Výzkumná témata

The study of metal diffusion (Ag, Au) into the polymer foils (PET, LDPE, HDPE). The prepared samples was modified by plasma discharge using various substrate temperature and various properties of plasma discharge. The depth profiles were analysed using the RBS. The RBS results were compared to the morphology determined AFM, to the chemical bonds on metal surface determined XPS. TEM gives us information about the size and numbers of metal particles at metal/polymer interfaces.

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Diffusion of Ag and Cu atoms in poly-ethylene-terephtalate (PET) and poly-imide (PI) was studied using Rutherford Backscattering Spectroscopy (RBS) and Elastic Recoil Detection Analysis (ERDA). The samples were prepared by deposition of Ag and Cu thin layers on polymer surface using CVD and diode sputtering techniques. Samples were annealed at temperatures up to 240°C. X-ray Photoelectron Spectroscopy (XPS) was used for determination of metal-polymer interaction and chemical state of atoms on metal- polymer interface. Faster diffusion of Ag atoms was observed from non-compact Ag layers prepared by diode sputtering than from those prepared by CVD technique. Ag atoms show higher mobility in PET in comparison with PI. XPS measurement gives an evidence of Ag clustering in Ag-PET samples prepared by cathode sputtering. In PI the Cu atoms exhibit higher diffusivity than Ag atoms due to their lower atomic radius.

Metallization of polymers is essential for their application in microelectronic elements and photonics devices. We performed a study of the diffusion of Ag and Au atoms in polyethyleneterephtalate (PET). Thin metal layers were deposited using the diode-sputtering technique on polymer foils at room temperature. Simultaneous post-deposition annealing and plasma treatment was used to induce metal/polymer intermixing. Concentration profiles of diffused metals were determined by Rutherford backscattering spectrometry (RBS) and diffusion coefficients were extracted. The influence of the plasma treatment on the surface morphology was studied using atomic force microscopy (AFM). Ag atoms exhibit deeper penetration into polymer structures after Ar plasma treatment than after Ar + O₂ plasma treatment. AFM measurements show more significant changes of surface roughness (increased roughness and porosity) of Ag on PET surfaces caused by the Ar + O₂ plasma treatment compared to Au surfaces. In the case of very rough surfaces, a decrease of metal diffusivity is observed probably owing to a reduction of surface concentration. The metal mobility is strongly influenced by temperature, which is increased either by direct heating of the sample holder or indirectly by plasma discharge.

Publications:

• Macková A.,Švorčík V., Strýhal Z., Pavlík J., Malinský P.: RBS, XPS and AFM Study of Ag Thin Films and Polyethylene Foils Interface Modified by Plasma Treatment, 16th Symposium on Application of Plasma Processes, Book of Abstracts, 219 – 220, Podbanské (2007)
• Macková A.,Švorčík V., Sajdl P., Strýhal Z., Pavlík J.,Šlouf M.,Malinský P.: RBS, XPS and TEM Study of Metal and Polymer Interface Modified by Plasma Treatment, JointVacuum Conference 11, Book of Abstracts, 95 – 95, Praha (2006), přijato pro publikaci v časopise Vacuum, Czech Vacuum Society
• Macková A., Švorčík V., Strýhal Z., Pavlík J.: RBS and AFM study of Ag and Au diffusion into PET foils influenced by plasma treatment, Surface and Interface Analysis, 38, 4: 335-338 (2006)

Whole article.

The study of the grow, modification and structure of thin layers or multilayers used in microelectronics, optics, optoelectronics and biomedicine. Study of interaction and interface properties of polymers and metals. Systems prepared by ion implantation, ion beam mixing, ion beam assisted deposition, ion degradation, plasma deposition are studied using nuclear analytical methods (RBS, ERDA etc.)

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Diffusion of Ag and Cu atoms in poly-ethylene-terephtalate (PET) and poly-imide (PI) was studied using Rutherford Backscattering Spectroscopy (RBS) and Elastic Recoil Detection Analysis (ERDA). The samples were prepared by deposition of Ag and Cu thin layers on polymer surface using CVD and diode sputtering techniques. Samples were annealed at temperatures up to 240°C. X-ray Photoelectron Spectroscopy (XPS) was used for determination of metal-polymer interaction and chemical state of atoms on metal- polymer interface. Faster diffusion of Ag atoms was observed from non-compact Ag layers prepared by diode sputtering than from those prepared by CVD technique. Ag atoms show higher mobility in PET in comparison with PI. XPS measurement gives an evidence of Ag clustering in Ag-PET samples prepared by cathode sputtering. In PI the Cu atoms exhibit higher diffusivity than Ag atoms due to their lower atomic radius.

Wide range of applications of metallized polymers in microelectronics has stimulated research of metal-polymer interaction. Polyimide encompassing low dielectric constant, high temperature and radiation stability is one of the best candidates for fabrication of multilayer metallization structures on the chip level and for packaging. In these structures, comprising alternate metal and insulating layers, high-temperature polymers are increasingly used and aluminum is replaced by the lower resistance copper. It has been observed that the microstructure and hence the mechanical and dielectric properties of the metal- polymer interface is strongly affected by the degree of metal-polymer diffusion and intermixing. Thus there is a basic need to understand the mechanism of metal diffusion in polymers and its effects on the structure and formation of metal-polymer interface. The diffusion depends on the physical and chemical properties of metal and the structure of the polymer as well. Cu and Ag for example exhibit higher mobility in polymers in comparison with that of more reactive metals such as Cr or Ti. In this study the diffusion of Cu and Ag in polyethyleneterephtalate (PET) and polyimide (PI) is examined using different methods with the aim to shed more light onto the diffusion mechanism.

