reactive Ar + N plasma were investigated. The characterisation was performed with HRTEM, SEM, glancing angle XRD and RBS methods. The present measurements confirmed the polycrystalline structure of AlN layers and enabled the evaluation of their grain size. The roughness and thickness of the layers were additionally determined by ellipsometric and profilometric measurements.

10

RBS/Channeling and TEM Study of Damage Buildup in Ion Bombarded GaN

64%

Pągowska K., Ratajczak R., Stonert A., Turos A., Nowicki L., Sathish N., Jóźwik P., Muecklich A.

Acta Physica Polonica A

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2011

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vol. 120

|

issue 1

153-155

EN

A systematic study on structural defect buildup in 320 keV Ar-ion bombarded GaN epitaxial layers has been reported, by varying ion fluences ranged from 5 × 10^{12} to 1 × 10^{17} at./cm^2. 1 μm thick GaN epitaxial layers were grown on sapphire substrates using the metal-organic vapor phase epitaxy technique. Rutherford backscattering/channeling with 1.7 MeV^4He beam was applied for analysis. As a complementary method high resolution transmission electron microscopy has been used. The later has revealed the presence of extended defects like dislocations, faulted loops and stacking faults. New version of the Monte Carlo simulation code McChasy has been developed that makes it possible to analyze such defects on the basis of the bent channel model. Damage accumulation curves for two distinct types of defects, i.e. randomly displaced atoms and extended defects (i.e. bent channel) have been determined. They were evaluated in the frame of the multistep damage accumulation model, allowing numerical parameterization of defect transformations occurring upon ion bombardment. Displaced atoms buildup is a three-step process for GaN, whereas extended defect buildup is always a two-step process.

11

Analysis of Crystal Lattice Deformation by Ion Channeling

52%

Jóźwik P., Sathish N., Nowicki L., Jagielski J., Turos A., Kovarik L., Arey B., Shutthanandan S., Jiang W., Dyczewski J., Barcz A.

Acta Physica Polonica A

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2013

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vol. 123

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issue 5

828-830

EN

A model of dislocations has been developed for the use in Monte Carlo simulations of ion channeling spectra obtained for defected crystals. High resolution transmission electron microscopy micrographs show that the dominant type of defects in the majority of ion irradiated crystals are dislocations. The RBS/channeling spectrum is then composed of two components: one is due to direct scattering on randomly displaced atoms and the second one is related to beam defocussing on dislocations, which produce predominantly crystal lattice distortions, i.e. bent channels. In order to provide a correct analysis of backscattering spectra for the crystals containing dislocations we have modified the existing Monte Carlo simulation code "McChasy". A new version of the code has been developed by implementing dislocations on the basis of the Peierls-Nabarro model. Parameters of the model have been determined from the high resolution transmission electron microscopy data. The newly developed method has been used to study the Ar-ion bombarded SrTiO_3 samples. The best fit to the Rutherford backscattering/channeling spectra has been obtained by optimizing the linear combination of two kinds of defects: displaced atoms and bent channels. The great virtue of the Monte Carlo simulation is that unlike a traditional dechanneling analysis it allows quantitative analysis of crystals containing a mixture of different types of defects.

Refine search results

Investigation of Phosphorus Release during Annealing of Au Contacts to InP

Heterogeneous Amorphization of P and As Implanted GaAs at Low Temperatures

X-ray Standing Waves and Rutherford backscattering Studies of the Structure of Si Single Crystals Implanted with Fe Ions

Lattice Deformation in Al_{x}Ga_{1-x}As Epitaxial Layers Caused by Implantation with High Doses of 1 Mev Si Ions

Defect Transformations in Ion Bombarded InGaAsP

Dual Role of TiN Reaction Barrier in Gold Based Metallization to GaAs

Stopping Power and Energy Straggling of Channeled He-Ions in GaN

The Use of Analytical Methods in Evaluation of Coptic Wall Paintings Conservation - A Case Study

Electron Microscopy and X-ray Diffraction Study of AlN Layers

RBS/Channeling and TEM Study of Damage Buildup in Ion Bombarded GaN

Analysis of Crystal Lattice Deformation by Ion Channeling