Main field of study:  011200 Physics
Area of specialization: Electronics of Nanosystems
Department of Electronics of Solid State
Scientific advisor: Prof. E.O.Filatova
Reviewer: Prof. A.A. Pavlychev

X-ray reflection spectroscopy study of formation and properties of porous organo-silicate glasses
A.S.Konashuk

The electronic atomic structure of organo-silicate glasses (OSG) with different permittivity values (k=1.8-2.5) is studied using X-ray reflection spectroscopy. The OSG films were synthesized by plasma enhanced chemical vapor deposition (PECVD) and “Black Diamond-3” techniques. The absorption spectra were calculated from measured reflection spectra using Kramers–Kronig relations.
It was established: 1) formation of low polarizable Si-CH3 bonds and introduction of porosity are two coexisting competing processes which are responsible for permittivity decreasing; main role in reducing of permittivity from 2.5 to 2.3 belongs to Si–CH3 bonds and their concentration in structure. Further reduction (to 2.2 -1.8) occurs by increasing the porosity of structure 2) C–C and C=C cross-linking does not affect permittivity value of studied OSG; 3) concentration of Si-CH3 bonds is maximal for “Black Diamond-3” technique; 4) increasing the number of Si-CH3 bonds is accompanied by formation of defect states in band gap, in contrast with introduction of porosity process.

The list of the publications
1. A. S. Konashuk, A. A. Sokolov, V. E. Drozd, A. A. Romanov, E. O. Filatova. The Influence of Porous Silica Substrate on the Properties of Alumina Films Studied by X-ray Reflection Spectroscopy// Technical Physics Letters. V. 38, № 6, 2012. P. 562–564. 
2. A.S. Konashuk, A.A. Sokolov, V.E. Drozd, F. Schaefers, E.O. Filatova. Study of Al2O3 nanolayers synthesized onto porous SiO2 using X-ray reflection spectroscopy// Thin Solid Films. V. 534, 2013. P. 363-366.
3. E.O. Filatova, I.V. Kozhevnikov, A.A. Sokolov, Yu V.Yegorova, A.S. Konashuk, O.Yu. Vilkov, F. Schaefers, M. Gorgoi, A.S. Shulakov. X-ray and photoelectron spectroscopic nondestructive methods for thin films and interfaces study. Application to SrTiO3 based heterostructures// Microelectronic Engineering. V. 109, 2013. P. 13-16.
4. E. O. Filatova, A. A. Sokolov, Yu. V. Egorova, A. S. Konashuk, O. Yu. Vilkov, M. Gorgoi, A. A. Pavlychev. X-ray spectroscopic study of SrTiOx films with different interlayers// Journal of Applied Physics. V. 113, 2013. P. 224301.
5. M.A. Konyushenko, A.S. Konashuk, A.A. Sokolov, F. Schaefers, E.O. Filatova. Effect of thermal annealing and Al2O3-interlayer on intermixing in the TiN/SiO2/Si structure// Journal of Electron Spectroscopy and Related Phenomena. V. 191, 2013. (http://www.sciencedirect.com/science/article/pii/S0368204813002363).
6. E.O. Filatova, I.V. Kozhevnikov, A.A. Sokolov, A.S. Konashuk, F. Schaefers, M. Popovici, V.V. Afanas’ev. Study of underlayer material influence on the structure of atomic-layer deposited SrTixOy films using soft X-ray Reflectometry// Journal of Electron Spectroscopy and Related Phenomena. V. 193, 2014. (http://www.sciencedirect.com/science/article/pii/S0368204814000395).
7. A.S. Konashuk, A.A. Sokolov, Schaefers, E.O. Filatova. Compositional and chemical bonding analysis of low-k Organosilicate Glasse: X-ray reflection spectroscopy study// Book of Abstracts VUVX-2013: 38th International Conference on International conference on Vacuum Ultraviolet and X-ray Physics – July 12-19, 2013 – Hefei, China. P. 166.
8. M.A. Konyushenko, A.S. Konashuk, E.O. Filatova. X-ray reflection spectroscopy study of Al2O3-based heterostructures// Book of Abstracts-VUVX-2013: 38th International Conference on Vacuum Ultraviolet and X-ray Physics – July 12-19, 2013 – Hefei, China. P. 178.
9. A.S. Konashuk, A.A. Socolov, E.O. Filatova. Chemical bonds of carbon atoms in organo-silicate glasses: X-ray reflection spectroscopy study// Book of Abstracts, Russian conference “X-ray and Electronic Spectra and Chemical Bonding” (RESCB-21) – 7-11 October 2013 – Novosibirsk, Russia. P. 37.
10. A.P. Baraban, A.A. Selivanov, A.S. Konashuk, V.E. Drozd, E.O. Filatova. Metal/IL/TiO2/metal nanostructures as the most promising switching materials in RRAM memory// Book of Abstracts-12th International Baltic ALD conference – May 12-13, 2014 Helsinki, Finland. P. 40.
11. E.O. Filatova, A.S. Konashuk, M.A. Konyushenko, A.A. Sokolov, V.E. Drozd. X-ray spectroscopic study of ALD transition-metal oxides films// Book of Abstracts-12th International Baltic ALD conference – May 12-13, 2014 Helsinki, Finland. P. 119.
12. E.O. Filatova, M.A. Konyushenko, A.S. Konashuk, A.A. Selivanov, V.E. Drozd, A.P. Baraban. Memristive switching in metal/TiO2/IL/metal nanostructures// Book of Abstracts- 2014 Spring Meeting Lille, France – May 26-30. P. S.9 9