Publications:

• Mackova A., Perina V., Krumeich J. and Kolouch A., RBS and XPS study of TiO_x layers prepared by PVD technique, Surface and Interface Analysis, 36 (2004) 1171-1173.
• Mackova A, Perina V, Hnatowicz V, Biederman H, Slavinska D, Choukourov A. Investigation of plasma polymer and nano composite polymer films by Rutherford Backscattering Spectrometry and by Elastic Recoil Detection Analysis analytical methods, Acta Physica Slovaca, 54 (1), 2004.

Whole article.

RBS-channeling is used to study crystalline materials and host atom positions , the fundamental studies concerning stopping power of channeled ions are realized.

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RBS-channeling gives opportunity for investigation of single-crystalline structures in the interstitial positions. The yield of back-scattered ions in aligned spectra (measured along the symmetry axis) is significantly decreased and the sensitivity on the light elements is enhanced due to reduced background. The preliminary RBS-channeling experiments were realized in the collaboration with Institute of Ion Beam Physics and Material Research -Forschungzentrum Rossendorf (FZR), which belongs to the best equipped IBA laboratories (Ion Beam Analysis) in Europe.

The samples of lithium niobate (LiNbO₃) were measured to determine the precise position of laser active atoms (Er, Yb) in crystalline lattice and damage level caused by the technology for wave-guide fabrication. X-ray Difraction (XRD) analysis was also performed to obtain the possible crystal lattice changes. The results are the axial channel scans of prepared structures from which the position of laser active ion has been determined.

New analytical technique, RBS-channeling, will be introduced for characterization of crystalline samples.

This technique will open quite new possibilities in :

• Measurement and determination of host atom position in crystalline lattice with the precision about 0.01 nm.
• Evaluation of absolute amount of implanted, diffused etc. optical active atoms in the crystalline substrates.
• Determination of lattice structure changes under the treatment connected with the preparation of wave guiding structure (the increasing of the crystal cell, point defects, lattice distortion, depth profiles of dislocation density)
• Study of mixing of two crystalline structures in bi-metal lattice

Publications:

• A. Mackova, R. Groetzschel, F. Eichhorn, P. Nekvindova, J. Spirkova, Characterization of Er: LiNbO₃ and APE:.Er:LiNbO₃ by RBS-channeling and XRD techniques, Surface and Interface Analysis, 36 (2004) 949-951

Whole article.

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Organosilicon plasma deposited polymers are of interest for different kinds of applications like packaging, passivation and dielectric layers. A large set of plasma processes is possible, among which are low-pressure plasma enhanced chemical vapour deposition (PECVD) and plasma assisted chemical vapour deposition (PACVD) often used. In this work, we studied the composition and surface morphology of the hexamethyldisiloxane (HMDSO) and tetramethyldisiloxane (TMDSO) layers produced by PECVD and PACVD deposition using three plasma generation processes (plasma reactors): RF inductively coupled plasma (RFICP), microwave distributed electron cyclotron resonance plasma (DECR) and microwave induced remote nitrogen afterglow (MIRA). The layer composition was investigated by Rutherford backscattering spectrometry (RBS) and by elastic recoil detection analysis (ERDA) and the layer surface morphology was determined by atomic force microscopy (AFM). Composition, density and morphology (roughness, porosity) of the layers is discussed in connection with deposition techniques used.

Publications:

• Mackova A, Perina V, Stryhal Z, Pavlik J, Svec M, Quede A, Supiot P, Borvon G, Granier A, Raynaud P, The combined study of the organosilicon films by RBS, ERDA and AFM analytical methods obtained from PECVD and PACVD Surface Science, 566: 1143-1146 Part 2, SEP 20 2004

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We present the ion beam analytical technique (RBS, PIXE) characterization of erbium incorporation into the glass surface. In this paper we report on the characterization of our samples These were fabricated by medium temperature doping of erbium into the glass using electric-field assisted diffusion from Er³⁺ containing reaction melt. RBS (Rutherford backscattering spectroscopy) is very powerful tool for Er depth profile determination in the glass substrate. Especially in the case of used glass as GIL 13K, which is free of the heavy trace elements. The PIXE (particle induced X-ray emission spectroscopy) is able to evaluate the Er integral amount in the glass substrate. The incorporated Er amount is influenced by experimental conditions as diffusion time, used current and wt.% of Er in the used melt or post-diffusion annealing treatment. (C) 2004 Elsevier B.V. All rights reserved.

Publications:

• Mackova A, Perina V, Havranek V, Tresnakova-Nebolova P, Spirkova J, Telezhnikova O, Ion-beam method characterization of erbium incorporation into glass surface for photonics applications Surface Science, 566: 111-114 Part 1, SEP 20 2004

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The Si-B-C-N films, prepared by magnetron sputtering, are very attractive due to their very high hardness (above 50 Gpa), temperature resistance and wide band gap. The composition of the films prepared under different conditions was determined using standard and resonance RBS (light element determination) and ERDA techniques. Correlation between sample preparation condition and film composition and its (mechanical) properties was found. This work is done in collaboration with University of West Bohemia. We collaborate with Sulzer Innotec, Switzerland on industry application of hard coating.

Publications:

• J. Vlček, M. Kormunda , J. Čížek, Z. Soukup, V. Peřina, J.Zemek, Diamond and related Materials 12 (2003) 1287
• J. Vlček, M. Kormunda, J. Čížek, V. Peřina, J.Zemek, Surface & Coatings Technology 160 (1) (2002) 74