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Plasma diagnostics during the organosilicone layers deposition
Jakobová, Martina ; Dvořák,, Pavel (referee) ; Krčma, František (advisor)
This Bachelor thesis deals with plasma diagnostics during deposition of thin organic-silicone layers. Hexamethyldisiloxane (HMDSO) was use as a precursor and emission spectroscopy of plasma was used as diagnostic method. Theoretical part describes plasma and its most important properties. Attention has been also paid to processes of plasma-chemical deposition of thin layers, their use and properties. Finally, principles of emission spectroscopy and calculation procedures of vibrational, rotational and electron temperatures in plasma are described. Deposition itself was realised both in pulse and continuous mode of RF discharge under decreased pressure of 60 Pa. Apart from deposition in pure HMDSO also depositions with HMDSO with addition of 10 and 25 % of oxygen were realised. Measurements were performed in wavelength interval from 320 to 780 nm. Individual lines of atomic hydrogen H-alpha and H-beta were identified in the obtained spectra, as well as molecular bands of CO transitions 0-0, 0-1, 0-2, 0-3 and the second positive nitrogen system transitions 0-0, 0-1. The spectral line of atomic O was identified if oxygen was added into the reaction gas mixture. The dependences of selected bands and lines intensities on the power supplied to plasma were observed. Electron temperature was determined from hydrogen atomic lines, and it was varied within the interval from 2700 to 5500 K in dependence on deposition conditions. It was impossible to determine vibrational and rotational temperatures, since the necessary molecular constants for the detected particles were not found. Based on the obtained results, it was possible to determine partly composition of plasma and to determine some of its properties. Results show that composition and supplied energy influence considerably plasma itself and that in future it will be necessary to investigate relation between these parameters and properties of created thin layers.
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Secondary electron spectroscopy and energy selective imaging for the engineering of carbon based materials
Rodenburg, C. ; Masters, R. ; Lidzey, D. ; Unčovský, M. ; Vystavěl, Tomáš ; Mika, Filip
That the fine structure of secondary electron emission spectra (SES) from carbon fibres is effected by fibre crystallinity and molecular orientation and linked to engineering materials properties such as modulus was reported over three decades ago. In spite of this\nlongstanding knowledge SES are not yet widely exploited for materials engineering of carbon based materials, probably due to a lack of instrumentation that is suitable to collect SES from beam sensitive materials and also has the capability to visualise, local variation based on SES shape. Thanks to rapid advances in low voltage SEM that offer energy selective imaging, it was recently demonstrated that differences in SES for different carbon based materials can be used to map chemical variations with sub-nanometer resolution when only SE 8 < eV were\nselected to form the SEM images. Such high resolution is not surprising as the implementation of energy filtering in SEMs to improve image resolutions was previously advocated. To fully exploit energy selective imaging for materials engineering the nature of the features in the SES must be determined.
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Plasma diagnostics during the organosilicone layers deposition
Jakobová, Martina ; Dvořák,, Pavel (referee) ; Krčma, František (advisor)
This Bachelor thesis deals with plasma diagnostics during deposition of thin organic-silicone layers. Hexamethyldisiloxane (HMDSO) was use as a precursor and emission spectroscopy of plasma was used as diagnostic method. Theoretical part describes plasma and its most important properties. Attention has been also paid to processes of plasma-chemical deposition of thin layers, their use and properties. Finally, principles of emission spectroscopy and calculation procedures of vibrational, rotational and electron temperatures in plasma are described. Deposition itself was realised both in pulse and continuous mode of RF discharge under decreased pressure of 60 Pa. Apart from deposition in pure HMDSO also depositions with HMDSO with addition of 10 and 25 % of oxygen were realised. Measurements were performed in wavelength interval from 320 to 780 nm. Individual lines of atomic hydrogen H-alpha and H-beta were identified in the obtained spectra, as well as molecular bands of CO transitions 0-0, 0-1, 0-2, 0-3 and the second positive nitrogen system transitions 0-0, 0-1. The spectral line of atomic O was identified if oxygen was added into the reaction gas mixture. The dependences of selected bands and lines intensities on the power supplied to plasma were observed. Electron temperature was determined from hydrogen atomic lines, and it was varied within the interval from 2700 to 5500 K in dependence on deposition conditions. It was impossible to determine vibrational and rotational temperatures, since the necessary molecular constants for the detected particles were not found. Based on the obtained results, it was possible to determine partly composition of plasma and to determine some of its properties. Results show that composition and supplied energy influence considerably plasma itself and that in future it will be necessary to investigate relation between these parameters and properties of created thin layers.
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Produkce atomárního jódu
Picková, Irena ; Jirásek, Vít ; Schmiedberger, Josef
In this article we describe our new experimental device for generation of atomic iodine in discharge for a COIL (chemical oxygen-iodine laser) and also DOIL (discharge oxygen-iodine laser) systems. For the new discharge method of atomic iodine generation, we are going to use the optical emission spectroscopy diagnostics, by which we will detect species present in plasma and use this information for optimization of iodine generation process.
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